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Note: This page contains sample records for the topic "metal catalysts platinum" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


1

Noble Metal Catalysts for Mercury Oxidation in Utility Flue Gas: Gold, Palladium and Platinum Formulations  

SciTech Connect (OSTI)

The use of noble metals as catalysts for mercury oxidation in flue gas remains an area of active study. To date, field studies have focused on gold and palladium catalysts installed at pilot scale. In this article, we introduce bench-scale experimental results for gold, palladium and platinum catalysts tested in realistic simulated flue gas. Our initial results reveal some intriguing characteristics of catalytic mercury oxidation and provide insight for future research into this potentially important process.

Presto, A.A.; Granite, E.J

2008-07-01T23:59:59.000Z

2

Particle size effects of methylcyclopentane hydrogenolysis and SMSI in lanthanide oxide-supported 1%-platinum metal catalysts  

E-Print Network [OSTI]

PARTICLE SIZE EFFECTS OF METHYLCYCLOPENTANE HYDROGENOLYSIS AND SMSI IN LANTHANIDE OXIDE-SUPPORTED 1%-PLATINUM METAL CATALYSTS A Thesis by KYTE HAMILTON TERHUNE Submitted to the Graduate College of Texas A&M University in partial fulfillment... of the requirement for the degree of MASTER OF SCIENCE May 1985 Major Subject: Chemistry PARTICLE SIZE EFFECTS OF METHYLCYCLOPENTANE HYDROGENOLYSIS AND SMSI IN LANTHANIDE OXIDE-SUPPORTED 1%-PLATINUM METAL CATALYSTS A Thesis by KYTE HAMILTON TERHUNE...

Terhune, Kyte Hamilton

1985-01-01T23:59:59.000Z

3

Ethanol oxidation on metal oxide-supported platinum catalysts  

SciTech Connect (OSTI)

Ethanol is a renewable fuel that can be used as an additive to gasoline (or its substitute) with the advantage of octane enhancement and reduced carbon monoxide exhaust emissions. However, on Ethanol is a renewable fuel that can be used as an additive to gasoline (or its substitute) with the advantage of octane enhancement and reduced carbon monoxide exhaust emissions. However, on the standard three-way catalysts, the conversion of unburned ethanol is low because both ethanol and some of its partially oxidized derivatives are highly resistant to oxidation. A combination of first-principles density-functional theory (DFT) based calculations and in-situ diffuse reflectance infrared spectroscopy (DRIFTS) analysis was applied to uncover some of the fundamental phenomena associated with ethanol oxidation on Pt containing catalysts. In particular, the objective was to analyze the role of the oxide (i.e., ?-Al2O3 or SiO2) substrate on the ethanol oxidation activity. The results showed that Pt nanoparticles trap and accumulate oxygen at their surface and perimeter sites and play the role of “stoves” that burn ethanol molecules and their partially oxidized derivatives to the “final” products. The ?-Al2O3 surfaces provided higher mobility of the fragments of ethanol molecules than the SiO2 surface and hence increased the supply rate of these objects to the Pt particles. This will in turn produce a higher conversion rate of unburned ethanol.and some of its partially oxidized derivatives are highly resistant to oxidation. A combination of first-principles density-functional theory (DFT) based calculations and in-situ diffuse reflectance infrared spectroscopy (DRIFTS) analysis was applied to uncover some of the fundamental phenomena associated with ethanol oxidation on Pt containing catalysts. In particular, the objective was to analyze the role of the oxide (i.e., ?-Al2O3 or SiO2) substrate on the ethanol oxidation activity. The results showed that Pt nanoparticles trap and accumulate oxygen at their surface and perimeter sites and play the role of “stoves” that burn ethanol molecules and their partially oxidized derivatives to the “final” products. The ?-Al2O3 surfaces provided higher mobility of the fragments of ethanol molecules than the SiO2 surface and hence increased the supply rate of these objects to the Pt particles. This will in turn produce a higher conversion rate of unburned ethanol.

L. M. Petkovic 090468; Sergey N. Rashkeev; D. M. Ginosar

2009-09-01T23:59:59.000Z

4

PLATINUM-GROUP METALS (Platinum, palladium, rhodium, ruthenium, iridium, osmium)  

E-Print Network [OSTI]

automobile exhaust emissions. Oxidation catalysts are also used in many air pollution abatement processes platinum-group metals (PGM) mine. The mine, located near Nye, MT, processed about 430,000 metric tons--United States: 1994 1995 1996 1997 1998e Mine production: Platinum 1,960 1,590 1,840 2,610 3,5001 Palladium 6

5

PLATINUM-GROUP METALS (Platinum, palladium, rhodium, ruthenium, iridium, osmium)  

E-Print Network [OSTI]

automobile exhaust emissions. Oxidation catalysts are also used in many air pollution abatement processes platinum-group metals (PGM) mine. The mine, located near Nye, MT, processed about 350,000 metric tons--United States: 1993 1994 1995 1996 1997e Mine production: Platinum 2,050 1,960 1,590 1,840 2,5002 Palladium 6

6

Dispersion enhanced metal/zeolite catalysts  

DOE Patents [OSTI]

Dispersion stabilized zeolite supported metal catalysts are provided as bimetallic catalyst combinations. The catalyst metal is in a reduced zero valent form while the dispersion stabilizer metal is in an unreduced ionic form. Representative catalysts are prepared from platinum or nickel as the catalyst metal and iron or chromium dispersion stabilizer.

Sachtler, W.M.H.; Tzou, M.S.; Jiang, H.J.

1987-03-31T23:59:59.000Z

7

PLATINUM-GROUP METALS (Platinum, palladium, rhodium, ruthenium, iridium, osmium)  

E-Print Network [OSTI]

of catalysts. Oxidation catalysts are also used in other air-pollution-abatement processes to remove organic in kilograms, unless otherwise noted) Domestic Production and Use: The Stillwater Mine is the only primary platinum-group metals (PGM) producer in the United States. The mine, located near Nye, MT, processed more

8

PLATINUM-GROUP METALS (Platinum, palladium, rhodium, ruthenium, iridium, osmium)  

E-Print Network [OSTI]

refining. The leading demand sector for PGMs continued to be catalysts to decrease harmful emissions refining sector; and in laboratory equipment, including crucibles for growing high-purity single crystals­7708, ploferski@usgs.gov] #12;121 PLATINUM-GROUP METALS Events, Trends, and Issues: The global economy continued

9

PLATINUM-GROUP METALS (Platinum, palladium, rhodium, ruthenium, iridium, osmium)  

E-Print Network [OSTI]

refining. The leading demand sector for PGMs continued to be catalysts to decrease harmful emissions refining sector; and in laboratory equipment, including crucibles for growing high-purity single crystals-7708, ploferski@usgs.gov] #12;121 PLATINUM-GROUP METALS Events, Trends, and Issues: The global economy continued

10

Extended Platinum Nanotubes as Fuel Cell Catalysts  

SciTech Connect (OSTI)

Energy consumption has relied principally on fossil fuels as an energy source; fuel cells, however, can provide a clean and sustainable alternative, an answer to the depletion and climate change concerns of fossil fuels. Within proton exchange membrane fuel cells, high catalyst cost and poor durability limit the commercial viability of the device. Recently, platinum nanotubes (PtNTs) were studied as durable, active catalysts, providing a platform to meet US Department of Energy vehicular activity targets.[1] Porous PtNTs were developed to increase nanotube surface area, improving mass activity for oxygen reduction without sacrificing durability.[2] Subsurface platinum was then replaced with palladium, forming platinum-coated palladium nanotubes.[3] By forming a core shell structure, platinum utilization was increased, reducing catalyst cost. Alternative substrates have also been examined, modifying platinum surface facets and increasing oxygen reduction specific activity. Through modification of the PtNT platform, catalyst limitations can be reduced, ensuring a commercially viable device.

Alia, S.; Pivovar, B. S.; Yan, Y.

2012-01-01T23:59:59.000Z

11

Influence of metal-support interactions and crystallite size on the adsorption and catalytic behavior of platinum catalysts  

SciTech Connect (OSTI)

Direct calorimetric measurements of the heats of adsorption of hydrogen, carbon monoxide and oxygen were made on a family of supported Pt catalysts using a modified differential scanning calorimeter. H/sub 2/ heats of adsorption were found to be independent of the support as well as crystallite site. CO heats of adsorption on Pt were affected by the support utilized and the lowest heat of adsorption were obtained on the catalyst found in an earlier study to be the most active for methanation. A slight increase in the CO heat of adsorption was observed on the smaller Pt crystallites. The hydrogenation of isolated and conjugated carbonyl bonds was studied using acetone and cronaldehyde as the probe molecules. The (HTR) titania-supported Pt catalysts were found to be 1000 times more active on a TOF basis and 10 times more active on a g-metal basis compared to silica-supported Pt. A model has been proposed based on the Bond Order Conservation approach and consistent with Langmuir-Hinshelwood kinetics which attributes the enhancement in rate over titania-supported Pt to the stabilization of the isopropoxide intermediate at the metal-support interface. In the hydrogenation of crotonaldehyde (C-C = C-C = O), titania-supported Pt catalysts were the only catalysts which showed any selectivity to the hydrogenation of the carbonyl bond. Based on the available evidence for the metal/TiO/sub 2/ systems and consistent with homogeneous polarization chemistry the unique selectivity of titania-supported Pt has been attributed to the stabilization of the adsorbed crotonaldehyde on these catalysts in a configuration which facilitates the activation of the carbonyl bond.

Sen, B.

1987-01-01T23:59:59.000Z

12

Porous platinum-based catalysts for oxygen reduction  

DOE Patents [OSTI]

A porous metal that comprises platinum and has a specific surface area that is greater than 5 m.sup.2/g and less than 75 m.sup.2/g. A fuel cell includes a first electrode, a second electrode spaced apart from the first electrode, and an electrolyte arranged between the first and the second electrodes. At least one of the first and second electrodes is coated with a porous metal catalyst for oxygen reduction, and the porous metal catalyst comprises platinum and has a specific surface area that is greater than 5 m.sup.2/g and less than 75 m.sup.2/g. A method of producing a porous metal according to an embodiment of the current invention includes producing an alloy consisting essentially of platinum and nickel according to the formula Pt.sub.xNi.sub.1-x, where x is at least 0.01 and less than 0.3; and dealloying the alloy in a substantially pH neutral solution to reduce an amount of nickel in the alloy to produce the porous metal.

Erlebacher, Jonah D; Snyder, Joshua D

2014-11-25T23:59:59.000Z

13

Study by IR-spectroscopy and adsorption of platinum-alumina catalysts modified by manganese  

SciTech Connect (OSTI)

Additions of Re are widely employed for modifying platinum-alumina catalysts (PAC). The effect of Mn on the catalysis of and the physicochemical properties of PAC has been less studied. It is only known that adding <0.2 wt. % Mn has no effect on the dispersity of the Pt crystallites. In this work the authors have studied the state of Pt in unmodified PAC by IR spectroscopy of adsorbed CO and by the adsorption of H/sub 2/ at elevated temperatures. The state of the metallic platinum in platinum-alumina catalysts modified by Mn is more heterogeneous than in the unmodified sample. When manganese is added, platinum crystallites with stronger electron-donor properties form on the surface of the catalyst. In platinum-alumina catalysts modified by manganese, there is an increase in the number of sites for the high-temperature dissociative adsorption of hydrogen located on the surface of the Mn-modified carrier.

Zaitsev, A.V.; Barkova, A.P.; Borovkov, B.Yu.; Sterligov, O.D.; Isagulyants, G.V.; Kazanskii, V.B.

1987-03-10T23:59:59.000Z

14

Monodisperse Platinum and Rhodium Nanoparticles as Model Heterogeneous Catalysts  

SciTech Connect (OSTI)

Model heterogeneous catalysts have been synthesized and studied to better understand how the surface structure of noble metal nanoparticles affects catalytic performance. In this project, monodisperse rhodium and platinum nanoparticles of controlled size and shape have been synthesized by solution phase polyol reduction, stabilized by polyvinylpyrrolidone (PVP). Model catalysts have been developed using these nanoparticles by two methods: synthesis of mesoporous silica (SBA-15) in the presence of nanoparticles (nanoparticle encapsulation, NE) to form a composite of metal nanoparticles supported on SBA-15 and by deposition of the particles onto a silicon wafer using Langmuir-Blodgett (LB) monolayer deposition. The particle shapes were analyzed by transmission electron microscopy (TEM) and high resolution TEM (HRTEM) and the sizes were determined by TEM, X-ray diffraction (XRD), and in the case of NE samples, room temperature H2 and CO adsorption isotherms. Catalytic studies were carried out in homebuilt gas-phase reactors. For the nanoparticles supported on SBA-15, the catalysts are in powder form and were studied using the homebuilt systems as plug-flow reactors. In the case of nanoparticles deposited on silicon wafers, the same systems were operated as batch reactors. This dissertation has focused on the synthesis, characterization, and reaction studies of model noble metal heterogeneous catalysts. Careful control of particle size and shape has been accomplished though solution phase synthesis of Pt and Rh nanoparticles in order to elucidate further structure-reactivity relationships in noble metal catalysis.

Coble, Inger M

2008-08-15T23:59:59.000Z

15

Noble metal catalysts for oxidation of mercury in flue gas  

SciTech Connect (OSTI)

The use of precious metals and platinum group metals as catalysts for oxidation of mercury in flue gas is an active area of study. To date, field studies have recently focused on gold and palladium catalysts installed at pilot-scale. In this work, we introduce bench-scale results for gold, platinum, and palladium catalysts tested in realistic simulated flue gas. Initial results reveal intriguing characteristics of catalytic mercury oxidation and provide insight for future research.

Presto, A.A.; Granite, E.J.

2008-04-01T23:59:59.000Z

16

PLATINUM-GROUP METALS (Platinum, palladium, rhodium, ruthenium, iridium, osmium)  

E-Print Network [OSTI]

are also used in other air pollution abatement processes to remove organic vapors, odors, or carbon platinum-group metals (PGM) mine. The mine, located near Nye, MT, processed more than 400,000 metric tons and biomedical devices. Salient Statistics--United States: 1995 1996 1997 1998 1999e Mine production:1 Platinum 1

17

The effects of gas adsorption on particle shapes in supported platinum catalysts  

SciTech Connect (OSTI)

Previous work has shown that the shapes of the metal particles in a supported platinum catalyst are substantially altered when the catalyst is treated in an appropriate adages. However, at present it is unclear why the shape changes occur. In the work here, simple first-order calculations were done to examine the effects of hydrogen, nitrogen, and carbon monoxide on the equilibrium crystal shape of the platinum particles in a supported platinum catalyst. The calculation assumed that the main effect of the gaseous environment was to change the surface free energy of the facets on the platinum particles. The results of the calculations showed that when a clean platinum particle is equilibrated in nitrogen, the shape should not change significantly. However, Pt(100) facets should grow in hydrogen while Pt(210) facets should grow in carbon monoxide. By comparison, previous experiments have shown the Pt(100) facets do grow in hydrogen. Little change in shape is observed in nitrogen. Thus, it seems that changes in the surface free energy of the facets in the metal particles on a supported metal catalyst due to the presence of an adgas play an important role in the shape changes which are observed.

Shi, A.C.; Masel, R.I. (Univ. of Illinois, Urbana (USA))

1989-12-01T23:59:59.000Z

18

Recent Strikes in South Africa's Platinum-Group Metal Mines--Effects Upon World Platinum-Group Metal  

E-Print Network [OSTI]

Recent Strikes in South Africa's Platinum-Group Metal Mines--Effects Upon World Platinum.J., 2012, Recent strikes in South Africa's platinum-group metal mines--Effects upon world platinum........................................................................................................................................................... 5 Figures 1. Maps showing the (A) distribution and (B) geology of South Africa's platinum

Torgersen, Christian

19

PLATINUM-GROUP METALS (Platinum, palladium, rhodium, ruthenium, iridium, osmium)  

E-Print Network [OSTI]

for air-pollution abatement in both light- and heavy-duty vehicles. PGMs are also used in the chemical in kilograms unless otherwise noted) Domestic Production and Use: The Stillwater and East Boulder Mines in south-central Montana were the only primary platinum-group metals (PGMs) mines in the United States

20

PLATINUM-GROUP METALS (Platinum, palladium, rhodium, ruthenium, iridium, osmium)  

E-Print Network [OSTI]

for air-pollution abatement in both light- and heavy-duty vehicles. PGMs are also used in the chemical in kilograms unless otherwise noted) Domestic Production and Use: The Stillwater and East Boulder Mines in south-central Montana are the only primary platinum-group metals (PGMs) mines in the United States

Note: This page contains sample records for the topic "metal catalysts platinum" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Nanolithographic Fabrication and Heterogeneous Reaction Studies ofTwo-Dimensional Platinum Model Catalyst Systems  

SciTech Connect (OSTI)

In order to better understand the fundamental components that govern catalytic activity, two-dimensional model platinum nanocatalyst arrays have been designed and fabricated. These catalysts arrays are meant to model the interplay of the metal and support important to industrial heterogeneous catalytic reactions. Photolithography and sub-lithographic techniques such as electron beam lithography, size reduction lithography and nanoimprint lithography have been employed to create these platinum nanoarrays. Both in-situ and ex-situ surface science techniques and catalytic reaction measurements were used to correlate the structural parameters of the system to catalytic activity.

Contreras, A.M.

2006-05-20T23:59:59.000Z

22

NREL Team Creates High-Activity, Durable Platinum Extended Surface Catalyst for Fuel Cells (Fact Sheet)  

SciTech Connect (OSTI)

Researchers with NREL's Fuel Cell team showed that platinum can replace copper nanowires in such a way that high-surface-area and high-specific-activity catalysts are produced, potentially allowing for lower-cost catalysts.

Not Available

2011-02-01T23:59:59.000Z

23

Supported molten-metal catalysts  

DOE Patents [OSTI]

An entirely new class of catalysts called supported molten-metal catalysts, SMMC, which can replace some of the existing precious metal catalysts used in the production of fuels, commodity chemicals, and fine chemicals, as well as in combating pollution. SMMC are based on supporting ultra-thin films or micro-droplets of the relatively low-melting (<600.degree. C.), inexpensive, and abundant metals and semimetals from groups 1, 12, 13, 14, 15 and 16, of the periodic table, or their alloys and intermetallic compounds, on porous refractory supports, much like supported microcrystallites of the traditional solid metal catalysts. It thus provides orders of magnitude higher surface area than is obtainable in conventional reactors containing molten metals in pool form and also avoids corrosion. These have so far been the chief stumbling blocks in the application of molten metal catalysts.

Datta, Ravindra (Iowa City, IA); Singh, Ajeet (Iowa City, IA); Halasz, Istvan (Iowa City, IA); Serban, Manuela (Iowa City, IA)

2001-01-01T23:59:59.000Z

24

Transition metal sulfide loaded catalyst  

DOE Patents [OSTI]

A zeolite based catalyst for activation and conversion of methane. A zeolite support includes a transition metal (Mo, Cr or W) sulfide disposed within the micropores of the zeolite. The catalyst allows activation and conversion of methane to C.sub.2 + hydrocarbons in a reducing atmosphere, thereby avoiding formation of oxides of carbon.

Maroni, Victor A. (Naperville, IL); Iton, Lennox E. (Downers Grove, IL); Pasterczyk, James W. (Westmont, IL); Winterer, Markus (Westmont, IL); Krause, Theodore R. (Lisle, IL)

1994-01-01T23:59:59.000Z

25

Transition metal sulfide loaded catalyst  

DOE Patents [OSTI]

A zeolite-based catalyst is described for activation and conversion of methane. A zeolite support includes a transition metal (Mo, Cr or W) sulfide disposed within the micropores of the zeolite. The catalyst allows activation and conversion of methane to C[sub 2]+ hydrocarbons in a reducing atmosphere, thereby avoiding formation of oxides of carbon.

Maroni, V.A.; Iton, L.E.; Pasterczyk, J.W.; Winterer, M.; Krause, T.R.

1994-04-26T23:59:59.000Z

26

PLATINUM-GROUP METALS (Platinum, palladium, rhodium, ruthenium, iridium, osmium)  

E-Print Network [OSTI]

. Automobile catalysts for air pollution abatement continued to be the largest demand sector for PGM of catalysts. Catalysts are also used in other air-pollution-abatement processes to remove organic vapors in kilograms, unless otherwise noted) Domestic Production and Use: The Stillwater Mine is the only primary

27

PLATINUM-GROUP METALS (Platinum, palladium, rhodium, ruthenium, iridium, osmium)  

E-Print Network [OSTI]

by companies in Texas and Utah. Catalysts for air pollution abatement continued to be the largest demand sector in the manufacture of catalytic converters. Catalysts were also used in other air-pollution-abatement processes in kilograms, unless otherwise noted) Domestic Production and Use: The Stillwater and East Boulder Mines

28

PLATINUM-GROUP METALS (Platinum, palladium, rhodium, ruthenium, iridium, osmium)  

E-Print Network [OSTI]

by companies in Texas and Utah. Catalysts for air-pollution- abatement continued to be the leading demand industry in the manufacture of catalytic converters. Catalysts were also used in other air-pollution in kilograms unless otherwise noted) Domestic Production and Use: The Stillwater and East Boulder Mines

29

PLATINUM-GROUP METALS (Platinum, palladium, rhodium, ruthenium, iridium, osmium)  

E-Print Network [OSTI]

. Catalysts for air pollution abatement continued to be the largest demand sector for PGM. In the United of catalytic converters. Catalysts were also used in other air-pollution-abatement processes to remove organic in kilograms, unless otherwise noted) Domestic Production and Use: The Stillwater Mine is the only primary

30

PLATINUM-GROUP METALS (Platinum, palladium, rhodium, ruthenium, iridium, osmium)  

E-Print Network [OSTI]

refining by companies in Texas and Utah. Catalysts for air- pollution abatement continued to be the leading demand sector for PGMs. Catalysts were also used in other air- pollution-abatement processes to remove in kilograms unless otherwise noted) Domestic Production and Use: The Stillwater and East Boulder Mines

31

PLATINUM-GROUP METALS (Platinum, palladium, rhodium, ruthenium, iridium, osmium)  

E-Print Network [OSTI]

. Catalysts for air pollution abatement continued to be the leading demand sector for PGMs. In the United of catalytic converters. Catalysts were also used in other air-pollution-abatement processes to remove organic in kilograms unless otherwise noted) Domestic Production and Use: The Stillwater and East Boulder Mines

32

Method for producing electricity using a platinum-ruthenium-palladium catalyst in a fuel cell  

DOE Patents [OSTI]

A method for producing electricity using a fuel cell that utilizes a ternary alloy composition as a fuel cell catalyst, the ternary alloy composition containing platinum, ruthenium and palladium. The alloy shows increased activity as compared to well-known catalysts.

Gorer, Alexander

2004-01-27T23:59:59.000Z

33

Interaction of carbon monoxide with supported platinum catalysts  

SciTech Connect (OSTI)

The interaction of carbon monoxide with Pt/..gamma..-Al/sub 2/O/sub 3/ containing 0.5-5% Pt by weight has been investigated by means of thermal desorption and IR spectroscopy. It has been shown that CO is adsorbed in three different forms, corresponding to the desorption temperature intervals 25-250/sup 0/C (I), and 250-700/sup 0/C (II), and 550-850/sup 0/C (III). In the adsorption of CO in the first two forms, the metal takes part (absorption band at 2080 cm/sup -1/), and also the support (1800, 1260, 1390, 1470, 1550, and 1640 cm/sup -1/). The adsorption in form III probably takes place on oxidized platinum centers with the formation of strong surface carbonate structures. High temperatures tend to increase the adsorption of CO in forms II and III.

Savel'eva, G.A.; Galeev, T.K.; Popova, N.M.; Vozdvizhenskii, V.F.; Mishchenko, V.M.

1982-04-01T23:59:59.000Z

34

Metal phthalocyanine catalysts  

DOE Patents [OSTI]

As a new composition of matter, alkali metal or ammonium or tetraalkylammonium diazidoperfluorophthalocyanatoferrate. Other embodiments of the invention comprise compositions wherein the metal of the coordination complex is cobalt, manganese and chromium.

Ellis, Jr., Paul E. (Downingtown, PA); Lyons, James E. (Wallingford, PA)

1994-01-01T23:59:59.000Z

35

Hydrogenation of anthraquinone on metal-containing catalysts  

SciTech Connect (OSTI)

The present work studied the reaction of hydrogen activated on metal-containing catalysts (platinum black, Pt/Al/sub 2/O/sub 3/ (AP-15), and the hydride ZrNiH/sub 2.8/ with anthraquinone. The hydrogenation of anthraquinone bound into a strong donor-acceptor complex on the surface of Al/sub 2/O/sub 3/ and AP-15 and physically absorbed on silica gel was investigated. Results indicated that under conditions of mechanical mixing of silica gel with catalysts containing platinum or hydrides of intermetallic compounds in an atmosphere of hydrogen, anthraquinone physically adsorbed on silica gel is able to undergo hydrogenation at temperature above 100/sup 0/ C with formation of anthracene.

Lunin, V.V.; Markaryan, G.L.; Chetina, O.V.

1982-12-01T23:59:59.000Z

36

Total oxidation of carbon monoxide and methane over transition metal-fluorite oxide composite catalysts. I. Catalyst composition and activity  

SciTech Connect (OSTI)

A novel metal oxide composite catalyst for the total oxidation of carbon monoxide and methane was prepared by combining fluorite oxides with active transition metals. The fluorite oxides, such as ceria and zirconia, are oxygen-ion-conducting materials having catalytic properties usually at high temperatures. Active base metal catalysts, such as copper, were used as additives to promote the catalytic properties of these oxides. The contact of the two types of materials gave rise to a high active oxidation catalyst. At a space velocity of about 42,000 h{sup {minus}1}, complete carbon monoxide oxidation in air occurred at room temperature on the Au{sub 0.05}[Ce(La)]{sub 0.95}L{sub x} catalyst and at ca. 100{degrees}C on Cu-Ce-O composite catalysts. At the same space velocity, total oxidation of methane on the Cu-Ce-O catalyst doped with La{sub 2}O{sub 3} or SrO took place at ca. 550{degrees}C. The specific carbon monoxide oxidation activity of the Cu-Ce-O catalyst was several orders of magnitude higher than that of conventional copper-based catalysts and comparable or superior to platinum catalysts. This type of composite catalyst also showed excellent resistance to water vapor poisoning. The enhanced catalyst activity and stability resulted from strong interaction of the transition metal and fluorite oxide materials. 44 refs., 14 figs., 5 tabs.

Liu, W.; Flytzani-Stephanopoulos, F. [Tufts Univ., Medford, MA (United States)] [Tufts Univ., Medford, MA (United States)

1995-05-01T23:59:59.000Z

37

Investigating the performance of catalyst layer micro-structures with different platinum loadings  

SciTech Connect (OSTI)

In this study a four-phase micro-structure of a PEFC catalyst layer was reconstructed by randomly placing overlapping spheres for each solid catalyst phase. The micro-structure was mirrored to make a micro-structure. A body-fit computational mesh was produced for the reconstructed micro-structure in OpenFOAM. Associated conservation equations were solved within all the phases with electrochemical reaction as the boundary condition at the interface between ionomer and platinum phases. The study is focused on the platinum loading of CL. The polarization curves of the micro-structure performance have been compared for different platinum loadings. This paper gives increased insight into the relatively greater losses at decreased platinum loadings.

Khakaz-Baboli, Moben; Harvey, David; Pharoah, Jon

2012-07-01T23:59:59.000Z

38

PLATINUM-GROUP METALS (Platinum, palladium, rhodium, ruthenium, iridium, osmium)  

E-Print Network [OSTI]

refining. The leading demand sector for PGMs continued to be catalysts to decrease harmful emissions refining sector; and in the fabrication of laboratory equipment. In the electronics sector, PGMs are used toward the middle of the year, then decreased. The slowly recovering global economy in 2010, compared

39

Solid-state NMR studies of the adsorption of acetylene on platinum/alumina catalysts  

E-Print Network [OSTI]

SOLID-STATE NMR STUDIES OF THE ADSORPTION OF ACETYLENE ON PLATINUM/ALUMINA CATALYSTS A Thesis by MARSHA JO LUPHER LAMBREGTS Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements... for the degree of MASTER OF SCIENCE December 1991 Major Subject: Chemistry SOLID-STATE NMR STUDIES OF THE ADSORPTION OF ACETYLENE ON PLATINUM/ALUMINA CATALYSTS A Thesis by MARSHA JO LUPHER LAMBREGTS Approved as to style and content by: ames F. Haw...

Lambregts, Marsha Jo Lupher

1991-01-01T23:59:59.000Z

40

Carbon Supported Polyaniline as Anode Catalyst: Pathway to Platinum-Free Fuel Cells  

E-Print Network [OSTI]

The effectiveness of carbon supported polyaniline as anode catalyst in a fuel cell (FC) with direct formic acid electrooxidation is experimentally demonstrated. A prototype FC with such a platinum-free composite anode exhibited a maximum room-temperature specific power of about 5 mW/cm2

Zabrodskii, A G; Malyshkin, V G; Sapurina, I Y

2006-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "metal catalysts platinum" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Development of Ultra-low Platinum Alloy Cathode Catalyst for...  

Energy Savers [EERE]

Alloy Cathode Catalyst for PEM Fuel Cells These slides were presented at the 2010 New Fuel Cell Projects Meeting on September 28, 2010. 7uscpopov.pdf More Documents &...

42

Reactivity and stability of platinum and platinum alloy catalysts toward the oxygen reduction reaction  

E-Print Network [OSTI]

Density functional theory (DFT) is used to study the reactivity of Pt and Pt-M (M: Pd, Co, Ni, V, and Rh) alloy catalysts towards the oxygen reduction reaction (ORR) as a function of the alloy overall composition and surface atomic distribution...

Calvo, Sergio Rafael

2009-05-15T23:59:59.000Z

43

Attrition resistant catalysts and sorbents based on heavy metal poisoned FCC catalysts  

DOE Patents [OSTI]

A heavy metal poisoned, spent FCC catalyst is treated by chemically impregnating the poisoned catalyst with a new catalytic metal or metal salt to provide an attrition resistant catalyst or sorbent for a different catalytic or absorption process, such as catalysts for Fischer-Tropsh Synthesis, and sorbents for removal of sulfur gases from fuel gases and flue-gases. The heavy metal contaminated FCC catalyst is directly used as a support for preparing catalysts having new catalytic properties and sorbents having new sorbent properties, without removing or passivating the heavy metals on the spent FCC catalyst as an intermediate step.

Gangwal, S.; Jothimurugesan, K.

1999-07-27T23:59:59.000Z

44

Single-layer transition metal sulfide catalysts  

DOE Patents [OSTI]

Transition Metal Sulfides (TMS), such as molybdenum disulfide (MoS.sub.2), are the petroleum industry's "workhorse" catalysts for upgrading heavy petroleum feedstocks and removing sulfur, nitrogen and other pollutants from fuels. We have developed an improved synthesis technique to produce SLTMS catalysts, such as molybdenum disulfide, with potentially greater activity and specificity than those currently available. Applications for this technology include heavy feed upgrading, in-situ catalysis, bio-fuel conversion and coal liquefaction.

Thoma, Steven G. (Albuquerque, NM)

2011-05-31T23:59:59.000Z

45

2006 Minerals Yearbook PLATINUM-GROUP METALS  

E-Print Network [OSTI]

it was shipped to the smelter. The company milled 1.29 million metric tons (Mt) of ore from the mines, slightly, the concentrates from both mines are processed first at the precious metal smelter. The concentrate, which contains treatment. The smelter has an offgas processing facility that captures more than 99.7% of the sulfur dioxide

46

PLATINUM--GROUP METALS--1998 58.1 PLATINUM-GROUP METALS  

E-Print Network [OSTI]

for platinum by the automotive industry fell by 2,180 kg, to 56,900 kg, owing to the further adoption of palladium-based technology. The growing use of palladium by the automotive industry continued unabated of industrial uses owing to its unique chemical and physical properties. The electronics and the glass

47

Platinum Group Metal Recycling Technology Development - Final Report  

SciTech Connect (OSTI)

BASF Catalysts LLC, formerly Engelhard Corporation, has completed a project to recover Pt from PEM fuel cell membrane electrode assemblies. The project, which began in 2003, has met the project objective of an environmentally-friendly, cost-effective method for recovery of platinum without release of hydrogen fluoride. This has been achieved using a combination of milling, dispersion and acid leaching. 99% recovery of Pt was achieved, and this high yield can be scaled up using one vessel for a single leach and rinse. Leaching was been successfully achieved using a 10% solids level, double the original target. At this solids content, the reagent and utility costs represent ~0.35% of the Pt value of a lot, using very conservative assumptions. The main cost of the process is capital depreciation, followed by labor.

Lawrence Shore

2009-08-19T23:59:59.000Z

48

Final Scientific Report : Development of Transition Metal/ Chalcogen Based Cathode Catalysts for PEM Fuel Cells  

SciTech Connect (OSTI)

The aim of this project was to investigate the potential for using base metal sulfides and selenides as low cost replacements for precious metal catalysts, such as platinum, currently being used in PEM fuel cells. The approach was to deposit thin films of the materials to be evaluated onto inert electrodes and evaluate their activity for the cathode reaction (oxygen reduction) as well as ex-situ structural and compositional characterization. The most active materials identified are CoS2 and the 50:50 solid solution (Co,Ni)S2. However, the OCP of these materials is still considered too low, at 0.83V and 0.89V vs. RHE respectively, for testing in fuel cells. The methods employed here were necessary to compare with the activity of platinum as, when nano-dispersed on carbon supports, the active surface area of these materials is difficult to measure, making comparisons inaccurate. This research adds to the knowledge of potential candidates for platinum replacement in order to reduce the cost of PEM fuel cell technology and promote commercialization. Although the fabrication methods employed here are strictly experimental, methods were also developed to produce nano-dispersed catalysts with similar compositions, structure and activity. Cycling of these catalysts to highly oxidizing potentials resulted in an increase of the open circuit voltage to approach that of platinum, however, it proved difficult to determine why using these dispersed materials. The potential for non-precious, non-metallic, low cost, compound catalysts for PEM fuel cells has been investigated and demonstrated.

Campbell, Stephen, A.

2008-02-29T23:59:59.000Z

49

Oxidation of carbon monoxide and hydrocarbons on platinum and palladium catalysts in the presence of sulfur dioxide  

SciTech Connect (OSTI)

The authors report on a study of the effect of sulfur dioxide on the activity of platinum and palladium catalysts with respect to oxidation of the principal toxic components in the exhaust gases of internal combustion engines: carbon monoxide and hydrocarbons (propylene (C/sub 3/H/sub 6/) and propane (C/sub 3/H/sub 8/)). The experiments were carried out in a flow system equipped with Beckman infrared analyzers to monitor the concentrations of CO and hydrocarbons and of sulfur dioxide. A series of thermal desorption experiments was carried out in a low-pressure flow system with mass spectrometric analysis of the gas phase. The results indicate that the low-temperature adsorption of sulfur dioxide on platinum (and also palladium) catalysts inhibits the oxidation of carbon monoxide and propylene. The poisoning effect of O/sub 2/ is due to blockage of the platinum centers for adsorption of the oxidizable compounds and oxygen.

Panchishnyi, V.I.; Bondareva, N.K.; Sklyarov, A.V.; Rozanov, V.V.; Chadina, G.P.

1988-11-10T23:59:59.000Z

50

Subnanometer platinum clusters highly active and selective catalysts for the oxidative dehydrogenation of propane.  

SciTech Connect (OSTI)

Small clusters are known to possess reactivity not observed in their bulk analogues, which can make them attractive for catalysis. Their distinct catalytic properties are often hypothesized to result from the large fraction of under-coordinated surface atoms. Here, we show that size-preselected Pt{sub 8-10} clusters stabilized on high-surface-area supports are 40-100 times more active for the oxidative dehydrogenation of propane than previously studied platinum and vanadia catalysts, while at the same time maintaining high selectivity towards formation of propylene over by-products. Quantum chemical calculations indicate that under-coordination of the Pt atoms in the clusters is responsible for the surprisingly high reactivity compared with extended surfaces. We anticipate that these results will form the basis for development of a new class of catalysts by providing a route to bond-specific chemistry, ranging from energy-efficient and environmentally friendly synthesis strategies to the replacement of petrochemical feedstocks by abundant small alkanes.

Vajda, S; Pellin, M. J.; Greeley, J. P.; Marshall, C. L.; Curtiss, L. A.; Ballentine, G. A.; Elam, J. W.; Catillon-Mucherie, S.; Redfern, P. C.; Mehmood, F.; Zapol, P.; Yale Univ.

2009-03-01T23:59:59.000Z

51

Cobalt discovery replaces precious metals as industrial catalyst  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

- The new material has the highest oxygen reduction reaction (ORR) activity in alkaline media of any non-precious metal catalyst developed to date. Los Alamos research better...

52

U.S. GEOLOGICAL SURVEY--MINERALS INFORMATION 1 PLATINUM-GROUP METALS  

E-Print Network [OSTI]

or copper. The major PGM mining countries are, in converters of automobiles and light trucks, where average price for unfabricated platinum commissioning of a base metal refinery adjacent to the smelter

53

Transition metal-promoted oxygen ion conductors as oxidation catalyst  

SciTech Connect (OSTI)

A novel metal oxide composite catalyst for the complete oxidation of carbon monoxide and hydrocarbons was prepared by combining oxygen ion conducting materials with active transition metals. The oxygen ion conductors used were typical fluorite-type oxides, such as ceria, zirconia, and others. Active base metal catalysts, such as copper, were used as additives to promote the catalytic properties of oxygen ion conductors. The intimate contact of the two kinds of materials gave rise to a highly active oxidation catalyst. On Cu-Ce-O composite catalysts, 95% of carbon monoxide was oxidized by air at {approximately} 100 C. Complete methane oxidation on the same catalyst took place at {approximately} 550 C. When the stoichiometric amount of sulfur dioxide was sued to oxidize carbon monoxide, 96% of sulfur dioxide was reduced to elemental sulfur at temperatures above 460 C with 99% of sulfur dioxide conversion. This type of composite catalyst also showed excellent resistance to water poisoning.

Liu, W.; Sarofim, A. [Massachusetts Inst. of Tech., Cambridge, MA (United States). Dept. of Chemical Engineering; Flytzani-Stephanopoulos, M. [Tufts Univ., Medford, MA (United States). Dept. of Chemical Engineering

1994-12-31T23:59:59.000Z

54

Method of making metal-polymer composite catalysts  

DOE Patents [OSTI]

A metal-polymer-carbon composite catalyst for use as a cathode electrocatalyst in fuel cells. The catalyst includes a heteroatomic polymer; a transition metal linked to the heteroatomic polymer by one of nitrogen, sulfur, and phosphorus, and a recast ionomer dispersed throughout the heteroatomic polymer-carbon composite. The method includes forming a heteroatomic polymer-carbon composite and loading the transition metal onto the composite. The invention also provides a method of making a membrane electrode assembly for a fuel cell that includes the metal-polymer-carbon composite catalyst.

Zelena, Piotr (Los Alamos, NM); Bashyam, Rajesh (Los Alamos, NM)

2009-06-23T23:59:59.000Z

55

Comparative studies of hydrodenitrogenation by mixed metal sulfide catalysts  

E-Print Network [OSTI]

. , Sanchez, K. M. , and Reibenspies, J. , "Synthesis and characterization of [Et4N][M(CO)5SR] and [Et4N]2[M2 (CO) 8 (SR) 2] complexes (M = Cr, Mo, W) . Ligand substitution... to mimic the commercial catalyst (ie. no sulfide bridges prior to activation) l a Ni/Mo sulfide catalyst which consisted of Ni and Mo atoms brought in intimate contact by sulfide bridges; Ni/Mo and Co/Mo organometallic catalysts whose central metal had...

Luchsinger, Mary Margaret

1990-01-01T23:59:59.000Z

56

Neutral bimetallic transition metal phenoxyiminato catalysts and related polymerization methods  

DOE Patents [OSTI]

A catalyst composition comprising a neutral bimetallic diphenoxydiiminate complex of group 10 metals or Ni, Pd or Pt is disclosed. The compositions can be used for the preparation of homo- and co-polymers of olefinic monomer compounds.

Marks, Tobin J. (Evanston, IL); Rodriguez, Brandon A. (Evanston, IL); Delferro, Massimiliano (Chicago, IL)

2012-08-07T23:59:59.000Z

57

Carbo-metallic oil-conversion process and catalysts  

SciTech Connect (OSTI)

This patent describes a continuous process for cracking of a residual hydrocarbon feedstock into lower molecular weight hydrocarbon transportation fuels. The cracking being carried out in the presence of a catalyst having catalyst parameters comprising porosity, metals content, rare earth content, and zeolite content. The residual hydrocarbon feedstock comprising metal contaminants, fractions boiling above 1025{degrees}F. comprising asphaltenes, polynuclear aromatics, naphthenes and prophyrins.

Hettinger, W.P.; Beck, W.

1989-10-31T23:59:59.000Z

58

Design Principles for Oxygen-Reduction Activity on Perovskite Oxide Catalysts for Fuel Cells and Metal-air Batteries  

SciTech Connect (OSTI)

The prohibitive cost and scarcity of the noble-metal catalysts needed for catalysing the oxygen reduction reaction (ORR) in fuel cells and metal-air batteries limit the commercialization of these clean-energy technologies. Identifying a catalyst design principle that links material properties to the catalytic activity can accelerate the search for highly active and abundant transition-metal-oxide catalysts to replace platinum. Here, we demonstrate that the ORR activity for oxide catalysts primarily correlates to {sigma}*-orbital (e{sub g}) occupation and the extent of B-site transition-metal-oxygen covalency, which serves as a secondary activity descriptor. Our findings reflect the critical influences of the {sigma}* orbital and metal-oxygen covalency on the competition between O{sub 2}{sup 2-}/OH{sup -} displacement and OH{sup -} regeneration on surface transition-metal ions as the rate-limiting steps of the ORR, and thus highlight the importance of electronic structure in controlling oxide catalytic activity.

J Suntivich; H Gasteiger; N Yabuuchi; H Nakanishi; J Goodenough; Y Shao-Horn

2011-12-31T23:59:59.000Z

59

Transition metal-free olefin polymerization catalyst  

DOE Patents [OSTI]

Ethylene and/or propylene are polymerized to form high molecular weight, linear polymers by contacting ethylene and/or propylene monomer, in the presence of an inert reaction medium, with a catalyst system which consists essentially of (1) an aluminum alkyl component, such as trimethylaluminum, triethylaluminum, triisobutylaluminum, tri-n-octylaluminum and diethylaluminum hydride and (2) a Lewis acid or Lewis acid derivative component, such as B (C.sub.6 F.sub.5).sub.3, [(CH.sub.3).sub.2 N (H) (C.sub.6 H.sub.5)].sup.+ [B (C.sub.6 F.sub.5)4].sup.-, [(C.sub.2 H.sub.5).sub.3 NH].sup.+ [B C.sub.6 F.sub.5).sub.4 ],.sup.-, [C(C.sub.6 F.sub.5).sub.3 ].sup.+ [B(C.sub.6 F.sub.5).sub.4 ].sup.-, (C.sub.2 H.sub.5).sub.2 Al(OCH.sub.3), (C.sub.2 H.sub.5).sub.2 Al(2,6-di-t-butyl-4-methylphenoxide), (C.sub.2 H.sub.5)Al(2,6 -di-t-butylphenoxide).sub.2, (C.sub.2 H.sub.5).sub.2 Al(2,6-di-t-butylphonoxide) , 2,6 -di-t-butylphenol.multidot.methylaluminoxane or an alkylaluminoxane, and which may be completely free any transition metal component(s).

Sen, Ayusman (State College, PA); Wojcinski, II, Louis M. (State College, PA); Liu, Shengsheng (State College, PA)

2001-01-01T23:59:59.000Z

60

Hydrous metal oxide catalysts for oxidation of hydrocarbons  

SciTech Connect (OSTI)

This report describes work performed at Sandia under a CRADA with Shell Development of Houston, Texas aimed at developing hydrous metal oxide (HMO) catalysts for oxidation of hydrocarbons. Autoxidation as well as selective oxidation of 1-octene was studied in the presence of HMO catalysts based on known oxidation catalysts. The desired reactions were the conversion of olefin to epoxides, alcohols, and ketones, HMOs seem to inhibit autoxidation reactions, perhaps by reacting with peroxides or radicals. Attempts to use HMOs and metal loaded HMOs as epoxidation catalysts were unsuccessful, although their utility for this reaction was not entirely ruled out. Likewise, alcohol formation from olefins in the presence of HMO catalysts was not achieved. However, this work led to the discovery that acidified HMOs can lead to carbocation reactions of hydrocarbons such as cracking. An HMO catalyst containing Rh and Cu that promotes the reaction of {alpha}-olefins with oxygen to form methyl ketones was identified. Although the activity of the catalyst is relatively low and isomerization reactions of the olefin simultaneously occur, results indicate that these problems may be addressed by eliminating mass transfer limitations. Other suggestions for improving the catalyst are also made. 57 refs.

Miller, J.E.; Dosch, R.G.; McLaughlin, L.I. [Sandia National Labs., Albuquerque, NM (United States). Process Research Dept.

1993-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "metal catalysts platinum" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Catalysts to reduce NO.sub.x in an exhaust gas stream and methods of preparation  

DOE Patents [OSTI]

Catalysts, systems and methods are described to reduce NO.sub.x emissions of an internal combustion engine. In one embodiment, an emissions treatment system for an exhaust stream is provided having a catalyst comprising silver and a platinum group metal on a particulate alumina support, the atomic fraction of the platinum group metal being less than or equal to about 0.25. Methods of manufacturing catalysts are described in which silver is impregnated on alumina particles.

Castellano, Christopher R. (Ringoes, NJ); Moini, Ahmad (Princeton, NJ); Koermer, Gerald S. (Basking Ridge, NJ); Furbeck, Howard (Hamilton, NJ); Schmieg, Steven J. (Troy, MI); Blint, Richard J. (Shelby Township, MI)

2011-05-17T23:59:59.000Z

62

Oxygen-reducing catalyst layer  

DOE Patents [OSTI]

An oxygen-reducing catalyst layer, and a method of making the oxygen-reducing catalyst layer, where the oxygen-reducing catalyst layer includes a catalytic material film disposed on a substrate with the use of physical vapor deposition and thermal treatment. The catalytic material film includes a transition metal that is substantially free of platinum. At least one of the physical vapor deposition and the thermal treatment is performed in a processing environment comprising a nitrogen-containing gas.

O'Brien, Dennis P. (Maplewood, MN); Schmoeckel, Alison K. (Stillwater, MN); Vernstrom, George D. (Cottage Grove, MN); Atanasoski, Radoslav (Edina, MN); Wood, Thomas E. (Stillwater, MN); Yang, Ruizhi (Halifax, CA); Easton, E. Bradley (Halifax, CA); Dahn, Jeffrey R. (Hubley, CA); O'Neill, David G. (Lake Elmo, MN)

2011-03-22T23:59:59.000Z

63

Effect of Nafion and platinum content in a catalyst layer processed in a  

E-Print Network [OSTI]

storage and fuel cell (FC) cost and efficiency. Proton Exchange Membrane Fuel Cells (PEMFC) using solid fuel cells (PEMFC). Electrodes with low Pt loading are prepared, assembled in custom-made membrane in the commercial cathode. Keywords: Fuel cells; Plasma; sputtering; Nafion® ; platinum; utilization PACS

Paris-Sud XI, Université de

64

Metal salt catalysts for enhancing hydrogen spillover  

DOE Patents [OSTI]

A composition for hydrogen storage includes a receptor, a hydrogen dissociating metal doped on the receptor, and a metal salt doped on the receptor. The hydrogen dissociating metal is configured to spill over hydrogen to the receptor, and the metal salt is configured to increase a rate of the spill over of the hydrogen to the receptor.

Yang, Ralph T; Wang, Yuhe

2013-04-23T23:59:59.000Z

65

A Bimetmallic Fuel-Borne Catalyst for Reduce Precious Metal Use...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

A Bimetmallic Fuel-Borne Catalyst for Reduce Precious Metal Use in Medium-Duty Diesel Engines A Bimetmallic Fuel-Borne Catalyst for Reduce Precious Metal Use in Medium-Duty Diesel...

66

Metal complexes of substituted Gable porphyrins as oxidation catalysts  

DOE Patents [OSTI]

Transition metal complexes of Gable porphyrins having two porphyrin rings connected through a linking group, and having on the porphyrin rings electron-withdrawing groups, such as halogen, nitro or cyano. These complexes are useful as catalysts for the oxidation of organic compounds, e.g. alkanes.

Lyons, James E. (Wallingford, PA); Ellis, Jr., Paul E. (Downingtown, PA); Wagner, Richard W. (Murrysville, PA)

1996-01-01T23:59:59.000Z

67

Metal complexes of substituted Gable porphyrins as oxidation catalysts  

DOE Patents [OSTI]

Transition metal complexes of Gable porphyrins are disclosed having two porphyrin rings connected through a linking group, and having on the porphyrin rings electron-withdrawing groups, such as halogen, nitro or cyano. These complexes are useful as catalysts for the oxidation of organic compounds, e.g. alkanes.

Lyons, J.E.; Ellis, P.E. Jr.; Wagner, R.W.

1996-01-02T23:59:59.000Z

68

Nanostructured tungsten carbide catalysts for polymer electrolyte fuel cells X. G. Yanga  

E-Print Network [OSTI]

a possibility of replacing precious metal anode catalysts with transition metal compounds for hydrogen oxidation density of states of tungsten carbides resembles that of noble metal platinum.4,5 FundamentalNanostructured tungsten carbide catalysts for polymer electrolyte fuel cells X. G. Yanga and C. Y

69

Characterization and Reaction Studies of Silica Supported Platinum and Rhodium Model Catalysts  

E-Print Network [OSTI]

at which a chemical reaction approaches equilibrium and does not itself undergo a net chemical change.1 When a catalyst is in a different phase (e.g. solid) than a reactant mixture it is defined as a heterogeneous catalyst. Two types of heterogeneous... concerning the active-nature of the surface. For what reasons, on an atomic level, are surfaces capable of sustaining a reaction and others deactivate? What effect does particle size/structure have on activity and selectivity? Is this an electronic...

Lundwall, Matthew James

2012-02-14T23:59:59.000Z

70

Metal catalyst technique for texturing silicon solar cells  

DOE Patents [OSTI]

Textured silicon solar cells and techniques for their manufacture utilizing metal sources to catalyze formation of randomly distributed surface features such as nanoscale pyramidal and columnar structures. These structures include dimensions smaller than the wavelength of incident light, thereby resulting in a highly effective anti-reflective surface. According to the invention, metal sources present in a reactive ion etching chamber permit impurities (e.g. metal particles) to be introduced into a reactive ion etch plasma resulting in deposition of micro-masks on the surface of a substrate to be etched. Separate embodiments are disclosed including one in which the metal source includes one or more metal-coated substrates strategically positioned relative to the surface to be textured, and another in which the walls of the reaction chamber are pre-conditioned with a thin coating of metal catalyst material.

Ruby, Douglas S. (Albuquerque, NM); Zaidi, Saleem H. (Albuquerque, NM)

2001-01-01T23:59:59.000Z

71

Modeling Low-Platinum-Loading Effects in Fuel-Cell Catalyst Layers  

SciTech Connect (OSTI)

The cathode catalyst layer within a proton-exchange-membrane fuel cell is the most complex and critical, yet least understood, layer within the cell. The exact method and equations for modeling this layer are still being revised and will be discussed in this paper, including a 0.8 reaction order, existence of Pt oxides, possible non-isopotential agglomerates, and the impact of a film resistance towards oxygen transport. While the former assumptions are relatively straightforward to understand and implement, the latter film resistance is shown to be critically important in explaining increased mass-transport limitations with low Pt-loading catalyst layers. Model results demonstrate agreement with experimental data that the increased oxygen flux and/or diffusion pathway through the film can substantially decrease performance. Also, some scale-up concepts from the agglomerate scale to the more macroscopic porous-electrode scale are discussed and the resulting optimization scenarios investigated.

