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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

Exhaust system having a gold-platinum group metal catalyst  

DOE Patents (OSTI)

A method of providing an exhaust treatment device is disclosed. The method includes applying a catalyst including gold and a platinum group metal to a particulate filter. The concentration of the gold and the platinum group metal is sufficient to enable oxidation of carbon monoxide and nitric oxide.

Ragle, Christie Susan (Havana, IL); Silver, Ronald G. (Peoria, IL); Zemskova, Svetlana Mikhailovna (Edelstein, IL); Eckstein, Colleen J. (Metamora, IL)

2011-12-06T23:59:59.000Z

2

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

3

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

4

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

5

Sandia National Laboratories: ECIS and Compass Metals: Platinum...  

NLE Websites -- All DOE Office Websites (Extended Search)

cell use * Compass Metals * cooperative research and development agreement * CRADA * fuel cell catalyst * hydrogen powered fuel cell * improve platinum nanomaterial synthesis *...

6

Optimization of carbon-supported platinum cathode catalysts for DMFC operation.  

SciTech Connect

In this paper, we describe performance and optimization of carbon-supported cathode catalysts at low platinum loading. We find that at a loading below 0.6 mg cm-2 carbon-supported platinum outperforms platinum black as a DMFC cathode catalyst. A catalyst with a 1:1 volume ratio of the dry NafionTM to the electronically conducting phase (platinum plus carbon support) provides the best performance in oxygen reduction reaction. Thanks to improved catalyst utilization, carbon-supported catalysts with a platinum content varying from 40 wt% to 80 wt% deliver very good DMFC performance, even at relatively modest precious metal loadings investigated in this work.

Zhu, Y. (Yimin); Brosha, E. L. (Eric L.); Zelenay, P. (Piotr)

2002-01-01T23:59:59.000Z

7

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

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 crystals-7708, ploferski@usgs.gov] #12;121 PLATINUM-GROUP METALS Events, Trends, and Issues: The global economy continued

9

Extended Platinum Nanotubes as Fuel Cell Catalysts  

SciTech Connect

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

10

Reinforced nickel and nickel-platinum catalysts for performing the thermally coupled reactions of methane steam reforming and hydrogen oxidation  

Science Journals Connector (OSTI)

The formation of composite nickel and nickel-platinum catalysts reinforced with steel gauze was studied. The catalysts were prepared by sintering powdered nickel metal and a supported nickel catalyst (GIAP-3 or N...

M. M. Danilova; Z. A. Sabirova; N. A. Kuzin; V. A. Kirillov…

11

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

Energy Savers (EERE)

Development of Ultra-low Platinum Alloy Cathode Catalyst for PEM Fuel Cells Development of Ultra-low Platinum Alloy Cathode Catalyst for PEM Fuel Cells These slides were presented...

12

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

SciTech Connect

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

13

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

14

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

SciTech Connect

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

15

Improving Platinum Catalyst Durability with a Doped Graphene Support  

Science Journals Connector (OSTI)

Improving the durability of a platinum catalyst is an important step in increasing its utility when incorporated as the anode or cathode of a proton-exchange membrane fuel cell. ... Carboxyl Group Enhanced CO Tolerant GO Supported Pt Catalysts: DFT and Electrochemical Analysis ... Chemical Structure of Nitrogen-Doped Graphene with Single Platinum Atoms and Atomic Clusters as a Platform for the PEMFC Electrode ...

Michael N. Groves; Cecile Malardier-Jugroot; Manish Jugroot

2012-04-13T23:59:59.000Z

16

Monodisperse Platinum and Rhodium Nanoparticles as Model Heterogeneous Catalysts  

SciTech Connect

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

17

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

E-Print Network (OSTI)

palladium-rich technology for gasoline cars, further eroding platinum's share of the gasoline engine market relatively low levels of platinum when compared with catalyst used with gasoline engines. Stage III limits

18

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

E-Print Network (OSTI)

hydrogen- olysis at 250'C and 300'C on 1%-Pt/La 0 catalysts as a function of hydrogen reduction temperature. 105 LIST OF FIGURES Figure Page 1 Recirculation ? batch reactor. . . . . . . . . . 30 2 Rates of ethylene hydrogenation on various catalysts... for calculations. The computer was inter- faced to a Micro-Term Co. ACT-5A display terminal, Digital Equipment Co. Model II DEC writer and two flexible disk drives. 4. Adsor tion S stem. Hydrogen and carbon monox- ide single point adsorptions were obtained...

Terhune, Kyte Hamilton

2012-06-07T23:59:59.000Z

19

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

20

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

SciTech Connect

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

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

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

22

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

23

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

24

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

SciTech Connect

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

25

Platinum-palladium catalysts for hydrogen fuel cell electrodes  

Science Journals Connector (OSTI)

Five series of Pt?Pd/C catalysts were prepared with different total metal loading and different atomic composition in Pt and Pd. The activity in electrooxidation of hydrogen were measured for all these catalys...

J. Barbier; E. Lamy; O. Outiki

26

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

E-Print Network (OSTI)

and truly tune the catalyst to the reaction. References 1.Gavriilidis, A. Varma, Catalyst Design, Cambridge UniversityStructure of Metallic Catalysts, Academic Press, London,

Contreras, A.M.

2006-01-01T23:59:59.000Z

27

Nanosegregated Cathode Catalysts with Ultra-Low Platinum Loading  

NLE Websites -- All DOE Office Websites (Extended Search)

2009 DOE EERE Kick-off Meeting 2009 DOE EERE Kick-off Meeting Announcement No: DE-PS36-08GO98010 Topic: 1A Nanosegregated Cathode Catalysts with Ultra-Low Platinum Loading Argonne National Laboratory Materials Science Division PI: Nenad M. Markovic Co-PI: Vojislav R. Stamenkovic Subcontractors: * Oak Ridge National Laboratory - Karren More * Jet Propulsion Laboratory - NASA - S.R. Narayan * Brown University - Shouheng Sun * Indiana University Purdue - Goufeng Wang * 3M Company - Radoslav Atanasoski Overview Timeline * Project start: 9/2009 * Project end: 9/2012 Barriers ~ 30-40% (!!!) Cathode kinetics * The main losses: CATHODE 1) High content of Pt 2) Poor activity: Pt/C = Pt-poly/10 3) Durability (Pt dissolves: power loss) 4) Carbon support corrosion Budget * Total Project funding $ 6.5M

28

Evaluation of platinum-based catalysts for methanol electro-oxidation in phosphoric acid electrolyte  

SciTech Connect

Carbon-supported catalysts of Pt, Pt/Ru, Pt/Ru/W, and Pt/Ru/Pd were evaluated for the electro-oxidation of methanol in phosphoric acid at 180 C. These catalysts were characterized using cyclic voltammetry and x-ray diffraction. Addition of Ru to a 0.5 mg/cm{sup 2} Pt catalyst (1:1 atomic ratio) caused a large reduction in polarization. The open-circuit voltage was reduced by 100 mV and polarization at 400 mA/cm{sup 2} was reduced by 180 mV. A Pt/Ru (5:2) catalyst with the same Pt content lowered the open-circuit voltage 70 mV. Additions of W to form Pt/Ru/W (1:1:1, atomic ratio) and Pd to form Pt/Ru/Pd (2:2:1), all with the same platinum loading, gave the same performance as Pt/Ru (1:1) without the additions. All of the catalysts showed two Tafel slopes, 140 mV/dec at lower polarizations and 100 to 120 mV/dec at higher polarizations, indicating that the reaction mechanisms are the same for all of the catalysts. Methanol oxidation is greatly enhanced at 180 C in phosphoric acid compared to the lower operating temperatures of a perfluorosulfonic acid electrolyte. The exchange current density for methanol oxidation is higher than that for O{sub 2} reduction. Ru metal dissolves from catalysts at high potentials. Hydrogen oxidation in the presence of 1 mole percent carbon monoxide showed carbon monoxide tolerance in the order: Pt/Ru/Pd > Pt/Ru > Pt.

He, C.; Kunz, H.R.; Fenton, J.M. [Univ. of Connecticut, Storrs, CT (United States). Dept. of Chemical Engineering

1997-03-01T23:59:59.000Z

29

Bridge to Fuel Cell Molecular Catalysis: 3D Non-Platinum Group Metal  

NLE Websites -- All DOE Office Websites (Extended Search)

Bridge to Fuel Cell Molecular Catalysis: 3D Non-Platinum Group Metal Bridge to Fuel Cell Molecular Catalysis: 3D Non-Platinum Group Metal Catalyst in MEAs Title Bridge to Fuel Cell Molecular Catalysis: 3D Non-Platinum Group Metal Catalyst in MEAs Publication Type Journal Article Year of Publication 2012 Authors Zhu, Xiaobing, John B. Kerr, Qinggang He, Gi Suk Hwang, Zulima Martin, Kyle Clark, Adam Z. Weber, and Nana Zhao Journal ECS Transactions Volume 45 Issue 2 Pagination 143 - 152 Date Published 04/2012 ISSN 1938-6737 Abstract Transition metal porphyrin complexes have been mounted in a three dimensional homogenous distribution inside the ionomer of catalyst layers in MEAs to achieve competitive fuel cell catalysis activity. The effect of electrode components including ionomer, carbon, catalyst, and mediator, and ionomer film thickness, is investigated in fuel cell molecular catalysis system. Membrane electrode assembly (MEA) durability testing has been conducted. SEM and TEM techniques are employed to investigate molecular catalysis electrode micro- and nano- structure and morphology. To date, surprisingly, the best fuel cell performance, i.e. 1280 mA/cm2 of maximum/short-circuit current density is achieved, approaching that of Pt-based electrode, indicating higher turnover frequencies than Pt although with poorer voltages.

30

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

31

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

32

Nanosegregated Surfaces as Catalysts for Fuel Cells | Argonne...  

NLE Websites -- All DOE Office Websites (Extended Search)

Catalysts for Fuel Cells Technology available for licensing: A method for creating a new class of platinum multi-metallic catalysts that are not only compositionally stable but...

33

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

34

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

35

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

36

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

37

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

38

Interaction of carbon monoxide with supported platinum catalysts  

SciTech Connect

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

39

DOE Hydrogen and Fuel Cells Program Record 11013: Platinum Group Metal Loading in PEMFC Stacks  

NLE Websites -- All DOE Office Websites (Extended Search)

3 Date: June 2, 2011 3 Date: June 2, 2011 Title: Platinum Group Metal Loading in PEMFC Stacks Originator: Jacob Spendelow and Dimitrios Papageorgopoulos Approved by: Sunita Satyapal Date: July 25, 2011 Item: Total loading of platinum group metals (PGMs) in state-of-the-art polymer electrolyte membrane fuel cell stacks has decreased by 2 orders of magnitude since the 1960s and 1 order of magnitude since the mid-1980s. Supporting Information: Prior to 1988, state-of-the-art polymer electrolyte membrane fuel cell (PEMFC) electrodes were constructed using Pt-based catalysts pressed directly into the surface of the polymer electrolyte membrane (PEM). Catalyst loadings were 35 mg/cm 2 in the PEMFC electrodes used in the 1960s in NASA's Gemini program [1], though

40

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

SciTech Connect

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

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

Nanostructured catalysts for cathodes of oxygen-hydrogen fuel cells  

Science Journals Connector (OSTI)

Bimetallic catalysts platinum-cobalt, platinum-chromium, and platinum-tungsten, deposited onto highly dispersed carbon black from complex cluster-type compounds of corresponding metals with a 1: 1 atomic ratio...

V. A. Grinberg; T. L. Kulova; N. A. Maiorova…

2007-01-01T23:59:59.000Z

42

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

43

Molecular-scale, Three-dimensional Non-Platinum Group Metal Electrodes for Catalysis of Fuel Cell Reactions  

NLE Websites -- All DOE Office Websites (Extended Search)

Molecular-scale, Three-dimensional Non-Platinum Group Molecular-scale, Three-dimensional Non-Platinum Group Metal Electrodes for Catalysis of Fuel Cell Reactions John B. Kerr Lawrence Berkeley National Laboratory (LBNL) September 30, 2009 Team Members: Adam Weber, Rachel Segalman, Robert Kostecki, Jeff Reimer, John Arnold, Martin Head-Gordon (LBNL). Piotr Zelenay, James Boncella, Yu Seung Kim, Neil Henson, Jerzy Chlistunoff (LANL). Steve Hamrock, Radoslav Atanasoski (3M) Budget: DOE share - $9.58MM over four years; 3M share - in-kind over four years. 2 Objectives 1) Demonstrate that non-platinum group metal catalysts can be used for oxygen reduction in polymer-coated electrode structures based on polyelectrolyte membranes. 2) Incorporate catalysts into polymer binders of composite electrodes for the construction of MEAs to demonstrate that this

44

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

E-Print Network (OSTI)

1 Effect of Nafion and platinum content in a catalyst layer processed in a radio frequency helicon fuel cells (PEMFC). Electrodes with low Pt loading are prepared, assembled in custom-made membrane, the electrical performance of the custom-made MEA with one plasma prepared electrode (either anode or cathode

Paris-Sud XI, Université de

45

DOE Hydrogen and Fuel Cells Program Record 9018: Platinum Group Metal Loading  

NLE Websites -- All DOE Office Websites (Extended Search)

8 Date: March 23, 2010 8 Date: March 23, 2010 Title: Platinum Group Metal Loading Originator: Jacob Spendelow, Kathi Epping Martin, and Dimitrios Papageorgopoulos Approved by: Sunita Satyapal Date: June 1, 2010 Item: Total content of platinum group metals (PGMs) in state-of-the-art polymer electrolyte membrane fuel cell stacks has decreased by more than 80% since 2005. Improvement in performance and durability at low catalyst loading has allowed fuel cell developers to produce stacks with PGM content lower than the DOE 2010 target. DOE is on track to meet the 2015 PGM total content target on schedule. Supporting Information: DOE regularly determines fuel cell technology status using results reported by fuel cell developers. The results are reviewed in consultation with the FreedomCAR & Fuel

46

Platinum and palladium nano-particles supported by graphitic nano-fibers as catalysts for PEM water electrolysis  

Science Journals Connector (OSTI)

Platinum and palladium nano-particles supported by graphitic nano-fibers (GNFs) have been prepared and used as cathodic electrocatalysts in proton-exchange membrane (PEM) water electrolysis cells for the hydrogen evolution reaction (HER). Raw GNF structures have been synthesized by chemical vapor deposition (CVD). Noble metal nano-particles have been deposited at the surface of \\{GNFs\\} using an impregnation-reduction method. Structural properties and electrochemical performances of the GNF-supported catalysts have been determined using TEM analysis and cyclic voltammetry. Current-voltage polarization curves have also been recorded using a PEM cell (7 cm2). The performances obtained with GNF-supported catalysts were found more efficient than those obtained with catalysts supported with conventional carbon black (Vulcan® XC-72). In particular, a reduced electrolysis cell voltage (1.67 instead 1.72 V at 1 A.cm?2 and 90 °C) has been obtained using Pt/GNF cathodes in place of Pt/XC-72 at the cathode and with similar platinum contents (40 wt.%).

S.A. Grigoriev; M.S. Mamat; K.A. Dzhus; G.S. Walker; P. Millet

2011-01-01T23:59:59.000Z

47

Nano-Structured Nobel Metal Catalysts  

NLE Websites -- All DOE Office Websites (Extended Search)

Nobel Metal Catalysts Nobel Metal Catalysts for Hydrocarbon Reforming Opportunity Research is active on the patent pending technology, titled "Nano- Structured Nobel Metal Catalysts Based on Hexametallate Architecture for the Reforming of Hydrocarbon Fuels." This technology is available for licensing and/or further collaborative research from the U.S. Department of Energy's National Energy Technology Laboratory. Overview Methods for generating synthesis gas from hydrocarbon feedstocks routinely involve the use of a catalyst-a material that speeds up the reaction, but itself is not consumed-to make this process economically feasible. Sulfur, higher hydrocarbons, and olefins present a major technical challenge since these components can deactivate conventional

48

Cobalt discovery replaces precious metals as industrial catalyst  

NLE Websites -- All DOE Office Websites (Extended Search)

replaces precious metals Cobalt discovery replaces precious metals as industrial catalyst Cobalt holds promise as an industrial catalyst with potential applications in such...

49

Cobalt discovery replaces precious metals as industrial catalyst  

NLE Websites -- All DOE Office Websites (Extended Search)

Replaces Precious Metals Cobalt discovery replaces precious metals as industrial catalyst Cobalt holds promise as an industrial catalyst with potential applications in such...

50

Sandia National Laboratories: fuel cell catalyst  

NLE Websites -- All DOE Office Websites (Extended Search)

fuel cell catalyst ECIS and Compass Metals: Platinum Nanostructures for Enhanced Catalysis On March 29, 2013, in Advanced Materials Laboratory, Capabilities, Energy, Energy...

51

Recent advances in activity and durability enhancement of Pt/C catalytic cathode in PEMFC: Part II: Degradation mechanism and durability enhancement of carbon supported platinum catalyst  

Science Journals Connector (OSTI)

Polymer electrolyte membrane fuel cell (PEMFC) technology has advanced rapidly in recent years, with one of active area focused on improving the long-term performance of carbon supported catalysts, which has been recognized as one of the most important issues to be addressed for the commercialization of the PEMFCs. The cathode catalyst layer in \\{PEMFCs\\} typically contains platinum group metal/alloy nanoparticles supported on a high-surface-area carbon. Carbon support corrosion and Pt dissolution/aggregation are considered as the major contributors to the degradation of the Pt/C catalysts. If the platinum particles cannot maintain their structure over the lifetime of the fuel cell, change in the morphology of the catalyst layer from the initial state will result in a loss of electrochemical activity. This paper reviews the recent advances in the stability improvement of the Pt/C cathodic catalysts in PEMFC, especially focusing on the durability enhancement through the improved Pt–C interaction. Future promising strategies towards the extension of catalysts operation life are also prospected.

Xingwen Yu; Siyu Ye

2007-01-01T23:59:59.000Z

52

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

53

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

54

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 processes, such as catalysts for Fischer-Tropsh Synthesis, and sorbents for removal of sulfur gasses 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, Santosh (Cary, NC); Jothimurugesan, Kandaswamy (Hampton, VA)

1999-01-01T23:59:59.000Z

55

Deposition of platinum catalyst by plasma sputtering for fuel cells: 3D simulation and experiments  

Science Journals Connector (OSTI)

Plasma sputtering is one of the most promising methods for reducing the amount of platinum catalyst in porous electrodes for low temperature fuel cells. Here, a simulation of the platinum deposition by radio frequency plasma sputtering has been developed and compared with experimental results to allow optimization of the deposition process. In the simulation, the transport of sputtered atoms through the argon plasma is obtained using a 3D Monte Carlo model called SPaTinG (Sputtered Particles Transport in Gas). The Yamamura formula provides the Pt sputtering yield on the target, and the initial energy distribution of sputtered atoms is given by the Thompson distribution. A 1D hybrid model is used to estimate the mean energy of argon ions impinging onto the platinum target. Experimentally, platinum is deposited on silicon in two plasma sputtering chambers with different geometries. The deposition rate is measured by Rutherford backscattering spectroscopy. The angular distribution of the Pt atoms ejected from the target surface and the condensation coefficient of the Pt atoms on silicon are calculated by adjusting the simulated and experimental deposition rates at 0.5?Pa. A good agreement between the simulation and the experiment is observed as a function of the target–substrate distance for the two system geometries at low pressure (0.5?Pa).

A Caillard; C Charles; R Boswell; A Meige; P Brault

2008-01-01T23:59:59.000Z

56

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

NLE Websites -- All DOE Office Websites (Extended Search)

Development of Ultra-low Platinum Alloy Development of Ultra-low Platinum Alloy C th d C t l t f PEM F l C ll Cathode Catalyst for PEM Fuel Cells 2010 DOE Hydrogen Program Fuel Cell Project Kick-Off P I : Branko N Popov P. I.: Branko N. Popov Center for Electrochemical Engineering University of South Carolina Columbia SC 29208. September 28, 2010 This presentation does not contain any proprietary, confidential, or otherwise restricted information Center for Electrochemical Engineering, University of South Carolina 1 Overview Timeline * S Start d date: J June 01 2010 01 2010 * End date: Nov 30 2012 (Phase I) : May 31 2014 (Phase II) Budget * Total project funding ¾ DOE share: $ 4 400 000 ¾ DOE share: $ 4,400,000 ¾ Contractor share: $1,100,000 * Incremental funding received in FY10: $750,000

57

Platinum Group Metal Recycling Technology Development - Final Report  

SciTech Connect

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

58

New applications of noble metal catalysts in hydrocracking  

SciTech Connect

The paper explores how a noble metal hydrocracking catalyst functions stably in a hydrogen sulfide and ammonia environment and, in particular, how the physical positioning of the noble metal molecules affects catalyst performance. A commercial example, HC-28 catalyst in the Unicracking unit at Marathon Oil Refinery in Robinson, Illinois, demonstrates the success of the noble metal catalyst approach for naphtha production. In addition, a new Unicracking catalyst, HC-35, which uses a noble metal component to produce high-quality middle distillates, is introduced. The paper also shows how refiners may derive increased economic and operational benefits from their catalyst investment by using the latest developments in reactor internals design.

Mitchell, D.H.G.; Bertram, R.V. [UOP, Des Plaines, IL (United States); Dencker, G.D. [Marathon Oil Co., Robinson, IL (United States). Illinois Refining Div.

1995-09-01T23:59:59.000Z

59

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

E-Print Network (OSTI)

on these catalysts. The mobility of benzene on these catalysts is independent of whether it is directly adsorbed or prepared from acetylene in situ. At 123 K the motionally averaged "C shielding tensor is accounted for by a model involving rapid rotation about... to the study of adsorbates on metals with large susceptibility anisotropies. ACKNOWLEDGEMENTS First, I would like to give recognition to my committee members: Chairman Dr. James F. Haw, Dr. Bruce Dale, Dr. Marcetta Darensbourg, and Dr. Russell...

Lambregts, Marsha Jo Lupher

2012-06-07T23:59:59.000Z

60

Effect of steam on supported metal catalysts  

SciTech Connect

In order to examine the effect of steam on supported metal catalysts, model supported metal catalysts of Ni, Co, or Fe on alumina have been heated in steam at 700/sup 0/C. The transmission electron micrographs show that for all these metals, patches of film extend from the crystallites. Prolonged heating results in the disappearance of the patches which probably spread as a contiguous film over the entire surface of the substrate. The degree of spreading is in the order: C0 > Ni > Fe. On subsequent heating in H/sub 2/, small crystallites were generated, probably via the rupture of the contiguous film. The contraction of the patches of film bridging two or several particles caused the coalescence of the latter. This subsequent heating in H/sub 2/ favors redispersion only when the heating time is sufficiently short. Prolonged heating in H/sub 2/ leads to the disappearance of the small particles.

Ruckenstein, E.; Hu, X.D.

1986-07-01T23:59:59.000Z

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

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

SciTech Connect

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

62

DOE Hydrogen Analysis Repository: Novel Non-Precious Metal Catalysts  

NLE Websites -- All DOE Office Websites (Extended Search)

Novel Non-Precious Metal Catalysts Novel Non-Precious Metal Catalysts Project Summary Full Title: Novel Non-Precious Metal Catalysts for PEMFC: Catalyst Selection through Molecular Modeling and Durability Studies Project ID: 147 Principal Investigator: Branko Popov Brief Description: The University of South Carolina is synthesizing novel non-precious metal electrocatalysts with similar activity and stability as Pt for oxygen reduction reaction (ORR). Keywords: Catalyst; oxygen reduction; non precious metals; molecular modeling; durability Purpose Develop highly active and stable carbon-based metal-free catalysts and carbon composite catalysts with strong Lewis basicity to facilitate the ORR. Performer Principal Investigator: Branko Popov Organization: University of South Carolina Address: 2C19 Swearingen, Chemical Engineering, 301 Main Street

63

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

SciTech Connect

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

64

Impact of Fuel Metal Impurities on Diesel Exhaust Catalysts  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Fuel Metal Impurities on Diesel Exhaust Catalysts Aaron Williams, Jonathan Burton, Robert McCormick National Renewable Energy Laboratory Todd Toops, Michael Lance, Andrew...

65

Pt–metal oxide aerogel catalysts: X-ray photoemission investigation  

Science Journals Connector (OSTI)

X-ray photoemission spectroscopy was used to study Pt–metal oxide aerogel catalysts that have been developed to respond to increased NO x emissions of lean-burn engines. Lean-burn engines critical components of low and zero emission vehicles produce much higher levels of engine-out NO x and current three-way catalytic converters are not sufficient to meet Clean Air Act standards. Platinum catalysts were formed by the reaction of modified Pt coordination compounds with selected transition–metal alkoxides through sol–gel techniques into aerogels. Photoemission measurements of the Pt 4f Si 2p Ti 2p O 1s and C 1s core lines were used to evaluate the chemistry of the material after each processing step. Results indicate Pt–O bonding and reduced Pt disbursed in the aerogel. In addition Si 2p Ti 2p and O 1s binding energies indicate an oxo-bridged network structure.

A. J. Nelson; John G. Reynolds; R. D. Sanner; P. R. Coronado; L. M. Hair

2001-01-01T23:59:59.000Z

66

Transition metal-promoted oxygen ion conductors as oxidation catalyst  

SciTech Connect

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

67

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

68

Platinum Nanoclusters Out-Perform Single Crystals  

NLE Websites -- All DOE Office Websites (Extended Search)

Platinum Nanoclusters Out-Perform Single Crystals Print Platinum Nanoclusters Out-Perform Single Crystals Print When it comes to metal catalysts, platinum is the standard. However, at about $2,000 an ounce, the high cost of the raw material presents major challenges for the future wide-scale use of platinum in fuel cells. Berkeley Lab research suggests that one possible way to meet these challenges is to think small. Researchers from Berkeley Lab's Materials Sciences Division have found that under high pressure-comparable to the pressures at which many industrial technologies operate-platinum surfaces can change their structure dramatically in response to the presence of high-coverage reactants. High-pressure scanning tunneling microscopes (STM) and ambient-pressure x-ray photoelectron spectroscopy (AP-XPS) at ALS Beamlines 9.3.2 and 11.0.2 allowed researchers to study catalysts' structure and composition under realistic conditions.

69

Platinum Nanoclusters Out-Perform Single Crystals  

NLE Websites -- All DOE Office Websites (Extended Search)

Platinum Nanoclusters Out-Perform Single Crystals Print Platinum Nanoclusters Out-Perform Single Crystals Print When it comes to metal catalysts, platinum is the standard. However, at about $2,000 an ounce, the high cost of the raw material presents major challenges for the future wide-scale use of platinum in fuel cells. Berkeley Lab research suggests that one possible way to meet these challenges is to think small. Researchers from Berkeley Lab's Materials Sciences Division have found that under high pressure-comparable to the pressures at which many industrial technologies operate-platinum surfaces can change their structure dramatically in response to the presence of high-coverage reactants. High-pressure scanning tunneling microscopes (STM) and ambient-pressure x-ray photoelectron spectroscopy (AP-XPS) at ALS Beamlines 9.3.2 and 11.0.2 allowed researchers to study catalysts' structure and composition under realistic conditions.

70

Platinum Nanoclusters Out-Perform Single Crystals  

NLE Websites -- All DOE Office Websites (Extended Search)

Platinum Nanoclusters Out-Perform Single Crystals Print Platinum Nanoclusters Out-Perform Single Crystals Print When it comes to metal catalysts, platinum is the standard. However, at about $2,000 an ounce, the high cost of the raw material presents major challenges for the future wide-scale use of platinum in fuel cells. Berkeley Lab research suggests that one possible way to meet these challenges is to think small. Researchers from Berkeley Lab's Materials Sciences Division have found that under high pressure-comparable to the pressures at which many industrial technologies operate-platinum surfaces can change their structure dramatically in response to the presence of high-coverage reactants. High-pressure scanning tunneling microscopes (STM) and ambient-pressure x-ray photoelectron spectroscopy (AP-XPS) at ALS Beamlines 9.3.2 and 11.0.2 allowed researchers to study catalysts' structure and composition under realistic conditions.

71

Platinum Nanoclusters Out-Perform Single Crystals  

NLE Websites -- All DOE Office Websites (Extended Search)

Platinum Nanoclusters Out-Perform Single Crystals Print Platinum Nanoclusters Out-Perform Single Crystals Print When it comes to metal catalysts, platinum is the standard. However, at about $2,000 an ounce, the high cost of the raw material presents major challenges for the future wide-scale use of platinum in fuel cells. Berkeley Lab research suggests that one possible way to meet these challenges is to think small. Researchers from Berkeley Lab's Materials Sciences Division have found that under high pressure-comparable to the pressures at which many industrial technologies operate-platinum surfaces can change their structure dramatically in response to the presence of high-coverage reactants. High-pressure scanning tunneling microscopes (STM) and ambient-pressure x-ray photoelectron spectroscopy (AP-XPS) at ALS Beamlines 9.3.2 and 11.0.2 allowed researchers to study catalysts' structure and composition under realistic conditions.

72

Platinum Nanoclusters Out-Perform Single Crystals  

NLE Websites -- All DOE Office Websites (Extended Search)

Platinum Nanoclusters Out-Perform Single Crystals Print Platinum Nanoclusters Out-Perform Single Crystals Print When it comes to metal catalysts, platinum is the standard. However, at about $2,000 an ounce, the high cost of the raw material presents major challenges for the future wide-scale use of platinum in fuel cells. Berkeley Lab research suggests that one possible way to meet these challenges is to think small. Researchers from Berkeley Lab's Materials Sciences Division have found that under high pressure-comparable to the pressures at which many industrial technologies operate-platinum surfaces can change their structure dramatically in response to the presence of high-coverage reactants. High-pressure scanning tunneling microscopes (STM) and ambient-pressure x-ray photoelectron spectroscopy (AP-XPS) at ALS Beamlines 9.3.2 and 11.0.2 allowed researchers to study catalysts' structure and composition under realistic conditions.

73

Platinum Nanoclusters Out-Perform Single Crystals  

NLE Websites -- All DOE Office Websites (Extended Search)

Platinum Nanoclusters Out-Perform Single Crystals Print Platinum Nanoclusters Out-Perform Single Crystals Print When it comes to metal catalysts, platinum is the standard. However, at about $2,000 an ounce, the high cost of the raw material presents major challenges for the future wide-scale use of platinum in fuel cells. Berkeley Lab research suggests that one possible way to meet these challenges is to think small. Researchers from Berkeley Lab's Materials Sciences Division have found that under high pressure-comparable to the pressures at which many industrial technologies operate-platinum surfaces can change their structure dramatically in response to the presence of high-coverage reactants. High-pressure scanning tunneling microscopes (STM) and ambient-pressure x-ray photoelectron spectroscopy (AP-XPS) at ALS Beamlines 9.3.2 and 11.0.2 allowed researchers to study catalysts' structure and composition under realistic conditions.

74

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

75

Cobalt discovery replaces precious metals as industrial catalyst  

NLE Websites -- All DOE Office Websites (Extended Search)

Cobalt Discovery Replaces Precious Metals Cobalt Discovery Replaces Precious Metals Cobalt discovery replaces precious metals as industrial catalyst Cobalt holds promise as an industrial catalyst with potential applications in such energy-related technologies such as production of biofuels and reduction of carbon dioxide. November 26, 2012 The artwork depicts the substitution of cobalt for precious metals in catalysis as a variation on the ancient alchemical theme of transmuting base metals into precious ones. The artwork depicts the substitution of cobalt for precious metals in catalysis as a variation on the ancient alchemical theme of transmuting base metals into precious ones. Contact Nancy Ambrosiano Communications Office (505) 699-1149 Email Catalysts are also integral to thousands of industrial, synthetic, and

76

Cobalt discovery replaces precious metals as industrial catalyst  

NLE Websites -- All DOE Office Websites (Extended Search)

Cobalt discovery replaces precious metals Cobalt discovery replaces precious metals Cobalt discovery replaces precious metals as industrial catalyst Cobalt holds promise as an industrial catalyst with potential applications in such energy-related technologies such as production of biofuels and reduction of carbon dioxide. November 26, 2012 The artwork depicts the substitution of cobalt for precious metals in catalysis as a variation on the ancient alchemical theme of transmuting base metals into precious ones. The artwork depicts the substitution of cobalt for precious metals in catalysis as a variation on the ancient alchemical theme of transmuting base metals into precious ones. Contact Nancy Ambrosiano Communications Office (505) 699-1149 Email Catalysts are also integral to thousands of industrial, synthetic, and

77

Cobalt discovery replaces precious metals as industrial catalyst  

NLE Websites -- All DOE Office Websites (Extended Search)

Cobalt Discovery Replaces Precious Metals Cobalt Discovery Replaces Precious Metals Cobalt discovery replaces precious metals as industrial catalyst Cobalt holds promise as an industrial catalyst with potential applications in such energy-related technologies such as production of biofuels and reduction of carbon dioxide. November 26, 2012 The artwork depicts the substitution of cobalt for precious metals in catalysis as a variation on the ancient alchemical theme of transmuting base metals into precious ones. The artwork depicts the substitution of cobalt for precious metals in catalysis as a variation on the ancient alchemical theme of transmuting base metals into precious ones. Contact Nancy Ambrosiano Communications Office (505) 699-1149 Email Catalysts are also integral to thousands of industrial, synthetic, and

78

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

79

Non-Noble Metal Water Electrolysis Catalysts - Energy Innovation...  

NLE Websites -- All DOE Office Websites (Extended Search)

Non-Noble Metal Water Electrolysis Catalysts Brookhaven National Laboratory Contact BNL About This Technology a) TEM image of the stacked MoN nanosheets on carbon supports. The...

80

Redox Active Catalysts Utilizing Earth Abundant Metals | Center...  

NLE Websites -- All DOE Office Websites (Extended Search)

Redox Active Catalysts Utilizing Earth Abundant Metals 14 Mar 2014 Ryan Trovitch has recently joined the team of the BISfuel PIs. He is an Assistant Professor at the Department of...

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

Supported Molten Metal Catalysis. A New Class of Catalysts  

SciTech Connect

We describe a new class of heterogeneous catalysts called supported molten metal catalysis (SMMC), in which molten metal catalysts are dispersed as nanodroplets on the surface of porous supports, allowing much larger active surface area than is possible in conventional contacting techniques for catalytic metals that are molten under reaction conditions, thus greatly enhancing their activity and potential utility. Specific examples of different types of reactions are provided to demonstrate the broad applicability of the technique in designing active, selective, and stable new catalysts. It is shown that dispersing the molten metal on a support in the suggested manner can enhance the rate of a reaction by three to four orders of magnitude as a result of the concomitant increase in the active surface area. New reaction examples include {gamma}-Al{sub 2}O{sub 3} supported molten Te (melting point 450 C) and Ga (MP 30 C) catalysts for bifunctional methylcyclohexane dehydrogenation. These catalysts provide activity similar to conventional Pt-based catalysts for this with better resistance to coking. In addition, results are described for a controlled pore glass supported molten In (MP 157 C) catalyst for the selective catalytic reduction of NO with ethanol in the presence of water, demonstrating activities superior to conventional catalysts for this reaction. A discussion is also provided on the characterization of the active surface area and dispersion of these novel supported catalysts. It is clear based on the results described that the development of new active and selective supported molten metal catalysts for practical applications is entirely plausible.

Ravindra Datta; Ajeet Singh; Manuela Serban; Istvan Halasz

2006-06-02T23:59:59.000Z

82

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

83

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

SciTech Connect

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

84

Application of a Turbulent Metal Foil Substrate for a PGM optimized DOC on a U.S. HD Diesel Engine  

Energy.gov (U.S. Department of Energy (DOE))

Lower platinum-metal group catalysts can be used to save money while offering equivalent or better hydrocarbon performanc and longer life and durability.

85

Partial oxidation of propane on ceria-and alumina-supported platinum catalysts.  

E-Print Network (OSTI)

??Three Pt/CeO2 catalysts and Pt/Al2O3 catalyst were studied for partial oxidation of propane. The 1 % Pt/CeO2 (C) catalyst which was prepared using CeO2 prepared… (more)

Bansode, Vijaya Anil.

2006-01-01T23:59:59.000Z

86

Less platinum means lower prices for autos | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Less platinum means lower prices for autos Less platinum means lower prices for autos Less platinum means lower prices for autos January 21, 2010 - 3:29pm Addthis Joshua DeLung You might wear a platinum wedding band, but tucked away in the guts of a car probably isn't where Americans prefer this pricey, precious metallic element to be. Luckily, researchers at 3M's Fuel Cell Component's Program in St. Paul, Minnesota have us covered. 3M has developed technology that will reduce the amount of platinum necessary in a fuel cell system by using nano-catalyst particles that actually make surface atoms more efficient at producing energy. Platinum is needed in fuel cells because no other metals are even close to being as effective at speeding up chemical reactions to make power. 3M is among a handful of fuel cell system suppliers in the U.S., and these advancements

87

Metal salt catalysts for enhancing hydrogen spillover  

SciTech Connect

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

88

Preparation and evaluation of novel hydrous metal oxide (HMO)-supported noble metal catalysts  

SciTech Connect

Hydrous Metal Oxides (HMOs) are chemically synthesized materials that, because of their high cation exchange capacity, possess a unique ability to allow the preparation of highly dispersed supported-metal catalyst precursors with high metal loadings. This study evaluates high weight loading Rh/HMO catalysts with a wide range of HMO support compositions, including hydrous titanium oxide (HTO), silica-doped hydrous titanium oxide (HTO:Si), hydrous zirconium oxide (HZO), and silica-doped hydrous zirconium oxide (HZO:Si), against conventional oxide-supported Rh catalysts with similar weight loadings and support chemistries. Catalyst activity measurements for a structure-sensitive model reaction (n-butane hydrogenolysis) as a function of catalyst activation conditions show superior activity and stability for the ZrO{sub 2}, HZO, and HZO:Si supports, although all of the Rh/HMO catalysts have high ethane selectivity indicative of high Rh dispersion. For the TiO{sub 2}-, HTO-, and HTO:Si supported Rh catalysts, a significant loss of both catalyst activity and Rh dispersion is observed at more aggressive activation conditions, consistent with TiO{sub x} migration associated with SMSI phenomena. Of all the Rh/HMO catalysts, the Rh/HZO:Si catalysts appear to offer the best tradeoff in terms of high Rh dispersion, high activity, and high selectivity.

Gardner, T.J.; McLaughlin, L.I.; Evans, L.R. [Sandia National Labs., Albuquerque, NM (United States). Catalysis and Chemical Technologies Dept.; Datye, A.K. [Univ. of New Mexico, Albuquerque, NM (United States)

1998-04-01T23:59:59.000Z

89

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

SciTech Connect

Uses for structured catalytic supports, such as ceramic straight-channel monoliths and ceramic foams, have been established for a long time. One of the most prominent examples is the washcoated ceramic monolith as a three-way catalytic converter for gasoline-powered automobiles. A distinct alternative to the ceramic monolith is the metal foam, with potential use in fuel cell-powered automobiles. The metal foams are characterized by their pores per inch (ppi) and density ({rho}). In previous research, using 5 wt% platinum (Pt) and 0.5 wt% iron (Fe) catalysts, washcoated metal foams, 5.08 cm in length and 2.54 cm in diameter, of both varying and similar ppi and {rho} were tested for their activity (X{sub CO}) and selectivity (S{sub CO}) on a CO preferential oxidation (PROX) reaction in the presence of a H{sub 2}-rich gas stream. The variances in these metal foams' activity and selectivity were much larger than expected. Other structured supports with 5 wt% Pt, 0-1 wt% Fe weight loading were also examined. A theory for this phenomenon states that even though these structured supports have a similar nominal catalyst weight loading, only a certain percentage of the Pt/Fe catalyst is exposed on the surface as an active site for CO adsorption. We will use two techniques, pulse chemisorption and temperature programmed desorption (TPD), to characterize our structured supports. Active metal count, metal dispersion, and other calculations will help clarify the causes for the activity and selectivity variations between the supports. Results on ceramic monoliths show that a higher Fe loading yields a lower dispersion, potentially because of Fe inhibition of the Pt surface for CO adsorption. This theory is used to explain the reason for activity and selectivity differences for varying ppi and {rho} metal foams; less active and selective metal foams have a lower Fe loading, which justifies their higher metal dispersion. Data on the CO desorption temperature and average metal crystallite size for TPD are also collected.

Paul Chin; George W. Roberts; James J. Spivey

2003-12-31T23:59:59.000Z

90

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...

91

Li?Air Rechargeable Battery Based on Metal-free Graphene Nanosheet Catalysts  

Science Journals Connector (OSTI)

Li?Air Rechargeable Battery Based on Metal-free Graphene Nanosheet Catalysts ... Aqueous Rechargeable Li and Na Ion Batteries ...

Eunjoo Yoo; Haoshen Zhou

2011-03-25T23:59:59.000Z

92

Process using noble metal-chromium alloy catalysts in an electrochemical cell  

SciTech Connect

A novel and improved noble metal-chromium alloy catalyst is disclosed with catalytic oxygen reduction activity at least twice that of the unalloyed noble metal. The noble metal-chromium alloy catalyst disclosed has particular utility as an electrocatalyst for the reduction of oxygen which makes it particularly useful as a cathode catalyst in an acid fuel cell.

Landsman, D.A.; Luczak, F.J.