Yoon, Wonseok; Weber, Adam Z.

2011-01-20T23:59:59.000Z

72

Author's personal copy Methanol oxidation in nanostructured platinum/cerium-phosphate thin films  

E-Print Network [OSTI]

rights reserved. 1. Introduction Direct methanol fuel cells (DMFCs) have been considered to be one chosen metals in low-temperature fuel cells. However, it is hard to avoid CO adsorption on a bare Pt and optimize several types of catalysts [1]. Pure platinum as an anode catalyst is one of the most frequently

Park, Byungwoo

73

Synthesis of metal-metal oxide catalysts and electrocatalysts using a metal cation adsorption/reduction and adatom replacement by more noble ones  

DOE Patents [OSTI]

The invention relates to platinum-metal oxide composite particles and their use as electrocatalysts in oxygen-reducing cathodes and fuel cells. The invention particularly relates to methods for preventing the oxidation of the platinum electrocatalyst in the cathodes of fuel cells by use of these platinum-metal oxide composite particles. The invention additionally relates to methods for producing electrical energy by supplying such a fuel cell with an oxidant, such as oxygen, and a fuel source, such as hydrogen. The invention also relates to methods of making the metal-metal oxide composites.

Adzic, Radoslav; Vukmirovic, Miomir; Sasaki, Kotaro

2010-04-27T23:59:59.000Z

74

NANOSTRUCTURED METAL OXIDE CATALYSTS VIA BUILDING BLOCK SYNTHESES  

SciTech Connect (OSTI)

A broadly applicable methodology has been developed to prepare new single site catalysts on silica supports. This methodology requires of three critical components: a rigid building block that will be the main structural and compositional component of the support matrix; a family of linking reagents that will be used to insert active metals into the matrix as well as cross link building blocks into a three dimensional matrix; and a clean coupling reaction that will connect building blocks and linking agents together in a controlled fashion. The final piece of conceptual strategy at the center of this methodology involves dosing the building block with known amounts of linking agents so that the targeted connectivity of a linking center to surrounding building blocks is obtained. Achieving targeted connectivities around catalytically active metals in these building block matrices is a critical element of the strategy by which single site catalysts are obtained. This methodology has been demonstrated with a model system involving only silicon and then with two metal-containing systems (titanium and vanadium). The effect that connectivity has on the reactivity of atomically dispersed titanium sites in silica building block matrices has been investigated in the selective oxidation of phenols to benezoquinones. 2-connected titanium sites are found to be five times as active (i.e. initial turnover frequencies) than 4-connected titanium sites (i.e. framework titanium sites).

Craig E. Barnes

2013-03-05T23:59:59.000Z

75

Method for hydrogen production and metal winning, and a catalyst/cocatalyst composition useful therefor  

DOE Patents [OSTI]

A catalyst/cocatalyst/organics composition of matter is useful in electrolytically producing hydrogen or electrowinning metals. Use of the catalyst/cocatalyst/organics composition causes the anode potential and the energy required for the reaction to decrease. An electrolyte, including the catalyst/cocatalyst composition, and a reaction medium composition further including organic material are also described.

Dhooge, Patrick M. (Corrales, NM)

1987-10-13T23:59:59.000Z

76

Method of inducing surface ensembles on a metal catalyst  

DOE Patents [OSTI]

A method of inducing surface ensembles on a transition metal catalyst used in the conversion of a reactant gas or gas mixture, such as carbon monoxide and hydrogen into hydrocarbons (the Fischer-Tropsch reaction) is disclosed which comprises adding a Lewis base to the syngas (CO+H.sub.2) mixture before reaction takes place. The formation of surface ensembles in this manner restricts the number and types of reaction pathways which will be utilized, thus greatly narrowing the product distribution and maximizing the efficiency of the Fischer-Tropsch reaction. Similarly, amines may also be produced by the conversion of reactant gas or gases, such as nitrogen, hydrogen, or hydrocarbon constituents.

Miller, Steven S. (Morgantown, WV)

1989-01-01T23:59:59.000Z

77

Method of inducing surface ensembles on a metal catalyst  

DOE Patents [OSTI]

A method of inducing surface ensembles on a transition metal catalyst used in the conversion of a reactant gas or gas mixture, such as carbon monoxide and hydrogen into hydrocarbons (the Fischer-Tropsch reaction) is disclosed which comprises adding a Lewis base to the syngas (CO + H/sub 2/) mixture before reaction takes place. The formation of surface ensembles in this manner restricts the number and types of reaction pathways which will be utilized, thus greatly narrowing the product distribution and maximizing the efficiency of the Fischer-Tropsch reaction. Similarly, amines may also be produced by the conversion of reactant gas or gases, such as nitrogen, hydrogen, or hydrocarbon constituents.

Miller, S.S.

1987-10-02T23:59:59.000Z

78

of hydrogen-powered cars," he says. But a major hurdle remains: the cost of platinum metal  

E-Print Network [OSTI]

of hydrogen-powered cars," he says. But a major hurdle remains: the cost of platinum metal needed to make fuel cells efficient. Fuel cells work by combining hydrogen gas with oxygen from the air for hydrogen-powered cars in mass production facilities," says SFU chemistry professor Steve Holdcroft, who

79

Outlooks of HLW Partitioning Technologies Usage for Recovering of Platinum Metals from Spent Fuel  

SciTech Connect (OSTI)

The existing practice of management of high level waste (HLW) generated by NPPs, call for a task of selective separation of the most dangerous long-lived radionuclides with the purpose of their subsequent immobilization and disposal. HLW partitioning allows to reduce substantially the cost of vitrified product storage owing to isolation of the most dangerous radionuclides, such as transplutonium elements (TPE) into separate fractions of small volumes, intended for ultimate storage. By now numerous investigations on partitioning of HLW of various composition have been carried out in many countries and a lot of processes permitting to recover cesium, strontium, TPE and rare earth elements (REE) have been already tested. Apart from enumerated radionuclides, a fair quantity of palladium and rhodium presents in spent fuel, but the problem of these elements recovery has not yet been decided at the operating radiochemical plants. A negative effect of platinum group metals (PGM) occurrence is determined by the formation of separate metal phase, which not only worsens the conditions of glass-melting but also shortens considerably the service life of the equipment. At the same time, the exhaustion of PGMs natural resources may finally lead to such a growth of their costs that the spent nuclear fuel would became a substituting source of these elements industrial production. Allowing above mentioned, it is of interest to develop the technique for ''reactor'' palladium and rhodium recovery process which would be compatible with HLW partitioning and could be realized using the same facilities. In the report the data on platinum metals distribution in spent fuel reprocessing products and the several flowsheets for palladium separation from HLW are presented.

Pokhitonov, Y. A.; Estimantovskiy, V.; Romanovski, v.; Zatsev, B.; Todd, T.

2003-02-24T23:59:59.000Z

80

Studies of Immobilized Homogeneous Metal Catalysts on Silica Supports  

SciTech Connect (OSTI)

The tethered, chiral, chelating diphosphine rhodium complex, which catalyzes the enantioselective hydrogenation of methyl-{alpha}-acetamidocinnamate (MAC), has the illustrated structure as established by {sup 31}P NMR and IR studies. Spectral and catalytic investigations also suggest that the mechanism of action of the tethered complex is the same as that of the untethered complex in solution. The rhodium complexes, [Rh(COD)H]{sub 4}, [Rh(COD){sub 2}]{sup +}BF{sub 4}{sup -}, [Rh(COD)Cl]{sub 2}, and RhCl{sub 3} {center_dot} 3H{sub 2}O, adsorbed on SiO{sub 2} are optimally activated for toluene hydrogenation by pretreatment with H{sub 2} at 200 C. The same complexes on Pd-SiO{sub 2} are equally active without pretreatments. The active species in all cases is rhodium metal. The catalysts were characterized by XPS, TEM, DRIFTS, and mercury poisoning experiments. Rhodium on silica catalyzes the hydrogenation of fluorobenzene to produce predominantly fluorocyclohexane in heptane and 1,2-dichloroethane solvents. In heptane/methanol and heptane/water solvents, hydrodefluorination to benzene and subsequent hydrogenation to cyclohexane occurs exclusively. Benzene inhibits the hydrodefluorination of fluorobenzene. In DCE or heptane solvents, fluorocyclohexane reacts with hydrogen fluoride to form cyclohexene. Reaction conditions can be chosen to selectively yield fluorocyclohexane, cyclohexene, benzene, or cyclohexane. The oxorhenium(V) dithiolate catalyst [-S(CH{sub 2}){sub 3}s-]Re(O)(Me)(PPh{sub 3}) was modified by linking it to a tether that could be attached to a silica support. Spectroscopic investigation and catalytic oxidation reactivity showed the heterogenized catalyst's structure and reactivity to be similar to its homogeneous analog. However, the immobilized catalyst offered additional advantages of recyclability, extended stability, and increased resistance to deactivation.

Keith James Stanger

2003-05-31T23:59:59.000Z

Note: This page contains sample records for the topic "metal catalysts platinum" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Autothermal reforming catalyst having perovskite structure  

DOE Patents [OSTI]

The invention addressed two critical issues in fuel processing for fuel cell application, i.e. catalyst cost and operating stability. The existing state-of-the-art fuel reforming catalyst uses Rh and platinum supported over refractory oxide which add significant cost to the fuel cell system. Supported metals agglomerate under elevated temperature during reforming and decrease the catalyst activity. The catalyst is a perovskite oxide or a Ruddlesden-Popper type oxide containing rare-earth elements, catalytically active firs row transition metal elements, and stabilizing elements, such that the catalyst is a single phase in high temperature oxidizing conditions and maintains a primarily perovskite or Ruddlesden-Popper structure under high temperature reducing conditions. The catalyst can also contain alkaline earth dopants, which enhance the catalytic activity of the catalyst, but do not compromise the stability of the perovskite structure.

Krumpel, Michael (Naperville, IL); Liu, Di-Jia (Naperville, IL)

2009-03-24T23:59:59.000Z

82

Oxidation catalysts comprising metal exchanged hexaaluminate wherein the metal is Sr, Pd, La, and/or Mn  

DOE Patents [OSTI]

The present invention provides metal-exchanged hexaaluminate catalysts that exhibit good catalytic activity and/or stability at high temperatures for extended periods with retention of activity as combustion catalysts, and more generally as oxidation catalysts, that make them eminently suitable for use in methane combustion, particularly for use in natural gas fired gas turbines. The hexaaluminate catalysts of this invention are of particular interest for methane combustion processes for minimization of the generation of undesired levels (less than about 10 ppm) of NOx species. Metal exchanged hexaaluminate oxidation catalysts are also useful for oxidation of volatile organic compounds (VOC), particularly hydrocarbons. Metal exchanged hexaaluminate oxidation catalysts are further useful for partial oxidation, particularly at high temperatures, of reduced species, particularly hydrocarbons (alkanes and alkenes).

Wickham, David (Boulder, CO); Cook, Ronald (Lakewood, CO)

2008-10-28T23:59:59.000Z

83

Structural and Electrochemical Characterization of Binary, Ternary, and Quaternary Platinum Alloy Catalysts for Methanol Electro-oxidation1  

E-Print Network [OSTI]

Structural and Electrochemical Characterization of Binary, Ternary, and Quaternary Platinum Alloy methanol fuel cells (DMFC's) at 60 °C show that the best Pt-Ru-Os-Ir compositions are markedly superior

84

CATALYSTS NHI Thermochemical Systems FY 2009 Year-End Report  

SciTech Connect (OSTI)

Fiscal Year 2009 work in the Catalysts project focused on advanced catalysts for the decomposition of sulfuric acid, a reaction common to both the Sulfur-Iodine (S-I) cycle and the Hybrid Sulfur cycle. Prior years’ effort in this project has found that although platinum supported on titanium oxide will be an acceptable catalyst for sulfuric acid decomposition in the integrated laboratory scale (ILS) project, the material has short comings, including significant cost and high deactivation rates due to sintering and platinum evaporation. For pilot and larger scale systems, the catalyst stability needs to be improved significantly. In Fiscal Year 2008 it was found that at atmospheric pressure, deactivation rates of a 1 wt% platinum catalyst could be reduced by 300% by adding either 0.3 wt% iridium (Ir) or 0.3 wt% ruthenium (Ru) to the catalyst. In Fiscal Year 2009, work focused on examining the platinum group metal catalysts activity and stability at elevated pressures. In addition, simple and complex metal oxides are known to catalyze the sulfuric acid decomposition reaction. These metal oxides could offer activities comparable to platinum but at significantly reduced cost. Thus a second focus for Fiscal Year 2009 was to explore metal oxide catalysts for the sulfuric acid decomposition reaction. In Fiscal Year 2007 several commercial activated carbons had been identified for the HI decomposition reaction; a reaction specific to the S-I cycle. Those materials should be acceptable for the pilot scale project. The activated carbon catalysts have some disadvantages including low activity at the lower range of reactor operating temperature (350 to 400°C) and a propensity to generate carbon monoxide in the presence of water that could contaminate the hydrogen product, but due to limited funding, this area had low priority in Fiscal Year 2009. Fiscal Year 2009 catalyst work included five tasks: development, and testing of stabilized platinum based H2SO4 catalysts, development and testing of metal oxide based H2SO4 catalysts, support of the ILS for catalyst studies, conducting a long term catalyst stability test at anticipated operating temperatures and pressures, and developing capabilities for conducting pressurized catalyst tests.

Daniel M. Ginosar

2009-09-01T23:59:59.000Z

85

Catalysts for oxidation of mercury in flue gas  

DOE Patents [OSTI]

Two new classes of catalysts for the removal of heavy metal contaminants, especially mercury (Hg) from effluent gases. Both of these classes of catalysts are excellent absorbers of HCl and Cl.sub.2 present in effluent gases. This adsorption of oxidizing agents aids in the oxidation of heavy metal contaminants. The catalysts remove mercury by oxidizing the Hg into mercury (II) moieties. For one class of catalysts, the active component is selected from the group consisting of iridium (Ir) and iridum-platinum (Ir/Pt) alloys. The Ir and Ir/Pt alloy catalysts are especially corrosion resistant. For the other class of catalyst, the active component is partially combusted coal or "Thief" carbon impregnated with Cl.sub.2. Untreated Thief carbon catalyst can be self-activating in the presence of effluent gas streams. The Thief carbon catalyst is disposable by means of capture from the effluent gas stream in a particulate collection device (PCD).

Granite, Evan J. (Wexford, PA); Pennline, Henry W. (Bethel Park, PA)

2010-08-17T23:59:59.000Z

86

Applications of hydrogenation and dehydrogenation on noble metal catalysts  

E-Print Network [OSTI]

Hydrogenation and dehydrogenation on Pd- and Pt- catalysts are encountered in many industrial hydrocarbon processes. The present work considers the development of catalysts and their kinetic modeling along a general and rigorous approach. The first...

Wang, Bo

2009-05-15T23:59:59.000Z

87

Supported metal catalysts for alcohol/sugar alcohol steam reforming  

SciTech Connect (OSTI)

Despite extensive studies on hydrogen production via steam reforming of alcohols and sugar alcohols, catalysts typically suffer a variety of issues from poor hydrogen selectivity to rapid deactivation. Here, we summarize recent advances in fundamental understanding of functionality and structure of catalysts for alcohol/sugar alcohol steam reforming, and provide perspectives on further development required to design highly efficient steam reforming catalysts.

Davidson, Stephen; Zhang, He; Sun, Junming; Wang, Yong

2014-08-21T23:59:59.000Z

88

Embedding Covalency into Metal Catalysts for Efficient Electrochemical Conversion of CO2  

E-Print Network [OSTI]

- throughput screening to propose silver-based catalysts for efficient electrochemical reduction of CO2 to CO. Many researchers anticipate the efficient transformation of CO2 from various emission sources into moreEmbedding Covalency into Metal Catalysts for Efficient Electrochemical Conversion of CO2 Hyung

Goddard III, William A.

89

Experimental Study of In Situ Combustion with Tetralin and Metallic Catalysts  

E-Print Network [OSTI]

Experimental studies showed the feasibility of adding metallic catalysts and tetralin for the upgrade and increased recovery of heavy oil during the in situ combustion process. Further experimental studies also showed the applicability of in situ...

Palmer-Ikuku, Emuobonuvie

2010-01-16T23:59:59.000Z

90

Metal/ceria water-gas shift catalysts for automotive polymer electrolyte fuel cell system.  

SciTech Connect (OSTI)

Polymer electrolyte fuel cell (PEFC) systems are a leading candidate for replacing the internal combustion engine in light duty vehicles. One method of generating the hydrogen necessary for the PEFC is reforming a liquid fuel, such as methanol or gasoline, via partial oxidation, steam reforming, or autothermal reforming (a combination of partial oxidation and steam reforming). The H{sub 2}-rich reformate can contain as much as 10% carbon monoxide. Carbon monoxide has been shown to poison the platinum-based anode catalyst at concentrations as low as 10 ppm,1 necessitating removal of CO to this level before passing the reformate to the fuel cell stack. The water-gas shift (WGS) reaction, CO + H{sub 2}O {rightleftharpoons} CO{sub 2} + H{sub 2}, is used to convert the bulk of the reformate CO to CO{sub 2}. Industrially, the WGS reaction is conducted over two catalysts, which operate in different temperature regimes. One catalyst is a FeCr mixed oxide, which operates at 350-450 C and is termed the high-temperature shift (HTS) catalyst. The second catalyst is a CuZn mixed oxide, which operates at 200-250 C and is termed the low-temperature shift (LTS) catalyst. Although these two catalysts are used industrially in the production of H{sub 2} for ammonia synthesis, they have major drawbacks that make them unsuitable for transportation applications. Both the LTS and the HTS catalysts must first be ''activated'' before being used. For example, the copper in the copper oxide/zinc oxide LTS catalyst must first be reduced to elemental copper in situ before it becomes active for the WGS reaction. This reduction reaction is exothermic and must be carried out under well- controlled conditions using a dilute hydrogen stream (1 vol% H{sub 2}) to prevent high catalyst temperatures, which can result in sintering (agglomeration) of the copper particles and loss of active surface area for the WGS reaction. Also, once the catalyst has been activated by reduction, it must be protected from exposure to ambient air to prevent re-oxidation of the copper. The activated catalyst must also be protected from the condensation of liquids, for example, during start-up or transient operation. For these reasons, a more thermally rugged catalyst is needed which has sufficient activity to operate at the low temperatures that are thermodynamically necessary to achieve low CO concentrations.

Myers, D. J.; Krebs, J. F.; Carter, J. D.; Kumar, R.; Krumpelt, M.

2002-01-11T23:59:59.000Z

91

Photo-oxidation catalysts  

DOE Patents [OSTI]

Photo-oxidation catalysts and methods for cleaning a metal-based catalyst are disclosed. An exemplary catalyst system implementing a photo-oxidation catalyst may comprise a metal-based catalyst, and a photo-oxidation catalyst for cleaning the metal-based catalyst in the presence of light. The exposure to light enables the photo-oxidation catalyst to substantially oxidize absorbed contaminants and reduce accumulation of the contaminants on the metal-based catalyst. Applications are also disclosed.

Pitts, J. Roland (Lakewood, CO); Liu, Ping (Irvine, CA); Smith, R. Davis (Golden, CO)

2009-07-14T23:59:59.000Z

92

Sulfur resistance of Group VIII transition metal promoted nickel catalysts for synthesis gas methanation  

E-Print Network [OSTI]

SULFUR RESISTANCE OF GROUP VIII TRANSITION METAL PROMOTED NICKEL CATALYSTS FOR SYNTHESIS GAS METHANATION A Thesis by KELLEE HALL HAMLIN Submitted to the Graduate College of Texas AgrM University in partial fulfillment of the requirement...: Aydin Akger n (Chairman of Co 'ttee) Ahme M. Gadalla (Member) Michael . Rosynek (Member) aries D. Holland . ( ead of Department) May 1986 ABSTRACT Sulfur Resistance of Group VIII Transition Metal Promoted Nickel Catalysts For Synthesis Gas...

Hamlin, Kellee Hall

2012-06-07T23:59:59.000Z

93

The role of hydrogen in methane formation from carbon and water over metal catalysts  

E-Print Network [OSTI]

THE ROLE OF HYDROGEN IN METHANE FORMATION FROM CARBON AND WATER OVER METAL CATALYSTS A Thesis by STANLEY EDWIN MOORE Submitted to the Graduate College of Texas AaM University in partial fulfillment of the requirement for the degree MASTER... OF SCIENCE December 1982 Major subject: chemistry THE ROLE OF HYDROGEN IN METHANE FORMATION FROM CARBON AND WATER OVER METAL CATALYSTS A Thesis by STANLEY EDWIN MOORE Approved as to style and content by: hairman of Commi ee) (Me r) (Member) ( d...

Moore, Stanley Edwin

1982-01-01T23:59:59.000Z

94

Transition-metal pi-complexes of vinyl alcohol: platinum and palladium  

E-Print Network [OSTI]

of acetylacetonato- chl oro(n-vinyl alcohol) platinum( I I ) in d -tetrahydrofuran 8 17 19 21 23 Page Figure 9 Figure 10 Figure 11 Figure 12 Geometry of the methyl groups of acetylacetonatochloro(olefin)- platinum(II) with respect to the olefin ligand...~( Pl H H C-O C~ HsC HO H I CI 2210 IGG IOGI IM 17W INO . 500 IOG 1100 WO ENUNOEO ON I Figure 1 Ir spectrum of acetyl acetonatochl oro(n-vinyl alcohol)platinum(II) Nujol mull between CsI plates Beckman IR12 3. 0 35 4P MICRONS 5P 6. 0 7. 0 8. 0...

Ori, Masaru

1971-01-01T23:59:59.000Z

95

Platinum-Alloy Cathode Catalyst Degradation in Proton Exchange Membrane Fuel Cells: Nanometer-Scale Compositional and Morphological Changes  

E-Print Network [OSTI]

Electrochemical measurements showed an ?75% Pt surface area loss and an ?40% specific activity loss for a membrane electrode assembly (MEA) cathode with acid-treated “Pt[subscript 3]Co ” catalyst particles in a H[subscript ...

Chen, Shuo

96

Surface segregation of silicon in platinum(111) Ulrike Diebold,a)  

E-Print Network [OSTI]

1995; accepted 26 February 1996 We present a study of an ultrathin surface layer of platinum silicide 750 and 1100 K results in the formation of a surface silicide. The highest Si coverage that can, the poisoning of industrial supported metal catalysts3 and temper embrittlement in metallurgy.1 The driving

Diebold, Ulrike

97

Low-cost, non-precious metal/polymer composite catalysts for fuel cells  

E-Print Network [OSTI]

will fuel cells take their place as a centerpiece of a hydrogen economy and position hydrogen as a major) activity in known-to-date non- precious metal. Fuel cell testing of the composite Figure 2 shows a hydrogenLow-cost, non-precious metal/polymer composite catalysts for fuel cells R. Bashyam and P. Zelenay 1

98

Mapping Metals Incorporation of a Single Catalyst Particle Using...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

andor heavy molecules of oil feedstock into smaller and lighter hydrocarbons, such as gasoline. The workhorse of the FCC process is a tiny catalyst particle of 50-150 m...

99

Impact of Fuel Metal Impurities on Diesel Exhaust Catalysts  

Broader source: Energy.gov (indexed) [DOE]

Alliance for Sustainable Energy, LLC Approach * Aged catalysts from a Ford F250 with biodiesel fuel containing Na, K and Ca. * Emissions measurement conducted after 150,000 miles...

100

Evaluation of coal minerals and metal residues as coal-liquefaction catalysts. Final report  

SciTech Connect (OSTI)

The catalytic activity of various minerals, metallic wastes, and transition metals was investigated in the liquefaction of various coals. The effects of coal type, process variables, coal cleaning, catalyst addition mode, solvent quality, and solvent modification on coal conversion and oil production were also studied. Coal conversion and oil production improved significantly by the addition of pyrite, reduced pyrite, speculite, red mud, flue dust, zinc sulfide, and various transition metal compounds. Impregnation and molecular dispersion of iron gave higher oil production than particulate incorporation of iron. However, the mode of molybdenum addition was inconsequential. Oil production increased considerably both by adding a stoichiometric mixture of iron oxide and pyrite and by simultaneous impregnation of coal with iron and molybdenum. Hydrogenation activity of disposable catalysts decreased sharply in the presence of nitrogen compounds. The removal of heteroatoms from process solvent improved thermal as well as catalytic coal liquefaction. The improvement in oil production was very dramatic with a catalyst.

Garg, D.; Givens, E. N.; Schweighardt, F. K.; Tarrer, A. R.; Guin, J. A.; Curtis, C. W.; Huang, W. J.; Shridharani, K.; Clinton, J. H.

1982-02-01T23:59:59.000Z

Note: This page contains sample records for the topic "metal catalysts platinum" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Progressive flow cracking of coal/oil mixtures with high metals content catalyst  

SciTech Connect (OSTI)

This patent describes a process for economically producing liquid fuel products at least partly from coal. It comprises: introducing a progressive flow catalytic cracking zone a charge stock comprising a pumpable mixture of solid, particulate coal and carbo-metallic oil and forming within the zone a stream having a linear velocity of at least about 25 feet per second. The stream comprising the charge stock and a hydrocarbon zeolite cracking catalyst promoting dehydrogenation of the charge stock; forming mobile hydrogen within the zone by the dehydrogenation; introducing the mobile hydrogen into the stream by dehydrogenation of the charge stock in the absence of added molecular hydrogen, thereby producing liquid products from the charge stock while laying down coke on the hydrocarbon cracking catalyst in the range of about 0.3% to about 3% and thereby producing spent catalyst; separating from the spent catalyst the liquid products.

Zandona, O.J.

1989-10-10T23:59:59.000Z

102

Finding a suitable platinum substitute for fuel cells | Argonne...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

to platinum. These new catalysts offer the promise of substantially reducing the fuel cell cost. The new approach developed by Liu and his team uses materials known as...

103

Deposition of Platinum Nanoparticles on Carbon Nanotubes by Supercritical Fluid Method  

SciTech Connect (OSTI)

Carbon nanotube-supported platinum nanoparticles with a 5-15 nm diameter size range can be synthesized by hydrogen reduction of platinum(II) acetylacetonate in methanol modified supercritical carbon dioxide. XPS and XRD spectra indicate that the carbon nanotubes contain zero-valent platinum metal and high-resolution TEM images show that the visible lattice fringes of the Pt particles are crystallites. Carbon nanotubes synthesized with 25% by weight of Pt nanoparticles exhibit a higher activity for hydrogenation of benzene compared with a commercial carbon black platinum catalyst. The carbon nanotube-supported Pt nanocatalyst can be reused at least six times for the hydrogenation reaction without losing activity. The carbon nanotube-supported Pt nanoparticles are also highly active for electrochemical oxidation of methanol and for reduction of oxygen suggesting their potential use as a new electrocatalyst for polymer electrode fuel cell applications.

Yen, Clive; Cui, Xiaoli; Pan, H. B.; Wang, S.; Lin, Yuehe; Wai, Chien M.

2005-11-05T23:59:59.000Z

104

DIRECT DECOMPOSITION OF METHANE TO HYDROGEN ON METAL LOADED ZEOLITE CATALYST  

SciTech Connect (OSTI)

The manufacture of hydrogen from natural gas is essential for the production of ultra clean transportation fuels. Not only is hydrogen necessary to upgrade low quality crude oils to high-quality, low sulfur ultra clean transportation fuels, hydrogen could eventually replace gasoline and diesel as the ultra clean transportation fuel of the future. Currently, refinery hydrogen is produced through the steam reforming of natural gas. Although efficient, the process is responsible for a significant portion of refinery CO2 emissions. This project is examining the direct catalytic decomposition of methane as an alternative to steam reforming. The energy required to produce one mole of hydrogen is slightly lower and the process does not require water-gas-shift or pressure-swing adsorption units. The decomposition process does not produce CO2 emissions and the product is not contaminated with CO -- a poison for PEM fuel cells. In this work we examined the direct catalytic decomposition of methane over a metal modified zeolite catalyst and the recovery of catalyst activity by calcination. A favorable production of hydrogen was obtained, when compared with previously reported nickel-zeolite supported catalysts. Reaction temperature had a strong influence on catalyst activity and on the type of carbon deposits. The catalyst utilized at 873 and 973 K could be regenerated without any significant loss of activity, however the catalyst utilized at 1073 K showed some loss of activity after regeneration.

Lucia M. Petkovic; Daniel M. Ginosar; Kyle C. Burch; Harry W. Rollins

2005-08-01T23:59:59.000Z

105

Catalytic hydrocracking of Athabasca bitumen with oil-soluble throw-away metal catalysts  

SciTech Connect (OSTI)

The mild hydrocracking of Athabasca bitumen at 400-425{degrees}C and 1000-2000 psig hydrogen in a stirred laboratory autoclave in the presence of various oil-soluble transition metal (carboxylates, naphthenates, acetylacetonate) catalysts has been investigated. Determined were the yields of liquid and solid products, the elemental and class compositions of the liquids as well as some of their physical properties as a function of catalyst type, amount and physical state, along with other experimental variables. Some of the chemical changes taking place at the molecular level were also explored and compared to those observed in the mild thermolysis of the bitumen.

Strausz, O.P.; Mojelsky, T.W.; Lown, E.M. [Univ. of Alberta, Edmonton (Canada)

1995-12-31T23:59:59.000Z

106

Operando Raman and Theoretical Vibration Spectroscopy of Non-PGM Catalysts  

Broader source: Energy.gov [DOE]

Presentation about spectroscopy techniques for non-platinum group metal (PGM) catalysts, presented by Eugene Smotkin, Northeastern University, at the kick-off meeting of the U.S. Department of Energy Fuel Cell Technologies Program's Catalysis Working Group, held May 14, 2012, in Arlington, Virginia.

107

Metal-Organic Frameworks as Biomimetic Catalysts | Center for Gas  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary)morphinanInformation Desert Southwest Regionat Cornell Batteries & Fuel Cells In ThisMetalCenter

108

Carbon monoxide oxidation over three different states of copper: Development of a model metal oxide catalyst  

SciTech Connect (OSTI)

Carbon monoxide oxidation was performed over the three different oxidation states of copper -- metallic (Cu), copper (I) oxide (Cu{sub 2}O), and copper (II) oxide (CuO) as a test case for developing a model metal oxide catalyst amenable to study by the methods of modern surface science and catalysis. Copper was deposited and oxidized on oxidized supports of aluminum, silicon, molybdenum, tantalum, stainless steel, and iron as well as on graphite. The catalytic activity was found to decrease with increasing oxidation state (Cu > Cu{sub 2}O > CuO) and the activation energy increased with increasing oxidation state (Cu, 9 kcal/mol < Cu{sub 2}O, 14 kcal/mol < CuO, 17 kcal/mol). Reaction mechanisms were determined for the different oxidation states. Lastly, NO reduction by CO was studied. A Cu and CuO catalyst were exposed to an equal mixture of CO and NO at 300--350 C to observe the production of N{sub 2} and CO{sub 2}. At the end of each reaction, the catalyst was found to be Cu{sub 2}O. There is a need to study the kinetics of this reaction over the different oxidation states of copper.

Jernigan, G.G. [California Univ., Berkeley, CA (United States). Dept. of Chemistry; [Lawrence Berkeley Lab., CA (United States). Materials and Chemical Sciences Div.

1994-10-01T23:59:59.000Z

109

Oligomer and mixed-metal compounds potential multielectron transfer catalysts  

SciTech Connect (OSTI)

Projects related to the design and characterization of multimetallic complexes has proceeded forward with a number of achievements. First, photoprocesses in hydrogel matrices lead to the conclusion that cationic metallochromophores could be ion exchanged into a hydrogel matrix ({kappa}-carageenan) and substantial photocurrents could be generated. Second, X-ray structures of Ru(bpy){sub 3}{sup 2+}, Ru(bpm){sub 3}{sup 2+} and Ru(bpz){sub 3}{sup 2+}, where bpy is 2,2{prime}-bipyridine, bpm is 2,2{prime}-bipyrimidine and bpz is 2,2{prime}-bipyrizine, were obtained and revealed similar Ru-N bond distances in each complex even though their {sigma}-donor and {pi}-acceptor character differ markedly. The structure parameters are expected to provide theoreticians with the information needed to probe the electronic character of the molecular systems and provide us with direction in our synthetic strategies. Third, a copper(I) complex was synthesized with a dimeric-ethane-bridged, 1,10-phenanthroline ligand that resulted in isolation of a bimetallic species. The copper(I) complex did luminesce weakly, suggesting that the dimer possesses potential electron transfer capability. Fourth, the photophysical properties of (Re(CO){sub 4}(L-L)){sup +}, where L-L = heterocyclic diimine ligands, and Pt(bph)X{sub 2}, where bph = the dianion of biphenyl and X = CH{sub 3}CN, py or ethylendiamine, displayed luminescence at high energy and underwent excited-state electron transfer. Such high energy emitters provide high driving forces for undergoing excited-state electron transfer. Fifth, both energy and electron transfer were observed in mixed-metal complexes bridged by 1,2-bis(2,2{prime}-bipyridyl-4{prime}-yl) ethane.

Rillema, D.P.

1992-03-30T23:59:59.000Z

110

Metal/metal oxide doped oxide catalysts having high deNOx selectivity for lean NOx exhaust aftertreatment systems  

DOE Patents [OSTI]

A lean NOx catalyst and method of preparing the same is disclosed. The lean NOx catalyst includes a ceramic substrate, an oxide support material, preferably .gamma.-alumina, deposited on the substrate and a metal promoter or dopant introduced into the oxide support material. The metal promoters or dopants are selected from the group consisting of indium, gallium, tin, silver, germanium, gold, nickel, cobalt, copper, iron, manganese, molybdenum, chromium, cerium, vanadium, oxides thereof, and combinations thereof. The .gamma.-alumina preferably has a pore volume of from about 0.5 to about 2.0 cc/g; a surface area of between about 80 to 350 m.sup.2 /g; an average pore size diameter of between about 3 to 30 nm; and an impurity level of less than or equal to 0.2 weight percent. In a preferred embodiment the .gamma.-alumina is prepared by a sol-gel method, with the metal doping of the .gamma.-alumina preferably accomplished using an incipient wetness impregnation technique.

Park, Paul W.

2004-03-16T23:59:59.000Z

111

Method for making oxygen-reducing catalyst layers  

DOE Patents [OSTI]

Methods are provided for making oxygen-reducing catalyst layers, which include simultaneous or sequential stops of physical vapor depositing an oxygen-reducing catalytic material onto a substrate, the catalytic material comprising a transition metal that is substantially free of platinum; and thermally treating the catalytic material. At least one of the physical vapor deposition and the thermal treatment is performed in a processing environment comprising a nitrogen-containing gas.

O'Brien, Dennis P.; Schmoeckel, Alison K.; Vernstrom, George D.; Atanasoski, Radoslav; Wood, Thomas E.; O'Neill, David G.

2010-06-22T23:59:59.000Z

112

Activation of Noble Metals on Metal-Carbide Surfaces: Novel Catalysts for CO Oxidation, Desulfurization and Hydrogenation Reactions  

SciTech Connect (OSTI)

This perspective article focuses on the physical and chemical properties of highly active catalysts for CO oxidation, desulfurization and hydrogenation reactions generated by depositing noble metals on metal-carbide surfaces. To rationalize structure-reactivity relationships for these novel catalysts, well-defined systems are required. High-resolution photoemission, scanning tunneling microscopy (STM) and first-principles periodic density-functional (DF) calculations have been used to study the interaction of metals of Groups 9, 10 and 11 with MC(001) (M = Ti, Zr, V, Mo) surfaces. DF calculations give adsorption energies that range from 2 eV (Cu, Ag, Au) to 6 eV (Co, Rh, Ir). STM images show that Au, Cu, Ni and Pt grow on the carbide substrates forming two-dimensional islands at very low coverage, and three-dimensional islands at medium and large coverages. In many systems, the results of DF calculations point to the preferential formation of admetal-C bonds with significant electronic perturbations in the admetal. TiC(001) and ZrC(001) transfer some electron density to the admetals facilitating bonding of the adatom with electron-acceptor molecules (CO, O{sub 2}, C{sub 2}H{sub 4}, SO{sub 2}, thiophene, etc.). For example, the Cu/TiC(001) and Au/TiC(001) systems are able to cleave both S-O bonds of SO{sub 2} at a temperature as low as 150 K, displaying a reactivity much larger than that of TiC(001) or extended surfaces of bulk copper and gold. At temperatures below 200 K, Au/TiC is able to dissociate O{sub 2} and perform the 2CO + O{sub 2} {yields} 2CO{sub 2} reaction. Furthermore, in spite of the very poor hydrodesulfurization performance of TiC(001) or Au(111), a Au/TiC(001) surface displays an activity for the hydrodesulfurization of thiophene higher than that of conventional Ni/MoS{sub x} catalysts. In general, the Au/TiC system is more chemically active than systems generated by depositing Au nanoparticles on oxide surfaces. Thus, metal carbides are excellent supports for enhancing the chemical reactivity of noble metals.

Rodriguez J. A.; Illas, F.

2012-01-01T23:59:59.000Z

113

Extending surface-enhanced Raman spectroscopy to transition-metal surfaces: carbon monoxide adsorption and electrooxidation on platinum- and palladium-coated gold electrodes  

SciTech Connect (OSTI)

Thin (ca. one to three monolayers) films of platinum and palladium electrodeposited on electrochemically roughened gold are observed to yield surface-enhanced Raman (SER) spectra for adsorbed carbon monoxide. The major vibrational band(s) on these surfaces are diagnosed from their frequencies as arising from C-O stretching vibrations, nu/sub CO/ bound to the transition-metal overlayers rather than to residual gold sites. The observed SFR nu/sub CO/ frequencies are closely similar to (within ca. 10 cm/sup -1/ of) those obtained for these systems from potential-difference infrared (PDIR) spectra. The major SERS and PDIR nu/sub CO/ features for the platinum and palladium surfaces appear at 2060-2090 and 1965-1985 cm/sup -1/, respectively, consistent with the presence of terminal and bridging CO on these two electrodes. The infrared as well as electrochemical properties of these systems are closely similar to those for the corresponding polycrystalline bulk electrodes. A difference between the SER- and IR-active adsorbed CO, however, is that the former undergoes electrooxidation on both surfaces at 0.2-0.3 V higher overpotentials than the latter form. Examination of the potential-dependent SERS bands for metal oxide vibrations, nu/sub PtO/, on the platinum surface shows that the electrooxidation potential for the SERS-active adsorbed CO coincides with that for the appearance of the nu/sub PtO/ band. Some broader implications to the utilization of SERS for examining transition-metal surfaces are pointed out.

Leung, L.W.H.; Weaver, M.J.

1987-08-19T23:59:59.000Z

114

Catalyst activator  

DOE Patents [OSTI]

A catalyst activator particularly adapted for use in the activation of metal complexes of metals of Group 3-10 for polymerization of ethylenically unsaturated polymerizable monomers, especially olefins, comprising two Group 13 metal or metalloid atoms and a ligand structure including at least one bridging group connecting ligands on the two Group 13 metal or metalloid atoms.

McAdon, Mark H. (Midland, MI); Nickias, Peter N. (Midland, MI); Marks, Tobin J. (Evanston, IL); Schwartz, David J. (Lake Jackson, TX)

2001-01-01T23:59:59.000Z

115

Method for forming gold-containing catalyst with porous structure  

DOE Patents [OSTI]

A method for forming a gold-containing catalyst with porous structure according to one embodiment of the present invention includes producing a starting alloy by melting together of gold and at least one less noble metal that is selected from the group consisting of silver, copper, rhodium, palladium, and platinum; and a dealloying step comprising at least partial removal of the less noble metal by dissolving the at least one less noble metal out of the starting alloy. Additional methods and products thereof are also presented.

Biener, Juergen; Hamza, Alex V; Baeumer, Marcus; Schulz, Christian; Jurgens, Birte; Biener, Monika M.

2014-07-22T23:59:59.000Z

116

Hydrogenation of aromatics in synthetic crude distillates catalyzed by platinum supported in molecular sieves  

SciTech Connect (OSTI)

Catalytic hydrogenation of synthetic crude distillates from Canadian oil sands was carried out over platinum metal supported in pillared interlayered clay (PILC) and Y-zeolite. The molecular sieve supports were employed to modify the properties of dispersed platinum particles and improve their resistance to poisoning by sulfur. The objective was to reduce the distillate aromatic content to meet diesel emission control standards and cetane number requirements. Catalysts were prepared in a series of steps, and metal precursor was loaded using ion-exchange procedures. Characterization was done using X-ray diffraction, hydrogen chemisorption, and proton-induced X-ray emission elemental analysis. Catalytic hydrogenation reactions were carried out by processing distillate feedstocks both high (>100 ppm) and low (<10 ppm) in sulfur using a continuous-flow automated microreactor system. Experimental runs were performed to determine the reaction kinetics and Arrhenius parameters as a means of evaluating and comparing catalyst performance. Significant differences in catalyst activity were found. The Pt/Y-zeolite-alumina catalyst showed a much superior hydrogenation performance under conditions of high sulfur content. The extent of cracking and ring opening was also evaluated and was shown to be minimal under the operating conditions employed.

Kimbara, N.; Charland, J.P. [CANMET, Ottawa, Ontario (Canada)] [CANMET, Ottawa, Ontario (Canada); Wilson, M.F. [CANMET, Devon, Alberta (Canada)] [CANMET, Devon, Alberta (Canada)

1996-11-01T23:59:59.000Z

117

Porous, sintered metal filter recovers 100% of catalyst in H/sub 2/O/sub 2/ process  

SciTech Connect (OSTI)

Recovery of catalyst and prevention of catalyst from entering the oxidizer were plant problems for the Interox America process for production of H/sub 2/O/sub 2/ by the catalyzed alternative hydrogenation and oxidation of anthraquinone. A porous metal filter element was inserted in the filter unit following the hydrogenation stage to collect the catalyst which forms a permeable cake that is recovered by backwashing on a timer cycle. The porous metal filters consisting of a rigid matrix containing small pores applicable for the collection of very small particles (> 0.5 ..mu.. in liquids and 0.05 ..mu.. in gases) have been in use in plants in UK for 25 years with 75% of the original filter elements still in use. (BLM)

Hall, G.L.; Isaacs, M.

1982-01-01T23:59:59.000Z

118

Clustering of metal atoms in organic media. 9. High-activity Ni/MgO catalysts prepared by metal vapor methods. Surface area and particle size effects  

SciTech Connect (OSTI)

A metal vapor method was employed to prepare highly dispersed Ni metal catalysts (solvated metal atom dispersed = SMAD catalyst) supported on MgO. Compared with conventional Ni/MgO compositions, the SMAD catalysts showed much greater activities for all reactions studied (hydrogenolysis of methylcyclopentane, MCP; hydrogenation/hydrogenolysis of toluene, TOL; methanation of carbon monoxide, CO; dehydration of isopropyl alcohol, IPA). These high activities for the SMAD catalysts are attributed to the high surface area of Ni on MgO and the high percentage of this Ni in a zero-valent state (reduction degree). Conventional methods for preparing Ni/MgO catalysts did not yield nearly such favorable surface areas or reduction degrees. Nickel particle size effects were observed during hydrogenolysis studies of MCP and hydrogenation studies of TOL. These phenomena are explained by assuming the size of an active Ni particle to be largest for hydrogenolysis of MCP > hydrogenation of TOL > methanation of CO approx. = dehydrogenation of IPA. 8 figures, 2 tables.

Matsuo, K.; Klabunde, K.J.

1982-02-01T23:59:59.000Z

119

Durable Catalysts for Fuel Cell Protection during Transient Conditions...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Working Group Meeting: June 2014 DOE's Fuel Cell Catalyst R&D Activities Contiguous Platinum Monolayer Oxygen Reduction Electrocatalysts on High-Stability-Low-Cost Supports...

120

Toward Photochemical Water Splitting Using Band-Gap-Narrowed Semiconductors and Transition-Metal Based Molecular Catalysts  

SciTech Connect (OSTI)

We are carrying out coordinated theoretical and experimental studies of toward photochemical water splitting using band-gap-narrowed semiconductors (BGNSCs) with attached multi-electron molecular water oxidation and hydrogen production catalysts. We focus on the coupling between the materials properties and the H{sub 2}O redox chemistry, with an emphasis on attaining a fundamental understanding of the individual elementary steps in the following four processes: (1) Light-harvesting and charge-separation of stable oxide or oxide-derived semiconductors for solar-driven water splitting, including the discovery and characterization of the behavior of such materials at the aqueous interface; (2) The catalysis of the four-electron water oxidation by dinuclear hydroxo transition-metal complexes with quinonoid ligands, and the rational search for improved catalysts; (3) Transfer of the design principles learned from the elucidation of the DuBois-type hydrogenase model catalysts in acetonitrile to the rational design of two-electron hydrogen production catalysts for aqueous solution; (4) Combining these three elements to examine the function of oxidation catalysts on BGNSC photoanode surfaces and hydrogen production catalysts on cathode surfaces at the aqueous interface to understand the challenges to the efficient coupling of the materials functions.

Muckerman,J.T.; Rodriguez, J.A.; Fujita, E.

2009-06-07T23:59:59.000Z

Note: This page contains sample records for the topic "metal catalysts platinum" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Fundamental investigations of supported monometallic and bimetallic catalysts by proton magnetic resonance spectroscopy  

SciTech Connect (OSTI)

Proton magnetic resonance spectroscopy, or nuclear magnetic resonance (NMR) of hydrogen, has been applied to investigate silica-supported Group VIII monometallic and Group VIII-Group IB bimetallic catalysts and alumina- and silica-supported platinum-rhenium bimetallic catalysts. Two adsorbed states of hydrogen, i.e., irreversible and reversible hydrogen, on the surfaces of monometallic Ru, Pt, and Cu particles and bimetallic Ru-Group Ib, Pt-Group Ib, and Pt-Re particles were observed directly via proton NMR. The same amounts of the irreversible hydrogen adsorbed on pure Ru catalysts were measured by both proton NMR and the volumetric technique. The electronic environments on surfaces of monometallic catalysts are sensitive to changes in metal dispersion, state of adsorbed hydrogen, and residual chlorine. Surface compositions for the Ru--Cu and Pt--Cu bimetallic catalysts were determined by NMR of adsorbed hydrogen. 297 refs., 96 figs., 19 tabs.

Wu, Xi.

1990-09-21T23:59:59.000Z

122

Syntheses and applications of soluble polyisobutylene (PIB)-supported transition metal catalysts  

E-Print Network [OSTI]

................................................. 34 Catalyst Recovery in Self-Separating Systems .............................. 39 Fluorous/Organic Biphasic Catalysis............................................. 41 Polymer-Supported Catalysts in Ionic Liquids... ................................................................................. 45 Results and Discussion................................................................. 51 Conclusions.................................................................................. 60 III POLYISOBUTYLENE-SUPPORTED RHODIUM...

Tian, Jianhua

2009-05-15T23:59:59.000Z

123

Doped palladium containing oxidation catalysts  

DOE Patents [OSTI]

A supported oxidation catalyst includes a support having a metal oxide or metal salt, and mixed metal particles thereon. The mixed metal particles include first particles including a palladium compound, and second particles including a precious metal group (PMG) metal or PMG metal compound, wherein the PMG metal is not palladium. The oxidation catalyst may also be used as a gas sensor.

Mohajeri, Nahid

2014-02-18T23:59:59.000Z

124

Breakthrough in platinum structures maintains high catalytic activity and could lead to reduced costs for  

E-Print Network [OSTI]

costs for hydrogen fuel cells, which hold the promise of powering vehicles and buildings. Hydrogen fuel be useful in hydrogen fuel cells while sharply driving down the cost compared to an all-platinum catalyst cells could power the vehicles of tomorrow. With platinum an essential catalyst in fuel cells

125

Composite catalysts supported on modified carbon substrates and methods of making the same  

DOE Patents [OSTI]

A method of producing a composite carbon catalyst is generally disclosed. The method includes oxidizing a carbon precursor (e.g., carbon black). Optionally, nitrogen functional groups can be added to the oxidized carbon precursor. Then, the oxidized carbon precursor is refluxed with a non-platinum transitional metal precursor in a solution. Finally, the solution is pyrolyzed at a temperature of at least about 500.degree. C.

Popov, Branko N. (Columbia, SC); Subramanian, Nalini (Kennesaw, GA); Colon-Mercado, Hector R. (Columbia, SC)

2009-11-17T23:59:59.000Z

126

Transition metal carbides, nitrides and borides, and their oxygen containing analogs useful as water gas shift catalysts  

DOE Patents [OSTI]

Mono- and bimetallic transition metal carbides, nitrides and borides, and their oxygen containing analogs (e.g. oxycarbides) for use as water gas shift catalysts are described. In a preferred embodiment, the catalysts have the general formula of M1.sub.A M2.sub.B Z.sub.C O.sub.D, wherein M1 is selected from the group consisting of Mo, W, and combinations thereof; M2 is selected from the group consisting of Fe, Ni, Cu, Co, and combinations thereof; Z is selected from the group consisting of carbon, nitrogen, boron, and combinations thereof; A is an integer; B is 0 or an integer greater than 0; C is an integer; O is oxygen; and D is 0 or an integer greater than 0. The catalysts exhibit good reactivity, stability, and sulfur tolerance, as compared to conventional water shift gas catalysts. These catalysts hold promise for use in conjunction with proton exchange membrane fuel cell powered systems.

Thompson, Levi T.; Patt, Jeremy; Moon, Dong Ju; Phillips, Cory

2003-09-23T23:59:59.000Z

127

Oxyhydrochlorination catalyst  

DOE Patents [OSTI]

An improved catalyst and method for the oxyhydrochlorination of methane is disclosed. The catalyst includes a pyrogenic porous support on which is layered as active material, cobalt chloride in major proportion, and minor proportions of an alkali metal chloride and of a rare earth chloride. On contact of the catalyst with a gas flow of methane, HCl and oxygen, more than 60% of the methane is converted and of that converted more than 40% occurs as monochloromethane. Advantageously, the monochloromethane can be used to produce gasoline boiling range hydrocarbons with the recycle of HCl for further reaction. This catalyst is also of value for the production of formic acid as are analogous catalysts with lead, silver or nickel chlorides substituted for the cobalt chloride.

Taylor, Charles E. (Pittsburgh, PA); Noceti, Richard P. (Pittsburgh, PA)

1992-01-01T23:59:59.000Z

128

Bridging the pressure gap: In situ atomic-level investigations of model platinum catalyst surfaces under reaction conditions by scanning tunneling microscopy  

SciTech Connect (OSTI)

Results of this thesis show that STM measurements can provide information about the surfaces and their adsorbates. Stability of Pt(110) under high pressures of H2, O2, and CO was studied (Chap. 4). In situ UHV and high vacuum experiments were carried out for sulfur on Pt(111) (Chap.5). STM studies of CO/S/Pt(111) in high CO pressures showed that the Pt substrate undergoes a stacking-fault-domain reconstruction involving periodic transitions from fcc to hcp stacking of top-layer atoms (Chap.6). In Chap.7, the stability of propylene on Pt(111) and the decomposition products were studied in situ with the HPSTM. Finally, in Chap.8, results are presented which show how the Pt tip of the HPSTM was used to locally rehydrogenate and oxidize carbonaceous clusters deposited on the Pt(111) surface; the Pt tip acted as a catalyst after activation by short voltage pulses.

McIntyre, B.J.

1994-05-01T23:59:59.000Z

129

Early transition metal catalysts for the living polymerization of olefins and alkynes  

E-Print Network [OSTI]

Zirconium and Hafnium Ziegler-Natta catalysts containing the [(2,6- C12C6H3NCH2CH2)2NMe]2- ([ArciN2NMe]2') ligand were prepared and employed in the polymerization of 1-hexene. Hafnium Ziegler-Natta catalysts containing the ...

Adamchuk, Jennifer

2006-01-01T23:59:59.000Z

130

The selective hydrogenation of crotonaldehyde over bimetallic catalysts  

SciTech Connect (OSTI)

The selective hydrogenation of crotonaldehyde has been investigated over a monometallic Pt/SiO{sub 2} catalyst and platinum bimetallic catalysts where the second metal was either silver, copper, or tin. The effects of addition of a second metal to the Pt/SiO{sub 2} system on the selectivity to crotyl alcohol were investigated. The Pt-Sn bimetallic catalysts were characterized by hydrogen chemisorption, {sup 1}H NMR and microcalorimetry. The Pt-Ag/SiO{sub 2} and Pt-Cu/SiO{sub 2} catalysts were characterized by hydrogen chemisorption. Pt-Sn/SiO{sub 2} catalysts selectively hydrogenated crotonaldehyde to crotyl alcohol and the method of preparation of these catalysts affected the selectivity. The most selective Pt-Sn/SiO{sub 2} catalysts for the hydrogenation of crotonaldehyde to crotyl alcohol were those in which the Sn precursor was dissolved in a HCl solution. Sn increased both the rate of formation of butyraldehyde and the rate of formation of crotyl alcohol. The Pt/SiO{sub 2}, Pt-Ag/SiO{sub 2} and Pt-Cu/SiO{sub 2} catalysts produced only butyraldehyde. Initial heats of adsorption ({approximately}90 kJ/mol) measured using microcalorimetry were not affected by the presence of Sn on Pt. We can conclude that there is no through metal electronic interaction between Pt and Sn at least with respect to hydrogen surface bonds since the Pt and Pt-Sn at least with respect to hydrogen surface bonds since the Pt and Pt-Sn had similar initial heats of adsorption coupled with the invariance of the {sup 1}H NMR Knight shift.

Schoeb, A.M.

1997-02-01T23:59:59.000Z

131

Process of making supported catalyst  

DOE Patents [OSTI]

Oxide supported metal catalysts have an additional metal present in intimate association with the metal catalyst to enhance catalytic activity. In a preferred mode, iridium or another Group VIII metal catalyst is supported on a titania, alumina, tungsten oxide, silica, or composite oxide support. Aluminum ions are readsorbed onto the support and catalyst, and reduced during calcination. The aluminum can be added as aluminum nitrate to the iridium impregnate solution, e.g. chloroiridic acid.

Schwarz, James A. (Fayetteville, NY); Subramanian, Somasundaram (Melvindale, MI)

1992-01-01T23:59:59.000Z

132

Reducible oxide based catalysts  

DOE Patents [OSTI]

A catalyst is disclosed herein. The catalyst includes a reducible oxide support and at least one noble metal fixed on the reducible oxide support. The noble metal(s) is loaded on the support at a substantially constant temperature and pH.

Thompson, Levi T.; Kim, Chang Hwan; Bej, Shyamal K.

2010-04-06T23:59:59.000Z

133

Electrochemical catalyst recovery method  

DOE Patents [OSTI]

A method of recovering catalyst material from latent catalyst material solids includes: (a) combining latent catalyst material solids with a liquid acid anolyte solution and a redox material which is soluble in the acid anolyte solution to form a mixture; (b) electrochemically oxidizing the redox material within the mixture into a dissolved oxidant, the oxidant having a potential for oxidation which is effectively higher than that of the latent catalyst material; (c) reacting the oxidant with the latent catalyst material to oxidize the latent catalyst material into at least one oxidized catalyst species which is soluble within the mixture and to reduce the oxidant back into dissolved redox material; and (d) recovering catalyst material from the oxidized catalyst species of the mixture. The invention is expected to be particularly useful in recovering spent catalyst material from petroleum hydroprocessing reaction waste products having adhered sulfides, carbon, hydrocarbons, and undesired metals, and as well as in other industrial applications. 3 figs.

Silva, L.J.; Bray, L.A.

1995-05-30T23:59:59.000Z

134

Model catalytic studies of single crystal, polycrystalline metal, and supported catalysts  

E-Print Network [OSTI]

This dissertation is focused on understanding the structure-activity relationship in heterogeneous catalysis by studying model catalytic systems. The catalytic oxidation of CO was chosen as a model reaction for studies on a variety of catalysts. A...

Yan, Zhen

2009-05-15T23:59:59.000Z

135

CO Oxidation on Pt-Group Metals from Ultrahigh Vacuum to Near Atmospheric Pressures. 2. Palladium and Platinum  

E-Print Network [OSTI]

paper.1 Figure 1b shows the corresponding polarization modulation infrared reflection absorptionCO Oxidation on Pt-Group Metals from Ultrahigh Vacuum to Near Atmospheric Pressures. 2. Palladium

Goodman, Wayne

136

DOE Award No. DE-FC36-03GO13108 NOVEL NON-PRECIOUS METAL CATALYSTS FOR PEMFC: CATALYST SELECTION THROUGH MOLECULAR MODELING AND DURABILITY STUDIES Final Report (September 2003 – October 2008)  

SciTech Connect (OSTI)

The objective of this project is to develop novel non-precious metal electrocatalysts for oxygen reduction reaction (ORR), and demonstrate the potential of the catalysts to perform at least as good as conventional Pt catalysts currently in use in polymer electrolyte membrane fuel cell (PEMFC) with a cost at least 50 % less than a target of 0.2 g (Pt loading)/peak kW and with durability > 2,000 h operation with less than 10 % power degradation. A novel nitrogen-modified carbon-based catalyst was obtained by modifying carbon black with nitrogen-containing organic precursor in the absence of transition metal precursor. The catalyst shows the onset potential of approximately 0.76 V (NHE) for ORR and the amount of H2O2 of approximately 3% at 0.5 V (NHE). Furthermore, a carbon composite catalyst was achieved through the high-temperature pyrolysis of the precursors of transition metal (Co and Fe) and nitrogen supported on the nitrogen-modified carbon-based catalyst, followed by chemical post-treatment. This catalyst showed an onset potential for ORR as high as 0.87 V (NHE), and generated less than 1 % of H2O2. The PEM fuel cell exhibited a current density of 2.3 A cm-2 at 0.2 V for a catalyst loading of 6.0 mg cm-2. No significant performance degradation was observed for 480 h continuous operation. The characterization studies indicated that the metal-nitrogen chelate complexes decompose at the temperatures above 800 oC. During the pyrolysis, the transition metals facilitate the incorporation of pyridinic and graphitic nitrogen groups into the carbon matrix, and the carbon surface modified with nitrogen is active for ORR. In order to elucidate the role of transition metal precursor played in the formation of active sites in the non-precious metal catalysts, a novel ruthenium-based chelate (RuNx) catalyst was synthesized by using RuCl3 and propylene diammine as the Ru and N precursors, respectively, followed by high-temperature pyrolysis. This catalyst exhibited comparable catalytic activity and selectivity for ORR as the Pt catalyst. A theoretical analysis is made of the four-electron reduction reaction of oxygen to water over the mixed anion and cation (202) surface of pentlandite structure Co9Se8, one of several selenide phases. Reversible potentials for forming adsorbed reaction intermediates in acid are predicted using adsorption energies calculated with the Vienna ab initio simulation program (VASP) and the known bulk solution values together in a linear Gibbs energy relationship. The effect of hydrophobic and structural properties of a single/dual-layer cathode gas diffusion layer on mass transport in PEM fuel cells was studied using an analytical expression. The simulations indicated that liquid water transport at the cathode is controlled by the fraction of hydrophilic surface and the average pore diameter in the cathode gas diffusion layer. The optimized hydrophobicity and pore geometry in a dual-layer cathode GDL leads to an effective water management, and enhances the oxygen diffusion kinetics.

Branko N. Popov

2009-03-03T23:59:59.000Z

137

DOE Award No. DE-FC36-03GO13108 NOVEL NON-PRECIOUS METAL CATALYSTS FOR PEMFC: CATALYST SELECTION THROUGH MOLECULAR MODELING AND DURABILITY STUDIES Final Report (September 2003 – October 2008)  

SciTech Connect (OSTI)

The objective of this project is to develop novel non-precious metal electrocatalysts for oxygen reduction reaction (ORR), and demonstrate the potential of the catalysts to perform at least as good as conventional Pt catalysts currently in use in polymer electrolyte membrane fuel cell (PEMFC) with a cost at least 50 % less than a target of 0.2 g (Pt loading)/peak kW and with durability > 2,000 h operation with less than 10 % power degradation. A novel nitrogen-modified carbon-based catalyst was obtained by modifying carbon black with nitrogen-containing organic precursor in the absence of transition metal precursor. The catalyst shows the onset potential of approximately 0.76 V (NHE) for ORR and the amount of H2O2 of approximately 3% at 0.5 V (NHE). Furthermore, a carbon composite catalyst was achieved through the high-temperature pyrolysis of the precursors of transition metal (Co and Fe) and nitrogen supported on the nitrogen-modified carbon-based catalyst, followed by chemical post-treatment. This catalyst showed an onset potential for ORR as high as 0.87 V (NHE), and generated less than 1 % of H2O2. The PEM fuel cell exhibited a current density of 2.3 A cm-2 at 0.2 V for a catalyst loading of 6.0 mg cm-2. No significant performance degradation was observed for 480 h continuous operation. The characterization studies indicated that the metal-nitrogen chelate complexes decompose at the temperatures above 800 oC. During the pyrolysis, the transition metals facilitate the incorporation of pyridinic and graphitic nitrogen groups into the carbon matrix, and the carbon surface modified with nitrogen is active for ORR. In order to elucidate the role of transition metal precursor played in the formation of active sites in the non-precious metal catalysts, a novel ruthenium-based chelate (RuNx) catalyst was synthesized by using RuCl3 and propylene diammine as the Ru and N precursors, respectively, followed by high-temperature pyrolysis. This catalyst exhibited comparable catalytic activity and selectivity for ORR as the Pt catalyst. A theoretical analysis is made of the four-electron reduction reaction of oxygen to water over the mixed anion and cation (202) surface of pentlandite structure Co9Se8, one of several selenide phases. Reversible potentials for forming adsorbed reaction intermediates in acid are predicted using adsorption energies calculated with the Vienna ab initio simulation program (VASP) and the known bulk solution values together in a linear Gibbs energy relationship. The effect of hydrophobic and structural properties of a single/dual-layer cathode gas diffusion layer on mass transport in PEM fuel cells was studied using an analytical expression. The simulations indicated that liquid water transport at the cathode is controlled by the fraction of hydrophilic surface and the average pore diameter in the cathode gas diffusion layer. The optimized hydrophobicity and pore geometry in a dual-layer cathode GDL leads to an effective water management, and enhances the oxygen diffusion kinetics.

Branko N. Popov

2009-02-20T23:59:59.000Z

138

Method and system for the combination of non-thermal plasma and metal/metal oxide doped .gamma.-alumina catalysts for diesel engine exhaust aftertreatment system  

DOE Patents [OSTI]

The present disclosure pertains to a system and method for treatment of oxygen rich exhaust and more specifically to a method and system that combines non-thermal plasma with a metal doped .gamma.-alumina catalyst. Current catalyst systems for the treatment of oxygen rich exhaust are capable of achieving only approximately 7 to 12% NO.sub.x reduction as a passive system and only 25 40% reduction when a supplemental hydrocarbon reductant is injected into the exhaust stream. It has been found that treatment of an oxygen rich exhaust initially with a non-thermal plasma and followed by subsequent treatment with a metal doped .gamma.-alumina prepared by the sol gel method is capable of increasing the NO.sub.x reduction to a level of approximately 90% in the absence of SO.sub.2 and 80% in the presence of 20 ppm of SO.sub.2. Especially useful metals have been found to be indium, gallium, and tin.

Aardahl, Christopher L. (Richland, WA); Balmer-Miller, Mari Lou (West Richland, WA); Chanda, Ashok (Peoria, IL); Habeger, Craig F. (West Richland, WA); Koshkarian, Kent A. (Peoria, IL); Park, Paul W. (Peoria, IL)

2006-07-25T23:59:59.000Z

139

Alkali or alkaline earth metal promoted catalyst and a process for methanol synthesis using alkali or alkaline earth metals as promoters  

DOE Patents [OSTI]

The present invention relates to a novel route for the synthesis of methanol, and more specifically to the production of methanol by contacting synthesis gas under relatively mild conditions in a slurry phase with a heterogeneous catalyst comprising reduced copper chromite impregnated with an alkali or alkaline earth metal. There is thus no need to add a separate alkali or alkaline earth compound. The present invention allows the synthesis of methanol to occur in the temperature range of approximately 100.degree.-160.degree. C. and the pressure range of 40-65 atm. The process produces methanol with up to 90% syngas conversion per pass and up to 95% methanol selectivity. The only major by-product is a small amount of easily separated methyl formate. Very small amounts of water, carbon dioxide and dimethyl ether are also produced. The present catalyst combination also is capable of tolerating fluctuations in the H.sub.2 /CO ratio without major deleterious effect on the reaction rate. Furthermore, carbon dioxide and water are also tolerated without substantial catalyst deactivation.

Tierney, John W. (Pittsburgh, PA); Wender, Irving (Pittsburgh, PA); Palekar, Vishwesh M. (Pittsburgh, PA)

1995-01-01T23:59:59.000Z

140

Alkali or alkaline earth metal promoted catalyst and a process for methanol synthesis using alkali or alkaline earth metals as promoters  

DOE Patents [OSTI]

The present invention relates to a novel route for the synthesis of methanol, and more specifically to the production of methanol by contacting synthesis gas under relatively mild conditions in a slurry phase with a heterogeneous catalyst comprising reduced copper chromite impregnated with an alkali or alkaline earth metal. There is thus no need to add a separate alkali or alkaline earth compound. The present invention allows the synthesis of methanol to occur in the temperature range of approximately 100--160 C and the pressure range of 40--65 atm. The process produces methanol with up to 90% syngas conversion per pass and up to 95% methanol selectivity. The only major by-product is a small amount of easily separated methyl formate. Very small amounts of water, carbon dioxide and dimethyl ether are also produced. The present catalyst combination also is capable of tolerating fluctuations in the H[sub 2]/CO ratio without major deleterious effect on the reaction rate. Furthermore, carbon dioxide and water are also tolerated without substantial catalyst deactivation.

Tierney, J.W.; Wender, I.; Palekar, V.M.

1995-01-31T23:59:59.000Z

Note: This page contains sample records for the topic "metal catalysts platinum" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

INVESTIGATION OF MIXED METAL SORBENT/CATALYSTS FOR THE SIMULTANEOUS REMOVAL OF SULFUR AND NITROGEN OXIDES  

SciTech Connect (OSTI)

Simultaneous removal of SO{sub 2} and NO{sub x} using a regenerable solid sorbent will constitute an important improvement over the use of separate processes for the removal of these two pollutants from stack gases and possibly eliminate several shortcomings of the individual SO{sub 2} and NO{sub x} removal operations. The work done at PETC and the DOE-funded investigation of the investigators on the sulfation and regeneration of alumina-supported cerium oxide sorbents have shown that they can perform well at relatively high temperatures (823-900 K) as regenerable desulfurization sorbents. Survey of the recent literature shows that addition of copper oxide to ceria lowers the sulfation temperature of ceria down to 773 K, sulfated ceria-based sorbents can function as selective SCR catalysts even at elevated temperatures, SO{sub 2} can be directly reduced to sulfur by CO on CuO-ceria catalysts, and ceria-based catalysts may have a potential for selective catalytic reduction of NO{sub x} by methane. These observations indicate a possibility of developing a ceria-based sorbent/catalyst which can remove both SO{sub 2} and NO{sub x} from flue gases within a relatively wide temperature window, produce significant amounts of elemental sulfur during regeneration, and use methane for the selective catalytic reduction of NO{sub x}.

Ates Akyurtlu; Jale F. Akyurtle

2001-08-01T23:59:59.000Z

142

Experimental Study of In Situ Combustion with Decalin and Metallic Catalyst  

E-Print Network [OSTI]

Using a hydrogen donor and a catalyst for upgrading and increasing oil recovery during in situ combustion is a known and proven technique. Based on research conducted on this process, it is clear that widespread practice in industry is the usage...

Mateshov, Dauren

2011-02-22T23:59:59.000Z

143

The Use of Soluble Polyolefins as Supports for Transition Metal Catalysts  

E-Print Network [OSTI]

times, with no loss in catalytic activity. To perform a thermomorphic solid/liquid separation, a polymer-bound catalyst that is completely insoluble at room temperature but soluble upon heating must be used. Our lab has pioneered the use of polyethylene...

Hobbs, Christopher Eugene

2012-10-19T23:59:59.000Z

144

Lattice-Strain Control of the Activity in Dealloyed Core-Shell Fuel Cell Catalysts  

SciTech Connect (OSTI)

Electrocatalysis will play a key role in future energy conversion and storage technologies, such as water electrolysers, fuel cells and metal–air batteries. Molecular interactions between chemical reactants and the catalytic surface control the activity and efficiency, and hence need to be optimized; however, generalized experimental strategies to do so are scarce. Here we show how lattice strain can be used experimentally to tune the catalytic activity of dealloyed bimetallic nanoparticles for the oxygen-reduction reaction, a key barrier to the application of fuel cells and metal–air batteries. We demonstrate the core–shell structure of the catalyst and clarify the mechanistic origin of its activity. The platinum-rich shell exhibits compressive strain, which results in a shift of the electronic band structure of platinum and weakening chemisorption of oxygenated species. We combine synthesis, measurements and an understanding of strain from theory to generate a reactivity–strain relationship that provides guidelines for tuning electrocatalytic activity.

Strasser, Peter; Shirlaine, Koh; Anniyev, Toyli; Greeley, Jeffrey P.; More, Karren L.; Yu, Chengfei; Liu, Zengcai; Kaya, Sarp; Nordlund, Dennis; Ogasawara, Hirohito; Toney, Michael F.; Nilsson, Anders R.

2010-04-30T23:59:59.000Z

145

Lattice-Strain Control of the Activity in Dealloyed Core-Shell Fuel Cell Catalysts  

SciTech Connect (OSTI)

Electrocatalysis will play a key role in future energy conversion and storage technologies, such as water electrolysers, fuel cells and metal-air batteries. Molecular interactions between chemical reactants and the catalytic surface control the activity and efficiency, and hence need to be optimized; however, generalized experimental strategies to do so are scarce. Here we show how lattice strain can be used experimentally to tune the catalytic activity of dealloyed bimetallic nanoparticles for the oxygen-reduction reaction, a key barrier to the application of fuel cells and metal-air batteries. We demonstrate the core-shell structure of the catalyst and clarify the mechanistic origin of its activity. The platinum-rich shell exhibits compressive strain, which results in a shift of the electronic band structure of platinum and weakening chemisorption of oxygenated species. We combine synthesis, measurements and an understanding of strain from theory to generate a reactivity-strain relationship that provides guidelines for tuning electrocatalytic activity.

Strasser, P. [Berlin Institute of Technology (Technische Universitat Berlin); Koh, Shirlaine [University of Houston, Houston; Anniyev, Toyli [SLAC National Accelerator Laboratory; Greeley, Jeff [Argonne National Laboratory (ANL); More, Karren Leslie [ORNL; Yu, Chengfei [University of Houston, Houston; Liu, Zengcai [University of Houston, Houston; Kaya, Sarpa [SLAC National Accelerator Laboratory; Nordlund, Dennis [SLAC National Accelerator Laboratory; Ogasawara, Hirohito [SLAC National Accelerator Laboratory; Toney, Michael F. [SLAC National Accelerator Laboratory; Anders, Nilsson [SLAC National Accelerator Laboratory

2010-01-01T23:59:59.000Z

146

INVESTIGATION OF MIXED METAL SORBENT/CATALYSTS FOR THE SIMULTANEOUS REMOVAL OF SULFUR AND NITROGEN OXIDES  

SciTech Connect (OSTI)

Simultaneous removal of SO{sub 2} and NO{sub x} using a regenerable solid sorbent will constitute an important improvement over the use of separate processes for the removal of these two pollutants from stack gases and possibly eliminate several shortcomings of the individual SO{sub 2} and NO{sub x} removal operations. The work done at PETC and the DOE-funded investigation of the investigators on the sulfation and regeneration of alumina-supported cerium oxide sorbents have shown that they can perform well at relatively high temperatures (823-900 K) as regenerable desulfurization sorbents. Survey of the recent literature shows that addition of copper oxide to ceria lowers the sulfation temperature of ceria down to 773 K, sulfated ceria-based sorbents can function as selective SCR catalysts even at elevated temperatures, SO{sub 2} can be directly reduced to sulfur by CO on CuO-ceria catalysts, and ceria-based catalysts may have a potential for selective catalytic reduction of NO{sub x} by methane. These observations indicate a possibility of developing a ceria-based sorbent/catalyst which can remove both SO{sub 2} and NO{sub x} from flue gases within a relatively wide temperature window, produce significant amounts of elemental sulfur during regeneration, and use methane for the selective catalytic reduction of NO{sub x}. The objective of this research is to conduct kinetic and parametric studies of the selective catalytic reduction of NO{sub x} with NH{sub 3} and CH{sub 4} over alumina-supported cerium oxide and copper oxide-cerium oxide sorbent/catalysts; investigate SO{sub 2} removal at lower temperatures by supported copper oxide-cerium oxide sorbents; and investigate the possibility of elemental sulfur production during regeneration with CO or with CH{sub 4}-air mixtures.

Ates Akyurtlu; Jale F. Akyurtlu

2000-04-10T23:59:59.000Z

147

INVESTIGATION OF MIXED METAL SORBENT/CATALYSTS FOR THE SIMULTANEOUS REMOVAL OF SULFUR AND NITROGEN OXIDES  

SciTech Connect (OSTI)

Simultaneous removal of SO{sub 2} and NO{sub x} using a regenerable solid sorbent will constitute an important improvement over the use of separate processes for the removal of these two pollutants from stack gases and possibly eliminate several shortcomings of the individual SO{sub 2} and NO{sub x} removal operations. The work done at PETC and the DOE-funded research of the investigators on the sulfation and regeneration of alumina-supported cerium oxide sorbents have shown that they can perform well at relatively high temperatures (823-900 K) as regenerable desulfurization sorbents. Survey of the recent literature shows that addition of copper oxide to ceria lowers the sulfation temperature of ceria down to 773 K, sulfated ceria-based sorbents can function as selective SCR catalysts even at elevated temperatures, SO{sub 2} can be directly reduced to sulfur by CO on CuO-ceria catalysts, and ceria-based catalysts may have a potential for selective catalytic reduction of NO{sub x} by methane. These observations indicate a possibility of developing a ceria-based sorbent/catalyst which can remove both SO{sub 2} and NO{sub x} from flue gases within a relatively wide temperature window, produce significant amounts of elemental sulfur during regeneration, and use methane for the selective catalytic reduction of NO{sub x}. The objective of this research is to conduct kinetic and parametric studies of the selective catalytic reduction of NO{sub x} with NH{sub 3} and CH{sub 4} over alumina-supported cerium oxide and copper oxide-cerium oxide sorbent/catalysts; investigate SO{sub 2} removal at lower temperatures by supported copper oxide-cerium oxide sorbents; and investigate the possibility of elemental sulfur production during regeneration with CO or with CH{sub 4} air mixtures.

Ates Akyurtlu; Jale F. Akyurtlu

1999-11-30T23:59:59.000Z

148

Investigation of mixed metal sorbent/catalysts for the simultaneous removal of sulfur and nitrogen oxides  

SciTech Connect (OSTI)

Simultaneous removal of SO{sub 2} and NO{sub x} using a regenerable solid sorbent will constitute an important improvement over the use of separate processes for the removal of these two pollutants from stack gases and possibly eliminate several shortcomings of the individual SO{sub 2} and NO{sub x} removal operations. The work done at PETC and the DOE-funded investigation of the investigators on the sulfation and regeneration of alumina-supported cerium oxide sorbents have shown that they can perform well at relatively high temperatures (823-900 K) as regenerable desulfurization sorbents. Survey of the recent literature shows that addition of copper oxide to ceria lowers the sulfation temperature of ceria down to 773 K, sulfated ceria-based sorbents can function as selective SCR catalysts even at elevated temperatures, SO{sub 2} can be directly reduced to sulfur by CO on CuO-ceria catalysts, and ceria-based catalysts may have a potential for selective catalytic reduction of NO{sub x} by methane. These observations indicate a possibility of developing a ceria-based sorbent/catalyst which can remove both SO{sub 2} and NO{sub x} from flue gases within a relatively wide temperature window, produce significant amounts of elemental sulfur during regeneration, and use methane for the selective catalytic reduction of NO{sub x}. The objective of this research is to conduct kinetic and parametric studies of the selective catalytic reduction of NO{sub x} with NH{sub 3} and CH{sub 4} over alumina-supported cerium oxide and copper oxide-cerium oxide sorbent/catalysts; investigate SO{sub 2} removal at lower temperatures by supported copper oxide-cerium oxide sorbents; and investigate the possibility of elemental sulfur production during regeneration with CO or with CH{sub 4}-air mixtures.

Akyurtlu, A.; Akyurtlu, J.F.

1999-03-31T23:59:59.000Z

149

Stable platinum nanoparticles on specific MgAl2O4 spinel facets...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

nm on its relatively abundant 111 facets during extremely severe aging at 800°C in air for 1 week (168 h). The aged catalysts retain platinum dispersions of 15.9% with...

150

Low platinum loading electrospun electrodes for proton exchange membrane fuel cells  

E-Print Network [OSTI]

An experimental study was performed to evaluate the utility of electrospun carbon nanofiber supports for sputtered platinum catalyst in proton exchange membrane fuel cells. The performance of the sputtered nanofiber supports ...

Singer, Simcha Lev

2006-01-01T23:59:59.000Z

151

OXYGEN REDUCTION WITH CARBON SUPPORTED METALLIC CLUSTER CATALYSTS IN ALKALINE ELECTROLYTE  

E-Print Network [OSTI]

transition metal oxide clusters. Acknowledgements This work was supported by the Assistant Secretary of Conservation and Renewable Energy,

Ross Jr., Philip N.

2013-01-01T23:59:59.000Z

152

Catalysts for the production of hydrocarbons from carbon monoxide and water  

DOE Patents [OSTI]

A method of converting low H/sub 2//CO ratio syngas to carbonaceous products comprising reacting the syngas with water or steam at 200 to 350/sup 0/C in the presence of a metal catalyst supported on zinc oxide. Hydrocarbons are produced with a catalyst selected from cobalt, nickel or ruthenium and alcohols are produced with a catalyst selected from palladium, platinum, ruthenium or copper on the zinc oxide support. The ratio of the reactants are such that for alcohols and saturated hydrocarbons: (2n + 1) greater than or equal to x greater than or equal to O and for olefinic hydrocarbons: 2n greater than or equal to x greater than or equal to O where n is the number of carbon atoms in the product and x is the molar amount of water in the reaction mixture.

Sapienza, R.S.; Slegeir, W.A.; Goldberg, R.I.

1985-11-06T23:59:59.000Z

153

Highly Dispersed Alloy Catalyst for Durability  

SciTech Connect (OSTI)

Achieving DOE�¢����s stated 5000-hr durability goal for light-duty vehicles by 2015 will require MEAs with characteristics that are beyond the current state of the art. Significant effort was placed on developing advanced durable cathode catalysts to arrive at the best possible electrode for high performance and durability, as well as developing manufacturing processes that yield significant cost benefit. Accordingly, the overall goal of this project was to develop and construct advanced MEAs that will improve performance and durability while reducing the cost of PEMFC stacks. The project, led by UTC Power, focused on developing new catalysts/supports and integrating them with existing materials (membranes and gas diffusion layers (GDLs)) using state-of-the-art fabrication methods capable of meeting the durability requirements essential for automotive applications. Specifically, the project work aimed to lower platinum group metals (PGM) loading while increasing performance and durability. Appropriate catalysts and MEA configuration were down-selected that protects the membrane, and the layers were tailored to optimize the movements of reactants and product water through the cell to maximize performance while maintaining durability.

Vivek S. Murthi (Primary Contact), Elise Izzo, Wu Bi, Sandra Guerrero and Lesia Protsailo

2013-01-08T23:59:59.000Z

154

Process for the production of hydrogen and carbonyl sulfide from hydrogen sulfide and carbon monoxide using a metal boride, nitride, carbide and/or silicide catalyst  

SciTech Connect (OSTI)

Hydrogen and carbonyl sulfide are produced by a process comprising contacting gaseous hydrogen sulfide with gaseous carbon monoxide in the presence of a metal boride, carbide, nitride and/or silicide catalyst, such as titanium carbide, vanadium boride, manganese nitride or molybdenum silicide.

McGuiggan, M.F.; Kuch, P.L.

1984-05-08T23:59:59.000Z

155

Supported metal carbonyls: new catalysts for the indirect liquefaction of coal. Semiannual report for period to July 1, 1980  

SciTech Connect (OSTI)

The synthesis, characterization and evaluation of two series of supported metal catalysts have been achieved during the first six months of the contract period. The first series of potentially catalytic materials consisted of iron and cobalt and iron/cobalt mixtures on synthetic zeolite supports; the second series comprised iron and iron/molybdenum, iron/manganese and iron/ruthenium mixtures on oxide supports. The materials were prepared by using procedures recently reported. Characterization of the materials was accomplished both in our laboratories at Virginia Commonwealth University and also by using facilities in the Analytical Chemistry Division at PETC; techniques employed included x-ray diffraction, ion-scattering spectrometry, secondary ion mass spectroscopy, electron spectroscopy for chemical analysis, scanning electron microscopy and thermogravimetric analysis. The ability of the prepared materials to catalyze the hydrogenation of carbon monoxide was evaluated by using micro-reactors in the Process Sciences Division at PETC.

Melson, Gordon A.

1980-01-01T23:59:59.000Z

156

Metal hydrides as electrode/catalyst materials for oxygen evolution/reduction in electrochemical devices  

DOE Patents [OSTI]

An at least ternary metal alloy of the formula, AB.sub.(5-Y)X(.sub.y), is claimed. In this formula, A is selected from the rare earth elements, B is selected from the elements of groups 8, 9, and 10 of the periodic table of the elements, and X includes at least one of the following: antimony, arsenic, and bismuth. Ternary or higher-order substitutions, to the base AB.sub.5 alloys, that form strong kinetic interactions with the predominant metals in the base metal hydride are used to form metal alloys with high structural integrity after multiple cycles of hydrogen sorption.

Bugga, Ratnakumar V. (Arcadia, CA); Halpert, Gerald (Pasadena, CA); Fultz, Brent (Pasadena, CA); Witham, Charles K. (Pasadena, CA); Bowman, Robert C. (La Mesa, CA); Hightower, Adrian (Whittier, CA)

1997-01-01T23:59:59.000Z

157

Catalyst system comprising a first catalyst system tethered to a supported catalyst  

DOE Patents [OSTI]

The present invention provides new catalyst formats which comprise a supported catalyst tethered to a second and different catalyst by a suitable tethering ligand. A preferred system comprises a heterogeneous supported metal catalyst tethered to a homogeneous catalyst. This combination of homogeneous and heterogeneous catalysts has a sufficient lifetime and unusually high catalytic activity in arene hydrogenations, and potentially many other reactions as well, including, but not limited to hydroformylation, hydrosilication, olefin oxidation, isomerization, hydrocyanidation, olefin metathesis, olefin polymerization, carbonylation, enantioselective catalysis and photoduplication. These catalysts are easily separated from the products, and can be reused repeatedly, making these systems very economical. 2 figs.

Angelici, R.J.; Gao, H.

1998-08-04T23:59:59.000Z

158

Foamlike Nanostructures Created from Dendritic Platinum Sheets on Liposomes  

E-Print Network [OSTI]

advantages over conventional platinum black in some applications. For example, they will likely exhibit) fuel cells,11,12 and as a catalyst in solar water-splitting devices.13,14 Because of the limited supply.; Hafele, W. Int. J. Hydrogen Energy 1990, 15, 727-737. (2) Kordesch, K. V.; Simader, G. R. Chem. ReV. 1995

Shelnutt, John A.

159

In situ formation of coal gasification catalysts from low cost alkali metal salts  

DOE Patents [OSTI]

A carbonaceous material, such as crushed coal, is admixed or impregnated with an inexpensive alkali metal compound, such as sodium chloride, and then pretreated with a stream containing steam at a temperature of 350.degree. to 650.degree. C. to enhance the catalytic activity of the mixture in a subsequent gasification of the mixture. The treatment may result in the transformation of the alkali metal compound into another, more catalytically active, form.

Wood, Bernard J. (Santa Clara, CA); Brittain, Robert D. (Cupertino, CA); Sancier, Kenneth M. (Menlo Park, CA)

1985-01-01T23:59:59.000Z

160

CHEMISTRY OF SO{sub 2} ON MODEL METAL AND OXIDE CATALYSTS: PHOTOEMISSION AND XANES STUDIES  

SciTech Connect (OSTI)

High-resolution synchrotron based photoemission and x-ray absorption spectroscopy have been used to study the interaction of SO{sub 2} with a series of metals and oxides. The chemistry of SO{sub 2} on metal surfaces is rich. At low coverages, the molecule fully decomposes into atomic S and O. At large coverages, the formation of SO{sub 3} and SO{sub 4} takes place. The following sequence was found for the reactivity of the metals towards SO{sub 2}: Pt {approx} Rh < Ru < Mo << Zn, Sn, Cs. Alloying can be useful for reducing the chemical affinity of a metal for SO{sub 2} and controlling S poisoning. Pd atoms bonded to Rh and Pt atoms bonded to Sn interact weakly with SO{sub 2}. In general, SO{sub 2} mainly reacts with the O centers of metal oxides. SO{sub 4} is formed on CeO{sub 2} and SO{sub 3} on ZnO. On these systems there is no decomposition of SO{sub 2}. Dissociation of the molecule is observed after introducing a large amount of Ce{sup 3+} sites in ceria, or after depositing Cu or alkali metals on the oxide surfaces. These promote the catalytic activity of the oxides during the destruction of SO{sub 2}.

RODRIGUEZ,J.A.; JIRSAK,T.; CHATURVEDI,S.; HRBEK,J.; FREITAG,A.; LARESE,J.Z.

2000-07-09T23:59:59.000Z

Note: This page contains sample records for the topic "metal catalysts platinum" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

Effect of modifier Pd metal on hydrocracking of polyaromatic compounds over Ni-loaded Y-type zeolite and its application as hydrodesulfurization catalysts  

SciTech Connect (OSTI)

Coal tar obtained from coal carbonization is a treasure of polyaromatic hydrocarbons, where more than 400 kinds of aromatic compounds are found to be contained. The development of new catalysts being able to convert these aromatics into mono or diaromatic compounds is one of objectives for utilization of polyaromatics. Hydrocracking of polyaromatic compounds is believed to proceed via formation of terminal-naphthenic ring of starting aromatic compounds, followed by cleavage of the naphthenic ring to produce alkylated aromatic compounds which has less numbers of ring than starting aromatics. Accordingly, hydrogenation of aromatic rings and cracking of resulting naphthenic rings are key steps of hydrocracking reaction, so that dual functional catalysts such as metal-supported acid catalysts are considered to be one of the best catalysts. Zeolite has controlled pore structures and strong acidity enough to crack naphthenic rings, being characteristics in exchanging metal species with ease. We have been studying the hydrocracking of polyaromatic compounds over Ni-loaded zeolite catalysts (ZSM-5, mordenite, and Y-type) and found the fact that pore size of zeolite exerts an interesting effect on product distribution. We also conducted computer-simulation for diffusion phenomena of the polyaromatic hydrocarbons in the pore of these zeolites and found that diffusion ability of the substrate affects strongly the product distributions Recently we found that modifying of Ni-loaded Y-type zeolite by Pd-loading enhanced hydrocracking ability of the catalyst. In this report, we would like to refer to the results of both hydrocracking reaction of pyrene and hydrodesulfurization of dibenzothiophene using Pd-modified Ni-loaded Y-type zeolite.

Wada, Takema; Murata, Satoru; Nomura, Masakatsu [Osaka Univ. (Japan)

1995-12-31T23:59:59.000Z

162

Electrocatalyst for oxygen reduction with reduced platinum oxidation and dissolution rates  

DOE Patents [OSTI]

The invention relates to platinum-metal oxide composite particles and their use as electrocatalysts in oxygen-reducing cathodes and fuel cells. The invention particularly relates to methods for preventing the oxidation of the platinum electrocatalyst in the cathodes of fuel cells by use of these platinum-metal oxide composite particles. The invention additionally relates to methods for producing electrical energy by supplying such a fuel cell with an oxidant, such as oxygen, and a fuel source, such as hydrogen.

Adzic, Radoslav; Zhang, Junliang; Vukmirovic, Miomir

2012-11-13T23:59:59.000Z

163

Electrocatalyst for oxygen reduction with reduced platinum oxidation and dissolution rates  

DOE Patents [OSTI]

The invention relates to platinum-metal oxide composite particles and their use as electrocatalysts in oxygen-reducing cathodes and fuel cells. The invention particularly relates to methods for preventing the oxidation of the platinum electrocatalyst in the cathodes of fuel cells by use of these platinum-metal oxide composite particles. The invention additionally relates to methods for producing electrical energy by supplying such a fuel cell with an oxidant, such as oxygen, and a fuel source, such as hydrogen.

Adzic, Radoslav (East Setauket, NY); Zhang, Junliang (Stony Brook, NY); Vukmirovic, Miomir (Port Jefferson Station, NY)

2011-11-22T23:59:59.000Z

164

Au/MxOy/TiO2 catalysts for CO oxidation: promotional effect of main-group, transition, and rare-earth metal oxide additives.  

SciTech Connect (OSTI)

Au/TiO2 catalysts are active for CO oxidation, but they suffer from high-temperature sintering of the gold particles, and few attempts have been made to promote or stabilize Au/TiO2. Our recent communication addressed these issues by loading gold onto Al2O3/TiO2 prepared via surface-sol-gel processing of Al(sec-OC4H9)3 on TiO2. In our current full paper, Au/Al2O3/TiO2 catalysts were prepared alternatively by thermal decomposition of Al(NO3)3 on TiO2 followed by loading gold, and the influences of the decomposition temperature and Al2O3 content were systematically surveyed. This facile method was subsequently extended to the preparation of a battery of metal oxide-modified Au/TiO2 catalysts virtually not reported. It was found that Au/TiO2 modified by CaO, NiO, ZnO, Ga2O3, Y2O3, ZrO2, La2O3, Pr2O3, Nd2O3, Sm2O3, Eu2O3, Gd2O3, Dy2O3, Ho2O3, Er2O3, or Yb2O3 could retain significant activity at ambient temperature even after aging in O2-He at 500 C, whereas unmodified Au/TiO2 lost its activity. Moreover, some 200 C-calcined promoted catalysts showed high activity even at about -100 C. The deactivation and regeneration of some of these new catalysts were studied. This work furnished novel catalysts for further fundamental and applied research.

Ma, Zhen [ORNL; Overbury, Steven {Steve} H [ORNL; Dai, Sheng [ORNL

2007-01-01T23:59:59.000Z

165

REFORMULATION OF COAL-DERIVED TRANSPORTATION FUELS: SELECTIVE OXIDATION OF CARBON MONOXIDE ON METAL FOAM CATALYSTS  

SciTech Connect (OSTI)

Hydrocarbon fuels must be reformed in a series of steps to provide hydrogen for use in proton exchange membrane fuel cells (PEMFCs). Preferential oxidation (PROX) is one method to reduce the CO concentration to less than 10 ppm in the presence of {approx}40% H{sub 2}, CO{sub 2}, and steam. This will prevent CO poisoning of the PEMFC anode. Structured supports, such as ceramic monoliths, can be used for the PROX reaction. Alternatively, metal foams offer a number of advantages over the traditional ceramic monolith.

Paul Chin; Xiaolei Sun; George W. Roberts; Amornmart Sirijarhuphan; Sourabh Pansare; James G. Goodwin Jr; Richard W. Rice; James J. Spivey

2005-06-01T23:59:59.000Z

166

The Science and Engineering of Durable Ultralow PGM Catalysts- 2012 DOE-EERE-FCT annual progress report  

SciTech Connect (OSTI)

Minimizing the quantity of Pt group metals used in polymer membrane fuel cells (PEMFCs) is one of the remaining grand challenges for fuel cell commercialization. Tremendous progress has been achieved over the last two decades in decreasing the Pt loading required for efficient fuel cell performance. Unfortunately, the fluctuations in the price of Pt represent a substantial barrier to the economics of widespread fuel cell use. Durability and impurity tolerance are also challenges that are tightly coupled to fuel cell Pt electrode loading. Traditional approaches to decreasing the amount of Pt required for good performance include: (1) Increasing mass activity by decreasing Pt particle size by supporting on carbon; (2) Alloy formulation Pt-Co, Pt-Cr alloys to improve mass activity; (3) Increasing Pt utilization by optimization of electronic and ionic contact of the Pt particles; (4) Improving conductivity of the electronic and ionic conducting constituents of the membrane electrode assembly; and (5) Improving reactant to and product mass transport away from the electroactive sites. Recent novel approaches include the nanoengineering of core shell catalysts and Pt particles of unusual geometries such as nanowires/whiskers. The success of the aforementioned approaches has been great; however further advances using such approaches have been hampered by a lack of underlining scientific understanding of the catalyst activity, particle growth mechanisms, and optimization strategies for designing composite electrodes The objectives of this report are: (1) Development of durable, high mass activity Platinum Group Metal (PGM) cathode catalysts-enabling lower cost fuel cells; (2) Elucidation of the fundamental relationships between PGM catalyst shape, particle size and activity to help design better catalysts; (3) Optimization of the cathode electrode layer to maximize the performance of PGM catalysts-improving fuel cell performance and lowering cost; (4) Understanding the performance degradation mechanisms of high mass activity cathode catalysts-provide insights to better catalyst design; and (5) Development and testing of fuel cells using ultra-low loading high activity PGM catalysts-validation of advanced concepts.

Garzon, Fernando H. [Los Alamos National Laboratory

2012-07-16T23:59:59.000Z

167

Chalcogen catalysts for polymer electrolyte fuel cell  

DOE Patents [OSTI]

A methanol-tolerant cathode catalyst and a membrane electrode assembly for fuel cells that includes such a cathode catalyst. The cathode catalyst includes a support having at least one transition metal in elemental form and a chalcogen disposed on the support. Methods of making the cathode catalyst and membrane electrode assembly are also described.

Zelenay, Piotr (Los Alamos, NM); Choi, Jong-Ho (Los Alamos, NM); Alonso-Vante, Nicolas (France, FR); Wieckowski, Andrzej (Champaign, IL); Cao, Dianxue (Urbana, IL)

2010-08-24T23:59:59.000Z

168

Oxidation catalyst  

DOE Patents [OSTI]

The present invention generally relates to catalyst systems and methods for oxidation of carbon monoxide. The invention involves catalyst compositions which may be advantageously altered by, for example, modification of the catalyst surface to enhance catalyst performance. Catalyst systems of the present invention may be capable of performing the oxidation of carbon monoxide at relatively lower temperatures (e.g., 200 K and below) and at relatively higher reaction rates than known catalysts. Additionally, catalyst systems disclosed herein may be substantially lower in cost than current commercial catalysts. Such catalyst systems may be useful in, for example, catalytic converters, fuel cells, sensors, and the like.

Ceyer, Sylvia T. (Cambridge, MA); Lahr, David L. (Cambridge, MA)

2010-11-09T23:59:59.000Z

169

Shape-selective catalysts for Fischer-Tropsch chemistry : atomic layer deposition of active catalytic metals. Activity report : January 1, 2005 - September 30, 2005.  

SciTech Connect (OSTI)

Argonne National Laboratory is carrying out a research program to create, prepare, and evaluate catalysts to promote Fischer-Tropsch (FT) chemistry - specifically, the reaction of hydrogen with carbon monoxide to form long-chain hydrocarbons. In addition to needing high activity, it is desirable that the catalysts have high selectivity and stability with respect to both mechanical strength and aging properties. The broad goal is to produce diesel fraction components and avoiding excess yields of both light hydrocarbons and heavy waxes. Originally the goal was to prepare shape-selective catalysts that would limit the formation of long-chain products and yet retain the active metal sites in a protected 'cage.' Such catalysts were prepared with silica-containing fractal cages. The activity was essentially the same as that of catalysts without the cages. We are currently awaiting follow-up experiments to determine the attrition strength of these catalysts. A second experimental stage was undertaken to prepare and evaluate active FT catalysts formed by atomic-layer deposition [ALD] of active components on supported membranes and particulate supports. The concept was that of depositing active metals (i.e. ruthenium, iron or cobalt) upon membranes with well defined flow channels of small diameter and length such that the catalytic activity and product molecular weight distribution could be controlled. In order to rapidly evaluate the catalytic membranes, the ALD coating processes were performed in an 'exploratory mode' in which ALD procedures from the literature appropriate for coating flat surfaces were applied to the high surface area membranes. Consequently, the Fe and Ru loadings in the membranes were likely to be smaller than those expected for complete monolayer coverage. In addition, there was likely to be significant variation in the Fe and Ru loading among the membranes due to difficulties in nucleating these materials on the aluminum oxide surfaces. The first series of experiments using coated membranes demonstrated that the technology needed further improvement. Specifically, observed catalytic FT activity was low. This low activity appeared to be due to: (1) low available surface area, (2) atomic deposition techniques that needed improvements, and (3) insufficient preconditioning of the catalyst surface prior to FT testing. Therefore, experimentation was expanded to the use of particulate silica supports having defined channels and reasonably high surface area. This later experimentation will be discussed in the next progress report. Subsequently, we plan to evaluate membranes after the ALD techniques are improved with a careful study to control and quantify the Fe and Ru loadings. The preconditioning of these surfaces will also be further developed. (A number of improvements have been made with particulate supports; they will be discussed in the subsequent report.) In support of the above, there was an opportunity to undertake a short study of cobalt/promoter/support interaction using the Advanced Photon Source (APS) of Argonne. Five catalysts and a reference cobalt oxide were characterized during a temperature programmed EXAFS/XANES experimental study with the combined effort of Argonne and the Center for Applied Energy Research (CAER) of the University of Kentucky. This project was completed, and it resulted in an extensive understanding of the preconditioning step of reducing Co-containing FT catalysts. A copy of the resulting manuscript has been submitted and accepted for publication. A similar project was undertaken with iron-containing FT catalysts; the data is currently being studied.

Cronauer, D. C. (Chemical Sciences and Engineering Division)

2011-04-15T23:59:59.000Z

170

Contiguous Platinum Monolayer Oxygen Reduction Electrocatalysts...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Contiguous Platinum Monolayer Oxygen Reduction Electrocatalysts on High-Stability-Low-Cost Supports Contiguous Platinum Monolayer Oxygen Reduction Electrocatalysts on...

171

Stabilization of Platinum Nanoparticle Electrocatalysts for Oxygen...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Platinum Nanoparticle Electrocatalysts for Oxygen Reduction Using Poly(diallyldimethylammonium chloride). Stabilization of Platinum Nanoparticle Electrocatalysts for Oxygen...

172

Direct Ethanol Fuel Cells: Platinum/Rhodium Anode  

E-Print Network [OSTI]

Direct Ethanol Fuel Cells: Platinum/Rhodium Anode Catalysis Ken Ellis-Guardiola PCCM REU 2010 #12 EtOH+3H2O 12H+ +2CO2+ 12e- Pt C 4H+ + 4e- + O2 2H2O O2 Anode Cathode The Direct Ethanol Fuel Cell #12;The addition of other metals to Platinum improves its fuel cell performance Pt alone is easily

Petta, Jason

173

Platinum- and Platinum Alloy-Coated Palladium and Palladium Alloy...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Hydrogen and Fuel Cell Hydrogen and Fuel Cell Find More Like This Return to Search Platinum- and Platinum Alloy-Coated Palladium and Palladium Alloy Particles and Uses Thereof...

174

Composite metal membrane  

DOE Patents [OSTI]

A composite metal membrane including a first metal layer of Group IVB met or Group VB metals, the first metal layer sandwiched between two layers of an oriented metal of palladium, platinum or alloys thereof is provided together with a process for the recovery of hydrogen from a gaseous mixture including contacting a hydrogen-containing gaseous mixture with a first side of a nonporous composite metal membrane including a first metal of Group IVB metals or Group VB metals, the first metal layer sandwiched between two layers of an oriented metal of palladium, platinum or alloys thereof, and, separating hydrogen from a second side of the nonporous composite metal membrane.

Peachey, Nathaniel M. (Espanola, NM); Dye, Robert C. (Los Alamos, NM); Snow, Ronny C. (Los Alamos, NM); Birdsell, Stephan A. (Los Alamos, NM)

1998-01-01T23:59:59.000Z

175

Composite metal membrane  

DOE Patents [OSTI]

A composite metal membrane including a first metal layer of Group IVB met or Group VB metals, the first metal layer sandwiched between two layers of an oriented metal of palladium, platinum or alloys thereof is provided together with a process for the recovery of hydrogen from a gaseous mixture including contacting a hydrogen-containing gaseous mixture with a first side of a nonporous composite metal membrane including a first metal of Group IVB metals or Group VB metals, the first metal layer sandwiched between two layers of an oriented metal of palladium, platinum or alloys thereof, and, separating hydrogen from a second side of the nonporous composite metal membrane.

Peachey, N.M.; Dye, R.C.; Snow, R.C.; Birdsell, S.A.

1998-04-14T23:59:59.000Z

176

Effects of boundaries on pattern formation: Catalytic oxidation of CO on platinum  

SciTech Connect (OSTI)

The effect of boundaries on pattern formation was studied for the catalytic oxidation of carbon monoxide on platinum surfaces. Photolithography was used to create microscopic reacting domains on polycrystalline foils and single-crystal platinum (110) surfaces with inert titanium overlayers. Certain domain geometries give rise to patterns that have not been observed on the untreated catalyst and bring to light surface mechanisms that have no analog in homogeneous reaction-diffusion systems.

Graham, M.D. (Univ. of Wisconsin, Madison (United States)); Kevrekidis, I.G. (Princeton Univ., NJ (United States)); Asakura, K.; Lauterbach, J.; Krischer, K.; Rotermund, H.H.; Ertl, G. (Fritz-Haber-Institut de Max-Planck-Gesellschaft, Berlin (Germany))

1994-04-01T23:59:59.000Z

177

Catalysts for carbon and coal gasification  

DOE Patents [OSTI]

Catalyst for the production of methane from carbon and/or coal by means of catalytic gasification. The catalyst compostion containing at least two alkali metal salts. A particulate carbonaceous substrate or carrier is used.

McKee, Douglas W. (Burnt Hills, NY); Spiro, Clifford L. (Scotia, NY); Kosky, Philip G. (Schenectady, NY)

1985-01-01T23:59:59.000Z

178

Crystalline titanate catalyst supports  

DOE Patents [OSTI]

A series of new crystalline titanates (CT) are shown to have considerable potential as catalyst supports. For Pd supported catalyst, the catalytic activity for pyrene hydrogenation was substantially different depending on the type of CT, and one was substantially more active than Pd on hydrous titanium oxide (HTO). For 1-hexene hydrogenation the activities of the new CTs were approximately the same as for the hydrous metal oxide supports.

Anthony, R.G.; Dosch, R.G.