1983-02-08T23:59:59.000Z

93

Coming up with platinum substitutes may be elemental  

NLE Websites -- All DOE Office Websites (Extended Search)

Coming up with platinum substitutes may be elemental Coming up with platinum substitutes may be elemental Community Connections: Our link to Northern New Mexico Communities Latest Issue:Dec. 2013 - Jan. 2014 All Issues » submit Coming up with platinum substitutes may be elemental Lab researchers are working with an abundant element to take their place: cobalt. February 1, 2013 dummy image Read our archives. Contacts Editor Linda Anderman Email Community Programs Office Kurt Steinhaus Email Initial findings by a Los Alamos team indicate that if a cobalt atom is captured within a complex molecule, it can mimic the reactivity of platinum group metals. Platinum and some related precious metals (palladium, iridium, rhodium and ruthenium) are frequently used as chemical catalysts and for countless laboratory processes. As rare metals, they are also expensive. To ensure

94

Nonprecious Metal Catalysts for Low Temperature Solid Oxide Fuel Cells  

Science Journals Connector (OSTI)

Nonprecious Metal Catalysts for Low Temperature Solid Oxide Fuel Cells ... Initial and final state geometries are found with standard geometry optimization, then a number of intermediate states are generated by interpolation of atomic positions. ... A special "metric" and a special "preconditioning" optimized for a plane-wave basis set will be introduced. ...

Timothy P. Holme; Fritz B. Prinz

2011-05-24T23:59:59.000Z

95

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

96

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

97

Low platinum, high limiting current density of the PEMFC (proton exchange membrane fuel cell) based on multilayer cathode catalyst approach  

Science Journals Connector (OSTI)

Abstract Novel multilayer cathode electrodes structures for PEMFC (proton exchange membrane fuel cell) based on sputtering technique were developed to provide high performance with low loading Pt of 0.05 mg/cm² compared to the standard MEA (membrane electrode assembly) cathode (?0.2–0.3 mg/cm²). Different configurations of cathode catalyst layer were made by altering Pt and CN (Carbon–Nafion) ink carefully prepared on gas diffusion layer containing MPL (micro porous layer). The performances of PEMFC containing the multilayer electrodes were compared based on their measured polarization curves. Higher limiting current densities were achieved compared to standard MEA with platinum loading of 0.2 mg/cm² both at the cathode and the anode sides. Limiting current densities over 1.1 A/cm2, 1.2 A/cm2 and 1.4 A/cm2 were reached whereas maximum powers were in the range of 500 mW/cm² at 600 mW/cm². The good performances obtained can be due to the structural improvement which has contributed to a better catalyst utilization compared to conventional methods. A CN loading inferior to 0.24 mg/cm² between each layer is preferred for multilayer electrode.

Daouda Fofana; Sadesh Kumar Natarajan; Jean Hamelin; Pierre Benard

2014-01-01T23:59:59.000Z

98

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

99

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

100

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

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,
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We encourage you to perform a real-time search of NLEBeta
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101

REDUCTION OF NITRIC OXIDE BY CARBON MONOXIDE OVER A SILICA SUPPORTED PLATINUM CATALYST: INFRARED AND KINETIC STUDIES  

E-Print Network (OSTI)

System. • B. Procedures. Catalyst Preparation Infrared DiskPreparation. Catalyst Characterization. PreliminaryReduction by CO Over a Pt Catalyst," M.S. thesis, Department

Lorimer, D.H.

2011-01-01T23:59:59.000Z

102

Oxidation and Surface Segregation Behavior of a Pt–Pd–Rh Alloy Catalyst  

Science Journals Connector (OSTI)

Platinum gauze catalysts are used extensively in the production of nitric acid from ammonia, where they are subject to harsh operating conditions combining elevated temperatures and oxidizing environments. These cause significant loss of metal species as ...

Paul A. J. Bagot; Karen Kruska; Daniel Haley; Xavier Carrier; Eric Marceau; Michael. P. Moody; George D. W. Smith

2014-10-16T23:59:59.000Z

103

Platinum Metals Rev., 2008, 52, (3), 144-154  

NLE Websites -- All DOE Office Websites (Extended Search)

Metals Rev., 2008, 52, (3), 144-154 Metals Rev., 2008, 52, (3), 144-154 144 1. Introduction Coal-fired utility boilers are the largest anthro- pogenic emitters of mercury in the United States, accounting for approximately one third of the 150 tons of mercury emitted annually (1, 2). In 2005, the U.S. Environmental Protection Agency (EPA) announced the Clean Air Mercury Rule, to limit mercury emissions from coal-fired utility boilers to 15 tons annually, approximately 30% of 1999 levels, by 2018 (3). At the time of publication (July 2008) this measure is under legal dispute. Of alter- native legislative proposals to regulate mercury along with other pollutants, most would require a 90% mercury reduction, with deadlines for control varying from 2011 to 2015. Mercury exists in three forms in coal-derived flue gas: elemental (Hg

104

Gasification of Organosolv-lignin Over Charcoal Supported Noble Metal Salt Catalysts in Supercritical Water  

Science Journals Connector (OSTI)

Charcoal supported metal salt catalysts showed activities for the lignin gasification at 673 K, especially the catalysts without chloride anion showed the complete gasification. The order of activity for the gasification

Aritomo Yamaguchi; Norihito Hiyoshi; Osamu Sato; Masayuki Shirai

2012-08-01T23:59:59.000Z

105

Platinum Nanoclusters Out-Perform Single Crystals  

NLE Websites -- All DOE Office Websites (Extended Search)

Platinum Nanoclusters Out-Perform Single Platinum Nanoclusters Out-Perform Single Crystals Platinum Nanoclusters Out-Perform Single Crystals Print Wednesday, 27 October 2010 00:00 When it comes to metal catalysts, platinum is the standard. However, at about $2,000 an ounce, the high cost of the raw material presents major challenges for the future wide-scale use of platinum in fuel cells. Berkeley Lab research suggests that one possible way to meet these challenges is to think small. Researchers from Berkeley Lab's Materials Sciences Division have found that under high pressure-comparable to the pressures at which many industrial technologies operate-platinum surfaces can change their structure dramatically in response to the presence of high-coverage reactants. High-pressure scanning tunneling microscopes (STM) and ambient-pressure x-ray photoelectron spectroscopy (AP-XPS) at ALS Beamlines 9.3.2 and 11.0.2 allowed researchers to study catalysts' structure and composition under realistic conditions.

106

Experimental Study of In Situ Combustion with Tetralin and Metallic Catalysts  

E-Print Network (OSTI)

or metallic catalysts; the second run used heavy oil premixed with 3 wt% tetralin and 500ppm nickel catalyst; and the third run was with heavy oil premixed with 3 wt% tetralin and 500ppm iron catalyst. For the three runs, the cell production pressure was kept...

Palmer-Ikuku, Emuobonuvie

2010-01-16T23:59:59.000Z

107

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

108

Studies of Immobilized Homogeneous Metal Catalysts on Silica Supports  

SciTech Connect

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

109

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

110

Comparison of the performance of activated carbon-supported noble metal catalysts in the hydrogenolysis of CCl{sub 2}F{sub 2}  

SciTech Connect

The hydrogenolysis of CCl{sub 2}F{sub 2} over 1 wt% palladium, platinum, rhodium, ruthenium, iridium, and rhenium on activated carbon has been studied in a micro-flow reactor, in a temperature range of 450--540 K, H{sub 2}/CCl{sub 2}F{sub 2} feed ratios between 1.5 and 6, a pressure of 0.4 MPa, and a WHSV of 1 g/(g{center_dot}h). The main products of the reaction for all investigated catalysts were CHClF{sub 2}, CH{sub 2}F{sub 2}, and methane. According to their performance, the catalysts could be divided into four groups: rhenium showing no conversion of CCl{sub 2}F{sub 2}, palladium with a high selectivity for CH{sub 2}F{sub 2}, iridium and ruthenium with a high selectivity for CHClF{sub 2}, and platinum and rhodium with moderate selectivity for CHClF{sub 2} and CH{sub 2}F{sub 2}. The adsorption of chlorine on the metal surface plays an important role in the selectivity. Strong chlorine adsorption leads to a higher selectivity for CHClF{sub 2}. These results are consistent with a reaction mechanism in which difluorocarbene is the key intermediate. Apparently, the same kinetic network applies to all metals studied. The performance of the catalysts changed as a function of time on stream. Palladium, rhodium, and especially ruthenium deactivated during reaction, whereas the activity of iridium and platinum increased. This can be explained by two opposite effects. On the one hand, the dispersion of all catalysts increased during reaction, which can explain an increase in activity as a function of time on stream. Apparently, CCl{sub 2}F{sub 2} hydrogenolysis conditions are suitable for dispersing noble metal catalysts on activated carbon. On the other hand, deactivation takes place by the adsorption of chlorine and deposits of heavy halogenated products.

Wiersma, A.; Sandt, E.J.A.X. van de; Hollander, M.A. den; Bekkum, H. van; Makkee, M.; Moulijn, J.A. [Delft Univ. of Technology (Netherlands)] [Delft Univ. of Technology (Netherlands)

1998-07-01T23:59:59.000Z

111

Thermal Processing Techniques to Improve Metal Sulfide Mixed Alcohol Catalyst Performance  

SciTech Connect

Research over several decades by several institutions has shown that alkali-promoted metal sulfide catalysts are capable of producing mixed alcohols from syngas with high selectivity and yield. Unfortunately, process models suggest that syngas to mixed alcohol processes, and especially thermochemical biomass to mixed alcohol processes, require improvements to sulfide catalyst activity and/or selectivity for acceptable economics. These improvements, if incremental, cannot result in increased process complexity, capital expenditure, or catalyst costs. It is well accepted among catalyst researchers that thermal processing techniques like calcining and reduction can have profound effects on the properties and performance of finished catalysts, and that small variations in thermal processing do not usually affect the overall cost of the catalyst. Metal sulfide catalysts are no exception but surprisingly, little attention has been given to the effects of thermal treatment on bulk metal sulfide mixed alcohol catalysts. This presentation will discuss how parameters like temperature, dwell time, metal ratios, and purge gas affect the performance and physical properties of K-Co/Mo catalysts.

Hensley, J.; Menart, M.; Costelow, K.; Thibodeaux, J.; Yung, M.

2011-01-01T23:59:59.000Z

112

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

113

Effect of Graphitic Content on Carbon Supported Catalyst Performance  

SciTech Connect

The effect of graphitic content on carbon supported platinum catalysts was investigated in order to investigate its influence on catalyst performance. Four catalysts of varying surface areas and graphitic content were analyzed using XPS, HREELS, and tested using RDE experiments. The catalysts were also heat treated at 150oC and 100%RH as means to uniformly age them. The heat treated samples were analyzed using the same methods to determine what changes had occurred due to this aging process. When compared to the BOL catalysts, heat treated catalysts displayed increased graphitic carbon and platinum metalic content, however they also showed depressed catalytic activity. The primary cause is still under investigation, though it is believed to be related to loss of amorphous carbon content.

Patel, Anant; Artyushkova, Kateryna; Atanassov, Plamen; Harvey, David; Dutta, Monica; Colbow, Vesna

2011-07-01T23:59:59.000Z

114

Effect of Graphitic Content on Carbon Supported Catalyst Performance  

SciTech Connect

The effect of graphitic content on carbon supported platinum catalysts was investigated in order to investigate its influence on catalyst performance. Four catalysts of varying surface areas and graphitic content were analyzed using XPS, HREELS, and tested using RDE experiments. The catalysts were also heat treated at 150 C and 100%RH as means to uniformly age them. The heat treated samples were analyzed using the same methods to determine what changes had occurred due to this aging process. When compared to the BOL catalysts, heat treated catalysts displayed increased graphitic carbon and platinum metallic content, however they also showed depressed catalytic activity. The primary cause is still under investigation, though it is believed to be related to loss of amorphous carbon content.

A. Patel; K. Artyushkova; P. Atanassov; David Harvey; M. Dutta; V. Colbow; S. Wessel

2011-07-01T23:59:59.000Z

115

Supported metal catalysts for alcohol/sugar alcohol steam reforming  

SciTech Connect

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

116

Development of a Titanium Dioxide-Supported Platinum Catalyst with Ultrahigh Stability for Polymer Electrolyte Membrane Fuel Cell Applications  

Science Journals Connector (OSTI)

The Pt/TiO2 cathode catalyst exhibited excellent fuel cell performance and ultrahigh stability under accelerated stress test conditions and can be considered as a promising alternative for improving the reliability and durability of PEMFCs. ... The design and synthesis of highly active oxygen reduction reaction (ORR) catalysts with strong durability at low cost is extremely desirable but still remains a significant challenge. ...

Sheng-Yang Huang; Prabhu Ganesan; Sehkyu Park; Branko N. Popov

2009-09-09T23:59:59.000Z

117

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

SciTech Connect

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

118

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

119

Influence of carbon support on the performance of platinum based oxygen reduction catalysts in a polymer electrolyte fuel cell  

Science Journals Connector (OSTI)

In a hydrogen fuelled PEMFC voltage losses are dominated by cathodic overvoltages. Considering the superior performance of DMFC anode catalysts based on carbon materials of the Sibunit...2 g?1 as supports for PEMFC

Jörg Kaiser; Pavel A. Simonov…

2007-12-01T23:59:59.000Z

120

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

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

Aerogel-Coated Metal Nanoparticle Colloids as Novel Entities for the Synthesis of Defined Supported Metal Catalysts  

Science Journals Connector (OSTI)

Aerogel-Coated Metal Nanoparticle Colloids as Novel Entities for the Synthesis of Defined Supported Metal Catalysts ... Nanometer metal particles of tailored size (3?5 nm) and composition prepared via inverse microemulsion were encapsulated by ultrathin coatings (aerogels covered with surface ?OH groups. ... Thus, the product and technology described may be suitable to synthesize these precursor entities of defined metal sizes (as inks) for wash coat/impregnation applications in catalysis. ...

Kai Man K. Yu; Connie M. Y. Yeung; David Thompsett; Shik Chi Tsang

2003-04-10T23:59:59.000Z

122

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

123

The Platinum-Group Elements:  

Science Journals Connector (OSTI)

...higher Pt emissions have been measured for diesel catalysts (Moldovan et al. 2002...1031-1036 Johnson Matthey (2007) Market Data Tables. Online information www...platinum-group elements released from gasoline and diesel engine catalytic converters. Science...

Sebastien Rauch; Gregory M. Morrison

124

Model heterogeneous acid catalysts and metal-support interactions: A combined surface science and catalysis study  

SciTech Connect

This (<100 [Angstrom]) silica-alumina layers were tested as potential model heterogeneous acid catalysts for combined surface science and catalysis studies. Three preparation methods were used: oxidation of r3 [times] r3 R30 Al/Si(111) structure in UHV; deposition on Si(lll) from aqueous solution; and argon ion beam sputter deposition in UHV. The homogeneous thin layers are amorphous, and the chemical environment of surface atoms is similar to that of Si, Al and oxygen atoms on high surface area acid catalysts. Since the ion beam-deposited thin layer of silica-alumina has the same composition as the target zeolite this deposition method is a promising tool to prepare model catalysts using practical catalyst targets. The silica-alumina layers are active in cumene cracking, a typical acid catalyzed reaction. In order to clearly distinguish background reactions and the acid catalyzed reaction at least 20 cm[sup 2] catalyst surface area is needed. Two series of model platinum-alumina catalysts were prepared in a combined UHV -- high pressure reactor cell apparatus by depositing alumina on polycrystalline Pt foil and by vapor depositing Pt on a thin alumina layer on Au. Both model surfaces have been prepared with and without chlorine. AES, CO desorption as well as methyl cyclopentane (MCP) hydrogenolysis studies indicate that the Pt surface area is always higher if a chlorination step is involved. Selectivity patterns in MCP ring opening on Pt-on-alumina'' and on alumina-on-Pt'' are different; only the former is a linear combination of selective and statistical ring opening. Product distribution, however, changes with coverage and reaction time. The properties of the two model catalyst systems and role of chlorine in MCP hydrogenolysis are also discussed.

Boszormenyi, I.

1991-05-01T23:59:59.000Z

125

Model heterogeneous acid catalysts and metal-support interactions: A combined surface science and catalysis study  

SciTech Connect

This (<100 {Angstrom}) silica-alumina layers were tested as potential model heterogeneous acid catalysts for combined surface science and catalysis studies. Three preparation methods were used: oxidation of r3 {times} r3 R30 Al/Si(111) structure in UHV; deposition on Si(lll) from aqueous solution; and argon ion beam sputter deposition in UHV. The homogeneous thin layers are amorphous, and the chemical environment of surface atoms is similar to that of Si, Al and oxygen atoms on high surface area acid catalysts. Since the ion beam-deposited thin layer of silica-alumina has the same composition as the target zeolite this deposition method is a promising tool to prepare model catalysts using practical catalyst targets. The silica-alumina layers are active in cumene cracking, a typical acid catalyzed reaction. In order to clearly distinguish background reactions and the acid catalyzed reaction at least 20 cm{sup 2} catalyst surface area is needed. Two series of model platinum-alumina catalysts were prepared in a combined UHV -- high pressure reactor cell apparatus by depositing alumina on polycrystalline Pt foil and by vapor depositing Pt on a thin alumina layer on Au. Both model surfaces have been prepared with and without chlorine. AES, CO desorption as well as methyl cyclopentane (MCP) hydrogenolysis studies indicate that the Pt surface area is always higher if a chlorination step is involved. Selectivity patterns in MCP ring opening on ``Pt-on-alumina`` and on ``alumina-on-Pt`` are different; only the former is a linear combination of selective and statistical ring opening. Product distribution, however, changes with coverage and reaction time. The properties of the two model catalyst systems and role of chlorine in MCP hydrogenolysis are also discussed.

Boszormenyi, I.

1991-05-01T23:59:59.000Z

126

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

127

Synthesis of Ammonium Cyanate and Urea by Reduction of Nitric Oxide on Platinum, Rhodium, and Ruthenium Catalysts  

Science Journals Connector (OSTI)

...E.G., RECOVERY OF NITROGEN...FIXATION OF ATMOSPHERIC NITROGEN IN...as NO, the recovery of NO from...pre-vent condensation of solid NH4OCN...through the water-gas shift...results for the recovery of fixed nitrogen...catalyst. Water, 02, and...Presumably, near-atmospheric partial pressures...

R. J. H. VOORHOEVE; L. E. TRIMBLE; D. J. FREED

1978-05-19T23:59:59.000Z

128

Nanostructured Catalyst Systems for Fuel Cells: Synthesis and Characterization of Low Platinum Content Electrocatalysts for O{sub 2} Reduction  

SciTech Connect

The objective of this project is to synthesize and characterize new O{sub 2} reduction catalysts with enhanced activity and ultra low Pt loading, and to test them in membrane electrode assemblies (MEAs) to determine their performance under fuel cell cathode operating conditions.

Adzic, Radoslav

2007-02-01T23:59:59.000Z

129

Transition Metal Decorated Graphyne: An Efficient Catalyst for Oxygen Reduction Reaction  

Science Journals Connector (OSTI)

(63, 64) In the case of TM-N4 catalysts also, often the TMs are found to be ferromagnetic in nature and are shown to catalyze ORR. ... The prohibitive cost and scarcity of the noble-metal catalysts needed for catalyzing the O redn. ... Polarization graphs for the ORR reaction in PEMFC with Pt/(f-G-f-MWNT) as an electrocatalyst resulted in the best performance of 540 mW/cm2 for the Pt/(50% f-G+50% f-MWNT) cathode catalyst, agreeing with the electrochem. ...

K. Srinivasu; Swapan K. Ghosh

2013-11-20T23:59:59.000Z

130

A Methodology for Investigating New Nonprecious Metal Catalysts for PEM Fuel Cells  

Science Journals Connector (OSTI)

A Methodology for Investigating New Nonprecious Metal Catalysts for PEM Fuel Cells ... Although recent technological improvements have reduced the amount of Pt required (optimizing the particle size and catalyst dispersion,2,3 the market-price limitations for mass production have not yet been satisfied. ... Thus far, no attempt has been made to optimize the behaviors of either type of catalyst, but their general relationship follows from similar Co?Se structural phases being present in the dispersed and thin-film forms. ...