1993-01-05T23:59:59.000Z

179

Role of metal components in Pd?Cu bimetallic catalysts supported on CeO2 for the oxygen-enhanced water gas shift  

SciTech Connect (OSTI)

Catalytic hydrogen production and CO removal in a post-reforming process are critical for low-temperature fuel cell applications. The present study aims at clarifying the role of metal components in bimetallic catalysts for oxygen-enhanced water gas shift (OWGS), wherein a small amount of O{sub 2} is added to H{sub 2}-rich reformate gas to enhance CO shift. Among CeO{sub 2}-supported bimetallic catalysts, Pd-Cu and Pt-Cu combinations were found to show strong synergetic promoting effect in OWGS, which leads to much higher CO conversion and higher H{sub 2} yield than WGS at low temperature around 250 C. Temperature programmed reduction (TPR) showed strong interaction between Pd and Cu in Pd-Cu/CeO{sub 2} by a single reduction peak in contrast to multiple peaks on monometallic Cu/CeO{sub 2}. Extended X-ray absorption fine structure (EXAFS) analysis revealed that such bimetallic Pd-Cu and Pt-Cu form alloy nanoparticles, where noble metal is mainly surrounded by Cu atoms. Oxygen storage capacity (OSC) measurements point to higher resistance of Pd-Cu to oxidation indicating that Pd keeps Cu in reduced state in air pulse condition. From kinetic study, Pd in Pd-Cu was found to promote CO shift, rather than CO oxidation by increasing the number of active sites and by suppressing H{sub 2} activation (that is inherent to monometallic Pd), which minimizes both the inhibition effect of H{sub 2} and the loss of H{sub 2} by oxidation in OWGS. Transient response technique revealed that Cu in Pd-Cu enhances desorption of strongly chemisorbed CO{sub 2} on catalyst surface in contrast to very slow CO{sub 2} desorption from surface of monometallic Pd. Thus, the excellent OWGS activity of Pd-Cu catalyst has been attributed to the complementary roles of the two metals for enhancing CO shift, which is realized by its alloy structure and the accompanying strong interaction between metal components.

Kugai, J.; Miller, J. T.; Guo, N.; Song, C. (Chemical Sciences and Engineering Division); ( PSC-USR); (Penn State Univ.)

2011-06-01T23:59:59.000Z

180

Platinum- and platinum alloy-coated palladium and palladium alloy particles and uses thereof  

DOE Patents [OSTI]

The present invention relates to particle and nanoparticle composites useful as oxygen-reduction electrocatalysts. The particle composites are composed of a palladium or palladium-alloy particle or nanoparticle substrate coated with an atomic submonolayer, monolayer, bilayer, or trilayer of zerovalent platinum atoms. The invention also relates to a catalyst and a fuel cell containing the particle or nanoparticle composites of the invention. The invention additionally includes methods for oxygen reduction and production of electrical energy by using the particle and nanoparticle composites of the invention.

Adzic, Radoslav; Zhang, Junliang; Mo, Yibo; Vukmirovic, Miomir Branko

2010-04-06T23:59:59.000Z

Note: This page contains sample records for the topic "metal catalysts platinum" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

In situ Fourier transform infrared spectroscopy of adsorbed species on mixed metal oxide catalysts for higher alcohol synthesis  

SciTech Connect (OSTI)

Fourier Transform Infrared Spectroscopy was utilized to identify adsorbed species on Zn/Cu/Cr oxide and potassium carbonate-promoted Zn/Cu/Cr oxide catalysts at 285/sup 0/C and atmospheric pressure. Adsorption of various molecules on catalysts provided information about the nature of the adsorbed species. As a result of CO/H/sub 2/ mixture, methanol and formaldehyde adsorption two types of species formed, namely a methoxy and a formate. The adsorption of ethanol, acetaldehyde and acetic acid at 285/sup 0/C revealed stable acetate species. Ethanol and acetaldehyde adsorption also produced an ethoxy species whose formation was much favored on promoted catalysts. 136 refs., 46 figs., 14 tabs.

Baysar, A.

1986-01-01T23:59:59.000Z

182

Development of Ultra-low Platinum Alloy C th d C t l t f PEM F l C ll  

E-Print Network [OSTI]

Fuel Cells 2010 DOE Hydrogen Program Fuel Cell Project Kick-Off P I : Branko N PopovP. I.: Branko N of the catalyst layers which increases the cell resistance. ¾¾ Pt catalyst accelerates the rate of carbonDevelopment of Ultra-low Platinum Alloy C th d C t l t f PEM F l C ll Cathode Catalyst for PEM

183

Adsorption of propane, isopropyl, and hydrogen on cluster models of the M1 phase of Mo-V-Te-Nb-O mixed metal oxide catalyst  

SciTech Connect (OSTI)

The Mo-V-Te-Nb-O mixed metal oxide catalyst possessing the M1 phase structure is uniquely capable of directly converting propane into acrylonitrile. However, the mechanism of this complex eight-electron transformation, which includes a series of oxidative H-abstraction and N-insertion steps, remains poorly understood. We have conducted a density functional theory study of cluster models of the proposed active and selective site for propane ammoxidation, including the adsorption of propane, isopropyl (CH{sub 3}CHCH{sub 3}), and H which are involved in the first step of this transformation, that is, the methylene C-H bond scission in propane, on these active site models. Among the surface oxygen species, the telluryl oxo (Te=O) is found to be the most nucleophilic. Whereas the adsorption of propane is weak regardless of the MO{sub x} species involved, isopropyl and H adsorption exhibits strong preference in the order of Te=O > V=O > bridging oxygens > empty Mo apical site, suggesting the importance of TeO{sub x} species for H abstraction. The adsorption energies of isopropyl and H and consequently the reaction energy of the initial dehydrogenation of propane are strongly dependent on the number of ab planes included in the cluster, which points to the need to employ multilayer cluster models to correctly capture the energetics of surface chemistry on this mixed metal oxide catalyst.

Govindasamy, Agalya [University of Cincinnati; Muthukumar, Kaliappan [University of Cincinnati; Yu, Junjun [University of Cincinnati; Xu, Ye [ORNL; Guliants, Vadim V. [University of Cincinnati

2010-01-01T23:59:59.000Z

184

Aerogel derived catalysts  

SciTech Connect (OSTI)

Aerogels area class of colloidal materials which have high surface areas and abundant mesoporous structure. SiO{sub 2} aerogels show unique physical, optical and structural properties. When catalytic metals are incorporated in the aerogel framework, the potential exists for new and very effective catalysts for industrial processes. Three applications of these metal-containing SiO{sub 2} aerogels as catalysts are briefly reviewed in this paper--NO{sub x} reduction, volatile organic compound destruction, and partial oxidation of methane.

Reynolds, J. G., LLNL

1996-12-11T23:59:59.000Z

185

Support shape effect in metal oxide catalysis: ceria nanoshapes supported vanadia catalysts for oxidative dehydrogenation of iso-butane  

SciTech Connect (OSTI)

The activation energy of VOx/CeO2 catalysts in oxidative dehydrogenation of iso-butane was found dependent on the shape of ceria support: rods < octahedra, closely related to the surface oxygen vacancy formation energy and defects amount of the two ceria supports with different crystallographic surface planes.

Wu, Zili [ORNL; Schwartz, Viviane [ORNL; Li, Meijun [ORNL; Rondinone, Adam Justin [ORNL; Overbury, Steven {Steve} H [ORNL

2012-01-01T23:59:59.000Z

186

Supported fischer-tropsch catalyst and method of making the catalyst  

SciTech Connect (OSTI)

A Fischer-Tropsch catalyst and a method of making the catalyst for a Fischer-Tropsch process utilizing the catalyst by which synthesis gas, particularly carbon-monoxide rich synthesis gas, is selectively converted to higher hydrocarbons of relatively narrow carbon number range is disclosed. In general, the selective and notably stable catalyst, consist of an inert carrier first treated with a Group IV B metal compound (such as zirconium or titanium), preferably an alkoxide compound, and subsequently treated with an organic compound of a Fischer-Tropsch metal catalyst, such as cobalt, iron or ruthenium carbonyl. Reactions with air and water and calcination are specifically avoided in the catalyst preparation procedure.

Dyer, Paul N. (Allentown, PA); Pierantozzi, Ronald (Orefield, PA); Withers, Howard P. (Douglassville, PA)

1987-01-01T23:59:59.000Z

187

Catalyst for selective conversion of synthesis gas and method of making the catalyst  

SciTech Connect (OSTI)

A Fischer-Tropsch (F-T) catalyst, a method of making the catalyst and an F-T process utilizing the catalyst by which synthesis gas, particularly carbon-monoxide rich synthesis gas is selectively converted to higher hydrocarbons of relatively narrow carbon number range. In general, the selective and notably stable catalyst, consists of an inert carrier first treated with a Group IV B metal compound (such as zirconium or titanium), preferably an alkoxide compound, and subsequently treated with an organic compound of an F-T metal catalyst, such as cobalt, iron or ruthenium carbonyl. Reactions with air and water and calcination are specifically avoided in the catalyst preparation procedure.

Dyer, Paul N. (Allentown, PA); Pierantozzi, Ronald (Macungie, PA)

1986-01-01T23:59:59.000Z

188

Catalysts and method  

DOE Patents [OSTI]

An improved catlayst and method for the oxyhydrochlorination of methane is disclosed. The catalyst includes a pyrogenic porous support on which is layered as active material, cobalt chloride in major proportion, and minor proportions of an alkali metal chloride and of a rare earth chloride. On contact of the catalyst with a gas flow of methane, HC1 and oxygen, more than 60% of the methane is converted and of that converted more than 40% occurs as monochloromethane. Advantageously, the monochloromethane can be used to produce gasoline boiling range hydrocarbons with the recycle of HCl for further reaction. This catalyst is also of value for the production of formic acid as are analogous catalysts with lead, silver or nickel chlorides substituted for the cobalt chloride.

Taylor, Charles E. (Pittsburgh, PA); Noceti, Richard P. (Pittsburgh, PA)

1991-01-01T23:59:59.000Z

189

Chemistry of Cobalt-Platinum Nanocatalysts  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Chemistry of Cobalt-Platinum Nanocatalysts Chemistry of Cobalt-Platinum Nanocatalysts Print Monday, 25 February 2013 15:59 Bimetallic cobalt-platinum (CoPt) nanoparticles are...

190

PLATINUM-GROUP METALS (Platinum, palladium, rhodium, ruthenium, iridium, osmium)  

E-Print Network [OSTI]

chemicals; in the petroleum refining sector; and in laboratory equipment, including crucibles for growing Defense Stockpile remained suspended through FY 2013. Stockpile Status--9­30­13 4 Uncommitted Authorized; iridium prices were stable until midyear and then decreased markedly toward yearend, reportedly owing

191

Chemistry of Cobalt-Platinum Nanocatalysts  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Chemistry of Cobalt-Platinum Nanocatalysts Print Bimetallic cobalt-platinum (CoPt) nanoparticles are drawing attention in many areas of catalysis as scientists attempt to reduce...

192

Chemically modified carbon, nickel and platinum electrodes. Progress report, 15 January-1 October 1980. [Viologen polymers  

SciTech Connect (OSTI)

Significant progress has been made in three areas: (1) heterobismetallic complexes have been prepared that will be investigated as electrode bound redox catalysts; (2) electrodes capable of catalyzing the reduction of certain alkyl halides have been prepared and are under further investigation; and (3) electrode surface bound viologen polymers have been prepared on carbon and platinum.

Not Available

1980-01-01T23:59:59.000Z

193

Monolithic Metal Oxide based Composite Nanowire Lean NOx Emission...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Monolithic Metal Oxide based Composite Nanowire Lean NOx Emission Control Catalysts Monolithic Metal Oxide based Composite Nanowire Lean NOx Emission Control Catalysts Presents...

194

Catalysts allow CO and CO/sub 2/ comethanation  

SciTech Connect (OSTI)

Kyoto University researchers have developed a series of composite catalysts that permit simultaneous methanation of carbon monoxide and carbon dioxide in mixtures with hydrogen at temperatures as low as 270/sup 0/C. The procedure may provide considerable simplifications for Fischer-Tropsch synthesis; offer a long-sought route for the direct use of carbon dioxide as a recyclable material in industrial processes; and replace some synthetic procedures based on carbon monoxide which are hindered by the presence of carbon dioxide. The best comethanation catalysts are small amounts of lanthanide oxides on iron group substrates with platinum group metals as promoters, e.g., 5% Ni, 2.7% La/sub 2/O/sub 3/, and 0.6% Ru supported on 3 mm dia spherical silica pellets which have pores having a bimodal size distribution between 5 and 600 nm. Test reactions at 160/sup 0/-400/sup 0/C showed considerable variation with temperature and a very complex adsorption sequence. Carbon dioxide apparently enhances carbon monoxide methanation at higher temperatures. The mechanism is not understood but does not involve a water/carbon monoxide shift effect.

Not Available

1980-10-13T23:59:59.000Z

195

Transition metal complexes of oxazolinylboranes and cyclopentadienyl-bis(oxazolinyl)borates: Catalysts for asymmetric olefin hydroamination and acceptorless alcohol decarbonylation  

SciTech Connect (OSTI)

The research presented and discussed in this dissertation involves the synthesis of transition metal complexes of oxazolinylboranes and cyclopentadienyl-bis(oxazolinyl)borates, and their application in catalytic enantioselective olefin hydroamination and acceptorless alcohol decarbonylation. Neutral oxazolinylboranes are excellent synthetic intermediates for preparing new borate ligands and also developing organometallic complexes. Achiral and optically active bis(oxazolinyl)phenylboranes are synthesized by reaction of 2-lithio-2-oxazolide and 0.50 equiv of dichlorophenylborane. These bis(oxazolinyl)phenylboranes are oligomeric species in solid state resulting from the coordination of an oxazoline to the boron center of another borane monomer. The treatment of chiral bis(oxazolinyl)phenylboranes with sodium cyclopentadienide provide optically active cyclopentadienyl-bis(oxazolinyl)borates H[PhB(C{sub 5}H{sub 5})(Ox{sup R}){sub 2}] [Ox{sup R} = Ox{sup 4S-iPr,Me2}, Ox{sup 4R-iPr,Me2}, Ox{sup 4S-tBu]}. These optically active proligands react with an equivalent of M(NMe{sub 2}){sub 4} (M = Ti, Zr, Hf) to afford corresponding cyclopentadienyl-bis(oxazolinyl)borato group 4 complexes {PhB(C{sub 5}H{sub 4})(Ox{sup R}){sub 2}}M(NMe{sub 2}){sub 2} in high yields. These group 4 compounds catalyze cyclization of aminoalkenes at room temperature or below, providing pyrrolidine, piperidine, and azepane with enantiomeric excesses up to 99%. Our mechanistic investigations suggest a non-insertive mechanism involving concerted C?N/C?H bond formation in the turnover limiting step of the catalytic cycle. Among cyclopentadienyl-bis(oxazolinyl)borato group 4 catalysts, the zirconium complex {PhB(C{sub 5}H{sub 4})(Ox{sup 4S-iPr,Me2}){sub 2}}Zr(NMe{sub 2}){sub 2} ({S-2}Zr(NMe{sub 2}){sub 2}) displays highest activity and enantioselectivity. Interestingly, {S-2}Zr(NMe{sub 2}){sub 2} also desymmetrizes olefin moieties of achiral non-conjugated aminodienes and aminodiynes during cyclization. The cyclization of aminodienes catalyzed by {S-2}Zr(NMe{sub 2}){sub 2} affords diastereomeric mixture of cis and trans cylic amines with high diasteromeric ratios and excellent enantiomeric excesses. Similarly, the desymmetrization of alkyne moieties in {S-2}Zr(NMe{sub 2}){sub 2}-catalyzed cyclization of aminodiynes provides corresponding cyclic imines bearing quaternary stereocenters with enantiomeric excesses up to 93%. These stereoselective desymmetrization reactions are significantly affected by concentration of the substrate, temperature, and the presence of a noncyclizable primary amine. In addition, both the diastereomeric ratios and enantiomeric excesses of the products are markedly enhanced by N-deuteration of the substrates. Notably, the cationic zirconium-monoamide complex [{S-2}Zr(NMe{sub 2})][B(C{sub 6}F{sub 5}){sub 4}] obtained from neutral {S-2}Zr(NMe{sub 2}){sub 2} cyclizes primary aminopentenes providing pyrrolidines with S-configuration; whereas {S-2}Zr(NMe{sub 2}){sub 2} provides R-configured pyrrolidines. The yttrium complex {S-2}YCH{sub 2}SiMe{sub 3} also affords S-configured pyrrolidines by cyclization of aminopentenes, however the enantiomeric excesses of products are low. An alternative optically active yttrium complex {PhB(C{sub 5}H{sub 4})(Ox{sup 4S-tBu}){sub 2}}YCH{sub 2}SiMe{sub 3} ({S-3}YCH{sub 2}SiMe{sub 3}) is synthesized, which displays highly enantioselective in the cyclization of aminoalkenes at room temperature affording S-configured cyclic amines with enantiomeric excesses up to 96%. A noninsertive mechanism involving a six-membered transition state by a concerted C?N bond formation and N?H bond cleavage is proposed for {S-3}YCH{sub 2}SiMe{sub 3} system based on the kinetic, spectroscopic, and stereochemical features. In the end, a series of bis- and tris(oxazolinyl)borato iridium and rhodium complexes are synthesized with bis(oxazolinyl)phenylborane [PhB(Ox{sup Me2}){sub 2}]{sub n}, tris(oxazolinyl)borane [B(Ox{sup Me2}){sub 3}]n, and tris(4,4-dimethyl-2-oxazolinyl)phenylborate [To{sup M}]{sup ?}. All these new an

Manna, Kuntal [Ames Laboratory

2012-12-17T23:59:59.000Z

196

Regeneration of Hydrotreating and FCC Catalysts  

SciTech Connect (OSTI)

Hydrotreating, hydrocracking, and fluid catalytic cracking (FCC) catalysts are important components of petroleum refining processes. Hydrotreating and hydrocracking catalysts are used to improve the yield of high-quality light oil fractions from heavier crude oil and petroleum feedstocks containing high levels of impurities. FCC catalysts improve the yield of higher octane gasoline from crude oil. Residuum hydrotreating and cracking catalysts are susceptible to irreversible deactivation caused by adsorption of sulfur and by metals impurities, such as vanadium and nickel. The gradual buildup of these impurities in a hydrotreating catalyst eventually plugs the pores and deactivates it. Nickel and vanadium adversely affect the behavior of cracking catalysts, reducing product yield and quality. Replacing deactivated catalysts represents a significant cost in petroleum refining. Equally important are the costs and potential liabilities associated with treating and disposing spent catalysts. For example, recent US Environmental Protection Agency rulings have listed spent hydrotreating and hydrorefining catalysts as hazardous wastes. FCC catalysts, though more easily disposed of as road-base or as filler in asphalt and cement, are still an economic concern mainly because of the large volumes of spent catalysts generated. New processes are being considered to increase the useful life of catalysts or for meeting more stringent disposal requirements for spent catalysts containing metals. This report discusses a collaborative effort between Pacific Northwest National Laboratory (PNNL) and Phillips Petroleum, Inc., to identify promising chemical processes for removing metals adhered to spent hydrodesulfurization (HDS, a type of hydrotreating catalyst) and FCC catalysts. This study, conducted by PNNL, was funded by the US Department of Energy's Bartlesville Project Office. Fresh and spent catalysts were provided by Phillips Petroleum. The FCC catalyst was a rare-earth exchanged Y zeolite in a silica-alumina matrix. X-ray fluorescence analyses showed that the rare earths used in preparing the catalysts were a mixture of lanthanum and cerium. Antimony found in the spent catalyst was added during operation of the FCC unit as a way to suppress the adverse effects of deposited nickel. The fresh HDS samples consisted of sulfided nickel and molybdenum on an alumina support. The spent catalyst showed nearly 10% vanadium on the catalyst and a modest increase in nickel and sulfur on the catalyst as a result of operations. Hydrocracking catalysts were not available for this study.

CM Wai; JG Frye; JL Fulton; LE Bowman; LJ Silva; MA Gerber

1999-09-30T23:59:59.000Z

197

Metal oxide films on metal  

DOE Patents [OSTI]

A structure including a thin film of a conductive alkaline earth metal oxide selected from the group consisting of strontium ruthenium trioxide, calcium ruthenium trioxide, barium ruthenium trioxide, lanthanum-strontium cobalt oxide or mixed alkaline earth ruthenium trioxides thereof upon a thin film of a noble metal such as platinum is provided.

Wu, Xin D. (Los Alamos, NM); Tiwari, Prabhat (Los Alamos, NM)

1995-01-01T23:59:59.000Z

198

Kinetic study of the reaction between nitric oxide and carbon monoxide catalyzed by clean polycrystalline platinum  

SciTech Connect (OSTI)

The kinetics of the platinum catalyzed reaction between NO and CO has been studied under conditions chosen to approximate those observed during operation of catalysts in automotive exhaust gas treatment applications. The catalysts were polycrystalline platinum foils and wires. The reaction was studied over a range of reactant partial pressures of 10 V Torr to 1 Torr and catalyst temperatures of 500 to 1500K. The steady-state kinetics results could not be fit by a simple Langmuir-Hinshelwood kinetic model over all experimental conditions studied. The kinetics at high coverage were most consistent with Langmuir-Hinshelwood kinetics assuming a bimolecular reaction between NO and CO as the rate-limiting step. At high temperature, the Langmuir-Hinshelwood assumption of fast adsorption-desorption equilibrium relative to the surface reaction rate was no longer appropriate and the mechanism of adsorption of NO had to be considered explicitly.

Klein, R.L.

1984-01-01T23:59:59.000Z

199

In situ Characterization of Pt Catalysts Supported on Ceria Modified TiO(2) for the WGS reaction: Influence of Ceria Loading  

SciTech Connect (OSTI)

This work analyzes the influence of cerium content (6-15 wt%) on a TiO{sub 2} support over the structure and water gas shift (WGS) activity of Pt catalysts. The structural properties of these Pt/Ce-TiO{sub 2} catalysts were characterized by XRD, TEM and XANES. Physicochemical characterization of the catalysts showed differences in the structure and dispersion of Ce entities on the support with Ce loading. For the samples with low ceria content (6 wt%), cerium is deposited on the support in the form of CeO{sub x} clusters in a highly dispersed state in close interaction with the Ti atoms. The formation of CeO{sub x} clusters at low Ce-loading on the support facilitates the dispersion of small particles of Pt and improves the reducibility of ceria component at low temperatures. The changes in platinum dispersion and support reducibility with Ce-loading on the TiO{sub 2} support lead to significant differences in the WGS activity. Pt supported on the sample with lower Ce content (6 wt%) shows better activity than those corresponding to catalysts with higher Ce content (15 wt%). Activity measurements coupled with catalysts characterization suggest that the improvement in the reducibility of the support with lower Ce content was associated with the presence of CeO{sub x} clusters of high reducibility that improve the chemical activity of the oxide-metal interfaces at which the WGS reaction takes place.

Rodriguez J. A.; Barrio, L.; Zhou, G.; Gonzalez, I.D.; Estrella, M.; Hanson, J.; Navarro, R.M.; Fierro, J.L.G.

2012-01-01T23:59:59.000Z

200

Catalyst and process development for hydrogen preparation from future fuel cell feedstocks. Quarterly progress report, January 1, 1980-March 31, 1980. [Pt/Rh, Pd, Pt, Rh, Ni/Rh, Rh/Re, Ni  

SciTech Connect (OSTI)

Catalysts are being screened to steam reform hydrocarbons in an autothermal reformer (STR). Twenty-one samples have been screened in a 1-in.-diam (ATR) reactor using No. 2 oil as the hydrocarbon feed. A series of platinum-rhodium catalysts were evaluated to study the effect of varying compositions. A sample containing 1.7% Pt/0.3% Rh was most active but the difference among the samples was within the range of test variability. Development of a more realistic test has been started. The effect of O/sub 2//C level on the gas composition leaving the catalytic partial oxidation section has been determined. The amount of unreacted oil increases as O/sub 2//C level decreases. The unreacted oil is more aromatic than the feedstock. The gas composition contains considerably more olefins as the O/sub 2//C level decreases. Post-run catalyst characterization indicates that the catalyst carrier does not deteriorate in the ATR test. A drastic decrease in CO chemisorption is noted on the Pt/Rh samples. This decline in CO chemisorption could either be due to metal sintering or to carbon deposition on the metal. Other analysis are required to determine which is causing the decline in CO chemisorption. Very low coke levels were found on Pt, Rh, and Pt/Rh samples. Addition of Rh to nickel reduces the coke level over that observed for nickel catalysts.

Yarrington, R M; Feins, I R; Hwang, H S

1980-04-01T23:59:59.000Z

Note: This page contains sample records for the topic "metal catalysts platinum" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Low temperature catalysts for methanol production  

DOE Patents [OSTI]

A catalyst and process useful at low temperatures (below about 160 C) and preferably in the range 80--120 C used in the production of methanol from carbon monoxide and hydrogen are disclosed. The catalyst is used in slurry form and comprises a complex reducing agent derived from the component structure NaH--RONa-M(OAc)[sub 2] where M is selected from the group consisting of Ni, Pd, and Co and R is a lower alkyl group containing 1--6 carbon atoms. This catalyst is preferably used alone but is also effective in combination with a metal carbonyl of a group VI (Mo, Cr, W) metal. The preferred catalyst precursor is Nic (where M = Ni and R = tertiary amyl). Mo(CO)[sub 6] is the preferred metal carbonyl if such component is used. The catalyst is subjected to a conditioning or activating step under temperature and pressure, similar to the parameters given above, to afford the active catalyst.

Sapienza, R.S.; Slegeir, W.A.; O'Hare, T.E.; Mahajan, D.

1986-09-30T23:59:59.000Z

202

An exploration of automotive platinum demand and its impacts on the platinum market  

E-Print Network [OSTI]

The platinum market is a material market of increasing interest, as platinum demand has grown faster than supply in recent years. As a result, the price of platinum has increased, causing end-user firms to experience ...

Whitfield, Christopher George

2009-01-01T23:59:59.000Z

203

Method of forming supported doped palladium containing oxidation catalysts  

DOE Patents [OSTI]

A method of forming a supported oxidation catalyst includes providing a support comprising a metal oxide or a metal salt, and depositing first palladium compound particles and second precious metal group (PMG) metal particles on the support while in a liquid phase including at least one solvent to form mixed metal comprising particles on the support. The PMG metal is not palladium. The mixed metal particles on the support are separated from the liquid phase to provide the supported oxidation catalyst.

Mohajeri, Nahid

2014-04-22T23:59:59.000Z

204

Efficient Oxygen Evolution Reaction Catalysts for Cell Reversal and Start/Stop Tolerance in Fuel Cells  

SciTech Connect (OSTI)

Minute amounts of ruthenium and iridium on platinum nanostructured thin films have been evaluated in an effort to reduce carbon corrosion and Pt dissolution during transient conditions in proton exchange membrane fuel cells. Electrochemical tests showed the catalysts had a remarkable oxygen evolution reaction (OER) activity, even greater than that of bulk, metallic thin films. Stability tests within a fuel cell environment showed that rapid Ru dissolution could be managed with the addition of Ir. Membrane electrode assemblies containing a Ru to Ir atomic ratio of 1:9 were evaluated under startup/shutdown and cell reversal conditions for OER catalyst loadings ranging from 1 to 10 g/cm2. These tests affirmed that electrode potentials can be controlled through the addition of OER catalysts without impacting the oxygen reduction reaction on the cathode or the hydrogen oxidation reaction on the anode. The morphology and chemical structure of the thin OER layers were characterized by scanning transmission electron microscopy and X-ray photoelectron spectroscopy in an effort to establish a correlation between interfacial properties and electrochemical behavior.

Atanasoski, Radoslav [3M Industrial Mineral Products; Atanasoska, Liliana [3M Industrial Mineral Products; Cullen, David A [ORNL

2013-01-01T23:59:59.000Z

205

Electrocatalysts having gold monolayers on platinum nanoparticle cores, and uses thereof  

DOE Patents [OSTI]

The invention relates to gold-coated particles useful as fuel cell electrocatalysts. The particles are composed of an electrocatalytically active core at least partially encapsulated by an outer shell of gold or gold alloy. The invention more particularly relates to such particles having a noble metal-containing core, and more particularly, a platinum or platinum alloy core. In other embodiments, the invention relates to fuel cells containing these electrocatalysts and methods for generating electrical energy therefrom.

Adzic, Radoslav; Zhang, Junliang

2010-04-27T23:59:59.000Z

206

In-situ Studies of the Reactions of Bifunctional and Heterocyclic Molecules over Noble Metal Single Crystal and Nanoparticle Catalysts Studied with Kinetics and Sum-Frequency Generation Vibrational Spectroscopy  

SciTech Connect (OSTI)

Sum frequency generation surface vibrational spectroscopy (SFG-VS) in combination with gas chromatography (GC) was used in-situ to monitor surface bound reaction intermediates and reaction selectivities for the hydrogenation reactions of pyrrole, furan, pyridine, acrolein, crotonaldehyde, and prenal over Pt(111), Pt(100), Rh(111), and platinum nanoparticles under Torr reactant pressures and temperatures of 300K to 450K. The focus of this work is the correlation between the SFG-VS observed surface bound reaction intermediates and adsorption modes with the reaction selectivity, and how this is affected by catalyst structure and temperature. Pyrrole hydrogenation was investigated over Pt(111) and Rh(111) single crystals at Torr pressures. It was found that pyrrole adsorbs to Pt(111) perpendicularly by cleaving the N-H bond and binding through the nitrogen. However, over Rh(111) pyrrole adsorbs in a tilted geometry binding through the {pi}-aromatic orbitals. A surface-bound pyrroline reaction intermediate was detected over both surfaces with SFG-VS. It was found that the ring-cracking product butylamine is a reaction poison over both surfaces studied. Furan hydrogenation was studied over Pt(111), Pt(100), 10 nm cubic platinum nanoparticles and 1 nm platinum nanoparticles. The product distribution was observed to be highly structure sensitive and the acquired SFG-VS spectra reflected this sensitivity. Pt(100) exhibited more ring-cracking to form butanol than Pt(111), while the nanoparticles yielded higher selectivities for the partially saturated ring dihydrofuran. Pyridine hydrogenation was investigated over Pt(111) and Pt(100). The {alpha}-pyridyl surface adsorption mode was observed with SFG-VS over both surfaces. 1,4-dihydropyridine was seen as a surface intermediate over Pt(100) but not Pt(111). Upon heating the surfaces to 350K, the adsorbed pyridine changes to a flat-lying adsorption mode. No evidence was found for the pyridinium cation. The hydrogenation of the {alpha},{beta}-unsaturated aldehydes acrolein, crotonaldehyde, and prenal were investigated over Pt(111) and Pt(100). The selectivity for the hydrogenation of the C=C bond was found to depend on the number of methyl groups added to the bond. The adsorption modes of the three aldehydes were determined. The hydrogenation of crotonaldehyde was found to be nearly structure insensitive as the TOF and selectivity were very close to the same over Pt(111) and Pt(100). SFG-VS indicated identical surface intermediates over the two crystal faces during crotonaldehyde hydrogenation.

Kliewer, Christopher J.

2009-06-30T23:59:59.000Z

207

Gold, Copper, and Platinum Nanoparticles Dispersed on CeOx/TiO2(110) Surfaces: High Water-Gas Shift Activity and the Nature of the Mixed-Metal Oxide at the Nanometer Level  

SciTech Connect (OSTI)

At small coverages of ceria on TiO{sub 2}(110), the CeO{sub x} nanoparticles have an unusual coordination mode. Scanning tunneling microscopy and density-functional calculations point to the presence of Ce{sub 2}O{sub 3} dimers, which form diagonal arrays that have specific orientations of 0, 24, and 42{sup o} with respect to the [1 -1 0] direction of the titania substrate. At high coverages of ceria on TiO{sub 2}(110), the surface exhibits two types of terraces. In one type, the morphology is not very different from that observed at low ceria coverage. However, in the second type of terrace, there is a compact array of ceria particles with structures that do not match the structures of CeO{sub 2}(111) or CeO{sub 2}(110). The titania substrate imposes on the ceria nanoparticles nontypical coordination modes, enhancing their chemical reactivity. This phenomenon leads to a larger dispersion of supported metal nanoparticles (M = Au, Cu, Pt) and makes possible the direct participation of the oxide in catalytic reactions. The M/CeO{sub x}/TiO{sub 2}(110) surfaces display an extremely high catalytic activity for the water-gas shift reaction that follows the sequence Au/CeO{sub x}/TiO{sub 2}(110) < Cu/CeO{sub x}/TiO{sub 2}(110) < Pt/CeO{sub x}/TiO{sub 2}(110). For low coverages of Cu and CeO{sub x}, Cu/CeO{sub x}/TiO{sub 2}(110) is 8-12 times more active than Cu(111) or Cu/ZnO industrial catalysts. In the M/CeO{sub x}/TiO{sub 2}(110) systems, there is a strong coupling of the chemical properties of the admetal and the mixed-metal oxide: The adsorption and dissociation of water probably take place on the oxide, CO adsorbs on the admetal nanoparticles, and all subsequent reaction steps occur at the oxide-admetal interface. The high catalytic activity of the M/CeO{sub x}/TiO{sub 2}(110) surfaces reflects the unique properties of the mixed-metal oxide at the nanometer level.

Park, J.; Graciani, J; Evans, J; Stacchiola, D; Senanayake, S; Barrio, L; Liu, P; Fdez. Sanz, J; Hrbek, J; Rodriguez, J

2010-01-01T23:59:59.000Z

208

Gold, Copper and Platinum Nanoparticles Dispersed on CeOx/TiO2(110) Surfaces: High Water-Gas Shift Activity and the Nature of the Mixed-Metal Oxide at the Nanometer Level  

SciTech Connect (OSTI)

At small coverages of ceria on TiO{sub 2}(110), the CeO{sub x} nanoparticles have an unusual coordination mode. Scanning tunneling microscopy and density-functional calculations point to the presence of Ce{sub 2}O{sub 3} dimers, which form diagonal arrays that have specific orientations of 0, 24, and 42{sup o} with respect to the [1 -1 0] direction of the titania substrate. At high coverages of ceria on TiO{sub 2}(110), the surface exhibits two types of terraces. In one type, the morphology is not very different from that observed at low ceria coverage. However, in the second type of terrace, there is a compact array of ceria particles with structures that do not match the structures of CeO{sub 2}(111) or CeO{sub 2}(110). The titania substrate imposes on the ceria nanoparticles nontypical coordination modes, enhancing their chemical reactivity. This phenomenon leads to a larger dispersion of supported metal nanoparticles (M = Au, Cu, Pt) and makes possible the direct participation of the oxide in catalytic reactions. The M/CeO{sub x}/TiO{sub 2}(110) surfaces display an extremely high catalytic activity for the water-gas shift reaction that follows the sequence Au/CeO{sub x}/TiO{sub 2}(110) < Cu/CeO{sub x}/TiO{sub 2}(110) < Pt/CeO{sub x}/TiO{sub 2}(110). For low coverages of Cu and CeO{sub x}, Cu/CeO{sub x}/TiO{sub 2}(110) is 8-12 times more active than Cu(111) or Cu/ZnO industrial catalysts. In the M/CeO{sub x}/TiO{sub 2}(110) systems, there is a strong coupling of the chemical properties of the admetal and the mixed-metal oxide: The adsorption and dissociation of water probably take place on the oxide, CO adsorbs on the admetal nanoparticles, and all subsequent reaction steps occur at the oxide-admetal interface. The high catalytic activity of the M/CeO{sub x}/TiO{sub 2}(110) surfaces reflects the unique properties of the mixed-metal oxide at the nanometer level.

Rodriguez, J.A.; Park, J.B.; Graciani, J.; Evans, J.; Stacchiola, D.; Senanayake, S.D.; Barrio, L.; Liu, P.; Sanz, J.F.; Hrbek, J.

2010-01-13T23:59:59.000Z

209

Stable catalyst layers for hydrogen permeable composite membranes  

DOE Patents [OSTI]

The present invention provides a hydrogen separation membrane based on nanoporous, composite metal carbide or metal sulfide coated membranes capable of high flux and permselectivity for hydrogen without platinum group metals. The present invention is capable of being operated over a broad temperature range, including at elevated temperatures, while maintaining hydrogen selectivity.

Way, J. Douglas; Wolden, Colin A

2014-01-07T23:59:59.000Z

210

Bioinspired Molecular Co-Catalysts Bonded to a Silicon Photocathode for Solar Hydrogen Evolution  

SciTech Connect (OSTI)

The production of fuels from sunlight represents one of the main challenges in the development of a sustainable energy system. Hydrogen is the simplest fuel to produce and although platinum and other noble metals are efficient catalysts for photoelectrochemical hydrogen evolution earth-abundant alternatives are needed for large-scale use. We show that bioinspired molecular clusters based on molybdenum and sulphur evolve hydrogen at rates comparable to that of platinum. The incomplete cubane-like clusters (Mo{sub 3}S{sub 4}) efficiently catalyse the evolution of hydrogen when coupled to a p-type Si semiconductor that harvests red photons in the solar spectrum. The current densities at the reversible potential match the requirement of a photoelectrochemical hydrogen production system with a solar-to-hydrogen efficiency in excess of 10% (ref. 16). The experimental observations are supported by density functional theory calculations of the Mo{sub 3}S{sub 4} clusters adsorbed on the hydrogen-terminated Si(100) surface, providing insights into the nature of the active site.

Hou, Yidong

2011-11-08T23:59:59.000Z

211

Monodisperse Platinum and Rhodium Nanoparticles as Model Heterogeneous Catalysts  

E-Print Network [OSTI]

He, H 2 , and O 2 (UHP, Praxair, used as-received) and anAirGas, CP grade), hydrogen (Praxair, UHP, 99.999%)and helium (Praxair, UHP, 99.999%) were used as received.

Coble, Inger M

2008-01-01T23:59:59.000Z

212

Nanosegregated Cathode Catalysts with Ultra-Low Platinum Loading...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Advanced Electrocatalysts for PEM Fuel Cells Fuel Cells: Just a Dream - or Future Reality Testing Oxygen Reduction Reaction Activity with the Rotating Disc Electrode Technique...

213

Monodisperse Platinum and Rhodium Nanoparticles as Model Heterogeneous Catalysts  

E-Print Network [OSTI]

D. , J. Am. Chem. Soc. 2003, (4) Konya, Z. ; Puntes, V. F. ;Chem. B 1999, 103, (25) Konya, Z. ; Puntes, V. F. ; Kiricsi,2, 907. (26) Zhu, J. ; Konya, Z. ; Puntes, V. F. ; Kiricsi,

Coble, Inger M

2008-01-01T23:59:59.000Z

214

Hydrothermally Stable, Sulfur-Tolerant Platinum-Based Oxidation Catalysts  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:YearRound-UpHeatMulti-Dimensionalthe U.S. Department of Energy andHydrothermal Processing ofvia

215

Nanosegregated Cathode Catalysts with Ultra-Low Platinum Loading |  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious RankCombustion | Department ofT ib l L d F S i DOEToward aInnovationHydrogenNRGA C U.S. Department

216

Improved catalysts for carbon and coal gasification  

DOE Patents [OSTI]

This invention relates to improved catalysts for carbon and coal gasification and improved processes for catalytic coal gasification for the production of methane. The catalyst is composed of at least two alkali metal salts and a particulate carbonaceous substrate or carrier is used. 10 figures, 2 tables.

McKee, D.W.; Spiro, C.L.; Kosky, P.G.

1984-05-25T23:59:59.000Z

217

Method of making chalcogen catalysts for polymer electrolyte fuel cells  

DOE Patents [OSTI]

A method of making an electrode catalyst material using aqueous solutions. The electrode catalyst material includes a support comprising at least one transition metal and at least one chalcogen disposed on a surface of the transition metal. The method includes reducing a metal powder, mixing the metal powder with an aqueous solution containing at least one inorganic compound of the chalcogen to form a mixture, and providing a reducing agent to the mixture to form nanoparticles of the electrode catalyst. The electrode catalyst may be used in a membrane electrode assembly for a fuel cell.

Choi, Jong-Ho (Los Alamos, NM); Zelenay, Piotr (Los Alamos, NM); Wieckowski, Andrzej (Champaign, IL); Cao, Dianxue (Harabin, CN)

2010-12-14T23:59:59.000Z

218

Catalysts for the selective oxidation of hydrogen sulfide to sulfur  

DOE Patents [OSTI]

This invention provides catalysts for the oxidation of hydrogen sulfide. In particular, the invention provides catalysts for the partial oxidation of hydrogen sulfide to elemental sulfur and water. The catalytically active component of the catalyst comprises a mixture of metal oxides containing titanium oxide and one or more metal oxides which can be selected from the group of metal oxides or mixtures of metal oxides of transition metals or lanthanide metals. Preferred metal oxides for combination with TiO.sub.2 in the catalysts of this invention include oxides of V, Cr, Mn, Fe, Co, Ni, Cu, Nb, Mo, Tc, Ru, Rh, Hf, Ta, W, Au, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu. Catalysts which comprise a homogeneous mixture of titanium oxide and niobium (Nb) oxide are also provided. A preferred method for preparing the precursor homogenous mixture of metal hydroxides is by coprecipitation of titanium hydroxide with one or more other selected metal hydroxides. Catalysts of this invention have improved activity and/or selectivity for elemental sulfur production. Further improvements of activity and/or selectivity can be obtained by introducing relatively low amounts (up to about 5 mol %)of a promoter metal oxide (preferably of metals other than titanium and that of the selected second metal oxide) into the homogeneous metal/titanium oxide catalysts of this invention.

Srinivas, Girish (Thornton, CO); Bai, Chuansheng (Baton Rouge, LA)

2000-08-08T23:59:59.000Z

219

Processes and catalysts for conducting fischer-tropsch synthesis in a slurry bubble column reactor  

DOE Patents [OSTI]

Processes and catalysts for conducting Fischer-Tropsch synthesis in a slurry bubble column reactor (SBCR). One aspect of the invention involves the use of cobalt catalysts without noble metal promotion in an SBCR. Another aspect involves using palladium promoted cobalt catalysts in an SBCR. Methods for preparing noble metal promoted catalysts via totally aqueous impregnation and procedures for producing attrition resistant catalysts are also provided.

Singleton, Alan H. (Marshall Township, Allegheny County, PA); Oukaci, Rachid (Allison Park, PA); Goodwin, James G. (Cranberry Township, PA)

1999-01-01T23:59:59.000Z

220

Processes and catalysts for conducting Fischer-Tropsch synthesis in a slurry bubble column reactor  

DOE Patents [OSTI]

Processes and catalysts are disclosed for conducting Fischer-Tropsch synthesis in a slurry bubble column reactor (SBCR). One aspect of the invention involves the use of cobalt catalysts without noble metal promotion in an SBCR. Another aspect involves using palladium promoted cobalt catalysts in an SBCR. Methods for preparing noble metal promoted catalysts via totally aqueous impregnation and procedures for producing attrition resistant catalysts are also provided. 1 fig.

Singleton, A.H.; Oukaci, R.; Goodwin, J.G.

1999-08-17T23:59:59.000Z

Note: This page contains sample records for the topic "metal catalysts platinum" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
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221

Exploration of the active center structure of nitrogen-doped graphene-based catalysts for oxygen reduction reaction  

E-Print Network [OSTI]

a breakthrough for metal-free, N-containing catalysts and their use in applications such as metal­air batteries activity, indicating their potential as a catalyst for fuel cells and metal air batteries. However-graphene) and demonstrate its use as a metal-free catalyst to study the catalytic active center for the oxygen reduction

222

Synthesis and characterisation of platinum (II) salphen complex and its interaction with calf thymus DNA  

SciTech Connect (OSTI)

A platinum (II) salphen complex was synthesised by condensation reaction of 2,4-dihydroxylbenzaldehyde and o-phenylenediamine with potassium tetrachloroplatinate to obtain N,N?-Bis-4-(hydroxysalicylidene)-phenylenediamine-platinum (II). The structure of the complex was confirmed by {sup 1}H and {sup 13}C NMR spectroscopy, FTIR spectroscopy, CHN elemental analyses and ESI-MS spectrometry. The platinum (II) salphen complex with four donor atoms N{sub 2}O{sub 2} from its salphen ligand coordinated to platinum (II) metal centre were determined. The binding mode and interaction of this complex with calf thymus DNA was determined by UV/Vis DNA titration and emission titration. The intercalation between the DNA bases by ?-? stacking due to its square planar geometry and aromatic rings structures was proposed.

Sukri, Shahratul Ain Mohd; Heng, Lee Yook; Karim, Nurul Huda Abd [School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43650 Bangi, Selangor (Malaysia)

2014-09-03T23:59:59.000Z

223

Catalyst for hydrotreating carbonaceous liquids  

DOE Patents [OSTI]

A catalyst for denitrogenating and desulfurating carbonaceous liquid such as solvent refined coal includes catalytic metal oxides impregnated within a porous base of mostly alumina with relatively large pore diameters, surface area and pore volume. The base material includes pore volumes of 0.7-0.85 ml/g, surface areas of 200-350 m.sup.2 /g and pore diameters of 85-200 Angstroms. The catalytic metals impregnated into these base materials include the oxides of Group VI metals, molybdenum and tungsten, and the oxides of Group VIII metals, nickel and cobalt, in various combinations. These catalysts and bases in combination have effectively promoted the removal of chemically combined sulfur and nitrogen within a continuous flowing mixture of carbonaceous liquid and hydrogen gas.

Berg, Lloyd (Bozeman, MT); McCandless, Frank P. (Bozeman, MT); Ramer, Ronald J. (Idaho Falls, ID)

1982-01-01T23:59:59.000Z

224

Perovskite catalysts for oxidative coupling  

DOE Patents [OSTI]

Perovskites of the structure A[sub 2]B[sub 2]C[sub 3]O[sub 10] are useful as catalysts for the oxidative coupling of lower alkane to heavier hydrocarbons. A is alkali metal; B is lanthanide or lanthanum, cerium, neodymium, samarium, praseodymium, gadolinium or dysprosium; and C is titanium.

Campbell, K.D.

1991-06-25T23:59:59.000Z

225

Catalysts for coal liquefaction processes  

DOE Patents [OSTI]

Improved catalysts for catalytic solvent refining or hydroliquefaction of non-anthracitic coal at elevated temperatures under hydrogen pressure in a hydrogen donor solvent comprise a combination of zinc or copper, or a compound thereof, and a Group VI or non-ferrous Group VIII metal, or a compound thereof.

Garg, D.

1986-10-14T23:59:59.000Z

226

Perovskite catalysts for oxidative coupling  

DOE Patents [OSTI]

Perovskites of the structure A.sub.2 B.sub.2 C.sub.3 O.sub.10 are useful as catalysts for the oxidative coupling of lower alkane to heavier hydrocarbons. A is alkali metal; B is lanthanide or lanthanum, cerium, neodymium, samarium, praseodymium, gadolinium or dysprosium; and C is titanium.

Campbell, Kenneth D. (Charleston, WV)

1991-01-01T23:59:59.000Z

227

Catalysts for coal liquefaction processes  

DOE Patents [OSTI]

Improved catalysts for catalytic solvent refining or hydroliquefaction of non-anthracitic coal at elevated temperatures under hydrogen pressure in a hydrogen donor solvent comprise a combination of zinc or copper, or a compound thereof, and a Group VI or non-ferrous Group VIII metal, or a compound thereof.

Garg, Diwakar (Macungie, PA)

1986-01-01T23:59:59.000Z

228

Thief carbon catalyst for oxidation of mercury in effluent stream  

SciTech Connect (OSTI)

A catalyst for the oxidation of heavy metal contaminants, especially mercury (Hg), in an effluent stream is presented. The catalyst facilitates removal of mercury through the oxidation of elemental Hg into mercury (II) moieties. The active component of the catalyst is partially combusted coal, or "Thief" carbon, which can be pre-treated with a halogen. An untreated Thief carbon catalyst can be self-promoting in the presence of an effluent gas streams entrained with a halogen.

Granite, Evan J. (Wexford, PA); Pennline, Henry W. (Bethel Park, PA)

2011-12-06T23:59:59.000Z

229

Catalyst for converting synthesis gas to liquid motor fuels  

DOE Patents [OSTI]

The addition of an inert metal component, such as gold, silver or copper, to a Fischer-Tropsch catalyst comprising cobalt enables said catalyst to convert synthesis gas to liquid motor fuels at about 240.degree.-370.degree. C. with advantageously reduced selectivity of said cobalt for methane in said conversion. The catalyst composition can advantageously include a support component, such as a molecular sieve, co-catalyst/support component or a combination of such support components.

Coughlin, Peter K. (Yorktown Heights, NY)

1986-01-01T23:59:59.000Z

230

Catalyst structure and method of Fischer-Tropsch synthesis  

DOE Patents [OSTI]

The present invention includes Fischer-Tropsch catalysts, reactions using Fischer-Tropsch catalysts, methods of making Fischer-Tropsch catalysts, processes of hydrogenating carbon monoxide, and fuels made using these processes. The invention provides the ability to hydrogenate carbon monoxide with low contact times, good conversion rates and low methane selectivities. In a preferred method, the catalyst is made using a metal foam support.

Wang, Yong; Vanderwiel, David P.; Tonkovich, Anna Lee; Gao, Yufei; Baker, Eddie G.

2004-06-15T23:59:59.000Z

231

Catalyst structure and method of fischer-tropsch synthesis  

DOE Patents [OSTI]

The present invention includes Fischer-Tropsch catalysts, reactions using Fischer-Tropsch catalysts, methods of making Fischer-Tropsch catalysts, processes of hydrogenating carbon monoxide, and fuels made using these processes. The invention provides the ability to hydrogenate carbon monoxide with low contact times, good conversion rates and low methane selectivities. In a preferred method, the catalyst is made using a metal foam support.

Wang, Yong [Richland, WA; Vanderwiel, David P [Richland, WA; Tonkovich, Anna Lee Y [Pasco, WA; Gao, Yufei [Kennewick, WA; Baker, Eddie G [Pasco, WA

2002-12-10T23:59:59.000Z

232

Low Cost Autothermal Diesel Reforming Catalyst Development  

SciTech Connect (OSTI)

Catalytic autothermal reforming (ATR) represents an important step of converting fossil fuel to hydrogen rich reformate for use in solid oxide fuel cell (SOFC) stacks. The state-of-the-art reforming catalyst, at present, is a Rh based material which is effective but costly. The objective of our current research is to reduce the catalyst cost by finding an efficient ATR catalyst containing no rhodium. A group of perovskite based catalysts have been synthesized and evaluated under the reforming condition of a diesel surrogate fuel. Hydrogen yield, reforming efficiency, and conversion selectivity to carbon oxides of the catalyst ATR reaction are calculated and compared with the benchmark Rh based material. Several catalyst synthesis improvements were carried out including: 1) selectively doping metals on the A-site and B-site of the perovskite structure, 2) changing the support from perovskite to alumina, 3) altering the method of metal addition, and 4) using transition metals instead of noble metals. It was found that the catalytic activity changed little with modification of the A-site metal, while it displayed considerable dependence on the B-site metal. Perovskite supports performed much better than alumina based supports.

Shihadeh, J.; Liu, D.

2004-01-01T23:59:59.000Z

233

Temperature dependent spin transport properties of platinum inferred from spin Hall magnetoresistance measurements  

SciTech Connect (OSTI)

We study the temperature dependence of the spin Hall magnetoresistance (SMR) in yttrium iron garnet/platinum hybrid structures via magnetization orientation dependent magnetoresistance measurements. Our experiments show a decrease of the SMR magnitude with decreasing temperature. Using the sensitivity of the SMR to the spin transport properties of the normal metal, we interpret our data in terms of a decrease of the spin Hall angle in platinum from 0.11 at room temperature to 0.075 at 10?K, while the spin diffusion length and the spin mixing conductance of the ferrimagnetic insulator/normal metal interface remain almost constant.

Meyer, Sibylle, E-mail: sibylle.meyer@wmi.badw-muenchen.de; Althammer, Matthias; Geprägs, Stephan; Opel, Matthias; Goennenwein, Sebastian T. B. [Walther-Meißner-Institut, Bayerische Akademie der Wissenschaften, 85748 Garching (Germany); Gross, Rudolf [Walther-Meißner-Institut, Bayerische Akademie der Wissenschaften, 85748 Garching (Germany); Physik-Department, Technische Universität München, 85748 Garching (Germany)

2014-06-16T23:59:59.000Z

234

Catalyst for coal liquefaction process  

DOE Patents [OSTI]

An improved catalyst for a coal liquefaction process; e.g., the H-Coal Process, for converting coal into liquid fuels, and where the conversion is carried out in an ebullated-catalyst-bed reactor wherein the coal contacts catalyst particles and is converted, in addition to liquid fuels, to gas and residual oil which includes preasphaltenes and asphaltenes. The improvement comprises a catalyst selected from the group consisting of the oxides of nickel molybdenum, cobalt molybdenum, cobalt tungsten, and nickel tungsten on a carrier of alumina, silica, or a combination of alumina and silica. The catalyst has a total pore volume of about 0.500 to about 0.900 cc/g and the pore volume comprises micropores, intermediate pores and macropores, the surface of the intermediate pores being sufficiently large to convert the preasphaltenes to asphaltenes and lighter molecules. The conversion of the asphaltenes takes place on the surface of micropores. The macropores are for metal deposition and to prevent catalyst agglomeration. The micropores have diameters between about 50 and about 200 angstroms (.ANG.) and comprise from about 50 to about 80% of the pore volume, whereas the intermediate pores have diameters between about 200 and 2000 angstroms (.ANG.) and comprise from about 10 to about 25% of the pore volume, and the macropores have diameters between about 2000 and about 10,000 angstroms (.ANG.) and comprise from about 10 to about 25% of the pore volume. The catalysts are further improved where they contain promoters. Such promoters include the oxides of vanadium, tungsten, copper, iron and barium, tin chloride, tin fluoride and rare earth metals.

Huibers, Derk T. A. (Pennington, NJ); Kang, Chia-Chen C. (Princeton, NJ)

1984-01-01T23:59:59.000Z

235

In Situ Studies of the Active Sites for the Water Gas Shift Reaction over Cu-CeO2 Catalysts: Complex Interaction Between Metallic Copper and Oxygen Vacancies of Ceria  

SciTech Connect (OSTI)

New information about the active sites for the water gas shift (WGS) reaction over Cu-CeO{sub 2} systems was obtained using in-situ, time-resolved X-ray diffraction (TR-XRD), X-ray absorption spectroscopy (TR-XAS, Cu K and Ce L3 edges), and infrared spectroscopy (DRIFTS). Cu-CeO{sub 2} nanoparticles prepared by a novel reversed microemulsion method (doped Ce1-xCuxO2 sample) and an impregnation method (impregnated CuO{sub x}/CeO{sub 2} sample) were studied. The results from all of the samples indicate that both metallic copper and oxygen vacancies in ceria were involved in the generation of active sites for the WGS reaction. Evidence was found for a synergistic Cu-O vacancy interaction. This interaction enhances the chemical activity of Cu, and the presence of Cu facilitates the formation of O vacancies in ceria under reaction conditions. Water dissociation occurred on the O vacancy sites or the Cu-O vacancy interface. No significant amounts of formate were formed on the catalysts during the WGS reaction. The presence of strongly bound carbonates is an important factor for the deactivation of the catalysts at high temperatures. This work identifies for the first time the active sites for the WGS reaction on Cu-CeO{sub 2} catalysts and illustrates the importance of in situ structural studies for heterogeneous catalytic reactions.

Wang,X.; Rodriguez, J.; Hanson, J.; Gamarra, D.; Martinez-Arias, A.; Fernandez-Garcia, M.

2006-01-01T23:59:59.000Z

236

Evidence for the Existence of a Late-Metal Terminal Sulfido Complex  

E-Print Network [OSTI]

and are active promoters in current hydrotreating catalysts.2 Under- standing the nature of the metal

Jones, William D.

237

Platinum Monolayer Electrocatalysts for Oxygen Reduction Reaction...  

Broader source: Energy.gov (indexed) [DOE]

Fuel Cell Technologies Program webinar ""BNL's Low-Platinum Electrocatalysts for Fuel Cell Electric Vehicles (FCEVs) webinarslidesbnlelectrocatalysts061912.pdf More Documents...

238

Attrition resistant fluidizable reforming catalyst  

DOE Patents [OSTI]

A method of preparing a steam reforming catalyst characterized by improved resistance to attrition loss when used for cracking, reforming, water gas shift and gasification reactions on feedstock in a fluidized bed reactor, comprising: fabricating the ceramic support particle, coating a ceramic support by adding an aqueous solution of a precursor salt of a metal selected from the group consisting of Ni, Pt, Pd, Ru, Rh, Cr, Co, Mn, Mg, K, La and Fe and mixtures thereof to the ceramic support and calcining the coated ceramic in air to convert the metal salts to metal oxides.

Parent, Yves O. (Golden, CO); Magrini, Kim (Golden, CO); Landin, Steven M. (Conifer, CO); Ritland, Marcus A. (Palm Beach Shores, FL)

2011-03-29T23:59:59.000Z

239

Science Magazine Highlight: Moving Towards Near Zero Platinum...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Science Magazine Highlight: Moving Towards Near Zero Platinum Fuel Cells Science Magazine Highlight: Moving Towards Near Zero Platinum Fuel Cells Presentation slides and speaker...

240

Deposition of Platinum Nanoparticles on Carbon Nanotubes by Supercriti...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Deposition of Platinum Nanoparticles on Carbon Nanotubes by Supercritical Fluid Method. Deposition of Platinum Nanoparticles on Carbon Nanotubes by Supercritical Fluid Method....

Note: This page contains sample records for the topic "metal catalysts platinum" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

Green approach for self-assembly of platinum nanoparticles into...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Green approach for self-assembly of platinum nanoparticles into nanowires in aqueous glucose solutions. Green approach for self-assembly of platinum nanoparticles into nanowires in...

242

Energy Department's New Laboratory at NREL Earns LEED Platinum...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Department's New Laboratory at NREL Earns LEED Platinum Energy Department's New Laboratory at NREL Earns LEED Platinum November 1, 2013 - 2:52pm Addthis The Energy Systems...

243

Platinum/Carbon Nanotube Nanocomposite Synthesized in Supercritical...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

PlatinumCarbon Nanotube Nanocomposite Synthesized in Supercritical Fluid as Electrocatalysts for Low-Temperature Fuel Cells. PlatinumCarbon Nanotube Nanocomposite Synthesized in...

244

catalyst beds | EMSL  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

catalyst beds catalyst beds Leads No leads are available at this time. Magnesium behavior and structural defects in Mg+ ion implanted silicon carbide. Abstract: As a candidate...

245

Method for producing iron-based catalysts  

DOE Patents [OSTI]

A method for preparing an acid catalyst having a long shelf-life is provided comprising doping crystalline iron oxides with lattice-compatible metals and heating the now-doped oxide with halogen compounds at elevated temperatures. The invention also provides for a catalyst comprising an iron oxide particle having a predetermined lattice structure, one or more metal dopants for said iron oxide, said dopants having an ionic radius compatible with said lattice structure; and a halogen bound with the iron and the metal dopants on the surface of the particle.

Farcasiu, Malvina (Pittsburgh, PA); Kaufman, Phillip B. (Library, PA); Diehl, J. Rodney (Pittsburgh, PA); Kathrein, Hendrik (McMurray, PA)

1999-01-01T23:59:59.000Z

246

Prealloyed catalyst for growing silicon carbide whiskers  

DOE Patents [OSTI]

A prealloyed metal catalyst is used to grow silicon carbide whiskers, especially in the .beta. form. Pretreating the metal particles to increase the weight percentages of carbon or silicon or both carbon and silicon allows whisker growth to begin immediately upon reaching growth temperature.

Shalek, Peter D. (Los Alamos, NM); Katz, Joel D. (Niagara Falls, NY); Hurley, George F. (Los Alamos, NM)

1988-01-01T23:59:59.000Z

247

Nitrated metalloporphyrins as catalysts for alkane oxidation  

DOE Patents [OSTI]

Compositions of matter comprising nitro-substituted metal complexes of porphyrins are catalysts for the oxidation of alkanes. The metal is iron, chromium, manganese, ruthenium, copper or cobalt. The porphyrin ring has nitro groups attached thereto in meso and/or [beta]-pyrrolic positions.

Ellis, P.E. Jr.; Lyons, J.E.

1994-01-18T23:59:59.000Z

248

Nitrated metalloporphyrins as catalysts for alkane oxidation  

DOE Patents [OSTI]

Compositions of matter comprising nitro-substituted metal complexes of porphyrins are catalysts for the oxidation of alkanes. The metal is iron, chromium, manganese, ruthenium, copper or cobalt. The porphyrin ring has nitro groups attached thereto in meso and/or .beta.-pyrrolic positions.

Ellis, Jr., Paul E. (Downingtown, PA); Lyons, James E. (Wallingford, PA)

1994-01-01T23:59:59.000Z

249

Process for magnetic beneficiating petroleum cracking catalyst  

DOE Patents [OSTI]

A process for beneficiating a particulate zeolite petroleum cracking catalyst having metal values in excess of 1000 ppm nickel equivalents. The particulate catalyst is passed through a magnetic field in the range of from about 2 Tesla to about 5 Tesla generated by a superconducting quadrupole open-gradient magnetic system for a time sufficient to effect separation of said catalyst into a plurality of zones having different nickel equivalent concentrations. A first zone has nickel equivalents of about 6,000 ppm and greater, a second zone has nickel equivalents in the range of from about 2000 ppm to about 6000 ppm, and a third zone has nickel equivalents of about 2000 ppm and less. The zones of catalyst are separated and the second zone material is recycled to a fluidized bed of zeolite petroleum cracking catalyst. The low nickel equivalent zone is treated while the high nickel equivalent zone is discarded.

Doctor, Richard D. (Lisle, IL)

1993-01-01T23:59:59.000Z

250

Process for magnetic beneficiating petroleum cracking catalyst  

DOE Patents [OSTI]

A process is described for beneficiating a particulate zeolite petroleum cracking catalyst having metal values in excess of 1000 ppm nickel equivalents. The particulate catalyst is passed through a magnetic field in the range of from about 2 Tesla to about 5 Tesla generated by a superconducting quadrupole open-gradient magnetic system for a time sufficient to effect separation of said catalyst into a plurality of zones having different nickel equivalent concentrations. A first zone has nickel equivalents of about 6,000 ppm and greater, a second zone has nickel equivalents in the range of from about 2000 ppm to about 6000 ppm, and a third zone has nickel equivalents of about 2000 ppm and less. The zones of catalyst are separated and the second zone material is recycled to a fluidized bed of zeolite petroleum cracking catalyst. The low nickel equivalent zone is treated while the high nickel equivalent zone is discarded. 1 figures.

Doctor, R.D.

1993-10-05T23:59:59.000Z

251

Platinum-GrouP metals--2004 57. Platinum-GrouP metals  

E-Print Network [OSTI]

and refinery is located on property it owns in Columbus. the smelter-refinery complex was shut down for 5 weeks

252

Development of FCC catalyst magnetic separation  

SciTech Connect (OSTI)

Magnetic separation has been historically active in several different industries, yet has not been utilized in petroleum refining until recently. Development of economical permanent magnets with high magnetic strength has led to a new process known as MagnaCat{reg_sign}. The MagnaCat{reg_sign}. Process separates less active (high metals) particles catalyst from equilibrium Fluid Catalytic Cracking (FCC) catalyst, producing a higher activity/lower metals catalyst for recycle. Pilot FCC studies showed lower hydrogen, dry gas, and coke make with higher wet gas and octane from catalyst separated by MagnaCat{reg_sign}. With the use of a MagnaCat{reg_sign} Process unit, a refiner would produce an economic advantage of $0.20 to $0.40/Barrel of FCC charge and enhance unit operability.

Goolsby, T.L.; Moore, H.F. [Ashland Petroleum Co., KY (United States)

1997-01-01T23:59:59.000Z

253

Synthesis and Understanding of Novel Catalysts  

SciTech Connect (OSTI)

The research took advantage of our capabilities to perform in-situ and operando Raman spectroscopy on complex systems along with our developing expertise in the synthesis of uniform, supported metal oxide materials to investigate relationships between the catalytically active oxide composition, atomic structure, and support and the corresponding chemical and catalytic properties. The project was organized into two efforts: 1) Synthesis of novel catalyst materials by atomic layer deposition (ALD). 2) Spectroscopic and chemical investigations of coke formation and catalyst deactivation. ALD synthesis was combined with conventional physical characterization, Raman spectroscopy, and probe molecule chemisorption to study the effect of supported metal oxide composition and atomic structure on acid-base and catalytic properties. Operando Raman spectroscopy studies of olefin polymerization leading to coke formation and catalyst deactivation clarified the mechanism of coke formation by acid catalysts.

Stair, Peter C. [Northwestern University] [Northwestern University

2013-07-09T23:59:59.000Z

254

Iron catalyst for preparation of polymethylene from synthesis gas and method for producing the catalyst  

DOE Patents [OSTI]

This invention relates to a process for synthesizing hydrocarbons; more particularly, the invention relates to a process for synthesizing long-chain hydrocarbons known as polymethylene from carbon monoxide and hydrogen or from carbon monoxide and water or mixtures thereof in the presence of a catalyst comprising iron and platinum or palladium or mixtures thereof which may be supported on a solid material, preferably an inorganic refractory oxide. This process may be used to convert a carbon monoxide containing gas to a product which could substitute for high density polyethylene.

Sapienza, Richard S. (1 Miller Ave., Shoreham, NY 11786); Slegeir, William A. (7 Florence Rd., Hampton Bays, NY 11946)

1990-01-01T23:59:59.000Z

255

Iron catalyst for preparation of polymethylene from synthesis gas and method for producing the catalyst  

DOE Patents [OSTI]

This invention relates to a process for synthesizing hydrocarbons; more particularly, the invention relates to a process for synthesizing long-chain hydrocarbons known as polymethylene from carbon monoxide and hydrogen or from carbon monoxide and water or mixtures thereof in the presence of a catalyst comprising iron and platinum or palladium or mixtures thereof which may be supported on a solid material, preferably an inorganic refractory oxide. This process may be used to convert a carbon monoxide containing gas to a product which could substitute for high density polyethylene.

Sapienza, R.S.; Slegeir, W.A.

1990-05-15T23:59:59.000Z

256

Methanol-Tolerant Cathode Catalyst Composite For Direct Methanol Fuel Cells  

DOE Patents [OSTI]

A direct methanol fuel cell (DMFC) having a methanol fuel supply, oxidant supply, and its membrane electrode assembly (MEA) formed of an anode electrode and a cathode electrode with a membrane therebetween, a methanol oxidation catalyst adjacent the anode electrode and the membrane, an oxidant reduction catalyst adjacent the cathode electrode and the membrane, comprises an oxidant reduction catalyst layer of a platinum-chromium alloy so that oxidation at the cathode of methanol that crosses from the anode through the membrane to the cathode is reduced with a concomitant increase of net electrical potential at the cathode electrode.

Zhu, Yimin (Los Alamos, NM); Zelenay, Piotr (Los Alamos, NM)

2006-03-21T23:59:59.000Z

257

Basic metal oxides as cocatalysts for Cu/SiO{sub 2} catalysts in the conversion of synthesis gas to methanol  

SciTech Connect (OSTI)

The catalytic behavior of Cu catalysts supported on ultrapure silica and promoted with Ca, Zn, and La oxides was investigated in the hydrogenation of CO and CO{sub 2} to methanol at high pressure. Cu on very pure silica produces hardly any methanol, while the addition of basic oxides and the use of {gamma}-alumina as support improve the catalyst performance. The strong promoting effect of Ca and La oxide on the silica-supported Cu and the weak promoting effect for alumina-supported Cu suggest that the basic oxide additives must be close to or in contact with the Cu particles to be effective in methanol synthesis. The methanol activity of Zn/Cu/SiO{sub 2} increased with increasing CO{sub 2} content in a CO-CO{sub 2}-H{sub 2} mixture, suggesting that CO{sub 2} is the main carbon source for methanol.

Gotti, A.; Prins, R. [Swiss Federal Inst. of Tech., Zuerich (Switzerland). Lab. of Technical Chemistry] [Swiss Federal Inst. of Tech., Zuerich (Switzerland). Lab. of Technical Chemistry

1998-09-10T23:59:59.000Z

258

Low temperature catalysts for methanol production  

DOE Patents [OSTI]

A catalyst and process useful at low temperatures (below about 160.degree. C.) and preferably in the range 80.degree.-120.degree. C. used in the production of methanol from carbon monoxide and hydrogen is disclosed. The catalyst is used in slurry form and comprises a complex reducing agent derived from the component structure NaH--RONa--M(OAc).sub.2 where M is selected from the group consisting of Ni, Pd, and Co and R is a lower alkyl group containing 1-6 carbon atoms. This catalyst is preferably used alone but is also effective in combination with a metal carbonyl of a group VI (Mo, Cr, W) metal. The preferred catalyst precursor is Nic (where M=Ni and R=tertiary amyl). Mo(CO).sub.6 is the preferred metal carbonyl if such component is used. The catalyst is subjected to a conditioning or activating step under temperature and pressure, similar to the parameters given above, to afford the active catalyst.

Sapienza, Richard S. (1 Miller Ave., Shoreham, NY 11786); Slegeir, William A. (7 Florence Rd., Hampton Bays, NY 11946); O'Hare, Thomas E. (11 Geiger Pl., Huntington Station, NY 11746); Mahajan, Devinder (14 Locust Ct., Selden, NY 11784)

1986-01-01T23:59:59.000Z

259

Low temperature catalysts for methanol production  

DOE Patents [OSTI]

A catalyst and process useful at low temperatures (below about 160/sup 0/C) and preferably in the range 80 to 120/sup 0/C used in the production of methanol from carbon monoxide and hydrogen is disclosed. The catalyst is used in slurry form and comprises a complex reducing agent derived from the component structure NaH-RONa-M(OAc)/sub 2/ where M is selected from the group consisting of Ni, Pd, and Co and R is a lower alkyl group containing 1 to 6 carbon atoms. This catalyst is preferably used alone but is also effective in combination with a metal carbonyl of a group VI (Mo, Cr, W) metal. The preferred catalyst precursor is Nic (where M = Ni and R = tertiary amyl). Mo(CO)/sub 6/ is the preferred metal carbonyl if such component is used. The catalyst is subjected to a conditioning or activating step under temperature and pressure, similar to the parameters given above, to afford the active catalyst.

Sapienza, R.S.; Slegeir, W.A.; O'Hare, T.E.; Mahajan, D.

1985-03-12T23:59:59.000Z

260

Low temperature catalysts for methanol production  

DOE Patents [OSTI]

A catalyst and process useful at low temperatures (below about 160 C) and preferably in the range 80--120 C used in the production of methanol from carbon monoxide and hydrogen are disclosed. The catalyst is used in slurry form and comprises a complex reducing agent derived from the component structure NaH--RONa-M(OAc)[sub 2] where M is selected from the group consisting of Ni, Pd, and Co and R is a lower alkyl group containing 1-6 carbon atoms. This catalyst is preferably used alone but is also effective in combination with a metal carbonyl of a group VI (Mo, Cr, W) metal. The preferred catalyst precursor is NiC (where M = Ni and R = tertiary amyl). Mo(CO)[sub 6] is the preferred metal carbonyl if such component is used. The catalyst is subjected to a conditioning or activating step under temperature and pressure, similar to the parameters given above, to afford the active catalyst.

Sapienza, R.S.; Slegeir, W.A.; O'Hare, T.E.; Mahajan, D.

1986-10-28T23:59:59.000Z

Note: This page contains sample records for the topic "metal catalysts platinum" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Investigation of mixed metal sorbent/catalysts for the simultaneous removal of sulfur and nitrogen oxides. Semiannual report, Apr 1, 1998--Oct 31, 1998  

SciTech Connect (OSTI)

Simultaneous removal of SO{sub 2} and NO{sub x} using a regenerable solid sorbent will constitute an important improvement over the use of separate processes for the removal of these two pollutants from stack gases and possibly eliminate several shortcomings of the individual SO{sub 2} and NO{sub x} removal operations. The work done at PETC and the DOE-funded investigation of the investigators on the sulfation and regeneration of alumina-supported cerium oxide sorbents have shown that they can perform well at relatively high temperatures (823--900 K) as regenerable desulfurization sorbents. Survey of the recent literature shows that addition of copper oxide to ceria lowers the sulfation temperature of ceria down to 773 K, sulfated ceria-based sorbents can function as selective SCR catalysts even at elevated temperatures, SO{sub 2} can be directly reduced to sulfur by CO on CuO-ceria catalysts, and ceria-based catalysts may have a potential for selective catalytic reduction of NO{sub x} by methane. These observations indicate a possibility of developing a ceria-based sorbent/catalyst which can remove both SO{sub 2} and NO{sub x} from flue gases within a relatively wide temperature window, produce significant amounts of elemental sulfur during regeneration, and use methane for the selective catalytic reduction of NO{sub x}. The objective of this research is to conduct kinetic and parametric studies of the selective catalytic reduction of NO{sub x} with NH{sub 3} and CH{sub 4} over alumina-supported cerium oxide and copper oxide-cerium oxide sorbent/catalysts; investigate SO{sub 2} removal at lower temperatures by supported copper oxide-cerium oxide sorbents; and investigate the possibility of elemental sulfur production during regeneration with CO or with CH{sub 4} air mixtures. The sorbents consisting of cerium oxide and copper oxide impregnated on alumina have been prepared and characterized. Their sulfation performance has been investigated in a TGA setup, studying mainly the effects of temperature and sorbent composition. The results of the sulfation experiments have been evaluated and presented in this report. A study to model the sulfation selectivity of the two constituents of the sorbents is also underway.

Dr. Ates Akyurtlu; Dr. Jale F. Akyurtlu

1998-10-31T23:59:59.000Z

262

Pyrochlore catalysts for hydrocarbon fuel reforming  

DOE Patents [OSTI]

A method of catalytically reforming a reactant gas mixture using a pyrochlore catalyst material comprised of one or more pyrochlores having the composition A2B2-y-zB'yB"zO7-.DELTA., where y>0 and z.gtoreq.0. Distribution of catalytically active metals throughout the structure at the B site creates an active and well dispersed metal locked into place in the crystal structure. This greatly reduces the metal sintering that typically occurs on supported catalysts used in reforming reactions, and reduces deactivation by sulfur and carbon. Further, oxygen mobility may also be enhanced by elemental exchange of promoters at sites in the pyrochlore. The pyrochlore catalyst material may be utilized in catalytic reforming reactions for the conversion of hydrocarbon fuels into synthesis gas (H2+CO) for fuel cells, among other uses.

Berry, David A.; Shekhawat, Dushyant; Haynes, Daniel; Smith, Mark; Spivey, James J.

2012-08-14T23:59:59.000Z

263

Use of ionic liquids as coordination ligands for organometallic catalysts  

DOE Patents [OSTI]

Aspects of the present invention relate to compositions and methods for the use of ionic liquids with dissolved metal compounds as catalysts for a variety of chemical reactions. Ionic liquids are salts that generally are liquids at room temperature, and are capable of dissolving a many types of compounds that are relatively insoluble in aqueous or organic solvent systems. Specifically, ionic liquids may dissolve metal compounds to produce homogeneous and heterogeneous organometallic catalysts. One industrially-important chemical reaction that may be catalyzed by metal-containing ionic liquid catalysts is the conversion of methane to methanol.

Li, Zaiwei (Moreno Valley, CA); Tang, Yongchun (Walnut, CA); Cheng; Jihong (Arcadia, CA)

2009-11-10T23:59:59.000Z

264

Conformal Metal Thin Films for H2 Purification and Fuel-Cell Catalyst Applications Tyler Munhollon, Coe College, SURF 2009 Fellow  

E-Print Network [OSTI]

that will become a hydrogen filter in syngas pipelines. The thin film metal membranes are fairly inexpensive- shaped substrate that replicates a syngas pipeline. The membranes are also permeable to only hydrogen a heightened need for pure hydrogen gas at a low cost. Research has begun on thin film metal membranes

Li, Mo

265

Oxygen reduction on platinum : an EIS study  

E-Print Network [OSTI]

The oxygen reduction reaction (ORR) on platinum over yttria-stabilized zirconia (YSZ) is examined via electrochemical impedance spectroscopy (EIS) for oxygen partial pressures between 10-4 and 1 atm and at temperatures ...

Golfinopoulos, Theodore

2009-01-01T23:59:59.000Z

266

Less platinum means lower prices for autos  

Broader source: Energy.gov [DOE]

How technology developed by researchers at 3M is reducing the amount of platinum necessary for a fuel cell system, helping to make the technology more practical for consumer vehicles.

267

Characterization of catalysts with metal-support effects and of the species adsorbed on their surfaces. Progress report, September 1, 1984-August 30, 1985  

SciTech Connect (OSTI)

During the past year we have succeeded in modifying our DSC-2C calorimeter to greatly enhance its sensitivity and stabilize the baseline behavior. The details of the changes required have been given in a recent publication. As a result we have extensively studied the influence of crystallite size and the support on heats of adsorption of H/sub 2/, CO, and O/sub 2/ on Pt and Pd. Isothermal, integral heats of adsorption have been measured for H/sub 2/ and CO adsorption on Pt and Pd dispersed on four supports, SiO/sub 2/, Al/sub 2/O/sub 3/, TiO/sub 2/ and SiO/sub 2/-Al/sub 2/O/sub 3/. These values were determined at 215K and 300 to 320K. Results are presented. For supported Pt the heats of adsorption were highest on Pt/SiO/sub 2/ and lowest on Pt/TiO/sub 2/. However, a clear trend existed between heats of adsorption and Pt exposed with large Pt crystallites having the highest values. The Pd catalysts exhibited behavior different than those for the Pt catalysts in two major aspects. First the heats of adsorption values tended to increase somewhat as crystallite sizes became very small. Second, the high temperature reduction step did not decrease the heats of adsorption values as significantly for Pd/TiO/sub 2/. 4 refs., 5 figs., 3 tabs.

Vannice, M.A.

1985-06-13T23:59:59.000Z

268

E-Print Network 3.0 - advanced heterogeneous catalysts Sample...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

and Hydrogen Summary: Fischer-Tropsch synthesis using Co and Ru supported on silica aerogels as catalysts 21 Metal impregnation... Hexane Fischer-Tropsch Synthesis over an...

269

E-Print Network 3.0 - ammonia synthesis catalyst Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

and Hydrogen Summary: Fischer-Tropsch synthesis using Co and Ru supported on silica aerogels as catalysts 21 Metal impregnation... Hexane Fischer-Tropsch Synthesis over an...

270

Investigation of the Effect of In-Situ Catalyst on the Steam Hydrogasification of Biomass  

E-Print Network [OSTI]

metal catalysts on CO 2 gasification reactivity of biomassfeasibility of biomass gasification for power generation,et al. , Biomass gasification in a circulating fluidized

FAN, XIN

2012-01-01T23:59:59.000Z

271

Tungsten Cathode Catalyst for PEMFC  

SciTech Connect (OSTI)

Final report for project to evaluate tungsten-based catalyst as a cathode catalyst for PEM cell applications.

Joel B. Christian; Sean P. E. Smith

2006-09-22T23:59:59.000Z

272

Catalysts via First Principles  

Broader source: Energy.gov (indexed) [DOE]

bond contraction (JACS, 128 (2006) 12068) HAADF-STEM mode clearly shows that the atomic make-up of these platinum nano- clusters involves on average between 10-20 atoms....

273

Volume 1, 1st Edition, Multiscale Tailoring of Highly Active and Stable Nanocomposite Catalysts, Final Technical Report  

SciTech Connect (OSTI)

Nanomaterials have gained much attention as catalysts since the discovery of exceptional CO oxidation activity of nanoscale gold by Haruta. However, many studies avoid testing nanomaterials at the high-temperatures relevant to reactions of interest for the production of clean energy (T > 700°C). The generally poor thermal stability of catalytically active noble metals has thus far prevented significant progress in this area. We have recently overcome the poor thermal stability of nanoparticles by synthesizing a platinum barium-hexaaluminate (Pt-BHA) nanocomposite which combines the high activity of noble metal nanoparticles with the thermal stability of hexaaluminates. This Pt-BHA nanocomposite demonstrates excellent activity, selectivity, and long-term stability in CPOM. Pt-BHA is anchored onto a variety of support structures in order to improve the accessibility, safety, and reactivity of the nanocatalyst. Silica felts prove to be particularly amenable to this supporting procedure, with the resulting supported nanocatalyst proving to be as active and stable for CPOM as its unsupported counterpart. Various pre-treatment conditions are evaluated to determine their effectiveness in removing residual surfactant from the active nanoscale platinum particles. The size of these particles is measured across a wide temperature range, and the resulting “plateau” of stability from 600-900°C can be linked to a particle caging effect due to the structure of the supporting ceramic framework. The nanocomposites are used to catalyze the combustion of a dilute methane stream, and the results indicate enhanced activity for both Pt-BHA as well as ceria-doped BHA, as well as an absence of internal mass transfer limitations at the conditions tested. In water-gas shift reaction, nanocomposite Pt-BHA shows stability during prolonged WGS reaction and no signs of deactivation during start-up/shut-down of the reactor. The chemical and thermal stability, low molecular weight, and wealth of literature on the formation of mesoporous silica materials motivated investigations of nanocomposite silica catalysts. High surface area silicas are synthesized via sol-gel methods, and the addition of metal-salts lead to the formation of stable nanocomposite Ni- and Fe- silicates. The results of these investigations have increased the fundamental understanding and improved the applicability of nanocatalysts for clean energy applications.

Veser, Goetz

2009-08-31T23:59:59.000Z

274

Catalyst poisoning during tar-sands bitumen upgrading  

SciTech Connect (OSTI)

A number of hydrotreating catalysts are used in commercial heavy oil upgrading facilities. One of these, a CoO/MoO{sub 3}/Al{sub 2}O{sub 3} catalyst has been evaluated in a pilot plant CSTR for Tar-Sands Bitumen upgrading. Following its use in a test of 200 hours duration, the catalyst was removed, de-oiled, regenerated by air-calcination to remove the coke, and then re-tested. Samples of the coked, fresh and regenerated catalyst were each examined using surface analytical techniques. ESCA and SIMS analysis of the coked and regenerated catalyst samples show, as expected, significant contamination of the catalyst with Ni and V. In addition, the SIMS analysis clearly reveals that the edges of the catalyst pellets are rich in Ca, Mg and Fe while the Ni, V and coke are evenly distributed. Regeneration of the catalyst by calcination removes the carbonaceous material but appears not to change the distribution of the metal contaminants. Retesting of the regenerated catalyst shows a performance similar to that of the fresh catalyst. These data serve to support the view that catalyst deactivation during early use is not due to the skin of Ca and Mg on the pellets but rather via the poisoning of active sites by carbonaceous species.

Carruthers, J.D.; Brinen, J.S.; Komar, D.A.; Greenhouse, S. [CYTEC Industries, Stamford, CT (United States)

1994-12-31T23:59:59.000Z

275

The Structure-Sensitivity of nHeptane Dehydrocyclization on Pt/ SiO2 Model Catalysts  

E-Print Network [OSTI]

on the nanoparticles are also compared with results obtained on Pt(100) and Pt(110) single crystals, which were run from the underlying silica support. INTRODUCTION Heterogeneous platinum catalysts often produce,3 Formation of aromatics are of particular interest to both industrial and academic communities since

Goodman, Wayne

276

Hydrocarbon conversion catalysts  

SciTech Connect (OSTI)

This patent describes a process for hydrocracking hydrocarbon oils into products of lower average molecular weight and lower average boiling point. It comprises contacting a hydrocarbon oil at a temperature between 250{sup 0}C and 500{sup 0}C and a pressure up to 300 bar in the presence of hydrogen with a catalyst consisting essentially of a Y zeolite modified to have a unit cell size below 24.35A, a water absorption capacity (at 25{sup 0}C and a rho/rho/sub o/ value of 0.2) of at least 8% by weight of the zeolite and a pore volume of at least 0.25 ml/g wherein between 10% and 60% of the total pore volume is made up of pores having a diameter of at least 8 nm; an alumina binder and at least one hydrogenation component selected from the group consisting of a Group VI metal, a Group VIII metal and mixtures thereof.

Hoek, A.; Huizinga, T.; Maxwell, I.E.

1989-08-15T23:59:59.000Z

277

Biofuels production from hydrotreating of vegetable oil using supported noble metals, and transition metal carbide and nitride.  

E-Print Network [OSTI]

?? The focus of this research is to prepare non-sulfided hydrotreating catalysts, supported noble metal and transition metal carbide/ nitride, and evaluate their hydrocracking activities… (more)

Wang, Huali

2012-01-01T23:59:59.000Z

278

Water addition for increased CO/H[sub 2] hydrocarbon synthesis activity over catalysts comprising cobalt, ruthenium and mixtures thereof which may include a promoter metal  

SciTech Connect (OSTI)

A once-through, fixed or slurry bed Fischer Tropsch process is described with enhanced CO conversion activity and C[sub 5] + liquid hydrocarbon selectivity comprising contacting a feed mixture of carbon monoxide and hydrogen in a reaction zone with about 1 Vol % to about 70 Vol % water based on the total volume of feed mixture, at a pressure above one atmosphere and a temperature ranging from about 150 C to about 300 C, with a catalyst selected from the group consisting of cobalt, ruthenium, and mixtures thereof on a titania support, wherein said titania support is less than 40 m[sup 2]/g, converting at least 90 Vol % of the carbon monoxide to liquid hydrocarbons, and in the substantial absence of CO[sub 2] formation.

Kim, C.J.

1993-07-13T23:59:59.000Z

279

Low temperature catalyst system for methanol production  

DOE Patents [OSTI]

This patent discloses a catalyst and process useful at low temperatures (150/sup 0/C) and preferably in the range 80 to 120/sup 0/C used in the production of methanol from carbon monoxide and hydrogen. The catalyst components are used in slurry form and comprise (1) a complex reducing agent derived from the component structure NaH-ROH-M(OAc)/sub 2/ where M is selected from the group consisting of Ni, Pd, and Co and R is a lower alkyl group containing 1 to 6 carbon atoms and (2) a metal carbonyl of a group VI (Mo, Cr, W) metal. For the first component, Nic is preferred (where M = Ni and R = tertiary amyl). For the second component, Mo(CO)/sub 6/ is preferred. The mixture is subjected to a conditioning or activating step under temperature and pressure, similar to the parameters given above, to afford the active catalyst.

Sapienza, R.S.; Slegeir, W.A.; O'Hare, T.E.

1984-04-20T23:59:59.000Z

280

Development of a Novel Catalyst for No Decomposition  

SciTech Connect (OSTI)

Air pollution arising from the emission of nitrogen oxides as a result of combustion taking place in boilers, furnaces and engines, has increasingly been recognized as a problem. New methods to remove NO{sub x} emissions significantly and economically must be developed. The current technology for post-combustion removal of NO is the selective catalytic reduction (SCR) of NO by ammonia or possibly by a hydrocarbon such as methane. The catalytic decomposition of NO to give N{sub 2} will be preferable to the SCR process because it will eliminate the costs and operating problems associated with the use of an external reducing species. The most promising decomposition catalysts are transition metal (especially copper)-exchanged zeolites, perovskites, and noble metals supported on metal oxides such as alumina, silica, and ceria. The main shortcoming of the noble metal reducible oxide (NMRO) catalysts is that they are prone to deactivation by oxygen. It has been reported that catalysts containing tin oxide show oxygen adsorption behavior that may involve hydroxyl groups attached to the tin oxide. This is different than that observed with other noble metal-metal oxide combinations, which have the oxygen adsorbing on the noble metal and subsequently spilling over to the metal oxide. This observation leads one to believe that the Pt/SnO{sub 2} catalysts may have a potential as NO decomposition catalysts in the presence of oxygen. This prediction is also supported by some preliminary data obtained for NO decomposition on a Pt/SnO{sub 2} catalyst in the PI's laboratory. The main objective of the research that is being undertaken is the evaluation of the Pt/SnO{sub 2} catalysts for the decomposition of NO in simulated power plant stack gases with particular attention to the resistance to deactivation by O{sub 2}, H{sub 2}O, and elevated temperatures. Temperature programmed desorption (TPD) and temperature programmed reaction (TPRx) studies on Pt/SnO{sub 2} catalysts having different noble metal concentrations and pretreated under different conditions were done. It is also planned to perform NO decomposition tests in a laboratory-size packed-bed reactor to obtain long-term deactivation data. Temperature programmed desorption and temperature controlled reaction runs were made with catalysts containing 15% Pt and 10% Pt on SnO{sub 2}. Catalysts containing 10% Pt resulted in significantly lower activities than 15% PT catalysts. Therefore, in the remainder of the tests 15% Pt/SnO{sub 2} catalysts were used. Isothermal reaction studies were made to elucidate the effects of temperature, oxygen, water vapor, pretreatment temperature, and space velocity on NO dissociation. It was found that the presence of oxygen and water vapor did not affect the activation energy of the NO dissociation reaction indicating the presence of the same rate controlling step for all feed compositions. Activation energy was higher for higher gas velocities suggesting the presence of mass transfer limitations at lower velocities. Presence of oxygen in the feed inhibited the NO decomposition. Having water vapor in the feed did not significantly affect the catalyst activity for catalysts pretreated at 373 K, but significantly reduced catalyst activity for catalysts pretreated at 900 K. Long-term deactivation studies indicated that the catalyst deactivated slowly both with and without the presence of added oxygen in the feed, Deactivation started later in the presence of oxygen. The activities of the catalysts investigated were too low below 1000 K for commercial applications. Their selectivity towards N{sub 2} was good at temperatures above 700 K. A different method for catalyst preparation is needed to improve the catalyst performance.

Ates Akyurtlu; Jale Akyurtlu

2007-06-22T23:59:59.000Z

Note: This page contains sample records for the topic "metal catalysts platinum" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Catalysts and process for hydrogenolysis of sugar alcohols to polyols  

DOE Patents [OSTI]

The present invention provides a process for preparation of low molecular weight polyols from high molecular weight polyols in a hydrogenolysis reaction under elevated temperature and hydrogen pressure. The process comprises providing in a reaction mixture the polyols, a base, and a metal catalyst prepared by depositing a transition metal salt on an inert support, reducing the metal salt to the metal with hydrogen, and passivating the metal with oxygen, and wherein the catalyst is reduced with hydrogen prior to the reaction. In particular, the process provides for the preparation of glycerol, propylene glycol, and ethylene glycol from sugar alcohols such as sorbitol or xylitol. In a preferred process, the metal catalyst comprises ruthenium which is deposited on an alumina, titania, or carbon support, and the dispersion of the ruthenium on the support increases during the hydrogenolysis reaction.

Chopade, Shubham P. (East Lansing, MI) [East Lansing, MI; Miller, Dennis J. (Okemos, MI) [Okemos, MI; Jackson, James E. (Haslett, MI) [Haslett, MI; Werpy, Todd A. (West Richland, WA) [West Richland, WA; Frye, Jr., John G [Richland, WA; Zacher, Alan H. (Richland, WA) [Richland, WA

2001-09-18T23:59:59.000Z

282

Catalyst and process for converting synthesis gas to liquid motor fuels  

DOE Patents [OSTI]

The addition of an inert metal component, such as gold, silver or copper, to a Fischer-Tropsch catalyst comprising cobalt enables said catalyst to convert synthesis gas to liquid motor fuels at about 240.degree.-370.degree. C. with advantageously reduced selectivity of said cobalt for methane in said conversion. The catalyst composition can advantageously include a support component, such as a molecular sieve, co-catalyst/support component or a combination of such support components.

Coughlin, Peter K. (Yorktown Heights, NY)

1987-01-01T23:59:59.000Z

283

Protocol development for evaluation of commercial catalytic cracking catalysts  

SciTech Connect (OSTI)

A complete, new set of testing protocols has been developed for qualification of catalysts for Ashland's commercial catalytic cracking units. The objective of this test development is to identify new generations of improved cracking catalysts. Prior test protocols have classically utilized microactivity (MAT) testing of steamed virgin catalysts, while more advanced methods have utilized fixed fluid bed and/or circulating pilot units. Each of these techniques, however, have been limited by their correlation to commercial operations, weaknesses in metallation and preparation of pseudo-equilibrium catalysts, and mechanical constraints on the use of heavy, vacuum bottoms-containing feedstocks. These new protocols have been baselined, compared to commercial Ashland results on known catalytic cracking catalysts, and utilized to evaluate a range of potentially new catalyst samples.

Mitchell, M.M. Jr.; Moore, H.F. (Ashland Petroleum Co., KY (USA))

1988-09-01T23:59:59.000Z

284

Time-Resolved XAFS Spectroscopic Studies of B-H and N-H Oxidative Addition to Transition Metal Catalysts Relevant to Hydrogen Storage  

SciTech Connect (OSTI)

Successful catalytic dehydrogenation of aminoborane, H3NBH3, prompted questions as to the potential role of N-H oxidative addition in the mechanisms of these processes. N-H oxidative addition reactions are rare, and in all cases appear to involve initial dative bonding to the metal by the amine lone pairs followed by transfer of a proton to the basic metal. Aminoborane and its trimethylborane derivative block this mechanism and, in principle, should permit authentic N-H oxidative attrition to occur. Extensive experimental work failed to confirm this hypothesis. In all cases either B-H complexation or oxidative addition of solvent C-H bonds dominate the chemistry.

Bitterwolf, Thomas E. [University of Idaho

2014-12-09T23:59:59.000Z

285

Nanoparticle growth Controlled Growth of Platinum Nanoparticles on Strontium  

E-Print Network [OSTI]

Nanoparticle growth Controlled Growth of Platinum Nanoparticles on Strontium Titanate Nanocubes nanoparticles platinum strontium titanate X-ray analysis 750 Ã? 2009 Wiley-VCH Verlag GmbH & Co. KGa

Poeppelmeier, Kenneth R.

286

Developments in the chemistry and nanodelivery of platinum anticancer agents  

E-Print Network [OSTI]

Approximately half of all patients receiving cancer chemotherapy are treated with a platinum-containing drug. Despite this intense clinical use, only three platinum complexes, cisplatin, carboplatin, and oxaliplatin, are ...

Johnstone, Timothy Charles

2014-01-01T23:59:59.000Z

287

Synthetic strategies for the design of platinum anticancer drug candidates  

E-Print Network [OSTI]

Chapter 1. The Synthetic Chemistry of Platinum Anticancer Agents Since the inception of cisplatin as a clinically approved anticancer agent, a large number of platinum compounds have been synthesized with the aim of finding ...

Wilson, Justin Jeff

2013-01-01T23:59:59.000Z

288

The role of oxygen in hydrogen sensing by a platinum-gate silicon carbide gas sensor: An ultrahigh vacuum study  

E-Print Network [OSTI]

The role of oxygen in hydrogen sensing by a platinum-gate silicon carbide gas sensor: An ultrahigh conditions that elucidate the role of oxygen in the functioning of silicon carbide field-effect gas sensors hydrogen-depleted state; competition between hydrogen oxidation and hydrogen diffusion to metal/ oxide

Tobin, Roger G.

289

Iron catalyst for preparation of polymethylene from synthesis gas  

DOE Patents [OSTI]

This invention relates to a process for synthesizing hydrocarbons; more particularly, the invention relates to a process for synthesizing long-chain hydrocarbons known as polymethylene from carbon monoxide and hydrogen or from carbon monoxide and water or mixtures thereof in the presence of a catalyst comprising iron and platinum or palladium or mixtures thereof which may be supported on a solid material, preferably an inorganic refractory oxide. This process may be used to convert a cabon monoxide containing gas to a product which could substitute for high density polyethylene.

Sapienza, Richard S. (Shoreham, NY); Slegeir, William A. (Hampton Bays, NY)

1990-01-01T23:59:59.000Z

290

New iron catalyst for preparation of polymethylene from synthesis gas  

DOE Patents [OSTI]

This invention relates to a process for synthesizing hydrocarbons; more particularly, the invention relates to a process for synthesizing long-chain hydrocarbons known as polymethylene from carbon monoxide and hydrogen or from carbon monoxide and water or mixtures thereof in the presence of a catalyst comprising iron and platinum or palladium or mixtures thereof which may be supported on a solid material, preferably an inorganic refractory oxide. This process may be used to convert a carbon monoxide containing gas to a product which could substitute for high density polyethylene.

Sapienza, R.S.; Slegeir, W.A.

1988-03-31T23:59:59.000Z

291

Effect of Fuel Cell System Contaminants on the Pt Catalyst  

SciTech Connect (OSTI)

The cost of the balance of plant (BOP) fuel cell system has increased in importance with recent decreases in fuel cell stack cost. In order to lower the cost of the BOP system, low cost but relatively clean components must be used. Selection of these materials requires an understanding of potential materials and the contaminants that evolve from them, which have been shown to affect the performance and durability of fuel cells. The present work evaluates the influence of leachable constituents from prospective materials and model compounds on the electrochemical performance of a platinum catalyst.

Wang, H.; Christ, J.; Macomber, C. S.; O'Neill, K.; Neyerlin, K. C.; O'Leary, K. A.; Reid, R.; Lakshmanan, B.; Das, M.; Ohashi, M.; Van Zee, J. W.; Dinh, H. N.

2012-01-01T23:59:59.000Z

292

Activity and Evolution of Vapor Deposited Pt-Pd Oxygen Reduction Catalysts for Solid Acid Fuel Cells  

SciTech Connect (OSTI)

The performance of hydrogen fuel cells based on the crystalline solid proton conductor CsH2PO4 is circumscribed by the mass activity of platinum oxygen reduction catalysts in the cathode. Here we report on the first application of an alloy catalyst in a solid acid fuel cell, and demonstrate an activity 4.5 times greater than Pt at 0.8 V. These activity enhancements were obtained with platinum-palladium alloys that were vapor-deposited directly on CsH2PO4 at 210 C. Catalyst mass activity peaks at a composition of 84 at% Pd, though smaller activity enhancements are observed for catalyst compositions exceeding 50 at% Pd. Prior to fuel cell testing, Pd-rich catalysts display lattice parameter expansions of up to 2% due to the presence of interstitial carbon. After fuel cell testing, a Pt-Pd solid solution absent of lattice dilatation and depleted in carbon is recovered. The structural evolution of the catalysts is correlated with catalyst de-activation.

Papandrew, Alexander B [ORNL; Chisholm, Calum R [ORNL; Zecevic, strahinja [LiOx, Inc., Pasadena, California 91106, United States; Veith, Gabriel M [ORNL; Zawodzinski, Thomas A [ORNL

2013-01-01T23:59:59.000Z

293

Thermally tolerant multilayer metal membrane  

DOE Patents [OSTI]

A composite metal membrane including a first metal layer of a Group IVB or Group VB metal sandwiched between two layers of a Group VIIIB metal selected from the group consisting of palladium, platinum, nickel, rhodium, iridium, cobalt, and alloys thereof, and a non-continuous layer of a metal chalcogenide upon one layer of the Group VIIIB metal is disclosed together with a process for the recovery of hydrogen from a gaseous mixture using such a composite membrane and a process for forming such a composite metal membrane.

Dye, Robert C. (Los Alamos, NM); Snow, Ronny C. (Los Alamos, NM)

2001-01-01T23:59:59.000Z

294

A study of aluminophosphate supported Ni-Mo catalysts for hydrocracking bitumen  

SciTech Connect (OSTI)

H-Oil and LC-Fining processes utilize a combination of thermal and catalytic hydroprocessing reactions to achieve high yields of distillate in upgrading bitumen or heavy oil residua. The processes are based on a well mixed (ebullated bed) reactor from which deactivated catalyst is continuously withdrawn and fresh catalyst is added to maintain yields. Catalyst activity and lifetime are two key factors controlling the economics of these processes. Catalyst deactivation occurs due to the deposition of coke and metals on the catalyst surface. The choice of catalyst is usually a compromise between two extremes: small pore catalyst with low metals capacity but higher activity that deactivates rapidly because of metals deposition and wide pore catalyst that has high metals deposition capacity but lower activity due to low surface area. Recently, aluminophosphate materials with large pores (< 10 nm--1,000 nm) and high surface areas (100--500 m{sup 2}/g) have been reported. The actual pore size distribution and surface area obtained depend on the Al/P ratio, preparation method and the calcination procedure. These materials are also thermally stable. The purpose of the present work was to determine if such materials, as a result of their pore size distribution and surface area, could decrease the rate of catalyst deactivation, increase catalyst activity and provide sufficient pore volume for high capacity of metals deposition during the upgrading of heavy oil residue.

Smith, K.J. [Univ. of British Columbia, Vancouver (Canada). Dept. of Chemical Engineering; Lewkowicz, L. [Alberta Research Council, Edmonton, Alberta (Canada); Oballa, M.C.; Krzywicki, A. [Novacor Research and Technology Corp., Calgary, Alberta (Canada)

1994-12-31T23:59:59.000Z

295

Platinum Nanoclusters Out-Perform Single Crystals  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 - September 2006Photovoltaic Theory andVelocity ProfileStorage forPlatinumPlatinum

296

Platinum Nanoclusters Out-Perform Single Crystals  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 - September 2006Photovoltaic Theory andVelocity ProfileStoragePlatinumPlatinum

297

Platinum Nanoclusters Out-Perform Single Crystals  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas ConchasPassive Solar Home Design Passive SolarCenterYou are here: SNPlatinumPlatinumPlatinum

298

Catalysts For Lean Burn Engine Exhaust Abatement  

DOE Patents [OSTI]

The present invention provides a process for catalytically reducing nitrogen oxides in an exhaust gas stream containing nitrogen oxides and a reductant material by contacting the gas stream under conditions effective to catalytically reduce the nitrogen oxides with a catalyst comprising a aluminum-silicate type material and a minor amount of a metal, the catalyst characterized as having sufficient catalytic activity so as to reduce the nitrogen oxides by at least 60 percent under temperatures within the range of from about 200.degree. C. to about 400.degree. C.

Ott, Kevin C. (Los Alamos, NM); Clark, Noline C. (Jemez Springs, NM); Paffett, Mark T. (Los Alamos, NM)

2004-04-06T23:59:59.000Z

299

Catalysts for lean burn engine exhaust abatement  

DOE Patents [OSTI]

The present invention provides a process for catalytically reducing nitrogen oxides in an exhaust gas stream containing nitrogen oxides and a reductant material by contacting the gas stream under conditions effective to catalytically reduce the nitrogen oxides with a catalyst comprising a aluminum-silicate type material and a minor amount of a metal, the catalyst characterized as having sufficient catalytic activity so as to reduce the nitrogen oxides by at least 60 percent under temperatures within the range of from about 200.degree. C. to about 400.degree. C.

Ott, Kevin C. (Los Alamos, NM); Clark, Noline C. (Jemez Springs, NM); Paffett, Mark T. (Los Alamos, NM)

2003-01-01T23:59:59.000Z

300

Development of a stable cobalt-ruthenium Fisher-Tropsch catalyst. Final report  

SciTech Connect (OSTI)

The reverse micelle catalyst preparation method has been used to prepare catalysts on four supports: magnesium oxide, carbon, alumina- titania and steamed Y zeolite. These catalysts were not as active as a reference catalyst prepared during previous contracts to Union Carbide Corp. This catalyst was supported on steamed Y zerolite support and was impregnated by a pore-filling method using a nonaqueous solvent. Additional catalysts were prepared via pore- filling impregnation of steamed Y zeolites. These catalysts had levels of cobalt two to three and a half times as high as the original Union Carbide catalyst. On a catalyst volume basis they were much more active than the previous catalyst; on an atom by atom basis the cobalt was about of the same activity, i.e., the high cobalt catalysts` cobalt atoms were not extensively covered over and deactivated by other cobalt atoms. The new, high activity, Y zerolite catalysts were not as stable as the earlier Union Carbide catalyst. However, stability enhancement of these catalysts should be possible, for instance, through adjustment of the quantity and/or type of trace metals present. A primary objective of this work was determination whether small amounts of ruthenium could enhance the activity of the cobalt F-T catalyst. The reverse micelle catalysts were not activated by ruthenium, indeed scanning transmission electronic microscopy (STEM) analysis provided some evidence that ruthenium was not present in the cobalt crystallites. Ruthenium did not seem to activate the high cobalt Y zeolite catalyst either, but additional experiments with Y zeolite-supported catalysts are required. Should ruthenium prove not to be an effective promoter under the simple catalyst activation procedure used in this work, more complex activation procedures have been reported which are claimed to enhance the cobalt/ruthenium interaction and result in activity promotion by ruthenium.