D. Susac; A. Sode; L. Zhu; P. C. Wong; M. Teo; D. Bizzotto; K. A. R. Mitchell; R. R. Parsons; S. A. Campbell

2006-05-17T23:59:59.000Z

131

Monodisperse metal nanoparticle catalysts on silica mesoporous supports: synthesis, characterizations, and catalytic reactions  

SciTech Connect

The design of high performance catalyst achieving near 100% product selectivity at maximum activity is one of the most important goals in the modern catalytic science research. To this end, the preparation of model catalysts whose catalytic performances can be predicted in a systematic and rational manner is of significant importance, which thereby allows understanding of the molecular ingredients affecting the catalytic performances. We have designed novel 3-dimensional (3D) high surface area model catalysts by the integration of colloidal metal nanoparticles and mesoporous silica supports. Monodisperse colloidal metal NPs with controllable size and shape were synthesized using dendrimers, polymers, or surfactants as the surface stabilizers. The size of Pt, and Rh nanoparticles can be varied from sub 1 nm to 15 nm, while the shape of Pt can be controlled to cube, cuboctahedron, and octahedron. The 3D model catalysts were generated by the incorporation of metal nanoparticles into the pores of mesoporous silica supports via two methods: capillary inclusion (CI) and nanoparticle encapsulation (NE). The former method relies on the sonication-induced inclusion of metal nanoparticles into the pores of mesoporous silica, whereas the latter is performed by the encapsulation of metal nanoparticles during the hydrothermal synthesis of mesoporous silica. The 3D model catalysts were comprehensively characterized by a variety of physical and chemical methods. These catalysts were found to show structure sensitivity in hydrocarbon conversion reactions. The Pt NPs supported on mesoporous SBA-15 silica (Pt/SBA-15) displayed significant particle size sensitivity in ethane hydrogenolysis over the size range of 1-7 nm. The Pt/SBA-15 catalysts also exhibited particle size dependent product selectivity in cyclohexene hydrogenation, crotonaldehyde hydrogenation, and pyrrole hydrogenation. The Rh loaded SBA-15 silica catalyst showed structure sensitivity in CO oxidation reaction. In addition, Pt-mesoporous silica core-shell structured NPs (Pt{at}mSiO{sub 2}) were prepared, where the individual Pt NP is encapsulated by the mesoporous silica layer. The Pt{at}mSiO{sub 2} catalysts showed promising catalytic activity in high temperature CO oxidation. The design of catalytic structures with tunable parameters by rational synthetic methods presents a major advance in the field of catalyst synthesis, which would lead to uncover the structure-function relationships in heterogeneous catalytic reactions.

Somorjai, G.A.

2009-09-14T23:59:59.000Z

132

Tar Reforming in Model Gasifier Effluents: Transition Metal/Rare Earth Oxide Catalysts  

Science Journals Connector (OSTI)

Tar Reforming in Model Gasifier Effluents: Transition Metal/Rare Earth Oxide Catalysts ... So in this work we investigated the action of transition metal oxides (TMOs) other than Ni (e.g., Fe, Mn) mixed with REOs for tar reforming, at a medium temperature range (923–1073 K) and under conditions where direct reforming would dominate. ... The heated gas mixture passed through a 1/2” stainless steel tube containing 0.2–1 g of catalyst (40–60 mesh size) diluted with mullite and positioned between beds of ?-Al2O3. ...

Rui Li; Amitava Roy; Joseph Bridges; Kerry M. Dooley

2014-04-24T23:59:59.000Z

133

Modeling nanostructured catalyst layer in PEMFC and catalyst utilization  

Science Journals Connector (OSTI)

A lattice model of the nanoscaled catalyst layer structure in proton exchange membrane fuel ... all the four components in a typical PEMFC catalyst layer: platinum (Pt), carbon, ionomer ... each average sized Pt ...

Jiejing Zhang; Pengzhen Cao; Li Xu…

2011-09-01T23:59:59.000Z

134

Deposition of Platinum Nanoparticles on Carbon Nanotubes by Supercritical Fluid Method  

SciTech Connect

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

135

Metal foam-supported Pd–Rh catalyst for steam methane reforming and its application to SOFC fuel processing  

Science Journals Connector (OSTI)

Abstract Pd–Rh/metal foam catalyst was studied for steam methane reforming and application to SOFC fuel processing. Performance of 0.068 wt% Pd–Rh/metal foam catalyst was compared with 13 wt% Ni/Al2O3 and 8 wt% Ru/Al2O3 catalysts in a tubular reactor. At 1023 K with GHSV 2000 h?1 and S/C ratio 2.5, CH4 conversion and H2 yield were 96.7% and 3.16 mol per mole of CH4 input for Pd–Rh/metal foam, better than the alumina-supported catalysts. In 200 h stability test, Pd–Rh/metal foam catalyst exhibited steady activity. Pd–Rh/metal foam catalyst performed efficiently in a heat exchanger platform reactor to be used as prototype SOFC fuel processor: at 983 K with GHSV 1200 h?1 and S/C ratio 2.5, CH4 conversion was nearly the same as that in the tubular reactor, except for more H2 and CO2 yields. Used Pd–Rh/metal foam catalyst was characterized by SEM, TEM, BET and CO chemisorption measurements, which provided evidence for thermal stability of the catalyst.

Partho Sarothi Roy; No-Kuk Park; Kiseok Kim

2014-01-01T23:59:59.000Z

136

DIRECT DECOMPOSITION OF METHANE TO HYDROGEN ON METAL LOADED ZEOLITE CATALYST  

SciTech Connect

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

137

Smoothing of low-intensity noisy X-ray diffraction data by Fourier filtering: application to supported metal catalyst studies  

Science Journals Connector (OSTI)

A Wiener filtering algorithm was used to smooth broad and noisy X-ray diffraction (XRD) patterns from highly dispersed catalysts with low metal loading. It enabled extraction of XRD patterns from the active phases of the catalysts interpretable in terms of phase composition.

Mierzwa, B.

1997-10-01T23:59:59.000Z

138

Operando Raman and Theoretical Vibration Spectroscopy of Non-PGM Catalysts  

Energy.gov (U.S. Department of Energy (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.

139

Nanostructural characterization and catalytic analysis of hybridized platinum/phthalocyanine nanocomposites  

Science Journals Connector (OSTI)

......precious Pt and Pt alloy catalysts is one of the significant...important issue for PEMFC development and is intensively...carbon supported platinum catalysts. J. Phys. Chem...Simon U. Low loading Pt cathode catalysts for direct methanol......

Kenji Kaneko; Kazuki Furuya; Ana B. Hungria; Juan-Carlos Hernandez-Garrido; Paul A. Midgley; Tsunenobu Onodera; Hitoshi Kasai; Yusuke Yaguchi; Hidetoshi Oikawa; Yohei Nomura; Hiroki Harada; Tatsumi Ishihara; Norio Baba

2009-10-01T23:59:59.000Z

140

Process for carbonaceous material conversion and recovery of alkali metal catalyst constituents held by ion exchange sites in conversion residue  

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 for the particles by contacting or washing them with an aqueous solution containing calcium or magnesium ions in an alkali metal recovery zone at a low temperature, preferably below about 249.degree. F. During the washing or leaching process, the calcium or magnesium ions displace alkali metal ions held by ion exchange sites in the particles thereby liberating the ions and producing an aqueous effluent containing alkali metal constituents. The aqueous effluent from the alkali metal recovery zone is then recycled to the conversion process where the alkali metal constituents serve as at least a portion of the alkali metal constituents which comprise the alkali metal-containing catalyst.

Sharp, David W. (Seabrook, TX)

1980-01-01T23:59:59.000Z

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.


141

Preparation of supported metal catalysts starting from hydrotalcites as the precursors and their improvements by adopting “memory effect”  

Science Journals Connector (OSTI)

Hydrotalcite-like compounds (HTlcs) can be used as the catalysts as it is since they contain various transition metal cations as the catalytically active species well dispersed on the basic support materials. ...

K. Takehira; T. Shishido

2007-06-01T23:59:59.000Z

142

Selective Hydrogenation of Biomass Based 5-Hydroxymethylfurfural over Catalyst of Palladium Immobilized on Amine-Functionalized Metal–Organic Frameworks  

Science Journals Connector (OSTI)

Selective Hydrogenation of Biomass Based 5-Hydroxymethylfurfural over Catalyst of Palladium Immobilized on Amine-Functionalized Metal–Organic Frameworks ... A catalyst of palladium [Pd/MIL-101(Al)-NH2] supported on amine-functionalized Metal–Organic Frameworks (MOFs) allows selective hydrogenation of biomass-based 5-hydroxymethylfurfural (HMF) to 2,5-dihydroxymethyl-tetrahydrofuran (DHMTHF) with 2,5-dihydroxymethylfuran (DHMF) as an observed “intermediate”. ...

Jinzhu Chen; Ruliang Liu; Yuanyuan Guo; Limin Chen; Hui Gao

2014-12-16T23:59:59.000Z

143

Crystal and molecular structure of a dinuclear ortho-metalated platinum ylid complex, cyclo-[Pt(.mu.-Cl)(MeCO)CHP(C6H4-o)Ph2]2.2CDCl3  

Science Journals Connector (OSTI)

Crystal and molecular structure of a dinuclear ortho-metalated platinum ylid complex, cyclo-[Pt(.mu.-Cl)(MeCO)CHP(C6H4-o)Ph2]2.2CDCl3 ...

Marvin L. Illingsworth; John A. Teagle; John L. Burmeister; William C. Fultz; Arnold L. Rheingold

1983-10-01T23:59:59.000Z

144

Science Magazine Highlight: Moving Towards Near Zero Platinum Fuel Cells Webinar  

NLE Websites -- All DOE Office Websites (Extended Search)

Magazine Highlight: Magazine Highlight: Moving Towards Near Zero Platinum Fuel Cells Piotr Zelenay Co-Authors Gang Wu, Hoon Chung, Christina Johnston, Patrick Turner, Zhongfen Ding, Jerzy Chlistunoff, Nate Mack, Mark Nelson Los Alamos National Laboratory Los Alamos, New Mexico 87545, USA 1 1 Fuel Cell Technologies Program Webinar - April 25, 2011 DOE Fuel Cell Technologies Webinar - April 25, 2011 Outline * Introduction: ─ rationale ─ recent developments in non-precious metal oxygen reduction reaction (ORR) catalysis ( ) y * Low-temperature Oxygen Reduction Reaction (ORR) catalysts (PPy-Co-C) * Catalysts obtained by heat treatment of organic and transition- metal precursors: ─ polyaniline-derived catalysts as a best combination of activity polyaniline derived catalysts as a best combination of activity

145

Metal?Support Interactions in Zeolite-Supported Noble Metals:? Influence of Metal Crystallites on the Support Acidity  

Science Journals Connector (OSTI)

The metal?support interactions on a series of catalysts of different acidities, including platinum-modified zeolites and H?MCM-41, are investigated by means of XPS, CO and pyridine adsorption, and a model reaction (ring opening of decalin). The electronic ...

David Kubi?ka; Narendra Kumar; Tapani Venäläinen; Hannu Karhu; Iva Kubi?ková; Heidi Österholm; Dmitry Yu. Murzin

2006-02-24T23:59:59.000Z

146

The Science And Engineering of Duralbe Ultralow PGM Catalysts  

NLE Websites -- All DOE Office Websites (Extended Search)

Fuel Cells and Infrastructure Technologies Fuel Cells and Infrastructure Technologies 2009 Kickoff Meeting The Science And Engineering of Durable Ultralow PGM Catalysts Eric Brosha, Neil Henson and Fernando Garzon (PI) LANL 1 Los Alamos National Laboratory (lead participant) Ballard Power Systems (BPS) University of California Riverside (UCR) University of New Mexico (UNM) Oak Ridge National Laboratory (ORNL) *Development of durable, high mass activity Platinum Group Metal cathode catalysts *Elucidation of the fundamental relationships between PGM catalyst shape, particle size and activity *Optimization of the cathode electrode layer to maximize the performance of PGM catalysts *Understanding the performance degradation mechanisms of high mass activity cathode catalysts *Development and testing of fuel cells using ultra-low loading high activity

147

High-activity fuel cell catalyst layers via block copolymer nanocomposites.  

E-Print Network (OSTI)

??Current polymer electrolyte membrane fuel cell (PEMFC) catalyst layers are disordered blends of carbon-supported platinum catalyst in an ionomeric matrix. The objective of this research… (more)

Alabi, Toheeb Bola

2008-01-01T23:59:59.000Z

148

Influence of OH/metal ratio on the stability of alfe-pilc catalyst for wet peroxide oxidation of phenol  

Science Journals Connector (OSTI)

AlFe-pillared clay catalyst with OH/metal = 4; 5 mmol metal/g clay and Al : Fe = 5:5 swells intensively in phenol-water solution and has no measurable catalytic activity in phenol removal from water solutions,...

Ern? E. Kiss; Tatjana J. Vuli?…

2005-05-01T23:59:59.000Z

149

Transition metal oxides deposited on rhodium and platinum: Surface chemistry and catalysis  

SciTech Connect

The surface chemistry and catalytic reactivity of transition metal oxides deposited on Rh and Pt substrates has been examined in order to establish the role of oxide-metal interactions in influencing catalytic activity. The oxides investigated included titanium oxide (TiOx), vanadium oxide (VOx), iron oxide (FeOx), zirconium oxide (ZrOx), niobium oxide (NbOx), tantalum oxide (TaOx), and tungsten oxide (WOx). The techniques used to characterize the sample included AES, XPS, LEED, TPD, ISS, and STM. After characterization of the surface in UHV, the sample was enclosed in an atmospheric reaction cell to measure the influence of the oxide deposits on the catalytic activity of the pure metal for CO and CO{sub 2} hydrogenation. The oxide deposits were found to strongly enhance the reactivity of the Rh foil. The rates of methane formation were promoted by up to 15 fold with the maximum in rate enhancement occurring at oxide coverages of approximately 0.5 ML. TiOx TaOx, and NbOx were the most effective promoters and were stable in the highest oxidation states during both reactions (compared to VOx, WOx, and FeOx). The trend in promoter effectiveness was attributed to the direct relationship between oxidation state and Lewis acidity. Bonding at the metal oxide/metal interface between the oxygen end of adsorbed CO and the Lewis acidic oxide was postulated to facilitate C-O bond dissociation and subsequent hydrogenation. 192 refs.

Boffa, A.B. [Univ. of California, Berkeley, CA (United States). Dept. of Chemistry; [Lawrence Berkeley Lab., CA (United States). Materials Sciences Div.

1994-07-01T23:59:59.000Z

150

Preparation and evaluation of advanced electro-catalysts for phosphoric acid fuel cells. Eighth quarterly report, October-December 1981. [Platinum  

SciTech Connect

In the development of new and highly efficient porous electrocatalysts, two cooperative phenomena are required. The first is an increase in the electrocatalytic activity of the catalyst particle, and the second is the availability of that electrocatalyst particle for the electrochemical reaction. These two processes interact with each other in such a way that improvements in the electrochemical activity must be coupled with improvements in the availability of the electrocatalyst for reaction. Since cost effective and highly reactive electrocatalysts have been developed under this program, the utilization of the electrocatalyst particles in the porous electrode structures is addressed. Based on the performance of the electrocatalysts in porous electrode structures, it is shown that a large percentage of the electrocatalyst in anode structures is not utilized. This low utilization translates directly and dramatically into a noble metal cost penalty for the fuel cell. Dramatic improvements in the cost effectiveness of the fuel cell will be achieved by improvements in electrocatalyst catalyzation technology and electrode structure technology.

Stonehart, P.; Baris, J.; Hochmuth, J.; Pagliaro, P.

1981-12-31T23:59:59.000Z

151

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

SciTech Connect

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

152

Cyclopentadienyl-containing low-valent early transition metal olefin polymerization catalysts  

DOE Patents (OSTI)

A catalyst system useful to polymerize and co-polymerize polar and non-polar olefin monomers is formed by in situ reduction with a reducing agent of a catalyst precursor comprising {Cp*MRR'.sub.n }.sup.+ {A}.sup.- wherein Cp* is a cyclopentadienyl or substituted cyclopentadienyl moiety; M is an early transition metal; R is a C.sub.1 -C.sub.20 hydrocarbyl; R' are independently selected from hydride, C.sub.1 -C.sub.20 hydrocarbyl, SiR".sub.3, NR".sub.2, OR", SR", GeR".sub.3, and SnR".sub.3 containing groups (R"=C.sub.1 -C.sub.10 hydrocarbyl); n is an integer selected to balance the oxidation state of M; and A is a suitable non-coordinating anionic cocatalyst or precursor. This catalyst system may form stereoregular olefin polymers including syndiotactic polymers of styrene and methylmethacrylate and isotactic copolymers of polar and nonpolar olefin monomers such as methylmethacrylate and styrene.

Marks, Tobin J. (Evanston, IL); Luo, Lubin (Baton Rouge, LA); Yoon, Sung Cheol (Evanston, IL)

2003-04-08T23:59:59.000Z

153

Cyclopentadienyl-Containing Low-Valent Early Transition Metal Olefin Polymerization Catalysts  

DOE Patents (OSTI)

A catalyst system useful to polymerize and co-polymerize polar and non-polar olefin monomers is formed by in situ reduction with a reducing agent of a catalyst precursor comprising {Cp*MRR'.sub.n }.sup.+ {A}.sup.- wherein Cp* is a cyclopentadienyl or substituted cyclopentadienyl moiety; M is an early transition metal; R is a C.sub.1 -C.sub.20 hydrocarbyl; R' are independently selected from hydride, C.sub.1 -C.sub.20 hydrocarbyl, SiR".sub.3, NR".sub.2, OR", SR", GeR".sub.3, SnR".sub.3, and C.dbd.C-containing groups (R"=C.sub.1 -C.sub.10 hydrocarbyl); n is an integer selected to balance the oxidation state of M; and A is a suitable non-coordinating anionic cocatalyst or precursor. This catalyst system may form stereoregular olefin polymers including syndiotactic polymers of styrene and methylmethacrylate and isotactic copolymers of polar and nonpolar olefin monomers such as methylmethacrylate and styrene.

Marks, Tobin J. (Evanston, IL); Luo, Lubin (Baton Rouge, LA); Yoon, Sung Cheol (Evanston, IL)

2004-06-08T23:59:59.000Z

154

Chemical Structure of Nitrogen-Doped Graphene with Single Platinum Atoms and Atomic Clusters as a Platform for the PEMFC Electrode  

Science Journals Connector (OSTI)

This work provides a new strategy for experimentally producing stable atomic and subnanometer cluster catalysts, which can greatly assist the proton exchange membrane fuel cell (PEMFC) development by producing the ultimate surface area to volume ratio catalyst. ... (2) Currently, platinum (Pt) has proven to perform the oxygen reduction reaction (ORR) as a homocatalyst at the cathode of the PEMFC most efficiently;(3) however, Pt-based electrocatalysts and their associated electrodes can be the largest expense during the production of the PEMFC. ... The development of fuel cells as clean-energy technol. is limited by the cost of the noble-metal catalysts needed for catalyzing the O redn. ...

Samantha Stambula; Nicolas Gauquelin; Matthieu Bugnet; Sandeep Gorantla; Stuart Turner; Shuhui Sun; Jian Liu; Gaixia Zhang; Xueliang Sun; Gianluigi A. Botton

2014-02-12T23:59:59.000Z

155

It's Elemental - The Element Platinum  

NLE Websites -- All DOE Office Websites (Extended Search)

Iridium Iridium Previous Element (Iridium) The Periodic Table of Elements Next Element (Gold) Gold The Element Platinum [Click for Isotope Data] 78 Pt Platinum 195.084 Atomic Number: 78 Atomic Weight: 195.084 Melting Point: 2041.55 K (1768.4°C or 3215.1°F) Boiling Point: 4098 K (3825°C or 6917°F) Density: 21.46 grams per cubic centimeter Phase at Room Temperature: Solid Element Classification: Metal Period Number: 6 Group Number: 10 Group Name: none What's in a name? From the Spainsh word for silver, platina. Say what? Platinum is pronounced as PLAT-en-em. History and Uses: Used by the pre-Columbian Indians of South America, platinum wasn't noticed by western scientists until 1735. Platinum can occur free in nature and is sometimes found in deposits of gold-bearing sands, primarily those found in

156

The Use of Soluble Polyolefins as Supports for Transition Metal Catalysts  

E-Print Network (OSTI)

, agrochemicals, etc.). Thus catalyst and ligand separations are of increasing importance. One method for the recovery and separation of catalysts is to use an insoluble or heterogeneous support. This has the advantage of allowing for separation of catalyst..., agrochemicals, etc.). Thus catalyst and ligand separations are of increasing importance. One method for the recovery and separation of catalysts is to use an insoluble or heterogeneous support. This has the advantage of allowing for separation of catalyst...

Hobbs, Christopher Eugene

2012-10-19T23:59:59.000Z

157

Experimental Investigation of the Effect of Composition on the Performance and Characteristics of PEM Fuel Cell Catalyst Layers.  