Frame, R.R.; Gala, H.B.

1995-02-01T23:59:59.000Z

Note: This page contains sample records for the topic "metal catalysts platinum" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

Hydrocarbon conversion process and catalysts  

SciTech Connect (OSTI)

This patent describes a catalyst composition. It comprises: a modified Y zeolite having a unit cell size below about 24.45 {angstrom}, a degree of crystallinity which is at least retained at increasing SiO{sub 2}/Al{sub 2}O{sub 3} molar ratios, a SiO{sub 2}/Al{sub 2}O{sub 3} molar ratio between about 8 to about 15, a water adsorption capacity at (25{degree}C and a p/p{sub {ital o}} value of 0.2) of between about 10--15% by weight of modified zeolite and a pore volume of at lest about 0.25 ml/g. Between about 10 to about 40% of the total pore volume is made up of pores having a diameter of at least about 8 nm; an amorphous cracking component comprising a silica-alumina containing 50--95% by weight of silica; a binder comprising alumina; from about 0.05 to about 10 percent by weight of nickel and from about 2 to about 40 percent by weight of tungsten, calculated as metals per 100 parts by weight of total catalyst. The modified Y zeolite and amorphous cracking component comprises about 60--85% by weight of the total catalyst, the binder comprises about 15--40% by weight of the total catalyst and the amount of modified Y zeolite ranges between about 10--75% of the combined amount of modified Y zeolite and amorphous cracking component.

Hoek, A.; Huizinga, T.; Maxwell, I.E.

1990-05-15T23:59:59.000Z

302

Scanning tunneling microscopic studies of SiO2 thin film supported metal nano-clusters  

E-Print Network [OSTI]

This dissertation is focused on understanding heterogeneous metal catalysts supported on oxides using a model catalyst system of SiO2 thin film supported metal nano-clusters. The primary technique applied to this study is scanning tunneling...

Min, Byoung Koun

2005-11-01T23:59:59.000Z

303

EMSL - catalyst beds  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

catalyst-beds en Magnesium behavior and structural defects in Mg+ ion implanted silicon carbide. http:www.emsl.pnl.govemslwebpublicationsmagnesium-behavior-and-structural-defe...

304

Novel catalysts for hydrogen fuel cell applications:Final report (FY03-FY05).  

SciTech Connect (OSTI)

The goal of this project was to develop novel hydrogen-oxidation electrocatalyst materials that contain reduced platinum content compared to traditional catalysts by developing flexible synthesis techniques to fabricate supported catalyst structures, and by verifying electrochemical performance in half cells and ultimately laboratory fuel cells. Synthesis methods were developed for making small, well-defined platinum clusters using zeolite hosts, ion exchange, and controlled calcination/reduction processes. Several factors influence cluster size, and clusters below 1 nm with narrow size distribution have been prepared. To enable electrochemical application, the zeolite pores were filled with electrically-conductive carbon via infiltration with carbon precursors, polymerization/cross-linking, and pyrolysis under inert conditions. The zeolite host was then removed by acid washing, to leave a Pt/C electrocatalyst possessing quasi-zeolitic porosity and Pt clusters of well-controlled size. Plotting electrochemical activity versus pyrolysis temperature typically produces a Gaussian curve, with a peak at ca. 800 C. The poorer relative performances at low and high temperature are due to low electrical conductivity of the carbon matrix, and loss of zeolitic structure combined with Pt sintering, respectively. Cluster sizes measured via adsorption-based methods were consistently larger than those observed by TEM and EXAFS, suggesting , that a fraction of the clusters were inaccessible to the fluid phase. Detailed EXAFS analysis has been performed on selected catalysts and catalyst precursors to monitor trends in cluster size evolution, as well as oxidation states of Pt. Experiments were conducted to probe the electroactive surface area of the Pt clusters. These Pt/C materials had as much as 110 m{sup 2}/g{sub pt} electroactive surface area, an almost 30% improvement over what is commercially (mfg. by ETEK) available (86 m{sup 2}/g{sub pt}). These Pt/C materials also perform qualitatively as well as the ETEK material for the ORR, a non-trivial achievement. A fuel cell test showed that Pt/C outperformed the ETEK material by an average of 50% for a 300 hour test. Increasing surface area decreases the amount of Pt needed in a fuel cell, which translates into cost savings. Furthermore, the increased performance realized in the fuel cell test might ultimately mean less Pt is needed in a fuel cell; this again translates into cost savings. Finally, enhanced long-term stability is a key driver within the fuel cell community as improvements in this area must be realized before fuel cells find their way into the marketplace; these Pt/C materials hold great promise of enhanced stability over time. An external laser desorption ion source was successfully installed on the existing Fourier transform ion-cyclotron resonance (FT-ICR) mass spectrometer. However, operation of this laser ablation source has only generated metal atom ions, no clusters have been found to date. It is believed that this is due to the design of the pulsed-nozzle/laser vaporization chamber. The final experimental configuration and design of the two source housings are described.

Thornberg, Steven Michael; Coker, Eric Nicholas; Jarek, Russell L.; Steen, William Arthur

2005-12-01T23:59:59.000Z

305

Catalyst for producing lower alcohols  

DOE Patents [OSTI]

A process and system for the production of the lower alcohols such as methanol, ethanol and propanol involves the reaction of carbon monoxide and water in the presence of a lead salt and an alkali metal formate catalyst combination. The lead salt is present as solid particles such as lead titanate, lead molybdate, lead vanadate, lead zirconate, lead tantalate and lead silicates coated or in slurry within molten alkali metal formate. The reactants, carbon monoxide and steam are provided in gas form at relatively low pressures below 100 atmospheres and at temperatures of 200-400.degree. C. The resulted lower alcohols can be separated into boiling point fractions and recovered from the excess reactants by distillation.

Rathke, Jerome W. (Bolingbrook, IL); Klingler, Robert J. (Woodridge, IL); Heiberger, John J. (Glen Ellyn, IL)

1987-01-01T23:59:59.000Z

306

DEVELOPMENT OF A NOVEL CATALYST FOR NO DECOMPOSITION  

SciTech Connect (OSTI)

Air pollution arising from the emission of nitrogen oxides as a result of combustion taking place in boilers, furnaces and engines, has increasingly been recognized as a problem. New methods to remove NO{sub x} emissions significantly and economically must be developed. The current technology for post-combustion removal of NO is the selective catalytic reduction (SCR) of NO by ammonia or possibly by a hydrocarbon such as methane. The catalytic decomposition of NO to give N{sub 2} will be preferable to the SCR process because it will eliminate the costs and operating problems associated with the use of an external reducing species. The most promising decomposition catalysts are transition metal (especially copper)-exchanged zeolites, perovskites, and noble metals supported on metal oxides such as alumina, silica, and ceria. The main shortcoming of the noble metal reducible oxide (NMRO) catalysts is that they are prone to deactivation by oxygen. It has been reported that catalysts containing tin oxide show oxygen adsorption behavior that may involve hydroxyl groups attached to the tin oxide. This is different than that observed with other noble metal-metal oxide combinations, which have the oxygen adsorbing on the noble metal and subsequently spilling over to the metal oxide. This observation leads one to believe that the Pt/SnO{sub 2} catalysts may have a potential as NO decomposition catalysts in the presence of oxygen. This prediction is also supported by some preliminary data obtained for NO decomposition on a Pt/SnO{sub 2} catalyst in the PI's laboratory. The main objective of the proposed research is the evaluation of the Pt/SnO{sub 2} catalysts for the decomposition of NO in simulated power plant stack gases with particular attention to the resistance to deactivation by O{sub 2}, CO{sub 2}, and elevated temperatures. Therefore, it is proposed to perform temperature programmed desorption (TPD) and temperature programmed reaction (TPRx) studies on Pt/SnO{sub 2} catalysts having different noble metal concentrations and pretreated under different conditions. It is also proposed to perform NO decomposition tests in a laboratory-size packed-bed reactor to obtain long-term deactivation data. In the current reporting period first the GC-MS system was calibrated. Then the TPD runs for the 15% Pt/SnO{sub 2} catalyst after treatment with NO and subsequent treatments with NO and O{sub 2} were done. For these runs the catalyst was pretreated with dry helium for 2 hours at 40 C.

Ates Akyurtlu; Jale F. Akyurtlu

2004-05-01T23:59:59.000Z

307

DEVELOPMENT OF A NOVEL CATALYST FOR NO DECOMPOSITION  

SciTech Connect (OSTI)

Air pollution arising from the emission of nitrogen oxides as a result of combustion taking place in boilers, furnaces and engines, has increasingly been recognized as a problem. New methods to remove NOx emissions significantly and economically must be developed. The current technology for post-combustion removal of NO is the selective catalytic reduction (SCR) of NO by ammonia or possibly by a hydrocarbon such as methane. The catalytic decomposition of NO to give N{sub 2} will be preferable to the SCR process because it will eliminate the costs and operating problems associated with the use of an external reducing species. The most promising decomposition catalysts are transition metal (especially copper)-exchanged zeolites, perovskites, and noble metals supported on metal oxides such as alumina, silica, and ceria. The main shortcoming of the noble metal reducible oxide (NMRO) catalysts is that they are prone to deactivation by oxygen. It has been reported that catalysts containing tin oxide show oxygen adsorption behavior that may involve hydroxyl groups attached to the tin oxide. This is different than that observed with other noble metal-metal oxide combinations, which have the oxygen adsorbing on the noble metal and subsequently spilling over to the metal oxide. This observation leads one to believe that the Pt/SnO{sub 2} catalysts may have a potential as NO decomposition catalysts in the presence of oxygen. This prediction is also supported by some preliminary data obtained for NO decomposition on a Pt/SnO{sub 2} catalyst in the PI's laboratory. The main objective of the proposed research is the evaluation of the Pt/SnO{sub 2} catalysts for the decomposition of NO in simulated power plant stack gases with particular attention to the resistance to deactivation by O{sub 2}, CO{sub 2}, and elevated temperatures. Therefore, it is proposed to perform temperature programmed desorption (TPD) and temperature programmed reaction (TPRx) studies on Pt/SnO{sub 2} catalysts having different noble metal concentrations and pretreated under different conditions. It is also proposed to perform NO decomposition tests in a laboratory-size packed-bed reactor to obtain long-term deactivation data. In the previous reporting period some TPRx runs with the catalysts containing 15% and 10% Pt were repeated due to the uncertainty of the oxygen content of the feed. In this reporting period runs were made with feed gas mixtures containing water vapor. Two reaction regimes, one below and the other above 750 K were observed. Presence of water vapor slightly enhanced the catalyst activity, but decreased the selectivity towards N{sub 2} at low temperatures.

Ates Akyurtlu; Jale F. Akyurtlu

2005-09-29T23:59:59.000Z

308

The Dynamics of Platinum Precipitation in an Ion Exchange Membrane  

E-Print Network [OSTI]

Microscopy of polymer electrolyte membranes that have undergone operation under fuel cell conditions, have revealed a well defined band of platinum in the membrane. Here, we propose a physics based model that captures the mechanism of platinum precipitation in the polymer electrolyte membrane. While platinum is observed throughout the membrane, the preferential growth of platinum at the band of platinum is dependent on the electrochemical potential distribution in the membrane. In this paper, the location of the platinum band is calculated as a function of the gas concentration at the cathode and anode, gas diffusion coefficients and solubility constants of the gases in the membrane, which are functions of relative humidity. Under H2/N2 conditions the platinum band is located near the cathode-membrane interface, as the oxygen concentration in the cathode gas stream increases and/or the hydrogen concentration in the anode gas stream decreases, the band moves towards the anode. The model developed in this paper...

Burlatsky, S F; Atrazhev, V V; Dmitriev, D V; Kuzminyh, N Y; Erikhman, N S

2013-01-01T23:59:59.000Z

309

De-alloyed platinum nanoparticles  

DOE Patents [OSTI]

A method of producing de-alloyed nanoparticles. In an embodiment, the method comprises admixing metal precursors, freeze-drying, annealing, and de-alloying the nanoparticles in situ. Further, in an embodiment de-alloyed nanoparticle formed by the method, wherein the nanoparticle further comprises a core-shell arrangement. The nanoparticle is suitable for electrocatalytic processes and devices.

Strasser, Peter (Houston, TX); Koh, Shirlaine (Houston, TX); Mani, Prasanna (Houston, TX); Ratndeep, Srivastava (Houston, TX)

2011-08-09T23:59:59.000Z

310

Standard Platinum Resistance Thermometer Calibrations from the  

E-Print Network [OSTI]

Standard Platinum Resistance Thermometer Calibrations from the Ar TP to the Ag FP G. F. Strouse Thermometer Calibrations from the Ar TP to the Ag FP G. F. Strouse Chemical Science and Technology Laboratory............................................................................................................. 2 2.2 ITS-90 thermometer specifications

Magee, Joseph W.

311

NO.sub.x catalyst and method of suppressing sulfate formation in an exhaust purification system  

DOE Patents [OSTI]

The activity and durability of a zeolite lean-burn NOx catalyst can be increased by loading metal cations on the outer surface of the zeolite. However, the metal loadings can also oxidize sulfur dioxide to cause sulfate formation in the exhaust. The present invention is a method of suppressing sulfate formation in an exhaust purification system including a NO.sub.x catalyst. The NO.sub.x catalyst includes a zeolite loaded with at least one metal. The metal is selected from among an alkali metal, an alkaline earth metal, a lanthanide metal, a noble metal, and a transition metal. In order to suppress sulfate formation, at least a portion of the loaded metal is complexed with at least one of sulfate, phosphate, and carbonate.

Balmer-Millar, Mari Lou (Chillicothe, IL); Park, Paul W. (Peoria, IL); Panov, Alexander G. (Peoria, IL)

2007-06-26T23:59:59.000Z

312

Homogeneous catalyst formulations for methanol production  

DOE Patents [OSTI]

There is disclosed synthesis of CH.sub.3 OH from carbon monoxide and hydrogen using an extremely active homogeneous catalyst for methanol synthesis directly from synthesis gas. The catalyst operates preferably between 100.degree.-150.degree. C. and preferably at 100-150 psia synthesis gas to produce methanol. Use can be made of syngas mixtures which contain considerable quantities of other gases, such as nitrogen, methane or excess hydrogen. The catalyst is composed of two components: (a) a transition metal carbonyl complex and (b) an alkoxide component. In the simplest formulation, component (a) is a complex of nickel tetracarbonyl and component (b) is methoxide (CH.sub.3 O.sup.-), both being dissolved in a methanol solvent system. The presence of a co-solvent such as p-dioxane, THF, polyalcohols, ethers, hydrocarbons, and crown ethers accelerates the methanol synthesis reaction.

Mahajan, Devinder (Port Jefferson, NY); Sapienza, Richard S. (Shoreham, NY); Slegeir, William A. (Hampton Bays, NY); O'Hare, Thomas E. (Huntington Station, NY)

1991-02-12T23:59:59.000Z

313

Homogeneous catalyst formulations for methanol production  

DOE Patents [OSTI]

There is disclosed synthesis of CH.sub.3 OH from carbon monoxide and hydrogen using an extremely active homogeneous catalyst for methanol synthesis directly from synthesis gas. The catalyst operates preferably between 100.degree.-150.degree. C. and preferably at 100-150 psia synthesis gas to produce methanol. Use can be made of syngas mixtures which contain considerable quantities of other gases, such as nitrogen, methane or excess hydrogen. The catalyst is composed of two components: (a) a transition metal carbonyl complex and (b) an alkoxide component. In the simplest formulation, component (a) is a complex of nickel tetracarbonyl and component (b) is methoxide (CH.sub.3 O.sup.13 ), both being dissolved in a methanol solvent system. The presence of a co-solvent such as p-dioxane, THF, polyalcohols, ethers, hydrocarbons, and crown ethers accelerates the methanol synthesis reaction.

Mahajan, Devinder (Port Jefferson, NY); Sapienza, Richard S. (Shoreham, NY); Slegeir, William A. (Hampton Bays, NY); O'Hare, Thomas E. (Huntington Station, NY)

1990-01-01T23:59:59.000Z

314

Method for dispersing catalyst onto particulate material  

DOE Patents [OSTI]

A method for dispersing finely divided catalyst precursors onto the surface of coal or other particulate material includes the steps of forming a wet paste mixture of the particulate material and a liquid solution containing a dissolved transition metal salt, for instance a solution of ferric nitrate. The wet paste mixture is in a state of incipient wetness with all of this solution adsorbed onto the surfaces of the particulate material without the presence of free moisture. On adding a precipitating agent such as ammonia, a catalyst precursor such as hydrated iron oxide is deposited on the surfaces of the coal. The catalyst is activated by converting it to the sulfide form for the hydrogenation or direct liquefaction of the coal.

Utz, Bruce R. (Pittsburgh, PA); Cugini, Anthony V. (Pittsburgh, PA)

1992-01-01T23:59:59.000Z

315

Is there a particle-size dependence for the mediation by colloidal redox catalysts of the light-induced hydrogen evolution from water  

SciTech Connect (OSTI)

Particle-size effects for the catalysis by platinum of the light-induced hydrogen evolution from water, using the (Ru(bpy)/sub 3//sup 2 +//methyl viologen/EDTA) model system, were investigated with widely polydispersed colloidal platinum hydrosols and samples with narrower size distributions obtained from the former hydrosols by centrifugation. The optimum values for the hydrogen-formation rates and yields were found to be very similar for all catalysts studied; this was true for those containing polydispersed or selected small (<100 A) as well as large particles (>1000 A). In fact, no platinum particle-size effects on the methyl viologen mediated hydrogen evolutions were observed in the investigated size range. These results are discussed in relation to studies on catalyst-dispersion effects in the field of heterogeous catalysis.

Keller, P.; Moradpour, A.

1980-11-19T23:59:59.000Z

316

Hydrocarbon cracking catalyst  

SciTech Connect (OSTI)

This patent describes a catalyst composition for cracking hydrocarbons to maximize gasoline comprising: rare earth exchanged ''Y'' crystalline faujasite dispersed in a clay containing matrix material; and which has been subsequently further ion exchanged to contain 0.20 to 3.0 wt% yttrium, calculated as the oxide, whereby the yttrium is chemically combined in the catalyst composition.

Lochow, C.F.; Kovacs, D.B.

1988-12-27T23:59:59.000Z

317

Nanostructured catalyst supports  

DOE Patents [OSTI]

The present invention relates to SiC nanostructures, including SiC nanopowder, SiC nanowires, and composites of SiC nanopowder and nanowires, which can be used as catalyst supports in membrane electrode assemblies and in fuel cells. The present invention also relates to composite catalyst supports comprising nanopowder and one or more inorganic nanowires for a membrane electrode assembly.

Zhu, Yimin; Goldman, Jay L.; Qian, Baixin; Stefan, Ionel C.

2012-10-02T23:59:59.000Z

318

Development of a Novel Catalyst for No Decomposition  

SciTech Connect (OSTI)

Air pollution arising from the emission of nitrogen oxides as a result of combustion taking place in boilers, furnaces and engines, has increasingly been recognized as a problem. New methods to remove NOx emissions significantly and economically must be developed. The current technology for post-combustion removal of NO is the selective catalytic reduction (SCR) of NO by ammonia or possibly by a hydrocarbon such as methane. The catalytic decomposition of NO to give N2 will be preferable to the SCR process because it will eliminate the costs and operating problems associated with the use of an external reducing species. The most promising decomposition catalysts are transition metal (especially copper)-exchanged zeolites, perovskites, and noble metals supported on metal oxides such as alumina, silica, and ceria. The main shortcoming of the noble metal reducible oxide (NMRO) catalysts is that they are prone to deactivation by oxygen. It has been reported that catalysts containing tin oxide show oxygen adsorption behavior that may involve hydroxyl groups attached to the tin oxide. This is different than that observed with other noble metal-metal oxide combinations, which have the oxygen adsorbing on the noble metal and subsequently spilling over to the metal oxide. This observation leads one to believe that the Pt/SnO2 catalysts may have a potential as NO decomposition catalysts in the presence of oxygen. This prediction is also supported by some preliminary data obtained for NO decomposition on a Pt/SnO2 catalyst in the PI's laboratory. The main objective of the research that is being undertaken is the evaluation of the Pt/SnO2 catalysts for the decomposition of NO in simulated power plant stack gases with particular attention to the resistance to deactivation by O2, CO{sub 2}, and elevated temperatures. Temperature programmed desorption (TPD) and temperature programmed reaction (TPRx) studies on Pt/SnO2 catalysts having different noble metal concentrations and pretreated under different conditions were done. It is also planned to perform NO decomposition tests in a laboratory-size packed-bed reactor to obtain long-term deactivation data. In the previous reporting periods, runs were made with catalysts containing 15% Pt and 10% Pt on SnO2 were done. Catalysts containing 10% Pt resulted in significantly lower actgivities than 15% PT catalysts. Therefore, in the following tests 15% Pt/SnO2 catalysts were used. Runs to elucidate the effects of temperature, oxygen, water vapor, pretreatment temperature, and space velocity on NO dissociation were completed. It was found that the presence of oxygen and water vapor did not affect the activation energy of the NO dissociation reaction indicating the presence of the same rate controlling step for all feed compositions. Activation energy was higher for higher gas velocities suggesting the presence of mass transfer limitations at lower velocities. Presence of oxygen in the feed inhibited the NO decomposition. Having water vapor in the feed did not significantly affect the catalyst activity for catalysts pretreated at 373 K, but significantly reduced catalyst activity for catalysts pretreated at 900 K. In this reporting period, since no release time was available, no laboratory work was undertaken. Focus was on obtaining equilibrium data on various feed mixtures at temperatures up to 1000 K.

Ates Akyurtlu; Jale F. Akyurtlu

2007-03-14T23:59:59.000Z

319

Development Of A Novel Catalyst For No Decomposition  

SciTech Connect (OSTI)

Air pollution arising from the emission of nitrogen oxides as a result of combustion taking place in boilers, furnaces and engines, has increasingly been recognized as a problem. New methods to remove NO{sub x} emissions significantly and economically must be developed. The current technology for post-combustion removal of NO is the selective catalytic reduction (SCR) of NO by ammonia or possibly by a hydrocarbon such as methane. The catalytic decomposition of NO to give N2 will be preferable to the SCR process because it will eliminate the costs and operating problems associated with the use of an external reducing species. The most promising decomposition catalysts are transition metal (especially copper)-exchanged zeolites, perovskites, and noble metals supported on metal oxides such as alumina, silica, and ceria. The main shortcoming of the noble metal reducible oxide (NMRO) catalysts is that they are prone to deactivation by oxygen. It has been reported that catalysts containing tin oxide show oxygen adsorption behavior that may involve hydroxyl groups attached to the tin oxide. This is different than that observed with other noble metal-metal oxide combinations, which have the oxygen adsorbing on the noble metal and subsequently spilling over to the metal oxide. This observation leads one to believe that the Pt/SnO{sub 2} catalysts may have a potential as NO decomposition catalysts in the presence of oxygen. This prediction is also supported by some preliminary data obtained for NO decomposition on a Pt/SnO2 catalyst in the PI's laboratory. The main objective of the research that is being undertaken is the evaluation of the Pt/SnO2 catalysts for the decomposition of NO in simulated power plant stack gases with particular attention to the resistance to deactivation by O{sub 2}, CO{sub 2}, and elevated temperatures. Temperature programmed desorption (TPD) and temperature programmed reaction (TPRx) studies on Pt/SnO2 catalysts having different noble metal concentrations and pretreated under different conditions were done. It is also planned to perform NO decomposition tests in a laboratory-size packed-bed reactor to obtain long-term deactivation data. In the previous reporting periods, runs were made with catalysts containing 15% Pt and 10% Pt on SnO{sub 2} were done. Catalysts containing 10% Pt resulted in significantly lower activities than 15% PT catalysts. Therefore, in the following tests 15% Pt/SnO{sub 2} catalysts were used. In the current reporting period runs to elucidate the effects of temperature, oxygen, water vapor, pretreatment temperature, and space velocity on NO dissociation were completed. It was found that the presence of oxygen and water vapor did not affect the activation energy of the NO dissociation reaction indicating the presence of the same rate controlling step for all feed compositions. Activation energy was higher for higher gas velocities suggesting the presence of mass transfer limitations at lower velocities. Presence of oxygen in the feed inhibited the NO decomposition. Having water vapor in the feed did not significantly affect the catalyst activity for catalysts pretreated at 373 K, but significantly reduced catalyst activity for catalysts pretreated at 900 K.

Ates Akyurtlu; Jale F. Akyurtlu

2006-09-14T23:59:59.000Z

320

Cyano- and polycyanometallo-porphyrins as catalysts for alkane oxidation  

DOE Patents [OSTI]

New compositions of matter comprising cyano-substituted metal complexes of porphyrins are catalysts for the oxidation of alkanes. The metal is iron, chromium, manganese, ruthenium, copper or cobalt. The porphyrin ring has cyano groups attached thereto in meso- and/or [beta]-pyrrolic positions.

Ellis, P.E. Jr.; Lyons, J.E.

1993-05-18T23:59:59.000Z

Note: This page contains sample records for the topic "metal catalysts platinum" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Cyano- and polycyanometallo-porphyrins as catalysts for alkane oxidation  

DOE Patents [OSTI]

New compositions of matter comprising cyano-substituted metal complexes of porphyrins are catalysts for the oxidation of alkanes. The metal is iron, chromium, manganese, ruthenium, copper or cobalt. The porphyrin ring has cyano groups attached thereto in meso and/or [beta]-pyrrolic positions.

Ellis, P.E. Jr.; Lyons, J.E.

1995-01-17T23:59:59.000Z

322

Cyano- and polycyanometallo-porphyrins as catalysts for alkane oxidation  

DOE Patents [OSTI]

New compositions of matter comprising cyano-substituted metal complexes of porphyrins are catalysts for the oxidation of alkanes. The metal is iron, chromium, manganese, ruthenium, copper or cobalt. The porphyrin ring has cyano groups attached thereto in meso and/or .beta.-pyrrolic positions.

Ellis, Jr., Paul E. (Downingtown, PA); Lyons, James E. (Wallingford, PA)

1993-01-01T23:59:59.000Z

323

Cyano- and polycyanometallo-porphyrins as catalysts for alkane oxidation  

DOE Patents [OSTI]

New compositions of matter comprising cyano-substituted metal complexes of porphyrins are catalysts for the oxidation of alkanes. The metal is iron, chromium, manganese, ruthenium, copper or cobalt. The porphyrin ring has cyano groups attached thereto in meso and/or .beta.-pyrrolic positions.

Ellis, Jr., Paul E. (Downingtown, PA); Lyons, James E. (Wallingford, PA)

1995-01-01T23:59:59.000Z

324

Aerogels as catalysts and catalyst supports  

SciTech Connect (OSTI)

Aerogels have been used as catalysts since the 1930`s. These materials are interesting because their high surface area means more active sites for gas/ solid interactions. Aerogels have important applications as catalyst supports and are stable as well, which is a real advantage for designing catalytic materials. The author discusses some recent work in his laboratory on developing aerogels as catalytic materials. An important step in preparing these materials is supercritical extraction with CO{sub 2}. Preparation and properties of titania, niobia, and titania-zirconia systems are discussed.

Ko, E.I. [Carnegie Mellon Univ., Pittsburgh, PA (United States)

1993-04-01T23:59:59.000Z

325

E-Print Network 3.0 - actinoid metal-transition metal-boron Sample...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Materials Science 97 Catalyst-Free Synthesis and Characterization of Metastable Boron Carbide Nanowires Summary: . Rogl, Phase Diagrams of Ternary Metal-Boron-Carbon Systems,...

326

Metal loading and reactivity of Zeolite Y  

E-Print Network [OSTI]

. XRD pattern for calcined MoNiY 13. IR spectra for NiY 14. IR spectra for MoNiY 15. HDN product distribution, alumina based catalyst 16. HDN product distribution, zeolite based catalyst 17. Adjusted HDN product distribution, alumina based catalyst...V) are transi- tion metal oxides or sulfides on an alumina support. These catalysts were not specifically developed for hydrodenitrogenaiion but were adopted from hydrocracking or hydrodesul- furization (HDS) processes. HDN is more difficult than HDS; thus...

Sa?enz, Marc Gerard

1988-01-01T23:59:59.000Z

327

Method of making maximally dispersed heterogeneous catalysts  

DOE Patents [OSTI]

A method of making a catalyst with monolayer or sub-monolayer metal by controlling the wetting characteristics on the support surface and increasing the adhesion between the catalytic metal and an oxide layer. There are two methods that have been demonstrated by experiment and supported by theory. In the first method, which is useful for noble metals as well as others, a negatively-charged species is introduced to the surface of a support in sub-ML coverage. The layer-by-layer growth of metal deposited onto the oxide surface is promoted because the adhesion strength of the metal-oxide interface is increased. This method can also be used to achieve nanoislands of metal upon sub-ML deposition. The negatively-charged species can either be deposited onto the oxide surface or a compound can be deposited that dissociates on, or reacts with, the surface to form the negatively-charged species. The deposited metal adatoms can thereby bond laterally to the negatively-charged species as well as vertically to the oxide surface. Thus the negatively-charged species serve as anchors for the metal. In the second method, a chemical reaction that occurs when most metals are deposited on a fully hydroxylated oxide surface is used to create cationic metal species that bind strongly both to the substrate and to metallic metal atoms. These are incorporated into the top layer of the substrate and bind strongly both to the substrate and to metallic metal atoms. In this case, these oxidized metal atoms serve as the anchors. Here, as in the previous method, nanoislands of catalytic metal can be achieved to increase catalytic activity, or monolayers or bilayers of reactive metal can also be made.

Jennison, Dwight R. (Albuquerque, NM)

2005-11-15T23:59:59.000Z

328

Catalyst for selective NO.sub.x reduction using hydrocarbons  

DOE Patents [OSTI]

A two phase catalyst is disclosed with one or more transition metals such as Cu, Co, Fe, Ag and Mo supported on a molecular sieve having a pore size not greater than 8 .ANG. along with a stabilizing oxide of one or more of the oxides of Zr, Mo, V, Nb or the rare earths coating the molecular sieve. A method of preparing the two phase catalyst and using same to remediate NO.sub.x in combustion gases is also described.

Marshall, Christopher L. (Naperville, IL); Neylon, Michael K. (Naperville, IL)

2007-05-22T23:59:59.000Z

329

Methods for making a supported iron-copper catalyst  

DOE Patents [OSTI]

A catalyst is described for the synthesis of hydrocarbons from CO+H.sub.2 utilizing a porous Al.sub.2 O.sub.3 support impregnated with iron and copper and optionally promoted with an alkali metal. The use of an Al.sub.2 O.sub.3 support results in the suppression of heavy waxes (C.sub.26 + hydrocarbons), particularly in slurry phase operation, when compared to unsupported or co-precipitated catalysts.

Dyer, Paul N. (Allentown, PA); Pierantozzi, Ronald (Macungie, PA)

1986-01-01T23:59:59.000Z

330

Hydrocracking and hydroisomerization of long-chain alkanes and polyolefins over metal-promoted anion-modified transition metal oxides  

SciTech Connect (OSTI)

A method is described for cracking a feedstock by contacting the feedstock with a metal-promoted anion-modified metal oxide catalyst in the presence of hydrogen gas. The metal oxide of the catalyst is one or more of ZrO{sub 2}, HfO{sub 2}, TiO{sub 2} and SnO{sub 2}, and the feedstock is principally chains of at least 20 carbon atoms. The metal-promoted anion-modified metal oxide catalyst contains one or more of Pt, Ni, Pd, Rh, Ir, Ru, (Mn and Fe) or mixtures of them present between about 0.2% to about 15% by weight of the catalyst. The metal-promoted anion-modified metal oxide catalyst contains one or more of SO{sub 4}, WO{sub 3}, or mixtures of them present between about 0.5% to about 20% by weight of the catalyst.

Venkatesh, Koppampatti R.; Hu, Jianli; Tierney, John W.; Wender, Irving

1996-12-01T23:59:59.000Z

331

The Use of Catalysts in Near-Critical Water Processing  

SciTech Connect (OSTI)

The use of heterogeneous catalysts in near-critical water processing provides many challenges of material stability in addition to the normal questions of chemical activity. Conventional catalyst materials developed in traditional organic chemistry or petroleum chemistry applications provide a source of information of materials with the required activities but often without the required stability when used in hot liquid water. The importance of the use of catalysts in near-critical water processing plays a particularly crucial role for the development of renewable fuels and chemicals based on biomass feedstocks. Stability issues include both those related to the catalytic metal and also to the catalyst support material. In fact, the stability of the support is the most likely concern when using conventional catalyst formulations in near-critical water processing. Processing test results are used to show important design parameters for catalyst formulations for use in wet biomass gasification in high-pressure water and in catalytic hydrogenations in water for production of value-added chemical products from biomass in the biorefinery concept. Analytical methods including powder x-ray diffraction for crystallite size and composition determination, surface area and porosity measurements, and elemental analysis have all been used to quantify differences in catalyst materials before and after use. By these methods both the chemical and physical stability of heterogeneous catalysts can be verified.

Elliott, Douglas C.

2005-06-26T23:59:59.000Z

332

Metal articles having ultrafine particles dispersed therein  

SciTech Connect (OSTI)

This patent describes a metal article of manufacture. It comprises: a metal selected from the group consisting of copper, silver, gold, lead, tin, nickel, zinc, cobalt, antimony, bismuth, iron, cadmium, chromium, germanium, gallium, selenium, tellurium, mercury, tungsten arsenic, manganese, iridium, indium, ruthenium, rhenium, rhodium, molybdenum, palladium, osmium and platinum; and a plurality of ultrafine particles.

Alexander, G.B.; Nadkarni, R.A.

1992-07-28T23:59:59.000Z

333

Catalyst for microelectromechanical systems microreactors  

DOE Patents [OSTI]

A microreactor comprising a silicon wafer, a multiplicity of microchannels in the silicon wafer, and a catalyst coating the microchannels. In one embodiment the catalyst coating the microchannels comprises a nanostructured material. In another embodiment the catalyst coating the microchannels comprises an aerogel. In another embodiment the catalyst coating the microchannels comprises a solgel. In another embodiment the catalyst coating the microchannels comprises carbon nanotubes.

Morse, Jeffrey D. (Martinez, CA); Sopchak, David A. (Livermore, CA); Upadhye, Ravindra S. (Pleasanton, CA); Reynolds, John G. (San Ramon, CA); Satcher, Joseph H. (Patterson, CA); Gash, Alex E. (Brentwood, CA)

2011-11-15T23:59:59.000Z

334

Epoxidation catalyst and process  

DOE Patents [OSTI]

Disclosed herein is a catalytic method of converting alkenes to epoxides. This method generally includes reacting alkenes with oxygen in the presence of a specific silver catalyst under conditions suitable to produce a yield of the epoxides. The specific silver catalyst is a silver nanocrystal having a plurality of surface planes, a substantial portion of which is defined by Miller indices of (100). The reaction is performed by charging a suitable reactor with this silver catalyst and then feeding the reactants to the reactor under conditions to carry out the reaction. The reaction may be performed in batch, or as a continuous process that employs a recycle of any unreacted alkenes. The specific silver catalyst has unexpectedly high selectivity for epoxide products. Consequently, this general method (and its various embodiments) will result in extraordinarily high epoxide yields heretofore unattainable.

Linic, Suljo (Ann Arbor, MI); Christopher, Phillip (Ann Arbor, MI)

2010-10-26T23:59:59.000Z

335

Molecularly engineering homogenous catalysts  

E-Print Network [OSTI]

quickly. To attempt to 1G overcome this problem, Bergbreiter's group began work on synthesis of palladacycles in an attempt to find a more robust catalyst. The group was spurred to do this by the success of Denmark using chiral bis (oxazoline) palladium... (II) catalysts that proved to be active. Denmark's use of oxazoline ligands avoided the problem of phosphine oxidation. They were also inspired by Milstein and coworkers description of a phosphorus-carbon-phosphorus (PCP)-type tridentate ligand...

Hughes, Reagan Rebekah

2013-02-22T23:59:59.000Z

336

Plasmatron-catalyst system  

DOE Patents [OSTI]

A plasmatron-catalyst system. The system generates hydrogen-rich gas and comprises a plasmatron and at least one catalyst for receiving an output from the plasmatron to produce hydrogen-rich gas. In a preferred embodiment, the plasmatron receives as an input air, fuel and water/steam for use in the reforming process. The system increases the hydrogen yield and decreases the amount of carbon monoxide.

Bromberg, Leslie (Sharon, MA); Cohn, Daniel R. (Chestnut Hill, MA); Rabinovich, Alexander (Swampscott, MA); Alexeev, Nikolai (Moscow, RU)

2007-10-09T23:59:59.000Z

337

Pyrochlore-type catalysts for the reforming of hydrocarbon fuels  

DOE Patents [OSTI]

A method of catalytically reforming a reactant gas mixture using a pyrochlore catalyst material comprised of one or more pyrochlores having the composition A.sub.2-w-xA'.sub.wA''.sub.xB.sub.2-y-zB'.sub.yB''.sub.zO.sub.7-.DELTA.. Distribution of catalytically active metals throughout the structure at the B site creates an active and well dispersed metal locked into place in the crystal structure. This greatly reduces the metal sintering that typically occurs on supported catalysts used in reforming reactions, and reduces deactivation by sulfur and carbon. Further, oxygen mobility may also be enhanced by elemental exchange of promoters at sites in the pyrochlore. The pyrochlore catalyst material may be utilized in catalytic reforming reactions for the conversion of hydrocarbon fuels into synthesis gas (H.sub.2+CO) for fuel cells, among other uses.

Berry, David A. (Morgantown, WV); Shekhawat, Dushyant (Morgantown, WV); Haynes, Daniel (Morgantown, WV); Smith, Mark (Morgantown, WV); Spivey, James J. (Baton Rouge, LA)

2012-03-13T23:59:59.000Z

338

Ignition and extinction in the catalytic oxidation of hydrocarbons over platinum  

SciTech Connect (OSTI)

The ignition-extinction behavior in the oxidation of methane, ethane, propane and isobutane, as well as of ethylene and propylene over a platinum-foil catalyst was studied over the entire range of fuel/air ratios at atmospheric pressure. Ignition and extinction of the heterogeneous surface reaction, homogeneous ignition and the autothermal behavior of these fuel-air mixtures were investigated. The results show a common trend in the ignition extinction behavior of the alkanes and a different trend for the olefins. This is discussed in terms of a simple model, which correctly predicts the composition dependence of the surface ignition curve for reasonable values of parameters, indicating a mainly oxygen-covered surface during ignition of the alkanes and a mainly hydrocarbon-covered surface in the case of the olefins. Different branches of the complete bifurcation diagrams are discussed separately, allowing qualitative conclusions about the catalytic activity of Pt for the oxidation reactions of different fuels.

Veser, G.; Schmidt, L.D. [Univ. of Minnesota, Minneapolis, MN (United States). Dept. of Chemical Engineering and Materials Science] [Univ. of Minnesota, Minneapolis, MN (United States). Dept. of Chemical Engineering and Materials Science

1996-04-01T23:59:59.000Z

339

Project: Contiguous Platinum Monolayer Oxygen Reduction Electrocatalysts on High-Stability-Low-Cost Supports  

E-Print Network [OSTI]

-Horn Massachusetts Institute of Technology Rachel O'Malley, David Thompsett, Sarah Ball, Graham Hard Johnson Matthey metal loading: 0.2 mgPGM /cm2 (cathode) ( 0.3 mgPGM /cm2 both electrodes) Activity (PGM catalysts): 0 - Method for depositing smooth, uniform Pt MLs Intensity profiles from the scan lines in (a) and (b) (open

340

Dilution effects in the dynamics of ammonia oxidation on platinum with an inert or a product species in the feed mixture  

SciTech Connect (OSTI)

In most experiments, the autothermal catalyst temperature was monitored, i.e., the temperature resulting from the combined effects of heat dissipation to the environment and heat generation by reaction. The results of these experiments have revealed stable steady states, sustained periodic oscillations and nonperiodic states. An excess of nitrogen in the feed gas stream leads to simpler single-peaked catalyst temperature oscillations of increasing periods of time - up to 5 min. Small amounts of water vapor produced nonperiodic states at all times. These factors indicate that an interplay of heat and mass transfer, convection, and a heterogeneous mechanism is the cause of the phenomena observed during the oxidation of ammonia by air on platinum, at atmospheric pressure. Catalyst memory may also contribute to these phenomena. 25 references, 4 figures.

Takoudis, C.G.; Schmidt, L.D.

1983-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "metal catalysts platinum" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Evaluation of the effect of impregnated platinum on PFSA degradation for PEM fuel cells.  

SciTech Connect (OSTI)

One of the main sources of membrane degradation in fuel cells is attack by radicals formed wherever Pt, H2, and O2 are present. The effect of Pt precipitated in the membrane is under debate. Although Pt can provide another site for radical formation, it can also scavenge hydrogen peroxide and radicals in the membrane and improve durability. In this work, the effects of Pt particles within the membrane are evaluated and related to membrane degradation. Membranes were ex situ impregnated with 0, 10, 30, and 50 mol% Pt and then tested for 100 h in a fuel cell, at 90 C/100% relative humidity. The highest degradation was observed with the membranes containing 10 mol% Pt, with fluoride emissions of the same magnitude as those of catalyst coated membranes containing Pt/C. Membranes containing 0, 30, and 50 mol% Pt resulted in very low fluoride emission. The high degradation in the 10 mol% membrane was attributed to the low density of platinum particles, which allows generated radicals to attack the membrane before being deactivated. In the 30 mol% and 50 mol% membranes, where the platinum particles were denser, the generated radicals became deactivated on neighboring particles before they attacked the membrane.

Rodgers, Marianne [ORNL] [ORNL; Pearman, Benjamin P [ORNL] [ORNL; Bonville, Leonard J. [Florida Solar Energy Center (FSEC)] [Florida Solar Energy Center (FSEC); Cullen, David A [ORNL] [ORNL; Mohajeri, Nahid [ORNL] [ORNL; Slattery, Darlene [Florida Solar Energy Center (FSEC)] [Florida Solar Energy Center (FSEC)

2013-01-01T23:59:59.000Z

342

Haloporphyrins and their preparation and use as catalysts  

DOE Patents [OSTI]

The invention provides novel catalyst compositions, useful in the oxidation of hydrocarbons with air or oxygen to form hydroxy-group containing compounds and in the decomposition of hydroperoxides to form hydroxy-group containing compounds. The catalysts comprise transition metal complexes of a porphyrin ring having 1 to 12 halogen substituents on the porphyrin ring, at least one of said halogens being in a meso position and/or the catalyst containing no aryl group in a meso position. The compositions are prepared by halogenating a transition metal complex of a porphyrin. In one embodiment, a complex of a porphyrin with a metal whose porphyrin complexes are not active for oxidation of hydrocarbons is halogenated, thereby to obtain a haloporphyrin complex of that metal, the metal is removed from the haloporphyrin complex to obtain the free base form of the haloporphyrin, and a metal such as iron whose porphyrin complexes are active for oxidation of hydrocarbons and for the decomposition of alkyl hydroperoxides is complexed with the free base to obtain an active catalyst for oxidation of hydrocarbons and decomposition of alkyl hydroperoxides.

Ellis, P.E. Jr.; Lyons, J.E.

1997-09-02T23:59:59.000Z

343

PLATINUM-GROUP METALS By Robert G. Reese  

E-Print Network [OSTI]

petroleum-refining industries. They are also used in the of scrap. Because of their high value, PGM, in Montana, The petroleum-refining industry used PGM, principally accounts for nearly all domestic primary activity bring them many uses. secondary materials were then sold to refiners. Most PGM's are used

344

Sandia National Laboratories: ECIS and Compass Metals: Platinum  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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345

PLATINUM-GROUP METALS By Robert G. Reese  

E-Print Network [OSTI]

of a new 530- PGM's include the electrical and electronic, meter shaft in October. dental and medical. dealers, largely in the Northeast. Identified world PGM resources at yearend Historically, the U.S. Bureau). The reserve base was estimated at 66 production, and consumption of PGM's from a million kg and reserves at 56

346

DEVELOPMENT OF A NOVEL CATALYST FOR NO DECOMPOSITION  

SciTech Connect (OSTI)

Air pollution arising from the emission of nitrogen oxides as a result of combustion taking place in boilers, furnaces and engines, has increasingly been recognized as a problem. New methods to remove NO{sub x} emissions significantly and economically must be developed. The current technology for post-combustion removal of NO is the selective catalytic reduction (SCR) of NO by ammonia or possibly by a hydrocarbon such as methane. The catalytic decomposition of NO to give N{sub 2} will be preferable to the SCR process because it will eliminate the costs and operating problems associated with the use of an external reducing species. The most promising decomposition catalysts are transition metal (especially copper)-exchanged zeolites, perovskites, and noble metals supported on metal oxides such as alumina, silica, and ceria. The main shortcoming of the noble metal reducible oxide (NMRO) catalysts is that they are prone to deactivation by oxygen. It has been reported that catalysts containing tin oxide show oxygen adsorption behavior that may involve hydroxyl groups attached to the tin oxide. This is different than that observed with other noble metal-metal oxide combinations, which have the oxygen adsorbing on the noble metal and subsequently spilling over to the metal oxide. This observation leads one to believe that the Pt/SnO{sub 2} catalysts may have a potential as NO decomposition catalysts in the presence of oxygen. This prediction is also supported by some preliminary data obtained for NO decomposition on a Pt/SnO{sub 2} catalyst in the PI's laboratory. The main objective of the proposed research is the evaluation of the Pt/SnO{sub 2} catalysts for the decomposition of NO in simulated power plant stack gases with particular attention to the resistance to deactivation by O{sub 2}, CO{sub 2}, and elevated temperatures. Therefore, it is proposed to perform temperature programmed desorption (TPD) and temperature programmed reaction (TPRx) studies on Pt/SnO{sub 2} catalysts having different noble metal concentrations and pretreated under different conditions. It is also proposed to perform NO decomposition tests in a laboratory-size packed-bed reactor to obtain long-term deactivation data. In the previous reporting period runs were made with feed gas mixtures containing water vapor. Two reaction regimes, one below and the other above 750 K were observed. Presence of water vapor slightly enhanced the catalyst activity, but decreased the selectivity towards N{sub 2} at low temperatures. For the current reporting period it was decided to Finish the runs with water vapor in the feed, check the effect of higher gas flow rate, and run experiments with catalyst treated at 900 K and 1000 K to drive off the OH groups. Unfortunately, shortly into the current period we had to change the gas feed preparation section. Then two flow controllers failed and we had to switch to rotameters and manual flow control as a stop gap measure. This affected the quality of the results and required repeated runs. Currently the results are satisfactory and the experiments are continuing. To take advantage of the down time the surface areas of the 15% Pt and 10% Pt catalysts were measured. The results indicate that when the catalysts are treated at 900 K for to hours to remove most of the OH groups on the surface, the activity of the 15% Pt catalyst increased.

Ates Akyurtlu; Jale F Akyurtlu

2005-03-31T23:59:59.000Z

347

Supported organoiridium catalysts for alkane dehydrogenation  

DOE Patents [OSTI]

Solid supported organoiridium catalysts, a process for preparing such solid supported organoiridium catalysts, and the use of such solid supported organoiridium catalysts in dehydrogenation reactions of alkanes is provided. The catalysts can be easily recovered and recycled.

Baker, R. Thomas; Sattelberger, Alfred P.; Li, Hongbo

2013-09-03T23:59:59.000Z

348

Catalysis Today 53 (1999) 433441 New insights into methanol synthesis catalysts from X-ray absorption  

E-Print Network [OSTI]

O and Cr2O3 mixtures and produced methanol in low yields from CO­H2 mixtures at high temperatures (593Catalysis Today 53 (1999) 433­441 New insights into methanol synthesis catalysts from X a consistent structural picture of methanol synthesis catalysts. Copper metal is the principal Cu species

Iglesia, Enrique

349

Tantalum-containing catalyst useful for producing alcohols from synthesis gas  

DOE Patents [OSTI]

A catalyst is described which is useful for selectively converting a mixture of carbon monoxide and hydrogen to a mixture of lower alkanols. The catalyst consists essentially of a mixture of molybdenum sulfide, an alkali metal compound and a tantalum compound.

Kinkade, N.E.

1992-04-07T23:59:59.000Z

350

Monolithic Metal Oxide based Composite Nanowire Lean NOx Emission...  

Broader source: Energy.gov (indexed) [DOE]

Monolithic Metal Oxide based Composite Nanowire Lean NO x Emission Control Catalysts Pu-Xian Gao Department of Chemical, Materials and Biomolecular Engineering & Institute of...

351

Deactivation Mechanisms of Base Metal/Zeolite Urea Selective...  

Broader source: Energy.gov (indexed) [DOE]

peden16807.pdf More Documents & Publications Understanding the Deactivation Mechanisms of CuZeolite SCR Catalysts in Diesel Application Deactivation Mechanisms of Base Metal...

352

Towards improved iron-based catalysts for direct coal liquefaction  

SciTech Connect (OSTI)

Iron-based catalysts for direct coal liquefaction (DCL) have several advantages: they are cheap and environmentally benign, and have a reasonable activity in the sulfide form. Work in this area has recently been collected and published. work in our laboratory has focussed on catalysts made with ferric sulfide as a precursor. This material is unstable even at room temperature, and disproportionates to form pyrite (FeS{sub x}; PY) , non-stoichiometric pyrrhotite (FeS{sub x}, x {approx} 1; PH) , and elemental S. The value of x and the relative amounts of PY and PH depend upon the time and temperature of disproportionation. Materials from hydrothermal disproportionation at 200{degrees}C for 1 h have roughly equal amounts of PH and PY (on an iron basis), and these materials appear to make the most active and selective catalysts for DCL. These catalyst precursors and catalyst materials have been characterized by atomic adsorption spectroscopy (AA), Auger electron spectroscopy (AES) and x-ray diffraction (XRD). The characterizations have been correlated to the reactions of Fe during disproportionation and to the performance of the catalysts. Improvements in these catalysts can be made in two ways: by altering the active sites, and by decreasing the particle sizes. In the present work, we present examples of both types. The active sites are altered by using small amounts of a second metal. The particle sizes are reduced by using an aerosol technique for preparation.

Dadyburjor, D.B.; Stiller, A.H.; Stinespring, C.D. [West Virginia Univ., Morgantown, WV (United States)] [and others

1994-12-31T23:59:59.000Z

353

Platinum Monolayer Electrocatalysts for Oxygen Reduction Reaction  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

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354

Platinum Nanoclusters Out-Perform Single Crystals  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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355

Platinum Nanoclusters Out-Perform Single Crystals  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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356

Platinum Nanoclusters Out-Perform Single Crystals  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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357

Platinum Nanoclusters Out-Perform Single Crystals  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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358

Highly Dispersed Metal Catalyst - Energy Innovation Portal  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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359

Long-Term Testing of Rhodium-Based Catalysts for Mixed Alcohol Synthesis – 2013 Progress Report  

SciTech Connect (OSTI)

The U.S. Department of Energy’s Pacific Northwest National Laboratory has been conducting research since 2005 to develop a catalyst for the conversion of synthesis gas (carbon monoxide and hydrogen) into mixed alcohols for use in liquid transportation fuels. Initially, research involved screening possible catalysts based on a review of the literature, because at that time, there were no commercial catalysts available. The screening effort resulted in a decision to focus on catalysts containing rhodium and manganese. Subsequent research identified iridium as a key promoter for this catalyst system. Since then, research has continued to improve rhodium/manganese/iridium-based catalysts, optimizing the relative and total concentrations of the three metals, examining baseline catalysts on alternative supports, and examining effects of additional promoters. Testing was continued in FY 2013 to evaluate the performance and long-term stability of the best catalysts tested to date. Three tests were conducted. A long-term test of over 2300 hr duration at a single set of operating conditions was conducted with the best carbon-supported catalyst. A second test of about 650 hr duration at a single set of operating conditions was performed for comparison using the same catalyst formulation on an alternative carbon support. A third test of about 680 hr duration at a single set of operating conditions was performed using the best silica-supported catalyst tested to date.