E-Print Network (OSTI)

??The catalyst layer of a proton exchange membrane (PEM) fuel cell is a mixture of polymer, carbon, and platinum. The characteristics of the catalyst layer… (more)

Baik, Jungshik

2006-01-01T23:59:59.000Z

158

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

159

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

SciTech Connect

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

160

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

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

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

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

SciTech Connect

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

162

Breakthrough Research on Platinum-Nickel Alloys  

NLE Websites -- All DOE Office Websites (Extended Search)

Breakthrough Research on Platinum-Nickel Alloys Print Breakthrough Research on Platinum-Nickel Alloys Print Two out of three of the kinetic barriers to the practical use of polymer electrolyte membrane (PEM) hydrogen fuel cells in automobiles have been breached: the impractically high amount of extra energy needed for the oxidation reduction reaction (ORR) on the catalyst and the loss of catalytic surface areas available for ORR. Using a combination of probes and calculations, a group of scientists has demonstrated that the Pt3Ni(111) alloy is ten times more active for ORR than the corresponding Pt(111) surface and ninety times more active than the current state-of-the-art Pt/C catalysts used in existing PEM fuel cells. This new variation of the platinum-nickel alloy is the most active oxygen-reducing catalyst ever reported.

163

Breakthrough Research on Platinum-Nickel Alloys  

NLE Websites -- All DOE Office Websites (Extended Search)

Breakthrough Research on Breakthrough Research on Platinum-Nickel Alloys Breakthrough Research on Platinum-Nickel Alloys Print Wednesday, 28 February 2007 00:00 Two out of three of the kinetic barriers to the practical use of polymer electrolyte membrane (PEM) hydrogen fuel cells in automobiles have been breached: the impractically high amount of extra energy needed for the oxidation reduction reaction (ORR) on the catalyst and the loss of catalytic surface areas available for ORR. Using a combination of probes and calculations, a group of scientists has demonstrated that the Pt3Ni(111) alloy is ten times more active for ORR than the corresponding Pt(111) surface and ninety times more active than the current state-of-the-art Pt/C catalysts used in existing PEM fuel cells. This new variation of the platinum-nickel alloy is the most active oxygen-reducing catalyst ever reported.

164

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

SciTech Connect

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

165

Ultralow platinum-loading PtPdRu@PtRuIr/C catalyst with excellent CO tolerance and high performance for the methanol oxidation reaction  

Science Journals Connector (OSTI)

Catalysts of Pd4%Pt10%Ru5%Ir2%/C, Pd4%@Pt10%Ru5%Ir2%/C, Pd4%Pt2%@Pt8%Ru5%Ir2%/C, and Pd4%Pt2%Ru2%@Pt8%Ru3%Ir2%/C were referred to as PDRI, D@PRI, PD@PRI, and PDR...

Yan-Ni Wu; Shi-Jun Liao; Hai-Fu Guo; Xiang-Ying Hao; Zhen-Xing Liang

2014-06-01T23:59:59.000Z

166

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

167

CO Desorption Rate Dependence on CO Partial Pressure over Platinum  

E-Print Network (OSTI)

CO Desorption Rate Dependence on CO Partial Pressure over Platinum Fuel Cell Catalysts J. C. Davies Membrane Fuel Cells (PEMFC) are the most likely fuel cells to achieve commercialisation for auto- motive. The protons formed then pass through a proton conducting mem- brane to the supported platinum cathode where

Li, Weixue

168

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

169

Development of Ultra-Low Platinum Alloy Cathode Catalyst for PEM Fuel Cells - DOE Hydrogen and Fuel Cells Program FY 2012 Annual Progress Report  

NLE Websites -- All DOE Office Websites (Extended Search)

3 3 FY 2012 Annual Progress Report DOE Hydrogen and Fuel Cells Program Branko N. Popov University of South Carolina (USC) 301 Main Street Columbia, SC 29208 Phone: (803) 777-7314 Email: popov@cec.sc.edu DOE Managers HQ: Donna Lee Ho Phone: (202) 586-8000 Email: Donna.Ho@ee.doe.gov GO: David Peterson Phone: (720) 356-1747 Email: David.Peterson@go.doe.gov Technical Advisor Thomas Benjamin Phone: (630) 252-1632 Email: benjamin@anl.gov Contract Number: DE-EE0000460 Subcontractor: Dr. Hansung Kim (Co-PI) Yonsei University, S. Korea. Project Start Date: September 1, 2010 Project End Date: May 31, 2014 Objectives Develop low-cost and durable hybrid cathode catalyst * (HCC). Develop Pt alloy/activated graphitic carbon catalyst. * Develop corrosion resistant supports. *

170

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

171

Studies on rejuvenation of spent residue hydroprocessing catalysts by leaching of foulant metals: influence of inorganic salt additives on the leaching efficiency of organic acids  

Science Journals Connector (OSTI)

A comparative study has been made on the efficiency of oxalic, malonic and acetic acids for selective removal of metal foulants (e.g. vanadium) from spent residue hydrotreating catalysts in the presence and ab...

M. Marafi; A. Stanislaus; C. J. Mumford

1993-01-01T23:59:59.000Z

172

Single crystal flow reactor for studying reactivities on metal oxide model catalysts at atmospheric pressure to bridge the pressure gap to the adsorption properties determined under UHV conditions  

Science Journals Connector (OSTI)

A flow reactor for the investigation of heterogeneous catalytic reactions on single crystalline metal oxide model catalysts has been designed. It is located in a high pressure cell attached to an UHV analysis cha...

C. Kuhrs; M. Swoboda; W. Weiss

2001-01-01T23:59:59.000Z

173

Conversion of gas-condensate straight-run gasolines to high-octane gasolines over zeolite catalysts modified with metal nanopowders  

Science Journals Connector (OSTI)

The acid and catalytic properties of zeolite catalysts modified with metal nanopowders (Cu, Zn, and W) were studied in the conversion of gas-condensate straight-run gasolines to high-liquid high-octane gasolines ...

V. I. Erofeev; A. S. Medvedev; I. S. Khomyakov…

2013-07-01T23:59:59.000Z

174

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

E-Print Network (OSTI)

Conformal Metal Thin Films for H2 Purification and Fuel-Cell Catalyst Applications Tyler Munhollon a heightened need for pure hydrogen gas at a low cost. Research has begun on thin film metal membranes that will become a hydrogen filter in syngas pipelines. The thin film metal membranes are fairly inexpensive

Li, Mo

175

Methods of making textured catalysts  

DOE Patents (OSTI)

A textured catalyst having a hydrothermally-stable support, a metal oxide and a catalyst component is described. Methods of conducting aqueous phase reactions that are catalyzed by a textured catalyst are also described. The invention also provides methods of making textured catalysts and methods of making chemical products using a textured catalyst.

Werpy, Todd (West Richland, WA); Frye, Jr., John G. (Richland, WA); Wang, Yong (Richland, WA); Zacher, Alan H. (Kennewick, WA)

2010-08-17T23:59:59.000Z

176

Preparation of non-precious metal catalysts for PEMFC cathode from pyrolyzed vitamin B12  

Science Journals Connector (OSTI)

In this study, the effect of non-precious metal catalysts in the form of pyrolyzed Vitamin B12 that is supported by carbon black on oxygen reduction reaction (ORR) is examined. Pyrolysis was carried out at temperatures of 300 °C (py-B12/C-300), 500 °C (py-B12/C-500), 700 °C (py-B12/C-700) and 900 °C (py-B12/C-900) in an N2-atmosphere. The ring-rotating disk electrode technique revealed that the electron-transfer numbers of py-B12/C-300, py-B12/C-500, py-B12/C-700 and py-B12/C-900 are 3.02, 3.42, 3.90 and 3.57, respectively: py-B12/C-700 exhibits near four-electron transfer. The X-ray absorption spectra demonstrate that during the pyrolysis, as the Co oxidation state of py-B12-700 is changed from Co(III) to Co(II), the Co coordination number changes from 6 to 4, suggesting that the structure is a square-planar Co–N4 chelate. However, the Co–N4 chelate is decomposed as the pyrolysis temperature increases to 900 °C, resulting in a loss of ORR activity. The H2–O2 PEMFC that uses py-B12/C-700 provides excellent performance, substantially outperforming py-CoTMPP/C.

Sun-Tang Chang; Hsin-Cheng Hsu; Hsin-Chih Huang; Chen-Hao Wang; He-Yun Du; Li-Chyong Chen; Jye-Fu Lee; Kuei-Hsien Chen

2012-01-01T23:59:59.000Z

177

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

SciTech Connect

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

178

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

179

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

180

Effects of noble metal-doping on Cu/ZnO/Al2O3 catalysts for water–gas shift reaction: Catalyst preparation by adopting “memory effect” of hydrotalcite  

Science Journals Connector (OSTI)

Trace amounts of noble metal were doped on Cu/ZnO/Al2O3 catalysts by adopting “memory effect” of hydrotalcite. Ternary Cu/ZnO/Al2O3 (molar ratio Cu/Zn = 1/1, Al content 0–25 mol%) catalysts were prepared by co-precipitation (cp) from metal nitrates; a mixture of hydrotalcite (Cu,Zn)6Al2(OH)16CO3·4H2O, and aurichalcite (Cu,Zn)5(CO3)2(OH)6, was formed at pH 9 with NaOH as the pH controller. Finally the sample, cp-Cu/Zn/Al(45/45/10) containing mainly aurichalcite together with a small amount of hydrotalcite, was selected as the precursor for the noble metal-doping. Noble metal-doping was conducted by dipping the precursor calcined at 300 °C in aqueous solutions of the noble metal nitrates; hydrotalcite was reconstituted by the “memory effect” and simultaneously noble metals were incorporated. The noble metal-doped samples were calcined at 300 °C and tested for the water–gas shift (WGS) reaction. Among the noble metals, Pt was the most effective for stabilizing the catalytic activity although some deactivation due to Cu sintering took place. An intrinsic promoting effect of Pt was clearly observed by evaluating the turnover frequency of the catalyst. Aurichalcite was indispensable for producing active Cu/ZnO sites, whereas a small amount of hydrotalcite was effective for improving the sustainability of the catalyst by the surface modification. It is likely that hydrogen-spillover from trace Pt to active Cu metal not only enhanced the activity via the reduction–oxidation cycle between Cu0 and Cu+ but also stabilized the active Cu metal species against oxidative sintering during the reaction.

Kazufumi Nishida; Ikuo Atake; Dalin Li; Tetsuya Shishido; Yasunori Oumi; Tsuneji Sano; Katsuomi Takehira

2008-01-01T23:59:59.000Z

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.


181

Study on separation of platinum group metals from high level liquid waste using macroporous (MOTDGA-TOA)/SiO{sub 2}-P silica-based absorbent  

SciTech Connect

The recovery of platinum group metals (PGMs) from high level liquid waste (HLLW) by macroporous silica-based adsorbent, (MOTDGA-TOA)/SiO{sub 2}-P has been developed by impregnating two extractants of N,N'-dimethyl-N,N'-di-n-octyl-thio-diglycolamide (MOTDGA) and tri-n-octylamine (TOA) into a silica/polymer composite support (SiO{sub 2}-P). The adsorption of Ru(III), Rh(III) and Pd(II) have been investigated in simulated HLLW by batch method. The adsorbent has shown good uptake property for Pd(II). In addition, the combined use of MOTDGA and TOA improved the adsorption of Ru(III) and Rh(III) better than the individual use of them. The usability of adsorbent in radiation fields was further confirmed by irradiation experiments. The adsorbent remained to have the uptake capability for PGMs over the absorbed dose of 100 kGy, corresponding with one really adsorbed by the adsorbent, and showed good retention capability for Pd(II) even at the absorbed dose of 800 kGy. The chromatographic separation of metal ions was demonstrated with the adsorbent packed column, there is no influence of Re(VII) (instead of Tc) on the excellent separation behavior of Pd(II). (authors)

Ito, Tatsuya [Department of Quantum Science and Energy Engineering, Graduate School of Engineering, Tohoku University, Aoba 6-6, Aramaki, Aoba-ku, Sendai, Miyagi 980-8579 (Japan); Japan Atomic Energy Agency, Tokai-mura Naka-gun, Ibarak319-1195 (Japan); Kim, Seong-Yun; Xu, Yuanlai; Hitomi, Keitaro [Cyclotron and Radioisotope Center, Tohoku University, Aoba 6-3, Aramaki, Aoba-ku, Sendai, Miyagi 980-8578 (Japan); Ishii, Keizo [Department of Quantum Science and Energy Engineering, Graduate School of Engineering, Tohoku University, Aoba 6-6, Aramaki, Aoba-ku, Sendai, Miyagi 980-8579 (Japan); Nagaishi, Ryuji; Kimura, Takaumi [Japan Atomic Energy Agency, Tokai-mura Naka-gun, Ibarak319-1195 (Japan)

2013-07-01T23:59:59.000Z

182

Biomimetic Synthesis of Noble Metal Nanoparticles and Their Applications as Electro-catalysts in Fuel Cells  

E-Print Network (OSTI)

PEMFC 21 1.3.2.2 Electro-catalysts in DMFC . 24 1.3.3 Cathodecatalyst for the PEMFC. For oxygen reduction reaction occurring at the cathode,

Li, Yujing

2012-01-01T23:59:59.000Z

183

Monolithic Metal Oxide based Composite Nanowire Lean NOx Emission Control Catalysts  

Energy.gov (U.S. Department of Energy (DOE))

Presents latest progress in the development of a new type of lean NOx trapping catalyst based on heterogenous composite nanowires, which could potentially be used in gasoline and diesel engines.

184

Metal oxide catalysts for the low temperature selective oxidation of propane to iso-propanol.  

E-Print Network (OSTI)

??A range of Ga203/Mo03 and C03O4 catalysts have been prepared and tested for the oxidative dehydrogenation of propane to propene. The Ga2(VMo03 physical mixture demonstrated… (more)

Davies, Thomas Edward.

2006-01-01T23:59:59.000Z

185

Metal segregation in supported bimetallic catalysts:. gamma. -Al/sub 2/O/sub 3/-supported CO hydrogenation catalysts prepared from RhOs/sub 3/, Rh/sub 4/, and FeOs/sub 3/ clusters  

SciTech Connect

Al/sub 2/O/sub 3/-supported metals were prepared from (H/sub 2/RhOs/sub 3/(CO)/sub 10/(acetylacetonate)), (Rh/sub 4/(CO)/sub 12/), and (H/sub 2/FeOs/sub 3/(CO)/sub 13/). The samples were characterized by infrared spectroscopy after reaction with CO + H/sub 2/ and tested as catalysts for conversion of CO + H/sub 2/ in a flow reactor at 200 and 270/sup 0/C and 10 atm. Used catalysts were characterized by transmission electron microscopy, X-ray photoelectron spectroscopy, infrared spectroscopy, and elemental analysis. The catalyst lost Os during operation, presumably as a result of formation of volatile carbonyls. The catalytic reaction products were a nearly Schulz-Flory-Anderson distribution of hydrocarbons with small yields of dimethyl ether (formed from methanol). The performance of the catalyst prepared from the RhOs/sub 3/ clusters was closely similar to that of the catalyst prepared from the Rh/sub 4/ cluster. Characterization of the samples after treatment in CO + H/sub 2/ and after catalysis demonstrated that the RhOs/sub 3/ clusters broke apart, first giving triosmium clusters and mononuclear Rh complexes and then, at higher temperatures, giving Rh crystallites and mononuclear Os complexes. The catalytic activity for hydrocarbon synthesis is attributed to the Rh metal; the activity for methanol synthesis is tentatively associated with ionic Rh complexes. The FeOs/sub 3/ catalyst was two orders of magnitude less active than the Rh Os/sub 3/ catalyst, apparently consisting of small iron oxide particles and mononuclear Os complexes. The selectivity of this catalyst for dimethyl ether formation increased markedly with time onstream in the flow reactor; after 55 h, 36 mol% of the organic product was ether. 25 refs., 5 figs., 3 tabs.

Budge, J.R.; Lucke, B.F.; Gates, B.C.; Toran, J.

1985-02-01T23:59:59.000Z

186

Tuning the Metal-Adsorbate Chemical Bond through the Ligand Effect on  

NLE Websites -- All DOE Office Websites (Extended Search)

Tuning the Metal-Adsorbate Chemical Bond through the Ligand Effect on Tuning the Metal-Adsorbate Chemical Bond through the Ligand Effect on Platinum Subsurface Alloys Tuesday, July 31, 2012 The ability to design and control the activities of transition metal catalysts, which are scarce in nature and thus expensive, has been of great importance to the development of economical industrial and energy-saving processes. Over the years several methods have been suggested, especially for processes using platinum, which is the 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 and corresponding shifts in Pt d-band center. Tuning chemical functionality by implementing a ligand effect - in other words, by changing the atomic nearest neighbor environment - is a

187

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

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

188

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

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

189

Recent Advances in Developing Platinum Monolayer Electrocatalysts for the O2 Reduction Reaction  

SciTech Connect

For Pt, the best single-element catalyst for many reactions, the question of content and loading is exceedingly important because of its price and availability. Using platinum as a fuel-cell catalyst in automotive applications will cause an unquantifiable increase in the demand for this metal. This big obstacle for using fuel cells in electric cars must be solved by decreasing the content of Pt, which is a great challenge of electrocatalysis Over the last several years we inaugurated a new class of electrocatalysts for the oxygen reduction reaction (ORR) based on a monolayer of Pt deposited on metal or alloy carbon-supported nanoparticles. The possibility of decreasing the Pt content in the ORR catalysts down to a monolayer level has a considerable importance because this reaction requires high loadings due to its slow kinetics. The Pt-monolayer approach has several unique features and some of them are: high Pt utilization, enhanced (or decreased) activity, enhanced stability, and direct activity correlations. The synthesis of Pt monolayer (ML) electrocatalysts was facilitated by our new synthesis method which allowed us to deposit a monolayer of Pt on various metals, or alloy nanoparticles [1, 2] for the cathode electrocatalyst. In this synthesis approach Pt is laid down by the galvanically displacing a Cu monolayer, which was deposited at underpotentials in a monolayer-limited reaction on appropriate metal substrate, with Pt after immersing the electrode in a K{sub 2}PtCl{sub 4} solution.

Vukmirovic,M.B.; Sasaki, K.; Zhou, W.-P.; Li, M.; Liu, P.; Wang, J.X.; Adzic, R.R.

2008-09-15T23:59:59.000Z

190

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

191

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

192

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

SciTech Connect

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

193

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

SciTech Connect

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

194

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

SciTech Connect

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

195

Platinum/Carbon Nanotube Nanocomposite Synthesized in Supercritical Fluid as Electrocatalysts for Low-Temperature Fuel Cells  

SciTech Connect

Carbon nanotube (CNT)-supported Pt nanoparticles catalysts have been synthesized in supercritical carbon dioxide (scCO2) using platinum (II) acetylacetonate as metal precursor. The structure of the catalysts has been characterized with transmission electron micrograph (TEM) and X-ray photoelectron spectroscopy (XPS). TEM images show that platinum particles size is in the range of 5-10nm. XPS analysis indicates the presence of zero-valence platinum. The Pt-CNT exhibited high catalytic activity both for methanol oxidation and oxygen reduction reaction. The higher catalytic activity has been attributed to the large surface area of carbon nanotubes and the decrease in the overpotential for methanol oxidation and oxygen reduction reaction. Cyclic voltammetric measurements at different scan rates showed that the oxygen reduction reaction at the Pt-CNT electrode is a diffusion-controlled process. Analysis of the electrode kinetics using Tafel plot suggests that Pt-CNT from scCO2 provides a strong electrocatalytic activity for oxygen reduction reaction. For the methanol oxidation reaction, a high ratio of forward anodic peak current to reverse anodic peak current was observed at room temperature, which implies good oxidation of methanol to carbon dioxide on the Pt-CNT electrode. This work demonstrates that Pt-CNT nanocomposites synthesized in supercritical carbon dioxide are effective electrocatalysts for low-temperature fuel cells.

Lin, Yuehe; Cui, Xiaoli; Yen, Clive; Wai, Chien M.

2005-07-28T23:59:59.000Z

196

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

SciTech Connect

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

197

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

SciTech Connect

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

198

Characterization of electrochemically modified polycrystalline platinum surfaces  

SciTech Connect

The characterization of electrochemically modified polycrystalline platinum surfaces has been accomplished through the use of four major electrochemical techniques. These were chronoamperometry, chronopotentiommetry, cyclic voltammetry, and linear sweep voltammetry. A systematic study on the under-potential deposition of several transition metals has been performed. The most interesting of these were: Ag, Cu, Cd, and Pb. It was determined, by subjecting the platinum electrode surface to a single potential scan between {minus}0.24 and +1.25 V{sub SCE} while stirring the solution, that the electrocatalytic activity would be regenerated. As a consequence of this study, a much simpler method for producing ultra high purity water from acidic permanganate has been developed. This method results in water that surpasses the water produced by pyrocatalytic distillation. It has also been seen that the wettability of polycrystalline platinum surfaces is greatly dependent on the quantity of oxide present. Oxide-free platinum is hydrophobic and gives a contact angle in the range of 55 to 62 degrees. We have also modified polycrystalline platinum surface with the electrically conducting polymer poly-{rho}-phenylene. This polymer is very stable in dilute sulfuric acid solutions, even under applied oxidative potentials. It is also highly resistant to electrochemical hydrogenation. The wettability of the polymer modified platinum surface is severely dependent on the choice of supporting electrolyte chosen for the electrochemical polymerization. Tetraethylammonium tetrafluoroborate produces a film that is as hydrophobic as Teflon, whereas tetraethylammonium perchlorate produces a film that is more hydrophilic than oxide-free platinum.

Krebs, L.C.; Ishida, Takanobu.

1991-12-01T23:59:59.000Z

199

A Novel Nanobio Catalyst for Biofuels | Advanced Photon Source  

NLE Websites -- All DOE Office Websites (Extended Search)

Multiple Crystal Cavities for Unlimited X-ray Energy Resolution and Multiple Crystal Cavities for Unlimited X-ray Energy Resolution and Coherence An Intriguing Twist in the Structure of a Cobalt Oxide Catalyst Breaking Records in Neurological Microradiology Exposing Valence-Bond Model Inadequacies Plants' Rapid Response System Revealed Science Highlights Archives: 2013 | 2012 | 2011 | 2010 2009 | 2008 | 2007 | 2006 2005 | 2004 | 2003 | 2002 2001 | 2000 | 1998 | Subscribe to APS Science Highlights rss feed A Novel Nanobio Catalyst for Biofuels AUGUST 27, 2012 Bookmark and Share Core shell nanoparticle inside Apo. Nanoparticles synthesized from noble metals such as ruthenium, rhodium, palladium, silver (Ag), osmium, iridium, platinum, and gold (Au) are attracting increased attention by researchers around the world looking for

200

Synthesis and Characterization of Cluster-Derived Supported Bimetallic Catalysts  

SciTech Connect

New procedures have been developed for synthesizing di- and tri-metallic cluster complexes. The chemical properties of the new complexes have been investigated, particularly toward the activation of molecular hydrogen. These complexes were then converted into bi- and tri-metallic nanoparticles on silica and alumina supports. These nanoparticles were characterized by electron microscopy and were then tested for their ability to produce catalytic hydrogenation of unsaturated hydrocarbons and for the preferential oxidation of CO in the presence of hydrogen. The bi- and tri-metallic nanoparticles exhibited far superior activity and selectivity as hydrogenation catalysts when compared to the individual metallic components. It was found that the addition of tin greatly improved the selectivity of the catalysts for the hydrogenation of polyolefins. The addition of iron improves the catalysts for the selective oxidation of CO by platinum in the presence of hydrogen. The observations should lead to the development of lower cost routes to molecules that can be used to produce polymers and plastics for use by the general public and for procedures to purify hydrogen for use as an alternative energy in the hydrogen economy of the future.

Adams, Richard D; Amiridis, Michael D

2008-10-10T23:59:59.000Z

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

Stable platinum nanoparticles on specific MgAl2O4 spinel facets...  

NLE Websites -- All DOE Office Websites (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...

202

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

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

203

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

204

Theoretical Study of the Structure, Stability and Oxygen Reduction Activity of Ultrathin Platinum Nanowires  

SciTech Connect

We use density functional theory to study the difference in the structure, stability and catalytic reactivity between ultrathin, 0.5- 1.0 nm diameter, platinum nanotubes and nanowires. Model nanowires were formed by inserting an inner chain of platinum atoms in small diameter nanotubes. In this way more stable, nonhollow structures were formed. The difference in the electronic structure of platinum nanotubes and nanowires was examined by inspecting the density of surface states and band structure. Furthermore, reactivity towards the oxygen reduction reaction of platinum nanowires was addressed by studying the change in the chemisorption energies of oxygen and hydroxyl groups, induced by inserting the inner chain of platinum atoms into the hollow nanotubes. Both ultrathin platinum nanotubes and nanowires show distinct properties compared to bulk platinum. Nanotubes with diameters larger than 1 nm show promise for use as oxygen reduction catalysts.

Matanovic, Ivana; Kent, Paul; Garzon, Fernando; Henson, Neil J.

2012-10-10T23:59:59.000Z

205

Density Functional Study of the Structure, Stability and Oxygen Reduction Activity of Ultrathin Platinum Nanowires  

SciTech Connect

We used density functional theory to study the difference in the structure, stability and catalytic reactivity between ultrathin, 0.5–1.0 nm diameter, platinum nanotubes and nanowires. Model nanowires were formed by inserting an inner chain of platinum atoms in small diameter nanotubes. In this way more stable, non-hollow structures were formed. The difference in the electronic structure of platinum nanotubes and nanowires was examined by inspecting the density of surface states and band structure. Furthermore, reactivity toward the oxygen reduction reaction of platinum nanowires was assessed by studying the change in the chemisorption energies of oxygen, hydroxyl, and hydroperoxyl groups, induced by converting the nanotube models to nanowires. Both ultrathin platinum nanotubes and nanowires show distinct properties compared to bulk platinum. Single-wall nanotubes and platinum nanowires with diameters larger than 1 nm show promise for use as oxygen reduction catalysts.

Matanovic, Ivana; Kent, Paul; Garzon, Fernando; Henson, Neil J.

2013-03-14T23:59:59.000Z

206

Monodisperse metal nanoparticle catalysts on silica mesoporous supports: synthesis, characterizations, and catalytic reactions  

E-Print Network (OSTI)

capillary inclusion (CI) and nanoparticle encapsulation (NE)metal nanostructures, and to collidal nanoparticle- based 2Dand 3D nanoparticle arrays. Figure 2. Preparation scheme of

Somorjai, G.A.

2010-01-01T23:59:59.000Z

207

Catalyst regeneration: the business case  

SciTech Connect

As an alternative to purchasing new catalyst, technological and economic advantages make a compelling case for regenerating rather than replacing the metal or ceramic that enables selective catalytic reduction systems to capture NOx. The article examines the differences in the process, economics and reliability of new catalyst versus regenerated catalyst, and in rejuvenation versus regeneration of catalysis. SCR-Tech has developed programs to evaluate most catalyst management scenarios. They can predict catalyst life, allow for mixing and matching different catalyst types, provide risk assessment associated with extending catalyst life and evaluate site-specific economics. 2 figs., 1 tab.

McMahon, B. [SCR-Tech (United States)

2006-01-15T23:59:59.000Z

208

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

E-Print Network (OSTI)

in air at 300 C for 2 h and at 400 C for 2 h. Calcination was followed by reduction under hydrogen at 300oC for 2 h, then at 425oC for 2 h. Before the catalyst was used, it was crushed using a mortar and pestle, and sieved to between 10 and 20 mesh... OR Figure 1. Diagram of On-line Gas Chromatograph 11 Rt the termination of an analysis, both hydrogen and carbon containing products of each reaction were compared to assure reproducibility. The detector unit for the on-line gas chromatograph...

Moore, Stanley Edwin

2012-06-07T23:59:59.000Z

209

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

210

One-Pot Formation of Functionalized Indole and Benzofuran Derivatives Using a Single Bifunctional Ruthenium Catalyst  

E-Print Network (OSTI)

Bifunctional Ruthenium Catalyst Reji N. Nair • Paul J. Lee •bifunctional ruthenium catalyst for cyclization of terminalof transi- tion metal based catalysts have been reported to

Nair, Reji N; Lee, Paul J; Grotjahn, Douglas B

2010-01-01T23:59:59.000Z

211

Efficient and selective conversion of fructose to 5-hydroxymethylfurfural over metal exchanged heteropoly tungstate supported on tin oxide catalysts  

Science Journals Connector (OSTI)

A series of Al exchanged heteropoly tungstate (AlTPA) supported on SnO2...catalysts were prepared and characterized by FT-Infrared, X-ray diffraction and temperature programmed desorption of ammonia. The catalyst...

G. Raveendra; M. Srinivas; P. S. Sai Prasad…

2013-12-01T23:59:59.000Z

212

Chemistry of Cobalt-Platinum Nanocatalysts  

NLE Websites -- All DOE Office Websites (Extended Search)

Chemistry of Cobalt-Platinum Nanocatalysts Print Chemistry of Cobalt-Platinum Nanocatalysts Print Bimetallic cobalt-platinum (CoPt) nanoparticles are drawing attention in many areas of catalysis as scientists attempt to reduce precious metal content while maintaining optimum catalytic selectivity and reactivity. Cobalt, an important transition metal used for catalytic hydrogenation reactions of CO and CO2 to produce gaseous or liquid hydrocarbons, has a long history of use in the industrial process of producing synthetic fuels. Researchers explored the role of Pt in Co reducing and oxidizing, and found that the catalytic properties of monometallic and bimetallic nanoparticles of Co are closely related to the oxidation state of Co, which informs the prediction of cobalt oxidation states as reaction conditions are altered. This research also suggests the presence of a tetrahedral cobalt oxide that differs from the Co3O4 spinel structure.

213

Phenylenediamine-Based FeNx/C Catalyst with High Activity for Oxygen Reduction in Acid Medium and Its Active-Site Probing  

Science Journals Connector (OSTI)

(2) Among NPM catalysts, FeNx/C catalyst is the most promising candidate because it exhibits considerable ORR activity in acid medium, thus compatible with strong acidic environment of Nafion-based PEMFC that is industrially more mature than alkaline membrane fuel cell. ... Fe-based cathode catalysts are promising contenders, but their power density has been low compared with Pt-based cathodes, largely due to poor mass-transport properties. ... The most active materials in the group catalyze the ORR at potentials within ~60 mV of that delivered by state-of-the-art carbon-supported platinum, combining their high activity with remarkable performance stability for non-precious metal catalysts (700 h at a fuel cell voltage of 0.4 V) as well as excellent four-electron selectivity (hydrogen peroxide yield <1.0%). ...

Qiang Wang; Zhi-You Zhou; Yu-Jiao Lai; Yong You; Jian-Guo Liu; Xia-Ling Wu; Ephrem Terefe; Chi Chen; Lin Song; Muhammad Rauf; Na Tian; Shi-Gang Sun

2014-07-17T23:59:59.000Z

214

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

215

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

SciTech Connect

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

216

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.

217

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

SciTech Connect

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

218

Molybdenum/alkali metal/ethylene glycol complexes useful as epoxidation catalysts  

SciTech Connect

This patent describes a clear, storage stable solution of a molybdenum/alkali metal/ethylene glycol complex in ethylene glycol made by the process comprising: reacting at an elevated temperature between about 25/sup 0/ and 150/sup 0/C a solid ammonium molybdate or a hydrate thereof and a solid alkali metal molybdate or a hydrate thereof with ethylene glycol, such that the ratio of moles of ethylene glycol to total gram atoms of molybdenum in the molybdates ranges from about 7:10 to 10:1, and the ratio of gram atoms of molybdenum in the ammonium molybdate or hydrate thereof to gram atoms of molybdenum in the alkali metal molybdate is from about 1:1 to about 20:1 to thereby provide a reaction product composed of a solution of an alkali metal-containing complex of molybdenum, alkali metal and ethylene glycol and by-products, including water, in the ethylene glycol and subsequently stripping the solution at a reduced pressure to remove from about 5 to about 25% of the reaction product, as distillate, to thereby provide a storage stable solution of the complex in the ethylene glycol having a molybdenum content of about 6 wt. % to about 20 wt. %, a water concentration of about 0.1 wt. % to about 6 wt. % and an acid number of more than about 60.

Marquis, E.T.; Sanderson, J.R.; Keating, K.P.

1987-10-27T23:59:59.000Z

219

New Catalysts for Direct Methanol Oxidation Fuel Cells  

SciTech Connect

A new class of efficient electrocatalytic materials based on platinum - metal oxide systems has been synthetized and characterized by several techniques. Best activity was found with NiWO{sub 4}-, CoWO{sub 4}-, and RuO{sub 2}- sr¡pported platinum catalysts. A very similar activity at room temperature was observed with the electrodes prepared with the catalyst obtained from International Fuel Cells Inc. for the same Pt loading. Surprisingly, the two tungstates per se show a small activity for methanol oxidation without any Pt loading. Synthesis of NiWO{sub 4} and CoWO{sub 4} were carried out by solid-state reactions. FTIR spectroscopy shows that the tungstates contain a certain amount of physically adsorbed water even after heating samples at 200{degrees}C. A direct relationship between the activity for methanol oxidation and the amount of adsorbed water on those oxides has been found. The Ru(0001) single crystal shows a very small activity for CO adsorption and oxidation, in contrast to the behavior of polycrystalline Ru. In situ extended x-ray absorption fine structure spectroscopy (EXAFS) and x-ray absorption near edge spectroscopy (XANES) showed that the OH adsorption on Ru in the Pt-Ru alloy appears to be the limiting step in methanol oxidation. This does not occur for Pt-RuO{SUB 2} electrocatalyst, which explains its advantages over the Pt-Ru alloys. The IFCC electrocatalyst has the properties of the Pt-Ru alloy.

Adzic, Radoslav

1998-08-01T23:59:59.000Z

220

Metal–organic frameworks of the MIL-101 family as heterogeneous single-site catalysts  

Science Journals Connector (OSTI)

...provided the size of pore entrances...contrast to zeolites and mesoporous...substrate conversion and enone...Unlike zeolites and metal-silicates...washed with methanol and dried...figure-6) studies confirmed...air; the conversion is usually...using just small additives...production of ethylene carbonate...titanosilicates and zeolites (Sakakura...synthesis of propylene (table-4...

2012-01-01T23:59:59.000Z

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.


221

Transition Metal Sulfide Electrocatalysts for PEM Fuel Cells  

NLE Websites -- All DOE Office Websites (Extended Search)

Transition Metal Sulfide Transition Metal Sulfide Electrocatalysts for PEM Fuel Cells Hua Zhang 1 , Ysmael Verde-Gómez 1 and Allan J. Jacobson 1 Alejandra Ramirez 2 and Russell R. Chianelli 2 1 Department of Chemistry, University of Houston Houston, TX 77204 2 Materials Research and Technology Institute, University of Texas at El Paso, El Paso, TX 79968 Transition Metal Sulfide Electrocatalysts for PEM Fuel Cells Hua Zhang 1 , Ysmael Verde-Gómez 1 and Allan J. Jacobson 1 Alejandra Ramirez 2 and Russell R. Chianelli 2 1 Department of Chemistry, University of Houston Houston, TX 77204 2 Materials Research and Technology Institute, University of Texas at El Paso, El Paso, TX 79968 March 21, 2003 Objectives ¾ Investigate non-platinum electro-catalysts with CO tolerance ¾ Focus on transition metal sulfides as electro-catalysts

222

Colloid Science of Metal Nanoparticle Catalysts in 2D and 3D Structures. Challenges of Nucleation, Growth, Composition, Particle Shape, Size Control and their Influence on Activity and Selectivity  

E-Print Network (OSTI)

which are all in the nanoparticle size range and toto the 2D and 3D nanoparticle arrays that are composed ofColloid Science of Metal Nanoparticle Catalysts in 2D and 3D

Somorjai, Gabor A.

2009-01-01T23:59:59.000Z

223

Pyrolyzed Fe–N–C Composite as an Efficient Non-precious Metal Catalyst for Oxygen Reduction Reaction in Acidic Medium  

Science Journals Connector (OSTI)

Aimed at developing a highly active and stable non-precious metal catalyst (NPMC) for oxygen reduction reaction (ORR) in acidic proton-exchange membrane fuel cells (PEMFCs), a novel NPMC was prepared by pyrolyzing a composite of carbon-supported Fe-doped graphitic carbon nitride (Fe–g-C3N4@C) above 700 °C. ... Furthermore, the pyrolyzed Fe–N–C composite exhibits superior durability in comparison to that of commercial 20 wt % Pt/C in acidic medium, making it a good candidate for an ORR electrocatalyst in PEMFCs. ... non-precious metal catalyst (NPMC); oxygen reduction reaction (ORR); proton-exchange membrane fuel cell (PEMFC); carbon-supported Fe-doped g-C3N4 (Fe?g-C3N4@C); pyrolysis; Fe?N?C composite ...

Mei-Qing Wang; Wei-Hua Yang; Hong-Hui Wang; Chi Chen; Zhi-You Zhou; Shi-Gang Sun

2014-09-23T23:59:59.000Z

224

Platinum Metals Magmatic Sulfide Ores  

Science Journals Connector (OSTI)

...Stumpfl (36) has suggested that hydro-thermal solutions have upgraded the ores. Hiemstra...Silver and Gold (Mineral Bulletin MR 185, Energy, Mines and Resources Canada, Ot-tawa...individuals. Sup-port has been received from Energy, Mines and Resources Canada grant 222-4-78...

A. J. Naldrett; J. M. Duke

1980-06-27T23:59:59.000Z

225

Structure, Mobility, and Composition of Transition Metal Catalyst Surfaces: High-Pressure Scanning Tunneling Microscopy and Ambient-Pressure X-ray Photoelectron Spectroscopy Studies  

E-Print Network (OSTI)

bimetallic nanoparticle catalysts is studied in Chapter 8.and Pt-based bimetallic nanoparticle catalysts, in order toseek the influence of catalyst surface structure on

Zhu, Zhongwei

2014-01-01T23:59:59.000Z

226

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

SciTech Connect

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

227

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

SciTech Connect

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

228

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

SciTech Connect

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

229

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

SciTech Connect

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

230

Comparative study of polyoxometalates and semiconductor metal oxides as catalyst. Photochemical oxidative degradation of thioethers  

SciTech Connect

The photochemical degradation of thioether substrates catalyzed by representative semiconductor metal oxides and sulfides (anatase TiO{sub 2}, SnO{sub 2}, cubic WO{sub 3}, and CdS) and photoredox-active early-transition-metal polyometalates (W{sub 10}O{sub 32}{sup 4{minus}}, PMo{sub 12}O{sub 40}{sup 3{minus}}, PW{sub 12}O{sub 40}{sup 3{minus}}, SiMo{sub 12}O{sub 40}{sup 4{minus}}, PV{sub 2}Mo{sub 10}O{sub 10}{sup 5{minus}}, and P{sub 2}W{sub 18}O{sub 62}{sup 6{minus}}) have been examined under both anaerobic and aerobic conditions. Under anaerobic conditions, all the semiconductors are completely ineffective at photochemically oxidizing or degrading the exemplary thioether substrate tetrahydrothiophene (THT) in the oxidatively resistant solvent acetonitrile. In contrast, all the homogeneous polyoxometalate systems under the same reaction condition, except the neutral tetra-n-butylammonium (Q) salt of PW{sub 12}O{sub 40}{sup 3{minus}}, are quite effective. The latter systems generate products derived from the carbon-based radical {alpha} to the sulfur atom and not sulfoxide or sulfone, the usual products of thioether oxidation by oxometal species. The rate for the most active anaerobic system, that involving the photochemical degradation of THT by Q{sub 4}W{sub 10}O{sub 32}, under optically dilute conditions, is first order in W{sub 10}O{sub 32} {sup 4{minus}} and light intensity and variable order in THT substrate. A rate law consistent with these data is given. Upon addition of O{sub 2}, TiO{sub 2} (with or without Pt(O)) becomes highly active, SnO{sub 2} becomes active, but WO{sub 3} and CdS remain inactive. Reactivity in thioether oxidation is dominated by the interactions of the semiconductors with O{sub 2} and O{sub 2}-derived intermediates; there is no correlation between reactivity and semiconductor band gap. Upon addition of O{sub 2}, all the polyoxometalate systems become more active. 29 refs., 4 figs., 3 tabs.

Chambers, R.C.; Hill, C.L. (Emory Univ., Atlanta, GA (United States))

1991-06-26T23:59:59.000Z

231

Oxygen Hydration Mechanism for the Oxygen Reduction Reaction at Pt and Pd Fuel Cell Catalysts  

Science Journals Connector (OSTI)

Oxygen Hydration Mechanism for the Oxygen Reduction Reaction at Pt and Pd Fuel Cell Catalysts ... Catalytic Reactions on the Open-Edge Sites of Nitrogen-Doped Carbon Nanotubes as Cathode Catalyst for Hydrogen Fuel Cells ... Despite significant progress made the past decade on reducing the platinum catalyst loading in the PEMFC electrodes, further ... ...

Yao Sha; Ted H. Yu; Boris V. Merinov; Pezhman Shirvanian; William A. Goddard; III

2011-02-24T23:59:59.000Z

232

Stabilization of Platinum Nanoparticle Electrocatalysts for Oxygen...  

NLE Websites -- All DOE Office Websites (Extended Search)

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

233

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

234

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

235

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

236

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

NLE Websites -- All DOE Office Websites (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...

237

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

SciTech Connect

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

238

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

239

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

SciTech Connect

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

240

Mass-selected Nanoparticles of PtxY as Model Catalysts for Oxygen...  