Gerber, Mark A.; Gray, Michel J.; Thompson, Becky L.

2013-09-23T23:59:59.000Z

360

DEVELOPMENT OF A NOVEL CATALYST FOR NO DECOMPOSITION  

SciTech Connect (OSTI)

Air pollution arising from the emission of nitrogen oxides as a result of combustion taking place in boilers, furnaces and engines, has increasingly been recognized as a problem. New methods to remove NO{sub x} emissions significantly and economically must be developed. The current technology for post-combustion removal of NO is the selective catalytic reduction (SCR) of NO by ammonia or possibly by a hydrocarbon such as methane. The catalytic decomposition of NO to give N{sub 2} will be preferable to the SCR process because it will eliminate the costs and operating problems associated with the use of an external reducing species. The most promising decomposition catalysts are transition metal (especially copper)-exchanged zeolites, perovskites, and noble metals supported on metal oxides such as alumina, silica, and ceria. The main shortcoming of the noble metal reducible oxide (NMRO) catalysts is that they are prone to deactivation by oxygen. It has been reported that catalysts containing tin oxide show oxygen adsorption behavior that may involve hydroxyl groups attached to the tin oxide. This is different than that observed with other noble metal-metal oxide combinations, which have the oxygen adsorbing on the noble metal and subsequently spilling over to the metal oxide. This observation leads one to believe that the Pt/SnO{sub 2} catalysts may have a potential as NO decomposition catalysts in the presence of oxygen. This prediction is also supported by some preliminary data obtained for NO decomposition on a Pt/SnO{sub 2} catalyst in the PI's laboratory. The main objective of the proposed research is the evaluation of the Pt/SnO{sub 2} catalysts for the decomposition of NO in simulated power plant stack gases with particular attention to the resistance to deactivation by O{sub 2}, CO{sub 2}, and elevated temperatures. Therefore, it is proposed to perform temperature programmed desorption (TPD) and temperature programmed reaction (TPRx) studies on Pt/SnO{sub 2} catalysts having different noble metal concentrations and pretreated under different conditions. It is also proposed to perform NO decomposition tests in a laboratory-size packed-bed reactor to obtain long-term deactivation data. In the previous reporting period the GC-MS system was calibrated and the TPD runs for the 15% Pt/SnO{sub 2} catalyst after treatment with NO and subsequent treatments with NO and O{sub 2} were done. For these runs the catalyst was pretreated with dry helium for 2 hours at 40 C. The Temperature Programmed Reaction (TPRx) of NO and NO+O{sub 2} mixtures on the catalysts containing 15% Pt and 10% Pt were also performed. In this reporting period some TPRx runs with the catalysts containing 15% and 10% Pt were repeated due to the uncertainty of the oxygen content of the feed.

Ates Akyurtlu; Jale F. Akyurtlu

2005-06-27T23:59:59.000Z

Note: This page contains sample records for the topic "metal catalysts platinum" from the National Library of EnergyBeta (NLEBeta).
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361

Autothermal reforming catalyst and process  

SciTech Connect (OSTI)

High activity steam reforming catalysts are described particularly adapted for use in autothermal reforming processes. A rhodium catalyst on a calcium oxide impregnated alumina substrate allow the autothermal reforming process to take place with substantially no carbon plugging at oxygen to carbon ratios below what had been considered critical for avoiding carbon plugging of the catalyst in the past.

Setzer, H. J.; Karavolis, S.; Lesieur, R. R.; Wnuck, W. G.

1984-09-25T23:59:59.000Z

362

Hydrocarbon conversion process and catalysts  

SciTech Connect (OSTI)

This patent describes a process for hydrocracking hydrocarbon oils into products of lower average molecular weight and lower average boiling point. It comprises contacting hydrocarbon oil at a temperature between 250{sup 0}C and 500{sup 0}C and a pressure up to 300 bar in the presence of hydrogen with a catalyst consisting essentially of a Y zeolite modified to have a unit cell size below 24.40 A, a water adsorption capacity (at 25{sup 0}C and a rho/rho/sub o/ value of 0.2) of between 10% and 15% by weight of the zeolite and a pore volume of at least 0.25 ml/g wherein between 10% and 60% of the total pore volume is made up of pores having a diameter of at least 8 nm; am amorphous cracking component, a binder and at least one hydrogenation component selected from the group consisting of a Group VI metal, a Group VIII metal and mixtures thereof.

Hoek, A.; Huizinga, T.; Maxwell, I.E.

1989-08-15T23:59:59.000Z

363

Thermodynamic stability and activity volcano for perovskite-based oxide as OER catalyst  

E-Print Network [OSTI]

Design of efficient and cost-effective catalysts for the oxygen evolution reaction (OER) is crucial for the development of electrochemical conversion technologies. Recent experiments show that perovskite transition-metal ...

Rong, Xi, S.M. Massachusetts Institute of Technology

2014-01-01T23:59:59.000Z

364

E-Print Network 3.0 - aqueous-phase rh-norbos catalysts Sample...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Pt-99 wt.% Al2O3... Fischer-Tropsch synthesis using Co and Ru supported on silica aerogels as catalysts 21 Metal impregnation Source: Consortium for Fossil Fuel Science, C1...

365

Tantalum-containing catalyst useful for producing alcohols from synthesis gas  

DOE Patents [OSTI]

A catalyst useful for selectively converting a mixture of carbon monoxide and hydrogen to a mixture of lower alkanols consisting essentially of a mixture of molybdenum sulfide, an alkali metal compound and a tantalum compound.

Kinkade, Nancy E. (Charleston, WV)

1992-01-01T23:59:59.000Z

366

Tantalum-containing catalyst useful for producing alcohols from synthesis gas  

DOE Patents [OSTI]

A catalyst useful for selectively converting a mixture of carbon monoxide and hydrogen to a mixture of lower alkanols consisting essentially of a mixture of molybdenum sulfide, an alkali metal compound and a tantalum compound.

Kinkade, Nancy E. (Charleston, WV)

1991-01-01T23:59:59.000Z

367

A Methanol and Hydrogen Peroxide Fuel Cell Using Non-Noble Catalysts in Alkaline Solution.  

E-Print Network [OSTI]

??A primary goal of this work is to develop a novel liquid-based microscale fuel cell using non-noble metal catalysts. The developed fuel cell is based… (more)

Sung, Woosuk

2006-01-01T23:59:59.000Z

368

Methane oxidation over dual redox catalysts  

SciTech Connect (OSTI)

Catalytic oxidation of methane to partial oxidation products, primarily formaldehyde and C[sub 2] hydrocarbons, was found to be directed by the catalyst used. In this project, it was discovered that a moderate oxidative coupling catalyst for C[sub 2] hydrocarbons, zinc oxide, is modified by addition of small amounts of Cu and Fe dopants to yield fair yields of formaldehyde. A similar effect was observed with Cu/Sn/ZnO catalysts, and the presence of a redox Lewis acid, Fe[sup III] or Sn[sup IV], was found to be essential for the selectivity switch from C[sub 2] coupling products to formaldehyde. The principle of double doping with an oxygen activator (Cu) and the redox Lewis acid (Fe, Sn) was pursued further by synthesizing and testing the CuFe-ZSM-5 zeolite catalyst. The Cu[sup II](ion exchanged) Fe[sup III](framework)-ZSM-5 also displayed activity for formaldehyde synthesis, with space time yields exceeding 100 g/h-kg catalyst. However, the selectivity was low and earlier claims in the literature of selective oxidation of methane to methanol over CuFe-ZSM-5 were not reproduced. A new active and selective catalytic system (M=Sb,Bi,Sn)/SrO/La[sub 2]O[sub 3] has been discovered for potentially commercially attractive process for the conversion of methane to C[sub 2] hydrocarbons, (ii) a new principle has been demonstrated for selectivity switching from C[sub 2] hydrocarbon products to formaldehyde in methane oxidations over Cu,Fe-doped zinc oxide and ZSM-5, and (iii) a new approach has been initiated for using ultrafine metal dispersions for low temperature activation of methane for selective conversions. Item (iii) continues being supported by AMOCO while further developments related to items (i) and (ii) are the objective of our continued effort under the METC-AMOCO proposed joint program.

Klier, K.; Herman, R.G.; Sojka, Z.; DiCosimo, J.I.; DeTavernier, S.

1992-06-01T23:59:59.000Z

369

Nano Catalysts for Diesel Engine Emission Remediation  

SciTech Connect (OSTI)

The objective of this project was to develop durable zeolite nanocatalysts with broader operating temperature windows to treat diesel engine emissions to enable diesel engine based equipment and vehicles to meet future regulatory requirements. A second objective was to improve hydrothermal durability of zeolite catalysts to at least 675 C. The results presented in this report show that we have successfully achieved both objectives. Since it is accepted that the first step in NO{sub x} conversion under SCR (selective catalytic reduction) conditions involves NO oxidation to NO{sub 2}, we reasoned that catalyst modification that can enhance NO oxidation at low-temperatures should facilitate NO{sub x} reduction at low temperatures. Considering that Cu-ZSM-5 is a more efficient catalyst than Fe-ZSM-5 at low-temperature, we chose to modify Cu-ZSM-5. It is important to point out that the poor low-temperature efficiency of Fe-ZSM-5 has been shown to be due to selective absorption of NH{sub 3} at low-temperatures rather than poor NO oxidation activity. In view of this, we also reasoned that an increased electron density on copper in Cu-ZSM-5 would inhibit any bonding with NH{sub 3} at low-temperatures. In addition to modified Cu-ZSM-5, we synthesized a series of new heterobimetallic zeolites, by incorporating a secondary metal cation M (Sc{sup 3+}, Fe{sup 3+}, In{sup 3+}, and La{sup 3+}) in Cu exchanged ZSM-5, zeolite-beta, and SSZ-13 zeolites under carefully controlled experimental conditions. Characterization by diffuse-reflectance ultra-violet-visible spectroscopy (UV-Vis), X-ray powder diffraction (XRD), extended X-ray absorption fine structure spectroscopy (EXAFS) and electron paramagnetic resonance spectroscopy (EPR) does not permit conclusive structural determination but supports the proposal that M{sup 3+} has been incorporated in the vicinity of Cu(II). The protocols for degreening catalysts, testing under various operating conditions, and accelerated aging conditions were provided by our collaborators at John Deere Power Systems. Among various zeolites reported here, CuFe-SSZ-13 offers the best NO{sub x} conversion activity in 150-650 C range and is hydrothermally stable when tested under accelerated aging conditions. It is important to note that Cu-SSZ-13 is now a commercial catalyst for NO{sub x} treatment on diesel passenger vehicles. Thus, our catalyst performs better than the commercial catalyst under fast SCR conditions. We initially focused on fast SCR tests to enable us to screen catalysts rapidly. Only the catalysts that exhibit high NO{sub x} conversion at low temperatures are selected for screening under varying NO{sub 2}:NO{sub x} ratio. The detailed tests of CuFe-SSZ-13 show that CuFe-SSZ-13 is more effective than commercial Cu-SSZ-13 even at NO{sub 2}:NO{sub x} ratio of 0.1. The mechanistic studies, employing stop-flow diffuse reflectance FTIR spectroscopy (DRIFTS), suggest that high concentration of NO{sup +}, generated by heterobimetallic zeolites, is probably responsible for their superior low temperature NO{sub x} activity. The results described in this report clearly show that we have successfully completed the first step in a new emission treatment catalyst which is synthesis and laboratory testing employing simulated exhaust. The next step in the catalyst development is engine testing. Efforts are in progress to obtain follow-on funding to carry out scale-up and engine testing to facilitate commercialization of this technology.

Narula, Chaitanya Kumar [ORNL; Yang, Xiaofan [ORNL; Debusk, Melanie Moses [ORNL; Mullins, David R [ORNL; Mahurin, Shannon Mark [ORNL; Wu, Zili [ORNL

2012-06-01T23:59:59.000Z

370

Zinc sulfide liquefaction catalyst  

DOE Patents [OSTI]

A process for the liquefaction of carbonaceous material, such as coal, is set forth wherein coal is liquefied in a catalytic solvent refining reaction wherein an activated zinc sulfide catalyst is utilized which is activated by hydrogenation in a coal derived process solvent in the absence of coal.

Garg, Diwakar (Macungie, PA)

1984-01-01T23:59:59.000Z

371

Modeling of on-line catalyst addition effects in a short contact time reactor  

SciTech Connect (OSTI)

Recently developed short-contact-time reactors (SCTR), consisting of porous alumina monoliths coated with platinum, have been shown to produce ethylene from rich ethane/oxygen(hydrogen) mixtures with yields and selectivities comparable to conventional steam cracking, using a reactor of much smaller size. Although the overall mechanism is clearly autothermal and catalytic, the details, in particular the relative contributions of heterogeneous and homogeneous chemistry, are a matter of considerable debate. Recent experiments show that reactor performance can be further enhanced by dripping a dilute platinum solution onto the SCTR front face during reaction, resulting in catalyst deposition within only a short (several millimeter) zone of the reactor. The authors have undertaken a computational study of this system, using two-dimensional computational fluid dynamics simulations with full heat and mass transport and detailed heterogeneous and homogeneous kinetic mechanisms. The results indicate that front-face catalyst loading enhances reactor performance by limiting the opportunity for heterogeneous ethane reactions that produce methane. As a result, ethylene selectivity increases and CH{sub 4} selectivity decreases. The results strongly support a mechanism recently proposed by the authors, in which rapid, heterogeneous oxidation of adsorbed hydrogen consumes most of the oxygen. The resulting heat is then released to the gas phase, causing homogeneous pyrolysis of ethane to occur in an environment containing much less oxygen. This mechanism explains not only the effects of on-line catalyst addition, but also the increase in ethylene selectivity observed upon addition of hydrogen to the reactant mixture.

D. K. Zerkle; M. d. Allendorf; M. Wolf; O. Deutschmann

2000-07-30T23:59:59.000Z

372

Composite catalyst for carbon monoxide and hydrocarbon oxidation  

DOE Patents [OSTI]

A method and composition for the complete oxidation of carbon monoxide and/or hydrocarbon compounds. The method involves reacting the carbon monoxide and/or hydrocarbons with an oxidizing agent in the presence of a metal oxide composite catalyst. The catalyst is prepared by combining fluorite-type oxygen ion conductors with active transition metals. The fluorite oxide, selected from the group consisting of cerium oxide, zirconium oxide, thorium oxide, hafnium oxide, and uranium oxide, and may be doped by alkaline earth and rare earth oxides. The transition metals, selected from the group consisting of molybdnum, copper, cobalt, maganese, nickel, and silver, are used as additives. The atomic ratio of transition metal to fluorite oxide is less than one.

Liu, Wei (Cambridge, MA); Flytzani-Stephanopoulos, Maria (Winchester, MA)

1996-01-01T23:59:59.000Z

373

Composite catalyst for carbon monoxide and hydrocarbon oxidation  

DOE Patents [OSTI]

A method and composition are disclosed for the complete oxidation of carbon monoxide and/or hydrocarbon compounds. The method involves reacting the carbon monoxide and/or hydrocarbons with an oxidizing agent in the presence of a metal oxide composite catalyst. The catalyst is prepared by combining fluorite-type oxygen ion conductors with active transition metals. The fluorite oxide, selected from the group consisting of cerium oxide, zirconium oxide, thorium oxide, hafnium oxide, and uranium oxide, and may be doped by alkaline earth and rare earth oxides. The transition metals, selected from the group consisting of molybdenum, copper, cobalt, manganese, nickel, and silver, are used as additives. The atomic ratio of transition metal to fluorite oxide is less than one.

Liu, W.; Flytzani-Stephanopoulos, M.

1996-03-19T23:59:59.000Z

374

Molybdenum sulfide/carbide catalysts  

DOE Patents [OSTI]

The present invention provides methods of synthesizing molybdenum disulfide (MoS.sub.2) and carbon-containing molybdenum disulfide (MoS.sub.2-xC.sub.x) catalysts that exhibit improved catalytic activity for hydrotreating reactions involving hydrodesulfurization, hydrodenitrogenation, and hydrogenation. The present invention also concerns the resulting catalysts. Furthermore, the invention concerns the promotion of these catalysts with Co, Ni, Fe, and/or Ru sulfides to create catalysts with greater activity, for hydrotreating reactions, than conventional catalysts such as cobalt molybdate on alumina support.

Alonso, Gabriel (Chihuahua, MX); Chianelli, Russell R. (El Paso, TX); Fuentes, Sergio (Ensenada, MX); Torres, Brenda (El Paso, TX)

2007-05-29T23:59:59.000Z

375

DEVELOPMENT OF A NOVEL CATALYST FOR NO DECOMPOSITION  

SciTech Connect (OSTI)

Air pollution arising from the emission of nitrogen oxides as a result of combustion taking place in boilers, furnaces and engines, has increasingly been recognized as a problem. New methods to remove NO{sub x} emissions significantly and economically must be developed. The current technology for post-combustion removal of NO is the selective catalytic reduction (SCR) of NO by ammonia or possibly by a hydrocarbon such as methane. The catalytic decomposition of NO to give N{sub 2} will be preferable to the SCR process because it will eliminate the costs and operating problems associated with the use of an external reducing species. The most promising decomposition catalysts are transition metal (especially copper)-exchanged zeolites, perovskites, and noble metals supported on metal oxides such as alumina, silica, and ceria. The main shortcoming of the noble metal reducible oxide (NMRO) catalysts is that they are prone to deactivation by oxygen. It has been reported that catalysts containing tin oxide show oxygen adsorption behavior that may involve hydroxyl groups attached to the tin oxide. This is different than that observed with other noble metal-metal oxide combinations, which have the oxygen adsorbing on the noble metal and subsequently spilling over to the metal oxide. This observation leads one to believe that the Pt/SnO{sub 2} catalysts may have a potential as NO decomposition catalysts in the presence of oxygen. This prediction is also supported by some preliminary data obtained for NO decomposition on a Pt/SnO{sub 2} catalyst in the PI's laboratory. The main objective of the proposed research is the evaluation of the Pt/SnO{sub 2} catalysts for the decomposition of NO in simulated power plant stack gases with particular attention to the resistance to deactivation by O{sub 2}, CO{sub 2}, and elevated temperatures. Therefore, it is proposed to perform temperature programmed desorption (TPD) and temperature programmed reaction (TPRx) studies on Pt/SnO{sub 2} catalysts having different noble metal concentrations and pretreated under different conditions. It is also proposed to perform NO decomposition tests in a laboratory-size packed-bed reactor to obtain long-term deactivation data. In the previous reporting period the GC-MS system was calibrated and the TPD runs for the 15% Pt/SnO{sub 2} catalyst after treatment with NO and subsequent treatments with NO and O{sub 2} were done. For these runs the catalyst was pretreated with dry helium for 2 hours at 40 C. In the current reporting period The Temperature Programmed Reaction (TPRx) of NO and NO+O{sub 2} mixtures on the catalysts containing 15% Pt and 10% Pt were completed.

Ates Akyurtlu; Jale F. Akyurtlu

2004-10-22T23:59:59.000Z

376

Accelerated deployment of nanostructured hydrotreating catalysts. Final CRADA Report.  

SciTech Connect (OSTI)

Nanomanufacturing offers an opportunity to create domestic jobs and facilitate economic growth. In response to this need, U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy issued a Research Call to develop nanomanufacturing capabilities at the National Laboratories. High performance catalysts represent a unique opportunity to deploy nanomanufacturing technologies. Re-refining of used lube oil offers an opportunity to create manufacturing jobs and decrease dependence on imported petroleum. Improved catalysts are required to produce a better quality product, decrease environmental impact, extend catalyst life, and improve overall economics of lube oil re-refining. Argonne National Laboratory (Argonne) in cooperation with Universal Lubricants, Inc. (ULI) and Chemical Engineering Partners (CEP) have carried out a Cooperative Research and Development Agreement (CRADA) to prepare nanostructured hydrotreating catalysts using atomic layer deposition (ALD) to exhibit superior performance for the re-refining of used lube oil. We investigated the upgrading of recycled lube oil by hydrogenation using commercial, synthetically-modified commercial catalysts, and synthesized catalysts. A down-flow (trickle bed) catalytic unit was used for the hydrogenation experiments. In addition to carrying out elemental analyses of the various feed and product fractions, characterization was undertaken using H{sup 1} and C{sup 13} NMR. Initially commercial were evaluated. Second these commercial catalysts were promoted with precious metals using atomic layer deposition (ALD). Performance improvements were observed that declined with catalyst aging. An alternate approach was undertaken to deeply upgrade ULI product oils. Using a synthesized catalyst, much lower hydrogenation temperatures were required than commercial catalysts. Other performance improvements were also observed. The resulting lube oil fractions were of high purity even at low reaction severity. The products recovered from both the ALD and other processes were water-white (even those from the low temperature, low residence time (high space velocity), low conversion runs). These results indicate that highly upgraded recycle lube oils can be produced using ALD-deposited active metal catalysts. The use of H{sup 1} and C{sup 13} NMR for the characterization of the treated lube oils has been shown to be effective.

Libera, J.A.; Snyder, S.W.; Mane, A.; Elam, J.W.; Cronauer, D.C.; Muntean, J.A.; Wu, T.; Miller, J.T. (Chemical Sciences and Engineering Division); ( ES)

2012-08-27T23:59:59.000Z

377

Review of Novel Catalysts for Biomass Tar Cracking and Methane Reforming  

SciTech Connect (OSTI)

A review of the literature was conducted to examine the performance of catalysts other than conventional nickel catalysts, and alkaline earth and olivine based catalysts for treating hot raw product gas from a biomass gasifier to convert methane and tars into synthesis gas. Metal catalysts other than Ni included precious metals Rh, Ru, Ir, Pt, and Pd, as well as Cu, Co, and Fe in limited testing. Nickel catalysts promoted with Rh, Zr, Mn, Mo, Ti, Ag, or Sn were also examined, as were Ni catalysts on Ce2O3, TiO2, ZrO2, SiO2, and La2O3. In general, Rh stood out as a consistently superior metal catalyst for methane reforming, tar cracking, and minimizing carbon buildup on the catalyst. Ru and Ir also showed significant improvement over Ni for methane reforming. Ceria stood out as good support material and particularly good promoter material when added in small quantities to another support material such as alumina, zirconia, or olivine. Other promising supports were lanthana, zirconia, and titania.

Gerber, Mark A.

2007-10-10T23:59:59.000Z

378

The morphology of electroless Ni deposition on a colloidal Pd(II) catalyst  

SciTech Connect (OSTI)

The surface morphology of a surface-bound colloidal Pd(II) catalyst and its effect on the particle sizes with the largest particles reaching approximately 50 nm in diameter. Catalyst surface coverages as low as 20% are found to be sufficient to initiate complete and homogeneous metallization. The distribution of particle sizes for the electroless metal deposit, found to be a function of plating time, is broad with the maximum Ni particle size exceeding 120 nm. Results indicate controlling the size of the bound catalyst is the principal determining factor in controlling the particle size of the electroless deposit. Modification of the surface by depleting the concentration of surface functional groups capable of binding catalyst is used to shift the size distribution of bound catalyst to smaller values. A resulting three-to fourfold reduction in the particle size of the electroless deposit is demonstrated.

Brandow, S.L.; Dressick, W.J.; Marrian, C.R.K.; Chow, G.M.; Calvert, J.M. [Naval Research Laboratory, Washington, DC (United States)

1995-07-01T23:59:59.000Z

379

Optimization of Rhodium-Based Catalysts for Mixed Alcohol Synthesis -- 2011 Progress Report  

SciTech Connect (OSTI)

Pacific Northwest National Laboratory has been conducting research to investigate the feasibility of producing mixed alcohols from biomass-derived synthesis gas (syngas). In recent years, this research has primarily involved the further development of catalysts containing rhodium and manganese based on the results of earlier catalyst screening tests. Research during FY 2011 continued to examine the performance of RhMn catalysts on alternative supports including selected zeolite, silica, and carbon supports. Catalyst optimization continued using both the Davisil 645 and Merck Grade 7734 silica supports. Research also was initiated in FY 2011, using the both Davisil 645 silica and Hyperion CS-02C-063 carbon supports, to evaluate the potential for further improving catalyst performance, through the addition of one or two additional metals as promoters to the catalysts containing Rh, Mn, and Ir.

Gerber, Mark A.; Gray, Michel J.; Albrecht, Karl O.; Rummel, Becky L.

2011-10-01T23:59:59.000Z

380

Nanolithographic Fabrication and Heterogeneous Reaction Studies of Two-Dimensional Platinum Model Catalyst Systems  

E-Print Network [OSTI]

2.25 Schematic of the hydraulic press built for nanoimprint52 Picture of the hydraulic press used for nanoimprintis then put into a hydraulic press which was built in our

Contreras, A.M.

2006-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "metal catalysts platinum" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Effects on Hydrogen Adsorption and Activation on Platinum in a Fuel Cell Catalyst.  

E-Print Network [OSTI]

??Proton exchange membrane fuel cells are a highly efficient source of power generation that is needed to sustain the energy demands of today's more environmentally… (more)

Zhang, Jack

2011-01-01T23:59:59.000Z

382

Development of Ultra-low Platinum Alloy Cathode Catalyst for PEM Fuel Cells  

Energy Savers [EERE]

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Office of Inspector General Office of Audit Services AuditTransatlantic RelationsDepartmentJon T. Carter,NOTand||

383

Modeling Low-Platinum-Loading Effects in Fuel-Cell Catalyst Layers  

E-Print Network [OSTI]

Energy, Office of Hydrogen, Fuel Cell, and Infrastructureof fuel cell reaction with respect to hydrogen referencefuel-cell conditions and CL structures, the ORR oxygen reaction order is around 0.8 (referenced to an imaginary hydrogen

Yoon, Wonseok

2013-01-01T23:59:59.000Z

384

Initiation of electroless nickel plating on copper, palladium-activated copper, gold, and platinum  

SciTech Connect (OSTI)

The catalytic activity of copper, palladium-activated copper, gold, and platinum for electro-oxidation of hypophosphite and electroless nickel plating was investigated in an ammoniacal solution of pH 8.8 at 50/sup 0/C by potential measurements and linear sweep voltammetry from -0.3 to -0.92V vs. SCE. Early stages of nickel plating on copper-palladium substrates were studied by scanning electron microscopy in conjunction with EDAX. It was found that palladium-activated copper and gold were catalytically active in the entire range of potentials examined; copper was active below -0.6 platinum was not active at all. Small amounts of electrolytically deposited nickel considerably increased the electro-oxidation rate of hypophosphite on copper, gold, and palladium. TEM examinations showed that activation of copper in a PdCl/sub 2//HCl solution resulted in the deposition of palladium in the form of separate patches. Electroless nickel deposition on copper substrates with separate palladium spots took place on copper and palladium independently of each other. The deposition on palladium was faster than that on copper. It was concluded that the activation of copper substrates around palladium spots occurred solely through a spontaneous potential shift, induced by electro-oxidation of hypophosphite on the palladium spots. It was suggested that small amounts of one metal synergistically enhanced the catalytic activity of the other metals.

Flis, J.; Duquette, D.J.

1984-02-01T23:59:59.000Z

385

Platinum dendritic nanoparticles with magnetic behavior  

SciTech Connect (OSTI)

Magnetic nanoparticles have attracted increasing attention for biomedical applications in magnetic resonance imaging, high frequency magnetic field hyperthermia therapies, and magnetic-field-gradient-targeted drug delivery. In this study, three-dimensional (3D) platinum nanostructures with large surface area that features magnetic behavior have been demonstrated. The well-developed 3D nanodendrites consist of plentiful interconnected nano-arms ?4?nm in size. The magnetic behavior of the 3D dendritic Pt nanoparticles is contributed by the localization of surface electrons due to strongly bonded oxygen/Pluronic F127 and the local magnetic moment induced by oxygen vacancies on the neighboring Pt and O atoms. The magnetization of the nanoparticles exhibits a mixed paramagnetic and ferromagnetic state, originating from the core and surface, respectively. The 3D nanodendrite structure is suitable for surface modification and high amounts of drug loading if the transition temperature was enhanced to room temperature properly.

Li, Wenxian, E-mail: wl240@uowmail.edu.au [Institute for Superconducting and Electronic Materials, University of Wollongong, NSW 2522 (Australia); Solar Energy Technologies, School of Computing, Engineering, and Mathematics, University of Western Sydney, Penrith NSW 2751 (Australia); Sun, Ziqi; Nevirkovets, Ivan P.; Dou, Shi-Xue [Institute for Superconducting and Electronic Materials, University of Wollongong, NSW 2522 (Australia); Tian, Dongliang [Key Laboratory of Bio-Inspired Smart Interfacial Science and Technology of the Ministry of Education, School of Chemistry and the Environment, Beihang University, Beijing 100191 (China)

2014-07-21T23:59:59.000Z

386

Integrated process and dual-function catalyst for olefin epoxidation  

DOE Patents [OSTI]

The invention discloses a dual-functional catalyst composition and an integrated process for production of olefin epoxides including propylene oxide by catalytic reaction of hydrogen peroxide from hydrogen and oxygen with olefin feeds such as propylene. The epoxides and hydrogen peroxide are preferably produced simultaneously in situ. The dual-functional catalyst comprises noble metal crystallites with dimensions on the nanometer scale (on the order of <1 nm to 10 nm), specially dispersed on titanium silicalite substrate particles. The dual functional catalyst catalyzes both the direct reaction of hydrogen and oxygen to generate hydrogen peroxide intermediate on the noble metal catalyst surface and the reaction of the hydrogen peroxide intermediate with the propylene feed to generate propylene oxide product. Combining both these functions in a single catalyst provides a very efficient integrated process operable below the flammability limits of hydrogen and highly selective for the production of hydrogen peroxide to produce olefin oxides such as propylene oxide without formation of undesired co-products.

Zhou, Bing (Cranbury, NJ); Rueter, Michael (Plymouth Meeting, PA)

2003-01-01T23:59:59.000Z

387

Catalyst for elemental sulfur recovery process  

DOE Patents [OSTI]

A catalytic reduction process is described for the direct recovery of elemental sulfur from various SO[sub 2]-containing industrial gas streams. The catalytic process provides high activity and selectivity, as well as stability in the reaction atmosphere, for the reduction of SO[sub 2] to elemental sulfur product with carbon monoxide or other reducing gases. The reaction of sulfur dioxide and reducing gas takes place over a metal oxide composite catalyst having one of the following empirical formulas: [(FO[sub 2])[sub 1[minus]n](RO)[sub n

Flytzani-Stephanopoulos, M.; Liu, W.

1995-01-24T23:59:59.000Z

388

Fernald Preserve Visitors Center Grand Opening and LEED Platinum...  

Energy Savers [EERE]

energy future. I am proud to announce today, on behalf of the Department, that the U.S. Green Building Council has awarded the Fernald Preserve Visitors Center platinum level...

389

Synthesis, Characterization, and Cytotoxicity of Platinum(IV) Carbamate Complexes  

E-Print Network [OSTI]

The synthesis, characterization, and cytotoxicity of eight new platinum(IV) complexes having the general formula cis,cis,trans-[Pt(NH[subscript 3)[subscript 2]Cl[subscript 2](O[subscript 2]CNHR)[subscript 2

Wilson, Justin Jeff

390

Cellular responses against DNA damaged by platinum anticancer drugs  

E-Print Network [OSTI]

The anticancer activity of platinum-based drugs such as cisplatin, carboplatin, and oxaliplatin is mediated by their ability to attack DNA such that generated adducts trigger numerous cellular responses. A better understanding ...

Jung, Yongwon, 1977-

2005-01-01T23:59:59.000Z

391

Fluorination process using catalysts  

DOE Patents [OSTI]

A process is given for converting an actinide compound selected from the group consisting of uranium oxides, plutonium oxides, uranium tetrafluorides, plutonium tetrafluorides and mixtures of said oxides and tetrafluorides, to the corresponding volatile actinide hexafluoride by fluorination with a stoichiometric excess of fluorine gas. The improvement involves conducting the fluorination of the plutonium compounds in the presence of a fluoride catalyst selected from the group consisting of CoF/sub 3/, AgF/sub 2/ and NiF/sub 2/, whereby the fluorination is significantly enhanced. The improvement also involves conducting the fluorination of one of the uranium compounds in the presence of a fluoride catalyst selected from the group consisting of CoF/sub 3/ and AgF/sub 2/, whereby the fluorination is significantly enhanced.

Hochel, R.C.; Saturday, K.A.

1983-08-25T23:59:59.000Z

392

Fluorination process using catalyst  

DOE Patents [OSTI]

A process for converting an actinide compound selected from the group consisting of uranium oxides, plutonium oxides, uranium tetrafluorides, plutonium tetrafluorides and mixtures of said oxides and tetrafluorides, to the corresponding volatile actinide hexafluoride by fluorination with a stoichiometric excess of fluorine gas. The improvement involves conducting the fluorination of the plutonium compounds in the presence of a fluoride catalyst selected from the group consisting of CoF.sub.3, AgF.sub.2 and NiF.sub.2, whereby the fluorination is significantly enhanced. The improvement also involves conducting the fluorination of one of the uranium compounds in the presence of a fluoride catalyst selected from the group consisting of CoF.sub.3 and AgF.sub.2, whereby the fluorination is significantly enhanced.

Hochel, Robert C. (Aiken, SC); Saturday, Kathy A. (Aiken, SC)

1985-01-01T23:59:59.000Z

393

Binary ferrihydrite catalysts  

DOE Patents [OSTI]

A method of preparing a catalyst precursor comprises dissolving an iron salt and a salt of an oxoanion forming agent, in water so that a solution of the iron salt and oxoanion forming agent salt has a ratio of oxoanion/Fe of between 0.0001:1 to 0.5:1. Next is increasing the pH of the solution to 10 by adding a strong base followed by collecting of precipitate having a binary ferrihydrite structure. A binary ferrihydrite catalyst precursor is also prepared by dissolving an iron salt in water. The solution is brought to a pH of substantially 10 to obtain ferrihydrite precipitate. The precipitate is then filtered and washed with distilled water and subsequently admixed with a hydroxy carboxylic acid solution. The admixture is mixed/agitated and the binary ferrihydrite precipitate is then filtered and recovered. 3 figs.

Huffman, G.P.; Zhao, J.; Feng, Z.

1996-12-03T23:59:59.000Z

394

Binary ferrihydrite catalysts  

DOE Patents [OSTI]

A method of preparing a catalyst precursor comprises dissolving an iron salt and a salt of an oxoanion forming agent, in water so that a solution of the iron salt and oxoanion forming agent salt has a ratio of oxoanion/Fe of between 0.0001:1 to 0.5:1. Next is increasing the pH of the solution to 10 by adding a strong base followed by collecting of precipitate having a binary ferrihydrite structure. A binary ferrihydrite catalyst precursor is also prepared by dissolving an iron salt in water. The solution is brought to a pH of substantially 10 to obtain ferrihydrite precipitate. The precipitate is then filtered and washed with distilled water and subsequently admixed with a hydroxy carboxylic acid solution. The admixture is mixed/agitated and the binary ferrihydrite precipitate is then filtered and recovered.

Huffman, Gerald P. (Lexington, KY); Zhao, Jianmin (Lexington, KY); Feng, Zhen (Lexington, KY)

1996-01-01T23:59:59.000Z

395

Chemical solution deposition of ferroelectric yttrium-doped hafnium oxide films on platinum electrodes  

SciTech Connect (OSTI)

Ferroelectric hafnium oxide films were fabricated by chemical solution deposition with a remnant polarization of >13 ?C/cm{sup 2}. The samples were prepared with 5.2?mol.?% yttrium-doping and the thickness varied from 18?nm to 70?nm. The hafnium oxide layer was integrated into a metal-insulator-metal capacitor using platinum electrodes. Due to the processing procedure, no thickness dependence of the ferroelectric properties was observed. To confirm the ferroelectric nature of the deposited samples, polarization, capacitance, and piezoelectric displacement measurements were performed. However, no evidence of the orthorhombic phase was found which has been proposed to be the non-centrosymmetric, ferroelectric phase in HfO{sub 2}.

Starschich, S.; Griesche, D.; Schneller, T.; Böttger, U. [Institut für Werkstoffe der Elektrotechnik 2, RWTH Aachen University, Sommerfeldstraße 24, D-52074 Aachen (Germany); Waser, R. [Institut für Werkstoffe der Elektrotechnik 2, RWTH Aachen University, Sommerfeldstraße 24, D-52074 Aachen (Germany); Peter Grünberg Institut 7, Forschungszentrum Jülich GmbH, D-52425 Jülich (Germany)

2014-05-19T23:59:59.000Z

396

Platinum-Based Electrocatalysts Synthesized by Depositing a Contiguous...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

inventive catalysts. Applications and Industries Supercapacitors, batteries, fuel cells; oxygen-reduction; heterogeneous catalysis Technology Status Technology ID Development...

397

Synthesis of Metal-Metal Oxide Catalysts and Electrocatalysts - Energy  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security AdministrationcontrollerNanocrystallineForeign Object Damage 3 B.

398

Cobalt-ruthenium catalysts for Fischer-Tropsch synthesis  

SciTech Connect (OSTI)

A hydrocarbon synthesis process is described which comprises reacting hydrogen and carbon monoxide in the presence of a catalyst comprised of cobalt and ruthenium on titania, at reaction conditions suitable for the formation of higher hydrocarbons. The catalyst is prepared by impregnating titania with solutions of cobalt and ruthenium salts, drying the impregnated support, reducing the cobalt and ruthenium, treating the reduced metals with an oxygen containing stream at conditions sufficient to form oxides of cobalt and oxides of ruthenium and reducing the cobalt and ruthenium oxides.

Iglesia, E.; Soled, S.L.; Fiato, R.A.

1989-04-18T23:59:59.000Z

399

Catalyst systems and uses thereof  

DOE Patents [OSTI]

A method of carbon monoxide (CO) removal comprises providing an oxidation catalyst comprising cobalt supported on an inorganic oxide. The method further comprises feeding a gaseous stream comprising CO, and oxygen (O.sub.2) to the catalyst system, and removing CO from the gaseous stream by oxidizing the CO to carbon dioxide (CO.sub.2) in the presence of the oxidation catalyst at a temperature between about 20 to about 200.degree. C.

Ozkan, Umit S. (Worthington, OH); Holmgreen, Erik M. (Columbus, OH); Yung, Matthew M. (Columbus, OH)

2012-07-24T23:59:59.000Z

400

Performance and cost of automotive fuel cell systems with ultra-low platinum loadings.  

SciTech Connect (OSTI)

An automotive polymer-electrolyte fuel cell (PEFC) system with ultra-low platinum loading (0.15 mg-Pt cm{sup -2}) has been analyzed to determine the relationship between its design-point efficiency and the system efficiency at part loads, efficiency over drive cycles, stack and system costs, and heat rejection. The membrane electrode assemblies in the reference PEFC stack use nanostructured, thin-film ternary catalysts supported on organic whiskers and a modified perfluorosulfonic acid membrane. The analyses show that the stack Pt content can be reduced by 50% and the projected high-volume manufacturing cost by >45% for the stack and by 25% for the system, if the design-point system efficiency is lowered from 50% to 40%. The resulting penalties in performance are a <1% reduction in the system peak efficiency; a 2-4% decrease in the system efficiency on the urban, highway, and LA92 drive cycles; and a 6.3% decrease in the fuel economy of the modeled hybrid fuel-cell vehicle on the combined cycle used by EPA for emission and fuel economy certification. The stack heat load, however, increases by 50% at full power (80 kW{sub e}) but by only 23% at the continuous power (61.5 kW{sub e}) needed to propel the vehicle on a 6.5% grade at 55 mph. The reduced platinum and system cost advantages of further lowering the design-point efficiency from 40% to 35% are marginal. The analyses indicate that thermal management in the lower efficiency systems is very challenging and that the radiator becomes bulky if the stack temperature cannot be allowed to increase to 90-95 C under driving conditions where heat rejection is difficult.

Ahluwalia, R.; Wang, X.; Kwon, K.; Rousseau, A.; Kalinoski, J.; James, B.; Marcinkoski, J. (Energy Systems); ( NE); (Directed Technologies Inc.); (ED)

2011-05-15T23:59:59.000Z

Note: This page contains sample records for the topic "metal catalysts platinum" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Electrochemical and Antimicrobial Properties of Diamondlike Carbon-Metal Composite Films  

SciTech Connect (OSTI)

Implants containing antimicrobial metals may reduce morbidity, mortality, and healthcare costs associated with medical device-related infections. We have deposited diamondlike carbon-silver (DLC-Ag), diamondlike carbon-platinum (DLC-Pt), and diamondlike carbon-silver-platinum (DLC-AgPt) thin films using a multicomponent target pulsed laser deposition process. Transmission electron microscopy of the DLC-silver and DLC-platinum composite films revealed that the silver and platinum self-assemble into nanoparticle arrays within the diamondlike carbon matrix. The diamondlike carbon-silver film possesses hardness and Young's modulus values of 37 GPa and 331 GPa, respectively. The diamondlike carbon-metal composite films exhibited passive behavior at open-circuit potentials. Low corrosion rates were observed during testing in a phosphate-buffered saline (PBS) electrolyte. In addition, the diamondlike carbon-metal composite films were found to be immune to localized corrosion below 1000 mV (SCE). DLC-silver-platinum films demonstrated exceptional antimicrobial properties against Staphylococcus bacteria. It is believed that a galvanic couple forms between platinum and silver, which accelerates silver ion release and provides more robust antimicrobial activity. Diamondlike carbon-silver-platinum films may provide unique biological functionalities and improved lifetimes for cardiovascular, orthopaedic, biosensor, and implantable microelectromechanical systems.

MORRISON, M. L.; BUCHANAN, R. A.; LIAW, P. K.; BERRY, C. J.; BRIGMON, R.; RIESTER, L.; JIN, C.; NARAYAN, R. J.

2005-05-11T23:59:59.000Z

402

Mixed Alcohol Synthesis Catalyst Screening  

SciTech Connect (OSTI)

National Renewable Energy Laboratory (NREL) and Pacific Northwest National Laboratory (PNNL) are conducting research to investigate the feasibility of producing mixed alcohols from biomass-derived synthesis gas (syngas). PNNL is tasked with obtaining commercially available or preparing promising mixed-alcohol catalysts and screening them in a laboratory-scale reactor system. Commercially available catalysts and the most promising experimental catalysts are provided to NREL for testing using a slipstream from a pilot-scale biomass gasifier. From the standpoint of producing C2+ alcohols as the major product, it appears that the rhodium catalyst is the best choice in terms of both selectivity and space-time yield (STY). However, unless the rhodium catalyst can be improved to provide minimally acceptable STYs for commercial operation, mixed alcohol synthesis will involve significant production of other liquid coproducts. The modified Fischer-Tropsch catalyst shows the most promise for providing both an acceptable selectivity to C2+ alcohols and total liquid STY. However, further optimization of the Fischer-Tropsch catalysts to improve selectivity to higher alcohols is highly desired. Selection of a preferred catalyst will likely entail a decision on the preferred coproduct slate. No other catalysts tested appear amenable to the significant improvements needed for acceptable STYs.

Gerber, Mark A.; White, James F.; Stevens, Don J.

2007-09-03T23:59:59.000Z

403

Low-cost and durable catalyst support for fuel cells: graphite submicronparticles  

SciTech Connect (OSTI)

Low-cost graphite submicronparticles (GSP) are employed as a possible catalyst support for polymer electrolyte membrane (PEM) fuel cells. Platinum nanoparticles are deposited on Vulcan XC-72 carbon black (XC-72), carbon nanotubes (CNT), and GSP via ethylene glycol (EG) reduction method. The morphologies and the crystallinity of Pt/XC-72, Pt/CNT, and Pt/GSP are characterized with X-ray diffraction and transmission electron microscope, which shows that Pt nanoparticles (~ 3.5 nm) are uniformly dispersed on GSP support. Pt/GSP exhibits the highest activity towards oxygen reduction reactions. The durability study indicates that Pt/GSP is 2 ~ 3 times durable than Pt/CNT and Pt/XC-72. The enhanced durability of Pt/GSP catalyst is attributed to the higher corrosion resistance of graphite submicronparticles, which results from higher graphitization degree of GSP support. Considering its low production cost, graphite submicronparticles are promising electrocatalyst support for fuel cells.

Zhang, Sheng; Shao, Yuyan; Li, Xiaohong; Nie, Zimin; Wang, Yong; Liu, Jun; Yin, Geping; Lin, Yuehe

2010-01-01T23:59:59.000Z

404

Platinum- and platinum alloy-coated palladium and palladium alloy particles  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 - September 2006Photovoltaic Theory andVelocity ProfileStoragePlatinumPlatinumand

405

Hydrogen generation by visible light irradiation of ruthenium complexes and colloidal platinum stabilized by viologen polymers in aqueous solutions  

SciTech Connect (OSTI)

The hydrogen generation from water on the irradiation of visible light has recently attracted the attention of many investigators, because it affords one of the most promising approaches to chemical conversion of solar energy and production of renewable energy resources. In an attempt to construct efficient systems for chemical conversion of light energy, the present authors have found that photoinduced redox reactions in various molecular assemblies are very well suited for the purpose. Along this line, water-soluble polymers with pendant viologen groups and colloidal platinum have been prepared to study the electron transport properties and hydrogen generation in the polymer system. An attempt has also been made to synthesize polysoap-type viologen polymers in order to concentrate photosensitizer, electron mediator, and multielectron redox catalyst so that the hydrogen-generating efficiency is increased by the cooperation of the relevant species on the same polymer. The results are described.

Nishijima, T.; Nagamura, T.; Matsuo, T.

1981-02-01T23:59:59.000Z

406

Investigating the effects of proton exchange membrane fuel cell conditions on carbon supported platinum electrocatalyst composition and performance  

SciTech Connect (OSTI)

Changes that carbon-supported platinum electrocatalysts undergo in a proton exchange membrane fuel cell environment were simulated by ex situ heat treatment of catalyst powder samples at 150 C and 100% relative humidity. In order to study modifications that are introduced to chemistry, morphology, and performance of electrocatalysts, XPS, HREELS and three-electrode rotating disk electrode experiments were performed. Before heat treatment, graphitic content varied by 20% among samples with different types of carbon supports, with distinct differences between bulk and surface compositions within each sample. Following the aging protocol, the bulk and surface chemistry of the samples were similar, with graphite content increasing or remaining constant and Pt-carbide decreasing for all samples. From the correlation of changes in chemical composition and losses in performance of the electrocatalysts, we conclude that relative distribution of Pt particles on graphitic and amorphous carbon is as important for electrocatalytic activity as the absolute amount of graphitic carbon present

A. Patel; K. Artyushkova; P. Atanassov; V. Colbow; M. Dutta; D. Harvey; S. Wessel

2012-04-30T23:59:59.000Z

407

Investigating the effects of proton exchange membrane fuel cell conditions on carbon supported platinum electrocatalyst composition and performance  

SciTech Connect (OSTI)

Changes that carbon-supported platinum electrocatalysts undergo in a proton exchange membrane fuel cell environment were simulated by ex situ heat treatment of catalyst powder samples at 150 #2;C and 100% relative humidity. In order to study modifications that are introduced to chemistry, morphology, and performance of electrocatalysts, XPS, HREELS and three-electrode rotating disk electrode experiments were performed. Before heat treatment, graphitic content varied by 20% among samples with different types of carbon supports, with distinct differences between bulk and surface compositions within each sample. Following the aging protocol, the bulk and surface chemistry of the samples were similar, with graphite content increasing or remaining constant and Pt-carbide decreasing for all samples. From the correlation of changes in chemical composition and losses in performance of the electrocatalysts, we conclude that relative distribution of Pt particles on graphitic and amorphous carbon is as important for electrocatalytic activity as the absolute amount of graphitic carbon present

Patel, Anant; Artyushkova, Kateryna; Atanassov, Plamen; Colbow, Vesna; Dutta, Monica; Harvey, Davie; Wessel, Silvia

2012-04-01T23:59:59.000Z

408

Novel Reforming Catalysts  

SciTech Connect (OSTI)

Aqueous phase reforming is useful for processing oxygenated hydrocarbons to hydrogen and other more useful products. Current processing is hampered by the fact that oxide based catalysts are not stable under high temperature hydrothermal conditions. Silica in the form of structured MCM-41 is thermally a more stable support for Co and Ni than conventional high surface area amorphous silica but hydrothermal stability is not demonstrated. Carbon nanotube supports, in contrast, are highly stable under hydrothermal reaction conditions. In this project we show that carbon nanotubes are stable high activity/selectivity supports for the conversion of ethylene glycol to hydrogen.

Pfefferle, Lisa D; Haller, Gary L

2012-10-16T23:59:59.000Z

409

Molecular water oxidation catalyst  

DOE Patents [OSTI]

A dimeric composition of the formula: ##STR1## wherein L', L", L'", and L"" are each a bidentate ligand having at least one functional substituent, the ligand selected from bipyridine, phenanthroline, 2-phenylpyridine, bipyrimidine, and bipyrazyl and the functional substituent selected from carboxylic acid, ester, amide, halogenide, anhydride, acyl ketone, alkyl ketone, acid chloride, sulfonic acid, phosphonic acid, and nitro and nitroso groups. An electrochemical oxidation process for the production of the above functionally substituted bidentate ligand diaqua oxo-bridged ruthenium dimers and their use as water oxidation catalysts is described.

Gratzel, Michael (St. Sulpice, CH); Munavalli, Shekhar (Bel Air, MD); Pern, Fu-Jann (Lakewood, CO); Frank, Arthur J. (Lakewood, CO)

1993-01-01T23:59:59.000Z

410

Nanoengineering Catalyst Supports via Layer-by Layer Surface Functionalization  

SciTech Connect (OSTI)

Recent progress in the layer-by-layer surface modification of oxides for the preparation of highly active and stable gold nanocatalysts is briefly reviewed. Through a layer-by-layer surface modification approach, the surfaces of various catalyst supports including both porous and nonporous silica materials and TiO{sub 2} nanoparticles were modified with monolayers or multilayers of distinct metal oxide ultra-thin films. The surface-modified materials were used as supports for Au nanoparticles, resulting in highly active nanocatalysts for low-temperature CO oxidation. Good stability against sintering under high-temperature treatment was achieved for a number of the Au catalysts through surface modification of the support material. The surface modification of supports can be a viable route to control both the composition and structure of support and nanoparticle interfaces, thereby tailoring the stability and activity of the supported catalyst systems.

Yan, Wenfu [ORNL; Mahurin, Shannon Mark [ORNL; Overbury, Steven {Steve} H [ORNL; Dai, Sheng [ORNL

2006-01-01T23:59:59.000Z

411

Focussing the view on Nature's water-splitting catalyst  

SciTech Connect (OSTI)

About 3 billion years ago Nature invented a catalyst that splits water with highefficiency into molecular oxygen and hydrogen equivalents (protons and electrons). This reaction is energetically driven by sun light and the active centre contains relatively cheap and abundant metals: manganese and calcium. This biological system therefore forms the paradigm for all man made attempts for direct solar fuel production and several studies are underway to determine the electronic and geometric structures of this catalyst. In this report we briefly summarize the problems and the current status of these efforts, and propose a DFT-based strategy for obtaining a reliable high resolution structure of this unique catalyst that includes both the inorganic core and the first ligand sphere.