NLE Websites -- All DOE Office Websites (Extended Search)

of PEMFCs has been hampered by the need for a large amount of platinum catalyst at the cathode, where oxygen reduction takes place. Even with current state-of-the-art technology,...

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

Biologically Inspired Phosphino Platinum Complexes  

SciTech Connect

Platinum complexes containing phosphino amino acid and amino acid ester ligands, built upon the PPhNR’2 platform, have been synthesized and characterized (PPhNR’2= [1,3-diaza]-5-phenyl phosphacyclohexane, R’=glycine or glycine ester). These complexes were characterized by 31P, 13C, 1H, 195Pt NMR spectroscopy and mass spectrometry. The X-ray crystal structure of one of the complexes, [PtCl2(PPhNGlyester 2)2], is also reported. These biologically inspired ligands have potential use in homogeneous catalysis, with special applications in chiral chemistry and water soluble chemistry. These complexes also provide a foundation upon which larger peptides can be attached, to allow the introduction of enzyme-like features onto small molecule catalysts. This work was supported by the US Department of Energy, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences & Biosciences. Pacific Northwest National Laboratory is operated by Battelle for the US Department of Energy.

Jain, Avijita; Helm, Monte L.; Linehan, John C.; DuBois, Daniel L.; Shaw, Wendy J.

2012-08-01T23:59:59.000Z

242

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

SciTech Connect

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

243

Hydrocarbon synthesis catalyst and method of preparation and use thereof. [DOE patent application  

SciTech Connect

A catalyst for the synthesis of hydrocarbons from carbon monoxide and hydrogen composed of palladium or platinum and cobalt supported on a solid phase is disclosed. The catalyst is prepared by heating a heterogeneous component of the palladium or platinum deposited on the solid support in a solution of cobalt carbonyl or precursors thereof. The catalyst exhibits excellent activity, stability in air, and produces highly desirable product fractions even with dilute gaseous reactants. The catalyst is preferably used in dilute slurry form, which is desirable from a heat transfer standpoint.

Sapienza, R.S.; Sansone, M.J.; Slegeir, W.A.R.

1981-08-14T23:59:59.000Z

244

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

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

245

Optimal topology and distribution of catalyst in PEMFC  

Science Journals Connector (OSTI)

Abstract The equations that govern the various transport phenomena occurring in a polymer electrolyte membrane fuel cell (PEMFC) were formulated and implemented in a commercial finite element software, in order to predict the fuel cell current density with respect to the operating conditions. The numerical model showed polarization curves in accordance with literature. The catalyst utilization was then improved by optimizing the platinum distribution (design variable) in the fuel cell, so as to maximize current density (objective function) for a fixed total amount of platinum (constraint). The first analysis showed that, for equal anode and cathode catalyst layer thicknesses, maximal current density was achieved by placing more catalyst in the cathode than in the anode. The second analysis showed that, for equal anode and cathode catalyst layer density, maximal current density was achieved by using a catalyst layer that is thicker on the cathode side than that on the anode side. Finally, a topological optimization of the platinum density within the cathode catalyst layer was performed with a gradient based algorithm, and the results showed that at a high stoichiometric ratio, the best design has most of its platinum placed where the reaction rate is the highest, i.e., close to the membrane layer.

François Mathieu-Potvin; Louis Gosselin

2014-01-01T23:59:59.000Z

246

todayELSEVIER CatalysisToday21 (1994) 141-156 Nature of metal catalyst precursors adsorbed onto  

E-Print Network (OSTI)

adsorbed onto oxide supports N. Santhanam, T.A. Conforti, W. Spieker, J.R. Regalbuto* Dept. of Chemical of experimentswere conductedto investigatethe nature of adsorbed catalyst precursor complexes during and after drying. In the first, PdC12- was adsorbed onto a positively charged A1203 surface and (NHa)aPd2+ onto negatively

Regalbuto, John R.

247

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

248

Supported fischer-tropsch catalyst and method of making the catalyst  

SciTech Connect

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

249

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

SciTech Connect

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

250

Natta catalyst  

Science Journals Connector (OSTI)

\\¦nät-(¦)tä-\\ n. Any of several catalysts used in the stereospecific polymerization of olefins, ... .g., ethylene and propylene, particularly a catalyst made from titanium chloride and aluminum alkyl...

2007-01-01T23:59:59.000Z

251

Natta Catalyst  

Science Journals Connector (OSTI)

\\?nät-(?)tä-\\ n Any of several catalysts used in the stereospecific polymerization of olefins, ... .g., ethylene and propylene, particularly a catalyst made from titanium chloride and aluminum alkyl...

Jan W. Gooch

2011-01-01T23:59:59.000Z

252

In Situ Studies of Surface Mobility on Noble Metal Model Catalysts Using STM and XPS at Ambient Pressure  

E-Print Network (OSTI)

3. Experimental Techniques UHV System Clean metal surfaces1]. Ultrahigh Vacuum (UHV) technology allows the preparation8 UHV

Butcher, Derek Robert

2010-01-01T23:59:59.000Z

253

In Situ Studies of Surface Mobility on Noble Metal Model Catalysts Using STM and XPS at Ambient Pressure  

E-Print Network (OSTI)

3. Experimental Techniques UHV System Clean metal surfaces1]. Ultrahigh Vacuum (UHV) technology allows the preparation7 UHV

Butcher, Derek Robert

2010-01-01T23:59:59.000Z

254

Steam reforming utilizing sulfur tolerant catalyst  

SciTech Connect

This patent describes a steam reforming process for converting hydrocarbon material to hydrogen gas in the presence of sulfur which consists of: adding steam to the hydrocarbon material and passing the steam and hydrocarbon material over catalyst material at elevated temperatures. The improvement comprises utilizing as a catalyst material high activity, sulfur tolerant catalyst of platinum supported on lanthanum stabilized alumina or magnesium promoted lanthanum stabilized alumina. It also describes a steam process for converting hydrocarbon material to hydrogen gas in the presence of sulfur which consists of steam to the hydrocarbon material over catalyst material at elevated temperatures. The improvement comprises utilizing as a catalyst material high activity, sulfur tolerant catalysts consisting essentially of iridium supported on lanthanum stabilized alumina or magnesium promoted lanthanum stabilized alumina. In addition a steam reforming process is described for converting hydrocarbon material to hydrogen gas in the presence of sulfur comprising adding steam to the hydrocarbon material and passing the steam and hydrocarbon material over catalyst material at elevated temperatures. The improvement comprises utilizing as a catalyst material high activity sulfur tolerant catalysts consisting essentially of palladium supported on lanthanum stabilized alumina or magnesium promoted lanthanum stabilized alumina.

Setzer, H.J.; Karavolis, S.; Bett, J.A.S.

1987-09-15T23:59:59.000Z

255

The effect of rhenium, sulfur and alumina on the conversion of hydrocarbons over platinum single crystals: Surface science and catalytic studies  

SciTech Connect

Conversion reactions of hydrocarbons over Pt-Re model catalyst surfaces modified by sulfur and alumina have been studied. A plasma deposition source has been developed to deposit Pt, Re, and Al on metal substrates variable coverage in ultrahigh vacuum without excessive heating. Conversion of n-hexane was performed over the Re-covered Pt and Pt-covered Re surfaces. The presence of the second metal increased hydrogenolysis activity of both Pt-Re surfaces. Addition of sulfur on the model Catalyst surfaces suppressed hydrogenolysis activity and increased the cyclization rate of n-hexane to methylcyclopentane over Pt-Re surfaces. Sulfiding also increased the dehydrogenation rate of cyclohexane to benzene Over Pt-Re surfaces. It has been proposed that the PtRe bimetallic catalysts show unique properties when combined with sulfur, and electronic interactions exist between platinum, rhenium and sulfur. Decomposition of hydrocarbons on the sulfur-covered Pt-Re surfaces supported that argument. For the conversion of 1-butene over the planar Pt/AlO{sub x}, the addition of Pt increased the selectivity of hydrogenation over isomerization.

Kim, C.

1992-04-01T23:59:59.000Z

256

The effect of rhenium, sulfur and alumina on the conversion of hydrocarbons over platinum single crystals: Surface science and catalytic studies  

SciTech Connect

Conversion reactions of hydrocarbons over Pt-Re model catalyst surfaces modified by sulfur and alumina have been studied. A plasma deposition source has been developed to deposit Pt, Re, and Al on metal substrates variable coverage in ultrahigh vacuum without excessive heating. Conversion of n-hexane was performed over the Re-covered Pt and Pt-covered Re surfaces. The presence of the second metal increased hydrogenolysis activity of both Pt-Re surfaces. Addition of sulfur on the model Catalyst surfaces suppressed hydrogenolysis activity and increased the cyclization rate of n-hexane to methylcyclopentane over Pt-Re surfaces. Sulfiding also increased the dehydrogenation rate of cyclohexane to benzene Over Pt-Re surfaces. It has been proposed that the PtRe bimetallic catalysts show unique properties when combined with sulfur, and electronic interactions exist between platinum, rhenium and sulfur. Decomposition of hydrocarbons on the sulfur-covered Pt-Re surfaces supported that argument. For the conversion of 1-butene over the planar Pt/AlO[sub x], the addition of Pt increased the selectivity of hydrogenation over isomerization.

Kim, C.

1992-04-01T23:59:59.000Z

257

Chemistry of Cobalt-Platinum Nanocatalysts  

NLE Websites -- All DOE Office Websites (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...

258

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

259

InGaAs heterostructure formation in catalyst-free GaAs nanopillars by selective-area metal-organic vapor phase epitaxy  

SciTech Connect

We investigate axial GaAs/InGaAs/GaAs heterostructures embedded in GaAs nanopillars via catalyst-free selective-area metal-organic chemical vapor deposition. Structural characterization by transmission electron microscopy with energy dispersive x-ray spectroscopy (EDS) indicates formation of axial In{sub x}Ga{sub 1-x}As (x{approx}0.20) inserts with thicknesses from 36 to 220 nm with {+-}10% variation and graded Ga:In transitions controlled by In segregation. Using the heterointerfaces as markers, the vertical growth rate is determined to increase linearly during growth. Photoluminescence from 77 to 290 K and EDS suggest the presence of strain in the shortest inserts. This capability to control the formation of axial nanopillar heterostructures is crucial for optimized device integration.

Shapiro, J. N.; Lin, A.; Wong, P. S.; Scofield, A. C.; Tu, C.; Senanayake, P. N.; Mariani, G.; Liang, B. L.; Huffaker, D. L. [Department of Electrical Engineering and California Nano-Systems Institute, University of California at Los Angeles, Los Angeles, California 90095 (United States)

2010-12-13T23:59:59.000Z

260

Platinum Monolayer Electrocatalysts for Oxygen Reduction Reaction...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Platinum Monolayer Electrocatalysts for Oxygen Reduction Reaction Platinum Monolayer Electrocatalysts for Oxygen Reduction Reaction Presentation slides from the June 19, 2012, Fuel...

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

Chemistry of Cobalt-Platinum Nanocatalysts  

NLE Websites -- All DOE Office Websites (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...

262

Catalysts allow CO and CO/sub 2/ comethanation  

SciTech Connect

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

263

Pt loaded carbon aerogel catalyst for catalytic exchange reactions between water and hydrogen gas  

Science Journals Connector (OSTI)

We report development and characterization of platinum doped carbon aerogel catalyst for catalytic exchange reactions between water and hydrogen gas. The carbon aerogel with uniformly dispersed platinum nanoparticles was prepared by adding platinum precursor during the sol-gel process. Thereafter colloidal PTFE was mixed with the platinum doped carbon aerogel powder and coated on Dixon rings to obtain hydrophobic catalyst with required mechanical strength. Detailed studies have been carried out to observe the effect of physical characteristics of the catalyst powder (surface area and pore size of aerogels Pt cluster size and its valence state etc) and the different coating parameters (PTFE to Pt-CA ratio and Pt loading on Dixon ring) on volume transfer rate (Ky.a) for H/D reaction. Ky.a values of ?0.8 m3 (STP).s?1. m?3 were obtained for Pt loading of 7% and Pt cluster size of 3 nm at atmospheric pressure.

P. K. Gupta

2013-01-01T23:59:59.000Z

264

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

SciTech Connect

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

265

What performance would non-Pt cathode catalysts need to achieve  

E-Print Network (OSTI)

require development of x2 more active cathode catalyst MEA/DM optimization required but less criticalWhat performance would non-Pt cathode catalysts need to achieve to be practical Motors Fuel Cell Activities Honeoye Falls, NY DOE Workshop on Non-Platinum Electrocatalysts 21

266

Regeneration of Hydrotreating and FCC Catalysts  

SciTech Connect

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

267

Extensive Isomerization of Alkenes Using a Bifunctional Catalyst:  An Alkene Zipper  

E-Print Network (OSTI)

Placement of the base in the catalyst is crucial: adding 1-of the heterocycle in the catalyst 21 is that complex 1e ismay or may not involve metal catalyst but for simplicity is

Grotjahn, Douglas B; Larsen, Casey R; Gustafson, Jeffery L; Nair, Reji; Sharma, Abhinandini

2007-01-01T23:59:59.000Z

268

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

269

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

SciTech Connect

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

270

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

SciTech Connect

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

271

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

272

Catalysts for Oxidation of Mercury in Flue Gas  

NLE Websites -- All DOE Office Websites (Extended Search)

Catalysts for Oxidation of Mercury in Flue Gas Catalysts for Oxidation of Mercury in Flue Gas Opportunity The Department of Energy's National Energy Technology Laboratory (NETL) is seeking licensing partners interested in implementing United States Patent Number 7,776,780 entitled "Catalysts for Oxidation of Mercury in Flue Gas." Disclosed in this patent are catalysts for the oxidation of elemental mercury in flue gas. These novel catalysts include iridium (Ir), platinum/iridium (Pt/Ir), and Thief carbons. The catalyst materials will adsorb the oxidizing agents HCl, Cl 2 , and other halogen species in the flue gas stream that are produced when fuel is combusted. These adsorbed oxidizing agents can then react with elemental mercury in the stream, which is difficult to capture, and oxidize it to form Hg (II) species,

273

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

SciTech Connect

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

274

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

275

Comparison of the activity and selectivity of activated carbon supported group VIII metal catalysts in the hydrogenolysis of CCl{sub 2}F{sub 2} into CH{sub 2}F{sub 2}  

SciTech Connect

The catalytic hydrogenolysis of waste and banked CCl{sub 2}F{sub 2} (CFC-12) is important for the reduction of ozone depletion caused by CFCs. Especially selective production of CH{sub 2}F{sub 2} (HFC-32) is attractive, because this product can be applied as an alternative, ozone friendly, refrigerant. Because of the limited time available for catalyst development, interaction between catalyst and process development is crucial. Several group VIII metal supported catalyst have been tested for the reaction. Activated carbon is selected as support material because of the corrosive reaction conditions. Large differences in both the activity and selectivity are found for the different metals. Palladium has been selected as very suitable for the selective conversion to CH{sub 2}F{sub 2} (85% selectivity at 90% conversion, stable for 1600 hours). Iridium and ruthenium are more selective to CHClF{sub 2} (HCFC-22) (60% and 53% selectivity at 15% and 20% conversion, respectively). In this presentation the different performances of the Group VIII metals will be illustrated with both performance and characterization data.

Wiersma, A.; Hollander, M.A. den; Makkee, M. [Delft Univ. of Technology (Netherlands)] [and others

1996-10-01T23:59:59.000Z

276

A thin-film/agglomerate model of a proton-exchange-membrane fuel cell cathode catalyst layer with consideration of solid-polymer-electrolyte distribution  

Science Journals Connector (OSTI)

Experimental work on the proton-exchange-membrane fuel cell (PEMFC) has revealed that a better utilization of carbon supported platinum catalyst (Pt/C) hinges on an appropriate...1–12...]. GDE is prepared by a po...

Ken-Ming Yin

2007-08-01T23:59:59.000Z

277

Optimization of catalyst system reaps economic benefits  

SciTech Connect

Champlin Refining and Chemicals Inc. is learning to optimize its catalyst systems for hydrotreating Venezuelan gas oils through a program of research, pilot plant testing, and commercial unit operation. The economic results of this project have been evaluated, and the benefits are most evident in improvements in product yields and qualities. The project has involved six commercial test runs, to date (Runs 10-15), with a seventh run planned. A summary of the different types of catalyst systems used in the test runs, and the catalyst philosophy that developed is given. Runs 10 and 11 used standard CoMo and NiMo catalysts for heavy gas oils hydrotreating. These catalysts had small pore sizes and suffered high deactivation rates because of metals contamination. When it was discovered that metals contamination was a problem, catalyst options were reviewed.

Le Roy, C.F.; Hanshaw, M.J.; Fischer, S.M.; Malik, T.; Kooiman, R.R. (Champlin Refining and Chemicals Inc., Corpus Christi, TX (US))

1991-06-03T23:59:59.000Z

278

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

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

279

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

280

Location of platinum clusters in PtCaY and PtNaY zeolites  

E-Print Network (OSTI)

Patterns. 73 12 Literature Values for Pt 4f, g, and Pt 4d, 7'~ Binding Energies. Percent Platinum Detected by XPS for Different Size Platinum Particles LIST OF FIGURES FIGURE PAGE Pyrex cell for infrared studies of the zeolites. Pyrex cell for x... shifts of leV were also detected for small clusters of reduced ruthenium when compared with larger metal particles within the zeolite or its external surface. ~Ob ective of research. The present study was undertaken primarily to determine...

Treybig, Duane Steven

2012-06-07T23:59:59.000Z

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.


281

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

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

282

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

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

283

TEMPERATURE-PROGRAMMED DESORPTION AND REACTION OF CO AND H2 ON ALUMINA-SUPPORTED RUTHENIUM CATALYST  

E-Print Network (OSTI)

over Group VIII Metal Catalysts" J.T. Kummer and P.H.and Fischer- Iron Catalyst", to be published. P.R. Wentrek,on Alumina-supported Ruthenium Catalyst" to be published. M.

Low, Gordon Gongngai

2011-01-01T23:59:59.000Z

284

Advanced Electrodes for Solid Acid Fuel Cells by Platinum Deposition on CsH2PO4  

Science Journals Connector (OSTI)

Advanced Electrodes for Solid Acid Fuel Cells by Platinum Deposition on CsH2PO4 ... The unique characteristics of the CDP electrolyte pose several challenges to SAFC optimization, particularly in the area of cathode microstructure. ... 1% CO demonstrates the potential of this approach with optimized reforming catalysts and also the tolerance to CO poisoning at these elevated temps. ...

Alexander B. Papandrew; Calum R.I. Chisholm; Ramez A. Elgammal; Mustafa M. Özer; Strahinja K. Zecevic

2011-03-15T23:59:59.000Z

285

Nanosegregated Cathode Catalysts with Ultra-Low Platinum Loading  

Energy.gov (U.S. Department of Energy (DOE))

Presented at the Department of Energy Fuel Cell Projects Kickoff Meeting, September 1 – October 1, 2009

286

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

287

CATALYST EVALUATION FOR A SULFUR DIOXIDE-DEPOLARIZED ELECTROLYZER  

SciTech Connect

Thermochemical processes are being developed to provide global-scale quantities of hydrogen. A variant on sulfur-based thermochemical cycles is the Hybrid Sulfur (HyS) Process which uses a sulfur dioxide depolarized electrolyzer (SDE) to produce the hydrogen. Testing examined the activity and stability of platinum and palladium as the electrocatalyst for the SDE in sulfuric acid solutions. Cyclic and linear sweep voltammetry revealed that platinum provided better catalytic activity with much lower potentials and higher currents than palladium. Testing also showed that the catalyst activity is strongly influenced by the concentration of the sulfuric acid electrolyte.

Hobbs, D; Hector Colon-Mercado, H

2007-01-31T23:59:59.000Z

288

Dynamic Restructuring Of Solid Catalyst Cluster During Carbon Nanotube CVD  

E-Print Network (OSTI)

Dynamic Restructuring Of Solid Catalyst Cluster During Carbon Nanotube CVD Stephan Hofmann1 , Renu, University of Cambridge, Cambridge, United Kingdom. It is commonly assumed that the catalyst metal forms a liquid intermediate and that bulk catalyst effects dominate CNT growth dynamics. Calculations of size

Dunin-Borkowski, Rafal E.