Messinger, Johannes; Yano, Junko

2008-01-01T23:59:59.000Z

412

Method for dispersing catalyst onto particulate material and product thereof  

DOE Patents [OSTI]

A method for dispersing finely divided catalyst precursors onto the surface of coal or other particulate material includes the steps of forming a wet paste mixture of the particulate material and a liquid solution containing a dissolved transition metal salt, for instance a solution of ferric nitrate. The wet paste mixture is in a state of incipient wetness with all of this solution adsorbed onto the surfaces of the particulate material without the presence of free moisture. On adding a precipitating agent such as ammonia, a catalyst precursor such as hydrated iron oxide is deposited on the surfaces of the coal. The catalyst is activated by converting it to the sulfide form for the hydrogenation or direct liquefaction of the coal.

Utz, Bruce R. (Pittsburgh, PA); Cugini, Anthony V. (Pittsburgh, PA)

1992-01-01T23:59:59.000Z

413

Materials - Efficient catalysts... | ornl.gov  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Materials - Efficient catalysts... Reduction of pollution from vehicles and power plants relies, in large part, on how effectively catalysts can oxidize nitric oxide (NO)....

414

Catalyst by Design - Theoretical, Nanostructural, and Experimental...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Treatment The overlap among theory, structure, and fully formed catalysts form the foundation of this study deer09narula.pdf More Documents & Publications Catalyst by Design -...

415

Co-Pt core-shell nanostructured catalyst prepared by selective chemical vapor pulse deposition of Pt on Co as a cathode in polymer electrolyte fuel cells  

SciTech Connect (OSTI)

A new type of PtCo/C catalyst for use as a cathode in polymer electrolyte fuel cells was prepared by selective chemical vapor pulse deposition (CVPD) of Pt on the surface of Co. The activity of the prepared catalyst for oxygen reduction was higher than that of a catalyst prepared by sequential impregnation (IMP) with the two metallic components. This catalytic activity difference occurs because the former catalyst has smaller Pt crystallites that produce stronger Pt-Co interactions and have a larger Pt surface area. Consequently, the CVPD catalyst has a great number of Co particles that are in close contact with the added Pt. The Pt surface was also electronically modified by interactions with Co, which were stronger in the CVPD catalyst than in the IMP catalyst, as indicated by X-ray diffraction, X-ray photoemission spectroscopy, and cyclic voltammetry measurements of the catalysts.

Seo, Sang-Joon; Chung, Ho-Kyoon [SKKU Advanced Institute of Nanotechnology (SAINT) and Center for Human Interface Nanotechnology (HINT), Sungkyunkwan University, Suwon, Gyeonggi 440-746 (Korea, Republic of); Yoo, Ji-Beom [SKKU Advanced Institute of Nanotechnology (SAINT) and Center for Human Interface Nanotechnology (HINT), Sungkyunkwan University, Suwon, Gyeonggi 440-746, Korea and School of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon, Gyeonggi 440-746 (Korea, Republic of); Chae, Heeyeop; Seo, Seung-Woo; Min Cho, Sung, E-mail: sungmcho@skku.edu [School of Chemical Engineering, Sungkyunkwan University, Suwon, Gyeonggi 440-746 (Korea, Republic of)

2014-01-15T23:59:59.000Z

416

Microemulsion impregnated catalyst composite and use thereof in a synthesis gas conversion process  

DOE Patents [OSTI]

A catalyst composition for synthesis gas conversion comprising a ruthenium metal component deposited on a support carrier wherein the average metal particle size is less than about 100 A. The method of manufacture of the composition via a reverse micelle impregnation technique and the use of the composition in a Fischer-Tropsch conversion process is also disclosed.

Abrevaya, Hayim (Chicago, IL); Targos, William M. (Palatine, IL)

1987-01-01T23:59:59.000Z

417

Microemulsion impregnated catalyst composite and use thereof in a synthesis gas conversion process  

DOE Patents [OSTI]

A catalyst composition is described for synthesis gas conversion comprising a ruthenium metal component deposited on a support carrier wherein the average metal particle size is less than about 100 A. The method of manufacture of the composition via a reverse micelle impregnation technique and the use of the composition in a Fischer-Tropsch conversion process is also disclosed.

Abrevaya, H.; Targos, W.M.

1987-12-22T23:59:59.000Z

418

Transcription Inhibition by Platinum DNA Cross-links in Live Mammalian Cells  

E-Print Network [OSTI]

We have investigated the processing of site-specific Pt?DNA cross-links in live mammalian cells to enhance our understanding of the mechanism of action of platinum-based anticancer drugs. The activity of platinum drugs ...

Ang, Wee Han

419

Non-traditional platinum compounds for improved cellular accumulation and tumor targeting  

E-Print Network [OSTI]

Chapter 1. Introduction to Non-Traditional Platinum Compounds for Improved Uptake, Oral Bioavailability, and Tumor Targeting The path to more potent platinum anticancer drugs with fewer side effects lies in the exploration ...

Lovejoy, Katherine Summer, 1981-

2009-01-01T23:59:59.000Z

420

Dramatically Improved Yields in Molecular Scale Electronic Devices Using Ultra-smooth Platinum Electrodes Prepared By  

E-Print Network [OSTI]

Dramatically Improved Yields in Molecular Scale Electronic Devices Using Ultra-smooth Platinum scale electronic devices by using ultra- smooth platinum (Pt) electrodes made with chemical mechanically Terms -- Molecular electronics, CMP, SAM, Langmuir-Blodgett, Device yields. I. INTRODUCTION Molecular

Islam, M. Saif

Note: This page contains sample records for the topic "metal catalysts platinum" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Schneider Electric Goes Platinum-and Silver-in Superior Energy...  

Broader source: Energy.gov (indexed) [DOE]

Schneider Electric Goes Platinum-and Silver-in Superior Energy Performance Schneider Electric Goes Platinum-and Silver-in Superior Energy Performance October 1, 2014 - 11:33am...

422

Hydrogen Oxidation and Evolution Reaction Kinetics on Platinum: Acid vs Alkaline Electrolytes  

E-Print Network [OSTI]

The kinetics of the hydrogen oxidation reaction (HOR) and hydrogen evolution reaction (HER) on polycrystalline platinum [Pt(pc)] and high surface area carbon-supported platinum nanoparticles (Pt/C) were studied in 0.1 M ...

Sheng, Wenchao

423

Experiments and Models Bearing on the Role of Chromite as a Collector of Platinum Group  

E-Print Network [OSTI]

Experiments and Models Bearing on the Role of Chromite as a Collector of Platinum Group Minerals PUBLICATION SEPTEMBER 6, 2008 Chromite is widely recognized to act as a collector for platinum group elements

Mcdonough, William F.

424

Tuning the Metal-Adsorbate Chemical Bond through the Ligand Effect...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

most active metal catalyst for many important reactions, including the reduction of oxygen in fuel cells. Figure 1. Figure 1. Schematic representation of Pt subsurface alloys...

425

Characterization of new Co and Ru on -WC catalysts for Fischer-Tropsch reaction. Influence of the carbide surface state.  

E-Print Network [OSTI]

of the metallic particles [8]. Among the group VI transition metal carbides, the hexagonal tungsten carbide WC monoxide and hydrogen. FT synthesis proceeds on supported transition metal catalysts, Co or Fe on oxide of the carbide surface state. A. Griboval-Constant(1) *, J.-M. Giraudon(1) , I. Twagishema(1) , G. Leclercq(1

Paris-Sud XI, Université de

426

Bifunctional Nanostructured Base Catalysts: Opportunities for BioFuels  

SciTech Connect (OSTI)

ABSTRACT This research studied and develop novel basic catalysts for production of renewable chemicals and fuels from biomass. We will focus on the development of unique porous structural-base catalysts formed by two techniques: from (mixed) metal-oxide bases and by nitrogen substitution for oxygen in zeolites. These catalysts will be compared to conventional solid base materials for aldol condensation, catalytic fast pyrolysis, and transesterification reactions. These reactions are important in processes that are currently being commercialized for production of fuels from biomass and will be pivotal in future biomass conversion to fuels and chemicals. Specifically, we have studied the aldol-condensation of acetone with furfural over oxides and zeolites, the conversion of sugars by rapid pyrolysis over zeolites and the trans-esterification of vegetable oil with methanol over mixed oxide catalysts. Our previous research has indicated that the base strength of framework nitrogen in nitrogen-substituted zeolites (NH-zeolites) is nearly twice as strong as in standard zeolites. Nitrogen substituted catalysts have been synthesized from several zeolites (including FAU, MFI, BEA, and LTL) using NH3 treatment.

Connor, William

2010-12-30T23:59:59.000Z

427

Non-Platinum Bimetallic Cathode Electrocatalysts  

E-Print Network [OSTI]

PGM in electrocatalyst particle core with base metal ­ C. Electrode performance: modifying surface to form surface "skins" Noble metals are the most stable in acidic environment ­ Pd Eo' for dissolution #12;Ir -4 -3.5 -3 -2.5 -2 -1.5 -1 -0.5 0 Pt PdRu -4 -3.5 -3 -2.5 -2 -1.5 -1 -0.5 0 The d-band centers

428

DEVELOPMENT OF IMPROVED CATALYSTS FOR THE SELECTIVE CATALYTIC REDUCTION OF NITROGEN OXIDES WITH HYDROCARBONS  

SciTech Connect (OSTI)

Significant work has been done by the investigators on the cerium oxide-copper oxide based sorbent/catalysts for the combined removal of sulfur and nitrogen oxides from the flue gases of stationary sources. Evaluation of these sorbents as catalysts for the selective reduction of NO{sub x} gave promising results with methane. Since the replacement of ammonia by methane is commercially very attractive, in this project, the effect of promoters on the activity and selectivity of copper oxide/cerium oxide-based catalysts and the reaction mechanism for the SCR with methane was investigated. Unpromoted and promoted catalysts were investigated for their SCR activity with methane in a microreactor setup and also, by the temperature-programmed desorption (TPD) technique. The results from the SCR experiments indicated that manganese is a more effective promoter than the other metals (Rh, Li, K, Na, Zn, and Sn) for the supported copper oxide-ceria catalysts under study. The effectiveness of the promoter increased with the increase in Ce/Cu ratio. Among the catalysts tested, the Cu1Ce3 catalyst promoted with 1 weight % Mn was found to be the best catalyst for the SCR of NO with methane. This catalyst was subjected to long-term testing at the facilities of our industrial partner TDA Research. TDA report indicated that the performance of this catalyst did not deteriorate during 100 hours of operation and the activity and selectivity of the catalyst was not affected by the presence of SO{sub 2}. The conversions obtained by TDA were significantly lower than those obtained at Hampton University due to the transport limitations on the reaction rate in the TDA reactor, in which 1/8th inch pellets were used while the Hampton University reactor contained 250-425-{micro}m catalyst particles. The selected catalyst was also tested at the TDA facilities with high-sulfur heavy oil as the reducing agent. Depending on the heavy oil flow rate, up to 100% NO conversions were obtained. The temperature programmed desorption studies a strong interaction between manganese and cerium. Presence of manganese not only enhanced the reduction rate of NO by methane, but also significantly improved the N{sub 2} selectivity. To increase the activity of the Mn-promoted catalyst, the manganese content of the catalyst need to be optimized and different methods of catalyst preparation and different reactor types need to be investigated to lower the transport limitations in the reactor.

Ates Akyurtlu; Jale F. Akyurtlu

2003-11-30T23:59:59.000Z

429

Heterogeneous catalyst for the production of ethylidene diacetate from acetic anhydride  

DOE Patents [OSTI]

This invention relates to a process for producing ethylidene diacetate by the reaction of acetic anhydride, acetic acid, hydrogen and carbon monoxide at elevated temperatures and pressures in the presence of an alkyl halide and a heterogeneous, bifunctional catalyst that is stable to hydrogenation and comprises an insoluble polymer having pendant quaternized heteroatoms, some of which heteroatoms are ionically bonded to anionic Group VIII metal complexes, the remainder of the heteroatoms being bonded to iodide. In contrast to prior art processes, no accelerator (promoter) is necessary to achieve the catalytic reaction and the products are easily separated from the catalyst by filtration. The catalyst can be recycled without loss in activity.

Ramprasad, Dorai (Allentown, PA); Waller, Francis Joseph (Allentown, PA)

1998-01-01T23:59:59.000Z

430

Heterogeneous catalyst for the production of ethylidene diacetate from acetic anhydride  

DOE Patents [OSTI]

This invention relates to a process for producing ethylidene diacetate by the reaction of acetic anhydride, acetic acid, hydrogen and carbon monoxide at elevated temperatures and pressures in the presence of an alkyl halide and a heterogeneous, bifunctional catalyst that is stable to hydrogenation and comprises an insoluble polymer having pendant quaternized heteroatoms, some of which heteroatoms are ionically bonded to anionic Group VIII metal complexes, the remainder of the heteroatoms being bonded to iodide. In contrast to prior art processes, no accelerator (promoter) is necessary to achieve the catalytic reaction and the products are easily separated from the catalyst by filtration. The catalyst can be recycled without loss in activity.

Ramprasad, D.; Waller, F.J.

1998-06-16T23:59:59.000Z

431

Photobiomolecular metallic particles and films  

DOE Patents [OSTI]

The method of the invention is based on the unique electron-carrying function of a photocatalytic unit such as the photosynthesis system I (PSI) reaction center of the protein-chlorophyll complex isolated from chloroplasts. The method employs a photo-biomolecular metal deposition technique for precisely controlled nucleation and growth of metallic clusters/particles, e.g., platinum, palladium, and their alloys, etc., as well as for thin-film formation above the surface of a solid substrate. The photochemically mediated technique offers numerous advantages over traditional deposition methods including quantitative atom deposition control, high energy efficiency, and mild operating condition requirements.

Hu, Zhong-Cheng

2003-05-06T23:59:59.000Z

432

Effect of Surface Modification by Chelating Agents on Fischer- Tropsch Performance of Co/SiO{sub 2} Catalysts  

SciTech Connect (OSTI)

The silica support of a Co-based catalyst for Fischer-Tropsch (FT) synthesis was modified by the chelating agents (CAs) nitrilotriacetic acid (NTA) and ethylenediaminetetraacetic acid (EDTA). After the modification, characterization of the fresh and spent catalysts show reduced crystallite sizes, a better-dispersed Co{sub 3}O{sub 4} phase on the calcined samples, and increased metal dispersions for the reduced samples. The CA-modified catalysts display higher CO conversions, product yields, reaction rates and rate constants. The improved FT performance of CA-modified catalysts is attributed to the formation of stable complexes with Co. The superior performance of the EDTA-modified catalyst in comparison to the NTA-modified catalyst is due to the higher affinity of the former for complex formation with Co ions.

Bambal, Ashish S.; Kugler, Edwin L.; Gardner, Todd H.; Dadyburjor, Dady B.

2013-11-27T23:59:59.000Z

433

Shape-selective catalysts for Fischer-Tropsch chemistry : iron-containing particulate catalysts. Activity report : January 1, 2001 - December 31, 2004.  

SciTech Connect (OSTI)

Argonne National Laboratory is carrying out a research program to create, prepare, and evaluate catalysts to promote Fischer-Tropsch (FT) chemistry--specifically, the reaction of hydrogen with carbon monoxide to form long-chain hydrocarbons. In addition to needing high activity, it is desirable that the catalysts have high selectivity and stability with respect to both mechanical strength and aging properties. It is desired that selectivity be directed toward producing diesel fraction components and avoiding excess yields of both light hydrocarbons and heavy waxes. The goal is to produce shape-selective catalysts that have the potential to limit the formation of longchain products and yet retain the active metal sites in a protected 'cage'. This cage also restricts their loss by attrition during use in slurry-bed reactors. The first stage of this program was to prepare and evaluate iron-containing particulate catalysts. This activity report centers upon this first stage of experimentation with particulate FT catalysts. (For reference, a second experimental stage is under way to prepare and evaluate active FT catalysts formed by atomic-layer deposition [ALD] of active components on supported membranes.) To date, experimentation has centered upon the evaluation of a sample of iron-based, spray-dried catalyst prepared by B.H. Davis of the Center of Applied Energy Research (CAER) and samples of his catalyst onto which inorganic 'shells' were deposited. The reference CAER catalyst contained a high level of dispersed fine particles, a portion of which was removed by differential settling. Reaction conditions have been established using a FT laboratory unit such that reasonable levels of CO conversion can be achieved, where therefore a valid catalyst comparison can be made. A wide range of catalytic activities was observed with SiO{sub 2}-coated FT catalysts. Two techniques were used for SiO{sub 2}coating. The first involved a caustic precipitation of SiO{sub 2} from an organo-silicate onto the CAER catalyst. The second was the acidic precipitation of an organo-silicate with aging to form fractal particles that were then deposited onto the CAER catalyst. Several resulting FT catalysts were as active as the coarse catalyst on which they were prepared. The most active ones were those with the least amount of coating, namely about 2.2 wt% SiO{sub 2}. In the case of the latter acid technique, the use of HCl and HNO{sub 3} was much more effective than that of H{sub 2}SO{sub 4}. Scanning electron microscopy (SEM) was used to observe and analyze as-received and treated FT catalysts. It was observed that (1) spherical particles of CAER FT catalyst were made up of agglomerates of particles that were, in turn, also agglomerates; (2) the spray drying process of CAER apparently concentrated the Si precursor at the surface during drying; (3) while SEM pointed out broad differences in the appearance of the prepared catalyst particles, there was little indication that the catalysts were being uniformly coated with a cage-like protective surface, with perhaps the exception of HNO{sub 3}-precipitated catalyst; and (4) there was only a limited penetration of carbon (i.e., CO) into the FT catalyst during the conditioning and FT reaction steps.

Cronauer, D.; Chemical Engineering

2006-05-12T23:59:59.000Z

434

New hydrocracking catalysts increase throughput, run length  

SciTech Connect (OSTI)

An improved, second-stage hydrocracking catalyst has been developed by combining stabilized Y zeolites with amorphous silica alumina cracking components. A commercial application of this catalyst, along with a new, first-stage zeolitic hydrocracking catalyst, resulted in increased unit throughput and cycle length. The paper discusses the hydrocracking process, first-stage catalysts, second-stage catalysts, hydrogenation process, commercial results, and product properties.

Huizinga, T. [Shell Internationale Petroleum Mij., The Hague (Netherlands); Theunissen, J.M.H. [Rayong Refinery Co. Ltd., Rayong (Thailand); Minderhoud, H.; Veen, R. van [Koninklijke/Shell-Lab., Amsterdam (Netherlands)

1995-06-26T23:59:59.000Z

435

as Catalyst in Public Health  

E-Print Network [OSTI]

Crisis as Catalyst in Public Health Immigration Reform and the Threat of Rhetorical Violence look at immigration reform and the impact of public discourse focused on this topic. The panel

Bushman, Frederic

436

Catalyst-free carbon nanotubes from coal-based material  

SciTech Connect (OSTI)

DC-Arc Discharge technique has been used to synthesize carbon nanotubes from super clean coal samples instead of graphite electrodes filled with metal catalysts. The adverse effect of the mineral matter present in coal may be, thus, avoided. The cathode deposits showed the presence of single walled carbon nanotubes as well, which are generally known to be formed only in presence of transition metal catalysts and lanthanides. The process also avoids the tedious purification treatments of carbon nanotubes by strong acids to get rid of metal catalysts produced as impurities along with nanotubes. Thus, coal may be refined and demineralized by an organorefining technique to obtain super clean coal, an ultra low ash coal which may be used for the production of carbon nanotubes. The residual coal obtained after the organorefining may be used as an energy source for raising steam for power generation. Thus, coal may afford its use as an inexpensive feedstock for the production of carbon nanotubes besides its conventional role as a fuel for power generation.

Mathur, R.B.; Lal, C.; Sharma, D.K. [Indian Institute of Technology, New Delhi (India)

2007-01-01T23:59:59.000Z

437

Ceramic wash-coat for catalyst support  

SciTech Connect (OSTI)

A wash-coat (16) for use as a support for an active catalyst species (18) and a catalytic combustor component (10) incorporating such wash-coat. The wash-coat is a solid solution of alumina or alumina-based material (Al2O3-0-3 wt % La2O3) and a further oxide exhibiting a coefficient of thermal expansion that is lower than that exhibited by alumina. The further oxide may be silicon dioxide (2-30 wt % SiO2), zirconia silicate (2-30 wt % ZrSiO4), neodymium oxide (0-4 wt %), titania (Al2O3-3-40% TiO2) or alumina-based magnesium aluminate spinel (Al2O3-25 wt % MgO) in various embodiments. The active catalyst species may be palladium and a second metal in a concentration of 10-50% of the concentration of the palladium.

Kulkarni, Anand A.; Subramanian, Ramesh; Sabol, Stephen M.

2012-08-14T23:59:59.000Z

438

Rational Catalyst Design Applied to Development of Advanced Oxidation...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Catalyst Design Applied to Development of Advanced Oxidation Catalysts for Diesel Emission Control Rational Catalyst Design Applied to Development of Advanced Oxidation...

439

Molybdenum-platinum-oxide electrodes for thermoelectric generators  

DOE Patents [OSTI]

The invention is directed to a composite article suitable for use in thermoelectric generators. The article comprises a solid electrolyte carrying a thin film comprising molybdenum-platinum-oxide as an electrode deposited by physical deposition techniques. The invention is also directed to the method of making same.

Schmatz, Duane J. (Dearborn Heights, MI)

1990-01-01T23:59:59.000Z

440

Platinum third electrode to improve float polarization of standby batteries  

SciTech Connect (OSTI)

An auxiliary electrode of platinum or palladium is immersed in the electrolyte of a lead-acid battery and connected to the negative plate of the battery so that, when the battery is employed in float service, hydrogen evolves on the auxiliary electrode whereby the parasitic current equivalent to the hydrogen evolution increases the float current to the positive plate of the battery.

Werth, J.

1982-09-14T23:59:59.000Z

Note: This page contains sample records for the topic "metal catalysts platinum" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Spectroscopic studies of metal growth on oxides  

E-Print Network [OSTI]

: Chemistry SPECTROSCOPIC STUDIES OF METAL GROWTH ON OXIDES A Thesis by KAI LUO Submitted to Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Approved as to style a d content by: avid W. Goodman.... , Jilin University, P. R. China Chair of Advisory Committee: Dr, David W. Goodman Metal/oxide chemistry and metal cluster growth on oxides are fundamental to our understanding of the catalytic activity and selectivity of metal catalysts, thus...

Luo, Kai

2000-01-01T23:59:59.000Z

442

Platinum-Coated Non-Noble Metal-Noble Metal Core-Shell Electrocatalysts -  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 - September 2006Photovoltaic Theory andVelocity

443

Hydrothermal alkali metal recovery process  

DOE Patents [OSTI]

In a coal gasification operation or similar conversion process carried out in the presence of an alkali metal-containing catalyst wherein solid particles containing alkali metal residues are produced, alkali metal constituents are recovered from the particles by treating them with a calcium or magnesium-containing compound in the presence of water at a temperature between about 250.degree. F. and about 700.degree. F. and in the presence of an added base to establish a pH during the treatment step that is higher than would otherwise be possible without the addition of the base. During the treating process the relatively high pH facilitates the conversion of water-insoluble alkali metal compounds in the alkali metal residues into water-soluble alkali metal constituents. The resultant aqueous solution containing water-soluble alkali metal constituents is then separated from the residue solids, which consist of the treated particles and any insoluble materials formed during the treatment step, and recycled to the gasification process where the alkali metal constituents serve as at least a portion of the alkali metal constituents which comprise the alkali metal-containing catalyst. Preferably, the base that is added during the treatment step is an alkali metal hydroxide obtained by water washing the residue solids produced during the treatment step.

Wolfs, Denise Y. (Houston, TX); Clavenna, Le Roy R. (Baytown, TX); Eakman, James M. (Houston, TX); Kalina, Theodore (Morris Plains, NJ)

1980-01-01T23:59:59.000Z

444

The adsorption of gold, palladium and platinum from acidic chloride solutions on mesoporous carbons.  

SciTech Connect (OSTI)

Studies on the adsorption characteristics of gold, palladium and platinum on mesoporous carbon (CMK-3) and sulfur-impregnated mesoporous carbon (CMK-3/S) evaluated the benefits/drawbacks of the presence of a layer of elemental sulfur inside mesoporous carbon structures. Adsorption isotherms collected for Au(III), Pd(II) and Pt(IV) on those materials suggest that sulfur does enhance the adsorption of those metal ions in mildly acidic environment (pH 3). The isotherms collected in 1 M HCl show that the benefit of sulfur disappears due to the competing influence of large concentration of hydrogen ions on the ion-exchanging mechanism of metal ions sorption on mesoporous carbon surfaces. The collected acid dependencies illustrate similar adsorption characteristics for CMK-3 and CMK-3/S in 1-5 M HCl concentration range. Sorption of metal ions from diluted aqueous acidic mixtures of actual leached electronic waste demonstrated the feasibility of recovery of gold from such liquors.

Peter Zalupski; Rocklan McDowell; Guy Dutech

2014-10-01T23:59:59.000Z

445

SISGR-Fundamental Experimental and Theoretical Studies on a Novel Family of Oxide Catalyst Supports for Water Electrolysis  

SciTech Connect (OSTI)

Identification and development of non-noble metal based electro-catalysts or electro-catalysts with significant reduction of expensive noble metal contents (E.g. IrO2, Pt) with comparable electrochemical performance as the standard noble metal/metal oxide for proton exchange membrane (PEM) based water electrolysis would constitute a major breakthrough in the generation of hydrogen by water electrolysis. Accomplishing such a system would not only result reduction of the overall capital costs of PEM based water electrolyzers, but also help attain the targeted hydrogen production cost [< $ 3.0 / gallon gasoline equivalent (gge)] comparable to conventional liquid fuels. In line with these goals, it was demonstrated that fluorine doped IrO2 thin films and nanostructured high surface area powders display remarkably higher electrochemical activity, and comparable durability as pure IrO2 electro-catalyst for the oxygen evolution reaction (OER) in PEM based water electrolysis. Furthermore, corrosion resistant SnO2 and NbO2 support has been doped with F and coupled with IrO2 or RuO2 for use as an OER electro-catalyst. A solid solution of SnO2:F or NbO2:F with only 20 - 30 mol.% IrO2 or RuO2 yielding a rutile structure in the form of thin films and bulk nanoparticles displays similar electrochemical activity and stability as pure IrO2/RuO2. This would lead to more than 70 mol.% reduction in the noble metal oxide content. Novel nanostructured ternary (Ir,Sn,Nb)O2 thin films of different compositions FUNDAMENTAL STUDY OF NANOSTRUCTURED ELECTRO-CATALYSTS WITH REDUCED NOBLE METAL CONTENT FOR PEM BASED WATER ELECTROLYSIS 4 have also been studied. It has been shown that (Ir0.40Sn0.30Nb0.30)O2 shows similar electrochemical activity and enhanced chemical robustness as compared to pure IrO2. F doping of the ternary (Ir,Sn,Nb)O2 catalyst helps in further decreasing the noble metal oxide content of the catalyst. As a result, these reduced noble metal oxide catalyst systems would potentially be preferred as OER electro-catalysts for PEM electrolysis. The excellent performance of the catalysts coupled with its robustness would make them great candidates for contributing to significant reduction in the overall capital costs of PEM based water electrolyzers. This s.thesis provides a detailed fundamental study of the synthesis, materials, characterization, theoretical studies and detailed electrochemical response and potential mechanisms of these novel electro-catalysts for OER processes.

Kumta, Prashant [University of Pittsburgh

2014-10-03T23:59:59.000Z

446

Adsorption and hydrogenation of ethylene, 1-hexene, and benzene and CO adsorption on Pt/Al/sub 2/O/sub 3/ and Pt-Sn/Al/sub 2/O/sub 3/ catalysts  

SciTech Connect (OSTI)

Adsorption and hydrogenation of ethylene, 1-hexene, and benzene, and carbon monoxide adsorption on alumina-supported Pt and Pt-Sn catalysts were studied. Gravimetric experiments and infrared (IR) absorption spectroscopy combined with chemisorption measurements were used for this purpose. Additionally fresh and coked catalysts were characterized by the IR spectra of CO and chemisorption data. Added tin causes a slight increase in benzene adsorption and a distinct decrease in ethylene and 1-hexene uptakes, whereas the hydrogenation activity is inhibited. Adsorption and catalytic data with benzene can be explained by a model of flat adsorption on Pt/Al/sub 2/O/sub 3/ and tilted adsorption on Pt-Sn/Al/sub 2/O/sub 3/ and are consistent with electronic modification of platinum by tin. Electronic interaction between platinum and tin is also indicated by the IR data. The most active sites for hydrocarbon decomposition on the platinum surface are the same as those on which carbon monoxide is multiply bonded. Deposited coke and tin block the same active sites on the platinum surface.

Palazov, A.; Bonev, C.; Shopov, D.; Lietz, G.; Sarkany, A.; Voelter, J.

1987-02-01T23:59:59.000Z

447

Zeolite based catalysts for hydrodenitrogenation of quinoline  

E-Print Network [OSTI]

for Reactor Reproducibility in HDN of quinoline at 648K Results for Comparison Between Comm. Catalyst in Oxide Form And Sulfided Commercial Catalyst at 648K 58 59 17 Result for Comparison of HDN Activity of Different Zeolite Based Catalyst at 648K.... Comparison of HDN Activity of Sulfided form of Commercial Catalyst and Zeolite Based E Catalyst at 648 K and Cold Hydrogen Pressure of 1400 psig. 71 17. Distribution of Nitrogen Compounds in HDN of Quinoline for Commercial Catalyst at 648 K and Cold Hydrogen...

Sanghvi, Bhavyen Suman

1982-01-01T23:59:59.000Z

448

Cyclic process for producing methane with catalyst regeneration  

DOE Patents [OSTI]

Carbon monoxide-containing gas streams are passed over a catalyst capable of catalyzing the disproportionation of carbon monoxide so as to deposit a surface layer of active surface carbon on the catalyst essentially without formation of inactive coke thereon. The surface layer is contacted with steam and is thus converted to methane and CO.sub.2, from which a relatively pure methane product may be obtained. For practical commercial operations utilizing the two-step process of the invention of a cyclic basis, nickel, cobalt, ruthenium, thenium and alloys thereof are especially prepared for use in a metal state, with CO disproportionation being carried out at temperatures up to about 350.degree. C. and with the conversion of active surface carbon to methane being carried out by reaction with steam. The catalyst is employed in such cyclic operations without the necessity for employing a regeneration step as part of each processing cycle. Inactive carbon or coke that tends to form on the catalyst over the course of continuous operations utilizing such cyclic process is effectively and advantageously removed, on a periodic basis, in place of conventional burn off with an inert stream containing a low concentration of oxygen.

Frost, Albert C. (Congers, NY); Risch, Alan P. (New Fairfield, CT)

1980-01-01T23:59:59.000Z

449

Congressionally Directed Project for Passive NOx Removal Catalysts Research  

SciTech Connect (OSTI)

The Recipient proposes to produce new scientific and technical knowledge and tools to enable the discovery and deployment of highly effective materials for the selective catalytic reduction (SCR) of nitrogen oxides (NOx) from lean combustion exhaust. A second goal is to demonstrate a closely coupled experimental and computational approach to heterogeneous catalysis research. These goals will be met through the completion of four primary technical objectives: First, an in-depth kinetic analysis will be performed on two prominent classes of NOx SCR catalysts, Fe- and Cu-exchanged beta and ZSM-5 zeolites, over a wide range of catalyst formulation and under identical, high conversion conditions as a function of gas phase composition. Second, the nanoscale structure and adsorption chemistry of these high temperature (HT) and low temperature (LT) catalysts will be determined using in situ and operando spectroscopy under the same reaction conditions. Third, first-principles molecular simulations will be used to model the metal-zeolite active sites, their adsorption chemistry, and key steps in catalytic function. Fourth, this information will be integrated into chemically detailed mechanistic and kinetic descriptions and models of the operation of these well- defined NOx SCR catalysts under practically relevant reaction conditions. The new knowledge and models that derive from this work will be published in the scientific literature.

Schneider, William

2014-08-29T23:59:59.000Z

450

Methods of selectively incorporating metals onto substrates  

DOE Patents [OSTI]

A method for forming multi-metallic sites on a substrate is disclosed and described. A substrate including active groups such as hydroxyl can be reacted with a pretarget metal complex. The target metal attached to the active group can then be reacted with a secondary metal complex such that an oxidation-reduction (redox) reaction occurs to form a multi-metallic species. The substrate can be a highly porous material such as aerogels, xerogels, zeolites, and similar materials. Additional metal complexes can be reacted to increase catalyst loading or control co-catalyst content. The resulting compounds can be oxidized to form oxides or reduced to form metals in the ground state which are suitable for practical use.

Ernst; Richard D. (Salt Lake City, UT), Eyring; Edward M. (Salt Lake City, UT), Turpin; Gregory C. (Salt Lake City, UT), Dunn; Brian C. (Salt Lake City, UT)

2008-09-30T23:59:59.000Z

451

Supported, Alkali-Promoted Cobalt Oxide Catalysts for NOx Removal from Coal Combustion Flue Gases  

SciTech Connect (OSTI)

A series of cobalt oxide catalysts supported on alumina ({gamma}-Al{sub 2}O{sub 3}) were synthesized with varying contents of cobalt and of added alkali metals, including lithium, sodium, potassium, rubidium, and cesium. Unsupported cobalt oxide catalysts and several cobalt oxide catalysts supported ceria (CeO{sub 2}) with varying contents of cobalt with added potassium were also prepared. The catalysts were characterized with UV-visible spectroscopy and were examined for NO{sub x} decomposition activity. The CoO{sub x}/Al{sub 2}O{sub 3} catalysts and particularly the CoO{sub x}/CeO{sub 2} catalysts show N{sub 2}O decomposition activity, but none of the catalysts (unsupported Co{sub 3}O{sub 4} or those supported on ceria or alumina) displayed significant, sustained NO decomposition activity. For the Al{sub 2}O{sub 3}-supported catalysts, N{sub 2}O decomposition activity was observed over a range of reaction temperatures beginning about 723 K, but significant (>50%) conversions of N{sub 2}O were observed only for reaction temperatures >900 K, which are too high for practical commercial use. However, the CeO{sub 2}-supported catalysts display N{sub 2}O decomposition rates similar to the Al{sub 2}O{sub 3}-supported catalysts at much lower reaction temperatures, with activity beginning at {approx}573 K. Conversions of >90% were achieved at 773 K for the best catalysts. Catalytic rates per cobalt atom increased with decreasing cobalt content, which corresponds to increasing edge energies obtained from the UV-visible spectra. The decrease in edge energies suggests that the size and dimensionality of the cobalt oxide surface domains increase with increasing cobalt oxide content. The rate data normalized per mass of catalyst that shows the activity of the CeO{sub 2}-supported catalysts increases with increasing cobalt oxide content. The combination of these data suggest that supported cobalt oxide species similar to bulk Co{sub 3}O{sub 4} are inherently more active than more dispersed cobalt oxide species, but this effect was only observed with the CeO{sub 2}-supported catalysts.

Morris D. Argyle

2005-12-31T23:59:59.000Z

452

The Influence of Metal Cluster Size on Adsorption Energies: CO Adsorbed on Au Clusters Supported on TiO2  

E-Print Network [OSTI]

applications, including the elimination of CO from automobile emissions, hydrogen gas (for fuel cell the discovery that small Au clusters supported on reducible metal oxides are effective catalysts for CO chemical feedstock.4,5 Many Au catalyst studies have focused on high surface area powdered catalysts (60

Goodman, Wayne

453

Durability of Low Platinum Fuel Cells Operating at High Power Density  

SciTech Connect (OSTI)

Understanding and improving the durability of cost-competitive fuel cell stacks is imperative to successful deployment of the technology. Stacks will need to operate well beyond today’s state-of-the-art rated power density with very low platinum loading in order to achieve the cost targets set forth by DOE ($15/kW) and ultimately be competitive with incumbent technologies. An accelerated cost-reduction path presented by Nuvera focused on substantially increasing power density to address non-PGM material costs as well as platinum. The study developed a practical understanding of the degradation mechanisms impacting durability of fuel cells with low platinum loading (?0.2mg/cm2) operating at high power density (?1.0W/cm2) and worked out approaches for improving the durability of low-loaded, high-power stack designs. Of specific interest is the impact of combining low platinum loading with high power density operation, as this offers the best chance of achieving long-term cost targets. A design-of-experiments approach was utilized to reveal and quantify the sensitivity of durability-critical material properties to high current density at two levels of platinum loading (the more conventional 0.45 mgPt.cm–1 and the much lower 0.2 mgPt.cm–2) across several cell architectures. We studied the relevance of selected component accelerated stress tests (AST) to fuel cell operation in power producing mode. New stress tests (NST) were designed to investigate the sensitivity to the addition of electrical current on the ASTs, along with combined humidity and load cycles and, eventually, relate to the combined city/highway drive cycle. Changes in the cathode electrochemical surface area (ECSA) and average oxygen partial pressure on the catalyst layer with aging under AST and NST protocols were compared based on the number of completed cycles. Studies showed elevated sensitivity of Pt growth to the potential limits and the initial particle size distribution. The ECSA loss was correlated with the upper potential limit in the cycle tests, although the performance degradation was found to be a strong function of initial Pt loading. A large fraction of the voltage degradation was found due to increased mass transfer overpotentials, especially in the lower Pt loading cells. Increased mass transfer overpotentials were responsible for a large fraction of the voltage degradation at high current densities. Analysis of the impedance and polarization data indicated O2 diffusion in the aged electrode ionomer to be the main source of the increased mass transfer overpotentials. Results from the experimental parametric studies were used to inform and calibrate newly developed durability model, simulating lifetime performance of the fuel cell under variety of load-cycle protocols, electrode loadings and throughout wide range of operating conditions, including elevated-to-3.0A/cm2 current densities. Complete durability model included several sub-models: platinum dissolution-and-growth as well as reaction-diffusion model of cathode electrode, applied sequentially to study the lifetime predictions of ECSA and polarization performance in the ASTs and NSTs. These models establish relations between changes in overpotentials, ECSA and oxygen mass transport in fuel cell cathodes. The model was calibrated using single cells with land-channel and open flowfield architectures. The model was validated against Nuvera Orion® (open flowfield) short stack data in the load cycle durability tests. The reaction-diffusion model was used to correlate the effective mass transfer coefficients for O2 diffusion in cathode ionomer and separately in gas pores with the operating conditions (pressure, temperature, gas velocity in flow field and current density), Pt loading, and ageing related growth in Pt particles and thinning of the electrode. Achievements of both modeling and experimental objectives were demonstrated in a full format, subscale stacks operating in a simulated but fully realistic ambient environment, using system-compatible operating protocols.

Polevaya, Olga [Nuvera Fuel Cells Inc.] [Nuvera Fuel Cells Inc.; Blanchet, Scott [Nuvera Fuel Cells Inc.] [Nuvera Fuel Cells Inc.; Ahluwalia, Rajesh [Argonne National Lab] [Argonne National Lab; Borup, Rod [Los-Alamos National Lab] [Los-Alamos National Lab; Mukundan, Rangachary [Los-Alamos National Lab] [Los-Alamos National Lab

2014-03-19T23:59:59.000Z

454

Preparation of ferric-sulfide-based catalysts using an aerosol technique  

SciTech Connect (OSTI)

Iron sulfides are used as catalysts for direct coal liquefaction. They are reasonably active, cheap, and environmentally benign. This permits their use as once-through, non-regenerated catalysts. Our work in this area is based on the products of disproportionation of ferric sulfide, produced in sufficiently small particle sizes. The small particle sizes have been produced by in-situ impregnation or by using an aerosol reactor. This talk will concentrate on the aerosol process. The resulting particles have been characterized and used as catalysts for coal liquefaction. The effects of precursor solution concentration and the pressure and temperature in the aerosol reactor on the performance of the catalysts have been noted. We have recently investigated the effect of adding small amounts of a second metal to the catalyst. Multi-metal catalysts prepared to date with the aerosol technique include Fe-Cu-S and Fe-Zn-S, each with 10% additive, and Fe-Cu-Zn-S, with 10% Cu and 5% Zn.

Stiller, A.H.; Dadyburjor, D.B.; Stinespring, C.D. [West Virginia Univ., Morgantown, WV (United States)] [and others

1995-12-01T23:59:59.000Z

455

Methanol and methyl fuel catalysts. Final technical report, September 1978-August 1980  

SciTech Connect (OSTI)

The Cu/ZnO methanol synthesis catalysts were investigated for (1) the role of additives such as alumina, ceria, and lanthana, (2) the effect of carbon dioxide in the H/sub 2//CO synthesis gas, (3) the chemisorption of hydrogen and carbon monoxide on the catalysts, and (4) the chemical poisoning of the catalysts by sulfur- and chlorine-containing compounds. Maximum activity and selectivity were obtained with a binary catalyst having a composition of Cu/ZnO = 30/70 metal atomic percent and with a synthesis gas of H/sub 2//CO/CO/sub 2/ = 70/28/2 volume percent in the absence of strongly reducing or strongly oxidizing chemical poisons. Both the binary and the ternary catalysts were fully characterized by scanning transmission electron microscopy (STEM), X-ray diffraction, electron spectroscopy, diffuse reflectance spectroscopy, and surface area-pore distribution measurements. Structural and morphologic information is presented in this report in detail for very active Cu/ZnO/Al/sub 2/O/sub 3/ catalysts prepared from acetates and for other catalysts in which the third component caused a loss of activity.

Klier, K.; Herman, R.G.

1980-12-15T23:59:59.000Z

456

A Novel Non-Platinum Group Electrocatalyst for PEM Fuel Cell Application  

SciTech Connect (OSTI)

Precious-metal catalysts (predominantly Pt or Pt-based alloys supported on carbon) have traditionally been used to catalyze the electrode reactions in polymer electrolyte membrane (PEM) fuel cells. However as PEM fuel systems begin to approach commercial reality, there is an impending need to replace Pt with a lower cost alternative. The present study investigates the performance of a carbon-supported tantalum oxide material as a potential oxygen reduction reaction (ORR) catalyst for use on the cathode side of the PEM fuel cell membrane electrode assembly. Although bulk tantalum oxide tends to exhibit poor electrochemical performance due to limited electrical conductivity, it displays a high oxygen reduction potential; one that is comparable to Pt. Analysis of the Pourbaix electrochemical equilibrium database also indicates that tantalum oxide (Ta2O5) is chemically stable under the pH and applied potential conditions to which the cathode catalyst is typically exposed during stack operation. Nanoscale tantalum oxide catalysts were fabricated using two approaches, by reactive oxidation sputtering and by direct chemical synthesis, each carried out on a carbon support material. Nanoscale tantalum oxide particles measuring approximately 6nm in size that were sputtered onto carbon paper exhibited a mass-specific current density as high as one-third that of Pt when measured at 0.6V vs. NHE. However because of the two-dimensional nature of this particle-on-paper structure, which limits the overall length of the triple phase boundary junctions where the oxide, carbon paper, and aqueous electrolyte meet, the corresponding area-specific current density was quite low. The second synthesis approach yielded a more extended, three-dimensional structure via chemical deposition of nanoscale tantalum oxide particles on carbon powder. These catalysts exhibited a high ORR onset potential, comparable to that of Pt, and displayed a significant improvement in the area-specific current density. Overall, the highest mass-specific current density of the carbon-powder supported catalyst was ~ 9% of that of Pt.

Kim, Jin Yong; Oh, Takkeun; Shin, Yongsoon; Bonnett, Jeff F.; Weil, K. Scott

2011-04-01T23:59:59.000Z

457

Evaluation of PEMFC System Contaminants on the Performance of Pt Catalyst via Cyclic Voltammetry: Preprint  

SciTech Connect (OSTI)

Using electrochemical cyclic voltammetry as a quick ex-situ screening tool, the impact of the extracted solution and the individual leachable constituents from prospective BOP component materials on the performance and recoverability of the platinum catalyst were evaluated. Taking an extract from Zytel{trademark} HTN51G35HSLR (PPA) as an example, the major leachable organic components are caprolactam and 1,6 hexanediol. While these organic compounds by themselves do poison the Pt catalyst to some extent, such influence is mostly recoverable by means of potential holding and potential cycling. The extracted solution, however, shows a more drastic poisoning effect and it was not recoverable. Therefore the non-recoverable poisoning effect observed for the extracted solution is not from the two organic species studied. This demonstrates the complexity of such a contaminant study. Inorganic compounds that are known poisons like sulfur even in very low concentrations, may have a more dominant effect on the Pt catalyst and the recoverability.

Wang, H.; Macomber, C.; Dinh, H. N.

2012-07-01T23:59:59.000Z

458

Catalyst containing oxygen transport membrane  

SciTech Connect (OSTI)

A composite oxygen transport membrane having a dense layer, a porous support layer and an intermediate porous layer located between the dense layer and the porous support layer. Both the dense layer and the intermediate porous layer are formed from an ionic conductive material to conduct oxygen ions and an electrically conductive material to conduct electrons. The porous support layer has a high permeability, high porosity, and a high average pore diameter and the intermediate porous layer has a lower permeability and lower pore diameter than the porous support layer. Catalyst particles selected to promote oxidation of a combustible substance are located in the intermediate porous layer and in the porous support adjacent to the intermediate porous layer. The catalyst particles can be formed by wicking a solution of catalyst precursors through the porous support toward the intermediate porous layer.

Christie, Gervase Maxwell; Wilson, Jamie Robyn; van Hassel, Bart Antonie

2012-12-04T23:59:59.000Z

459

Heterogeneous catalyst for the production of acetic anhydride from methyl acetate  

DOE Patents [OSTI]

This invention relates to a process for producing acetic anhydride by the reaction of methyl acetate, carbon monoxide, and hydrogen at elevated temperatures and pressures in the presence of an alkyl halide and a heterogeneous, bifunctional catalyst that contains an insoluble polymer having pendant quaternized phosphine groups, some of which phosphine groups are ionically bonded to anionic Group VIII metal complexes, the remainder of the phosphine groups being bonded to iodide. In contrast to prior art processes, no accelerator (promoter) is necessary to achieve the catalytic reaction and the products are easily separated from the catalyst by filtration. The catalyst can be recycled for consecutive runs without loss in activity. Bifunctional catalysts for use in carbonylating dimethyl ether are also provided.

Ramprasad, D.; Waller, F.J.

1999-04-06T23:59:59.000Z

460

Heterogeneous catalyst for the production of acetic anhydride from methyl acetate  

DOE Patents [OSTI]

This invention relates to a process for producing acetic anhydride by the reaction of methyl acetate, carbon monoxide, and hydrogen at elevated temperatures and pressures in the presence of an alkyl halide and a heterogeneous, bifunctional catalyst that contains an insoluble polymer having pendant quaternized phosphine groups, some of which phosphine groups are ionically bonded to anionic Group VIII metal complexes, the remainder of the phosphine groups being bonded to iodide. In contrast to prior art processes, no accelerator (promoter) is necessary to achieve the catalytic reaction and the products are easily separated from the catalyst by filtration. The catalyst can be recycled for consecutive runs without loss in activity. Bifunctional catalysts for use in carbonylating dimethyl ether are also provided.

Ramprasad, Dorai (Allentown, PA); Waller, Francis Joseph (Allentown, PA)

1999-01-01T23:59:59.000Z

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461

Development of Ni-based Sulfur Resistant Catalyst for Diesel Reforming  

SciTech Connect (OSTI)

In order for diesel fuel to be used in a solid oxide fuel cell auxiliary power unit, the diesel fuel must be reformed into hydrogen, carbon monoxide and carbon dioxide. One of the major problems facing catalytic reforming is that the level of sulfur found in low sulfur diesel can poison most catalysts. This report shows that a proprietary low cost Ni-based reforming catalyst can be used to reform a 7 and 50 ppm sulfur containing diesel fuel for over 500 hours of operation. Coking, which appears to be route of catalyst deactivation due to metal stripping, can be controlled by catalyst modifications, introduction of turbulence, and/or by application of an electromagnetic field with a frequency from {approx}50 kHz to 13.56 MHz with field strength greater than about 100 V/cm and more preferably greater about 500 V/cm.

Gunther Dieckmann

2006-06-30T23:59:59.000Z

462

Tetraalklylammonium polyoxoanionic oxidation catalysts  

DOE Patents [OSTI]

Alkanes are catalytically oxidized in air or oxygen using iron-substituted polyoxoanions (POAs) of the formula: H{sub e{minus}z}[(n-C{sub 4}H{sub 9}){sub 4}N]{sub z}(XM{sub 11}M{prime}O{sub 39}){sup {minus}e}. The M{prime} (e.g., iron(III)/iron(II)) reduction potential of the POAs is affected by selection of the central atom X and the framework metal M, and by the number of tetrabutyl-ammonium groups. Decreased Fe(III)/Fe(II) reduction potential has been found to correlate to increased oxidation activity.

Ellis, P.E.; Lyons, J.E.; Myers, H.K. Jr.; Shaikh, S.N.

1998-10-06T23:59:59.000Z

463

Tetraalykylammonium polyoxoanionic oxidation catalysts  

DOE Patents [OSTI]

Alkanes are catalytically oxidized in air or oxygen using iron-substituted polyoxoanions (POAs) of the formula: H.sub.e-z ›(n-C.sub.4 H.sub.9).sub.4 N!.sub.z (XM.sub.11 M'O.sub.39).sup.-e The M' (e.g., iron(III)/iron(II)) reduction potential of the POAs is affected by selection of the central atom X and the framework metal M, and by the number of tetrabutyl-ammonium groups. Decreased Fe(III)/Fe(II) reduction potential has been found to correlate to increased oxidation activity.

Ellis, Paul E. (Downingtown, PA); Lyons, James E. (Wallingford, PA); Myers, Jr., Harry K. (Cochranville, PA); Shaikh, Shahid N. (Media, PA)

1998-01-01T23:59:59.000Z

464

Role of support in adsorption and catalysts on supported metals. II. IR spectroscopic study of adsorption of CO and CO/sub 2/ on Rh/ZrO/sub 2/  

SciTech Connect (OSTI)

IR spectroscopy has been used in a study of the adsorption of CO on Rh/ZrO/sub 2/. It has been found that, the same as in the case of Rh/La/sub 2/O/sub 3/, complexes of CO are formed on the surface of this system, these complexes being coordinated simultaneously by atoms of the metal and surface atoms of the support. This was demonstrated in experiments on selective blockage of the support surface by adsorbed CO/sub 2/.

Bredikhin, M.N.; Lokhov, Yu.A.

1987-12-01T23:59:59.000Z

465

Carbon-Supported bimetallic Pd-Fe catalysts for vapor-phase hydrodeoxygenation of guaiacol  

SciTech Connect (OSTI)

Abstract Carbon supported metal catalysts (Cu/C, Fe/C, Pd/C, Pt/C, PdFe/C and Ru/C) have been prepared, characterized and tested for vapor-phase hydrodeoxygenation (HDO) of guaiacol (GUA) at atmospheric pressure. Phenol was the major intermediate on all catalysts. Over the noble metal catalysts saturation of the aromatic ring was the major pathway observed at low temperature (250 °C), forming predominantly cyclohexanone and cyclohexanol. Substantial ring opening reaction was observed on Pt/C and Ru/C at higher reaction temperatures (e.g., 350 °C). Base metal catalysts, especially Fe/C, were found to exhibit high HDO activity without ring-saturation or ring-opening with the main products being benzene, phenol along with small amounts of cresol, toluene and trimethylbenzene (TMB). A substantial enhancement in HDO activity was observed on the PdFe/C catalysts. Compared with Fe/C, the yield to oxygen-free aromatic products (i.e., benzene/toluene/TMB) on PdFe/C increased by a factor of four at 350 °C, and by approximately a factor of two (83.2% versus 43.3%) at 450 °C. The enhanced activity of PdFe/C is attributed to the formation of PdFe alloy as evidenced by STEM, EDS and TPR.

Sun, Junming; Karim, Ayman M.; Zhang, He; Kovarik, Libor; Li, Xiaohong S.; Hensley, Alyssa; McEwen, Jean-Sabin; Wang, Yong

2013-10-01T23:59:59.000Z