289

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

290

Microwave-assisted Pt–Co–Cr/C ternary compound preparation applied as a cathode catalyst for PEMFC  

Science Journals Connector (OSTI)

The present study describes the preparation of catalyst nanocomposites comprised of 20 wt.% Pt–Co–Cr (2:1:1) particles attached on the surface of carbon Vulcan XC-72R by microwave radiation; cases of carbon being chemically treated and untreated are considered. Ethylene glycol was used as the solvent and electron source for the microwave-assisted reduction reaction, whereas H2PtCl6?xH2O, Co(NO3)3?6H2 O and Cr(NO3)3?9H2 O were used as metal precursors. The C powder surface was chemically modified by stirring the C in 8N H2 O2 for 48?h. For the nanocomposite in which C was not treated, EDS analysis showed a content of 4.9 wt.% Pt and 1.2 wt.% Cr with only a trace amount of Co. Higher Pt and Cr contents were observed in the catalyst sample prepared from treated carbon (5.6% Pt and 2.2% Cr), but no Co was detected. Chromium appeared as Cr3 O4 in both samples confirmed by the XAS spectrum. The obtained phase was therefore Pt–Cr3 O4 /C for both samples. The TEM results indicated that the average particle size of Pt–Cr3O4 was 2.22 ±0.41?nm on treated C and 1.93 ±0.34?nm on untreated C. By the CV technique, it was observed that the catalytic activity of the treated carbon Pt–Cr3O4 catalyst was not only higher than that of the untreated carbon Pt– Cr3 O4 catalyst, but also higher than that of the standard platinum catalyst.

T Sarakonsri; S Thungprasert; W Klysubun; T Vilaithong

2010-01-01T23:59:59.000Z

291

Pt-Based Core–Shell Catalyst Architectures for Oxygen Fuel Cell Electrodes  

Science Journals Connector (OSTI)

Currently, platinum nanoparticles are the most used cathode electrode materials to catalyze the sluggish oxygen reduction reaction (ORR, O2 + 4 H+ + 4 e– ? 2 H2O) to water in PEMFC systems. ... The development of DFT-based theoretical predictions of efficient ORR catalysts provided progress in our understanding of ORR activity and yielded promising catalyst materials for fuel cell experimentalists. ... This work demonstrates the essential role of particle size and crossover hydrogen on the degrdn. of platinum polymer electrolyte membrane fuel cell (PEMFC) cathodes. ...

Mehtap Oezaslan; Frédéric Hasché; Peter Strasser

2013-09-12T23:59:59.000Z

292

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

293

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

294

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

295

Thief Carbon Catalyst for Oxidation of Mercury in Effluent Stream  

NLE Websites -- All DOE Office Websites (Extended Search)

Carbon Catalyst for Oxidation of Mercury in Effluent Carbon Catalyst for Oxidation of Mercury in Effluent Stream Contact NETL Technology Transfer Group techtransfer@netl.doe.gov January 2012 Significance * Oxidizes heavy metal contaminants, especially mercury, in gas streams * Uses partially combusted coal ("Thief" carbon) * Yields an inexpensive catalyst * Cheap enough to be a disposable catalyst * Cuts long-term costs * Simultaneously addresses oxidation and adsorption issues Applications * Any process requiring removal of heavy

296

Fuel Cell Catalyst Layers: A Polymer Science Perspective  

Science Journals Connector (OSTI)

With the approaching commercialization of PEM fuel cell technol., developing active, inexpensive non-precious metal ORR catalyst materials to replace currently used Pt-based catalysts is a necessary and essential requirement in order to reduce the overall system cost. ... Polymer electrolyte membranes were catalyzed by direct application of thin film layers cast from solns. of suspended Pt/C catalyst and solubilized Nafion ionomer. ... Identification of dominant transport mechanisms in PEMFC cathode catalyst layers operated under low RH ...

Steven Holdcroft

2013-06-28T23:59:59.000Z

297

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

298

Catalyst and process for steam-reforming of hydrocarbons  

SciTech Connect

An improved catalyst and an improved process for use of the catalyst in the steam-hydrocarbon reforming reaction are disclosed. The catalyst comprises a group VIII metal on a cylindrical ceramic support consisting essentially of alpha alumina and having a plurality of gas passages extending axially therethrough. These supported catalysts display a higher geometric surface area and a lower pressure drop than do standard rings.

Atwood, K.; Merriam, J.S.; Wright, J.H.

1980-11-11T23:59:59.000Z

299

Thief carbon catalyst for oxidation of mercury in effluent stream  

DOE Patents (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

300

Low Cost Autothermal Diesel Reforming Catalyst Development  

SciTech Connect

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

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

Catalysts for Lean Engine Emission Control - Emissions & Emission Controls  

NLE Websites -- All DOE Office Websites (Extended Search)

Catalysts for Lean Engine Emission Control Catalysts for Lean Engine Emission Control Catalysts for controlling NOx from lean engines are studied in great detail at FEERC. Lean NOx Traps (LNTs) and Selective Catalytic Reduction (SCR) are two catalyst technologies of interest. Catalysts are studied from the nanoscale to full scale. On the nanoscale, catalyst powders are analyzed with chemisorptions techniques to determine the active metal surface area where catalysis occurs. Diffuse Reflectance Infrared Fourier Transform (DRIFT) spectroscopy is used to observe the chemical reactions occurring on the catalyst surface during catalyst operation. Both powder and coated catalyst samples are analyzed on bench flow reactors in controlled simulated exhaust environments to better characterize the chemical

302

Page 1 of 20 Catalyst preparation for CMOS-compatible silicon  

E-Print Network (OSTI)

Page 1 of 20 Catalyst preparation for CMOS-compatible silicon nanowire synthesis Vincent T. Renard many of the metallic catalysts required for nanowire growth are not compatible with standard CMOS of silicon nanowires using copper based catalysts is limited by catalyst preparation. We show

Paris-Sud XI, Université de

303

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

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

304

Novel Intermetallic Catalysts to Enhance PEM Membrane Durability  

SciTech Connect

The research examined possible sources of degradation of platinum based anode catalysts under long term use. Scientists at the United Technologies Research Center had shown that the anode as well as the cathode catalysts degrade in hydrogen fuel cells. This goal of this research was to see if mechanisms of anode degradation could be understood using forefront electrochemical techniques in an aqueous system. We found that this method is limited by the very low levels of impurities (perhaps less than a part per trillion) in the electrolyte. This limitation comes from the relatively small catalyst surface area (a few sq cm or less) compared to the electrolyte volume of 10 to 25 ml. In real fuel cells this ratio is completelyreversed: high catalyst surface area and low electrolyte violume, making the system much less sensitive to impurities in the electrolyte. We conclude that degradation mechanisms should be studied in real fuel cell systems, rather than in ex-situ, large electrolyte volume experiments.

Francis J. DiSalvo

2009-01-06T23:59:59.000Z

305

Hydrogenation of unsaturated, aromatic, and heterocyclic compounds with polymer-supported catalysts  

SciTech Connect

The authors synthesized and studied catalysts based upon complexes of platinum, palladium, rhodium, and nickel with the following polymeric microligands: copolymers of styrene with maleic acid (S-MA), copolymers of maleic acid with methyl methacrylate (MA-MMA), and polyacrylic acid (PAA). The catalysts showed high activity and selectivity in the hydrogenation of furan and its derivatives, benzofuran, benzodioxane, benzene, nitrobenzene, phenol, olefins and cyclic olefins, and cyclic dienes. 2 tables.

Karakhanov, E.A.; Pshezhetskii, V.S.; Dedov, A.G.; Loktev, A.S.; Lebedeva, T.S.

1984-04-01T23:59:59.000Z

306

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.

307

Characteristics of platinum-based electrocatalysts for mobile PEMFC applications  

Science Journals Connector (OSTI)

Platinum-based electrocatalysts play an important role in the development of high performance PEMFC stacks for mobile applications. This paper reviews objectives, development work, and results of a Research and Development Program funded by the German Ministry of Education, Science, Research and Technology (BMBF) to develop the basic technology as well as components for mobile PEMFC applications. In the framework of this program, Degussa-Hüls developed precious metal-based electrocatalysts for operation under practical reformate/air PEMFC conditions which yield high power densities up to 0.5 W/cm2 at low total platinum loadings of less than 0.5 mg Pt/cm2. A CO-tolerant anode electrocatalyst, exhibiting a CO-tolerance of 100 ppm CO, was developed and characterized. The features of the new electrocatalyst materials were verified by DaimlerChrysler in a 2.7 kW PEMFC stack at the end of the program.

K.A Starz; E Auer; Th Lehmann; R Zuber

1999-01-01T23:59:59.000Z

308

New Generation of Catalyst Layers for PEMFCs Based on Carbon Aerogel Supported Pt Catalyst (CASPC)  

Science Journals Connector (OSTI)

The mass production of PEMFC power generators requires a price reduction and, ... the amount of noble metals present in the cathode and anode catalyst layers. Automotive, residential, military, and small scale ap...

Alevtina Smirnova; Xing Dong; Hiro Hara; Nigel M. Sammes

2006-01-01T23:59:59.000Z

309

Low Loading Pt Cathode Catalysts for Direct Methanol Fuel Cell Derived from the Particle Size Effect  

Science Journals Connector (OSTI)

Recent results have shown that with sputtered Pt cathode catalysts, the metal loading in PEMFC can be reduced to cathode metal loading in PEMFC, less attention has been paid to DMFC. ... The long-term performance of catalyst Pt14-050 in DMFC was examined to explore the stability of the small-sized Pt catalysts. ...

Fei Wen; Ulrich Simon

2007-06-16T23:59:59.000Z

310

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

311

Process for alkane group dehydrogenation with organometallic catalyst  

DOE Patents (OSTI)

An improved process is described for the catalytic dehydrogenation of organic molecules having a ##STR1## group to produce a ##STR2## group. The organic molecules are: ##STR3## wherein: A.sup.1, A.sup.2, A.sup.3, and A.sup.4 are each independently P, As or N: E.sup.2 is independently C or N; E.sup.3 is independently C, Si or Ge; E.sup.4 is independently C, Si, or Ge; and E.sup.5 is independently C, Si or Ge; M.sup.1, M.sup.2, M.sup.3, and M.sup.4 each is a metal atom independently selected from the group consisting of ruthenium, rhodium, palladium, osmium, iridium and platinum; Q.sup.1, Q.sup.2, Q.sup.3, and Q.sup.4 are each independently a direct bond, --CH.sub.2 --, --CH.sub.2 CH.sub.2 --, or CH.dbd.CH--; in structure I, structure II or structure IV, R.sup.1, R.sup.2, R.sup.3, and R.sup.4 are each independently selected from alkyl, alkenyl, cycloalkyl, and aryl, or R.sup.1 and R.sup.2 together and R.sup.3 and R.sup.4 together form a ring structure having from 4 to 10 carbon atoms, or in structure III, R.sup.5, R.sup.6, R.sup.7, and R.sup.8 are each independently selected from alkyl, alkenyl, cycloalkyl, and aryl, or R.sup.5 and R.sup.6 together and R.sup.7 and R.sup.8 together form a ring structure having from 4 to 10 carbon atoms, at a temperature of between about 100.degree. and 250.degree. C. for between about 1 hr and 300 days in the absence of N.sub.2. The surprisingly stable catalyst is a complex of an organic ligand comprising H, C, Si, N, P atoms, and a platinum group metal. The dehydrogenation is performed between about 100 to 200.degree. C., and has increased turnover.

Kaska, W.C.; Jensen, C.M.

1998-07-14T23:59:59.000Z

312

Advanced Cathode Catalysts  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

new catalysts, this research program will also target other issues crucial to PEMFC cathode electrocatalysis: novel electrode structures; catalyst durability meeting the...

313

The Platinum-Group Elements:  

Science Journals Connector (OSTI)

...measured for diesel catalysts (Moldovan...for example, engine ignition problems...compiled from general literature data...Sures 2004). In general, Pd is found...Rosner G (1999a) Engine dynamometer experiments...gasoline and diesel engine catalytic converters...

Sebastien Rauch; Gregory M. Morrison

314

Formic acid decomposition on polycrystalline platinum and palladized platinum electrodes  

SciTech Connect

This is a comprehensive study in which a formic acid decomposition reaction is examined as a probe of catalytic properties of polycrystalline platinum and palladized platinum electrodes. The electrode potential varies in a broad range, and the reaction is carried out in perchloric acid and sulfuric acid solutions containing different concentrations of HCOOH. Analytical methods used to access the decomposition reaction are chronoamperometry and cyclic voltammetry. At very short times, the authors prove that only a negligible amount of surface CO is formed, and the CO unaffected decomposition reaction, leading to CO{sub 2} formation, can be interrogated. Surprisingly, the decomposition reaction displays Tafel behavior only in a very narrow potential range. This observation, made with both clean Pt and Pt/Pd electrodes, suggests that water-surface interactions, and/or (bi)sulfate-surface interactions, increase with increasing electrode potential and create a steric/electronic barrier for the decomposition of formic acid (and methanol). The authors therefore offer a pessimistic view about platinum as a universal material for heterogeneous catalysis applications involving rearrangements of organic molecules. Such rearrangements may only be fulfilled with a low electrochemical driving force, at least at room temperature, but at higher potentials, the electrode becomes deactivated due to the unique attributes of the double layer structure on the platinum electrode. The authors have also found that the deceleration of formic acid oxidation (to CO{sub 2}) is primarily due to CO chemisorption only at potentials overlapping with those from the hydrogen adsorption range, or not too positive from this range. At more positive potentials, the decay in formic acid decomposition is neither due to CO formation nor to solution mass transfer limitations. The presence of interfacial CO{sub 2} or adsorption of formic acid and/or formate anion, could account for the decay. Finally, a detailed analysis of kinetic isotherms involved in the two pathways, CO{sub 2} formation and CO chemisorption, is made and the mechanism of formic acid decomposition on platinum is discussed. The electrolyte anion effects involved in formic acid oxidation in HClO{sub 4} and in H{sub 2}SO{sub 4} solutions are also presented.

Lu, G.Q.; Crown, A.; Wieckowski, A.

1999-11-04T23:59:59.000Z

315

A Heart of Gold? Try Platinum | Department of Energy  

NLE Websites -- All DOE Office Websites (Extended Search)

A Heart of Gold? Try Platinum A Heart of Gold? Try Platinum December 1, 2014 - 3:21pm Addthis This coronary stent is made with a lab-developed, award-winning platinum-chromium...

316

Breakthrough Research on Platinum-Nickel Alloys  

NLE Websites -- All DOE Office Websites (Extended Search)

Third, an approximately fivefold reduction in the amount of platinum in current PEM fuel cell stacks is needed to meet the cost requirements of large-scale automotive...

317

Platinum Monolayer Electrocatalysts for Oxygen Reduction Reaction  

Energy.gov (U.S. Department of Energy (DOE))

Presentation slides from the June 19, 2012, Fuel Cell Technologies Program webinar ""BNL's Low-Platinum Electrocatalysts for Fuel Cell Electric Vehicles (FCEVs)

318

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

319

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

320

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

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

Lithium phosphate catalyst, III. New supported catalyst  

Science Journals Connector (OSTI)

Some new non-stoichiometric Li3PO4 supported on ?-Al2O3, ?-Al2O3, TiO2 and SiO2 are described as catalysts. The catalysts are used in the isomerization of propene oxide. The catalyst supported on SiO2...is more a...

A. M. Delgado; J. V. Sinisterra

1992-07-01T23:59:59.000Z

322

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

323

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

324

Fuel Cell Technologies Office: Non-Platinum Electrocatalysts Workshop  

NLE Websites -- All DOE Office Websites (Extended Search)

Non-Platinum Non-Platinum Electrocatalysts Workshop to someone by E-mail Share Fuel Cell Technologies Office: Non-Platinum Electrocatalysts Workshop on Facebook Tweet about Fuel Cell Technologies Office: Non-Platinum Electrocatalysts Workshop on Twitter Bookmark Fuel Cell Technologies Office: Non-Platinum Electrocatalysts Workshop on Google Bookmark Fuel Cell Technologies Office: Non-Platinum Electrocatalysts Workshop on Delicious Rank Fuel Cell Technologies Office: Non-Platinum Electrocatalysts Workshop on Digg Find More places to share Fuel Cell Technologies Office: Non-Platinum Electrocatalysts Workshop on AddThis.com... Publications Program Publications Technical Publications Educational Publications Newsletter Program Presentations Multimedia Conferences & Meetings Annual Merit Review Proceedings

325

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

NLE Websites -- All DOE Office Websites (Extended Search)

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

326

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...

327

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

NLE Websites -- All DOE Office Websites (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...

328

Automation of amperometric titrations with rotating platinum electrodes  

Science Journals Connector (OSTI)

Automation of amperometric titrations with rotating platinum electrodes ... A modification of an earlier described apparatus allows for the automation of amperometric titrations with rotating platinum electrodes. ...

Eugene D. Olsen; Roger D. Walton

1966-01-01T23:59:59.000Z

329

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...

330

Synthesis and Understanding of Novel Catalysts  

SciTech Connect

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

331

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

332

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

333

The reconstruction of supported platinum particles monitored by methylcyclohexane dehydrogenation and H[sub 2] TPD  

SciTech Connect

Alteration of the dehydrogenation activity of [alpha]-alumina-supported platinum particles induced by a high-temperature (723 K) treatment in argon atmosphere has been investigated. The methyl-cyclohexane dehydrogenation rate over reduced platinum particles is highly dependent on the argon treatment applied at 723 K after hydrogen treatment at the same temperature. With an increasing exposure time to the argon stream, the reaction rate increases sharply to a maximum and gradually diminishes afterwards to a stable value for a prolonged exposure time. This change is the result of two modifying actions induced by inert gas: (1) the desorption of tightly bound hydrogen species, responsible for the low initial activity, and (2) the reconstruction of the platinum crystallite surface toward a more stable active surface. The presence of [open quotes]high-temperature hydrogen[close quotes] is systematically observed on small particles after hydrogen treatment at 723 K and seems to be related to the specific electronic properties of small particles and not to their surface structure. The reconstruction of the surface of the particles is by contrast very important for obtaining stable catalytic activity. Highly dispersed (80-90%), restructured catalysts were found to be similar in stability to mediumly dispersed (45%) catalysts. 32 refs., 4 figs., 1 tab.

Rochefort, A.; Le Peltier, F.; Boitiaux, J.P. (Institut Francais du Petrole, Rueil-Malmaison (France))

1994-02-01T23:59:59.000Z

334

High-Activity, Durable Oxygen Reduction Electrocatalyst: Nanoscale Composite of Platinum?Tantalum Oxyphosphate on Vulcan Carbon  

Science Journals Connector (OSTI)

active surface area, and the performance of the cathode catalyst layer were significantly reduced. ... Swider-Lyons, K. E.; Teliska, M. E.; Baker, W. S.; Bouwman, P. J.; Pietron, J. J.Leveraging Metal?Support Interactions to Improve the Activity of PEMFC Cathode Catalysts ECS Trans. ... The goal is to reduce the Pt loading in PEMFC cathodes using catalysts modified by metal support interactions (MSIs), an approach commonly used in heterogeneous catalysis. ...

Yannick Garsany; Albert Epshteyn; Andrew P. Purdy; Karren L. More; Karen E. Swider-Lyons

2010-06-11T23:59:59.000Z

335

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

SciTech Connect

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

336

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 in the second quarter of 2004 for rebricking of the smelting furnace. mine operations continued during

337

Atomic-Scale Design of Iron Fischer-Tropsch Catalysts; A Combined Computational Chemistry, Experimental, and Microkinetic Modeling Approach  

SciTech Connect

This work focuses on (1) searching/summarizing published Fischer-Tropsch synthesis (FTS) mechanistic and kinetic studies of FTS reactions on iron catalysts; (2) preparation and characterization of unsupported iron catalysts with/without potassium/platinum promoters; (3) measurement of H{sub 2} and CO adsorption/dissociation kinetics on iron catalysts using transient methods; (3) analysis of the transient rate data to calculate kinetic parameters of early elementary steps in FTS; (4) construction of a microkinetic model of FTS on iron, and (5) validation of the model from collection of steady-state rate data for FTS on iron catalysts. Three unsupported iron catalysts and three alumina-supported iron catalysts were prepared by non-aqueous-evaporative deposition (NED) or aqueous impregnation (AI) and characterized by chemisorption, BET, temperature-programmed reduction (TPR), extent-of-reduction, XRD, and TEM methods. These catalysts, covering a wide range of dispersions and metal loadings, are well-reduced and relatively thermally stable up to 500-600 C in H{sub 2} and thus ideal for kinetic and mechanistic studies. Kinetic parameters for CO adsorption, CO dissociation, and surface carbon hydrogenation on these catalysts were determined from temperature-programmed desorption (TPD) of CO and temperature programmed surface hydrogenation (TPSR), temperature-programmed hydrogenation (TPH), and isothermal, transient hydrogenation (ITH). A microkinetic model was constructed for the early steps in FTS on polycrystalline iron from the kinetic parameters of elementary steps determined experimentally in this work and from literature values. Steady-state rate data were collected in a Berty reactor and used for validation of the microkinetic model. These rate data were fitted to 'smart' Langmuir-Hinshelwood rate expressions derived from a sequence of elementary steps and using a combination of fitted steady-state parameters and parameters specified from the transient measurements. The results provide a platform for further development of microkinetic models of FTS on Fe and a basis for more precise modeling of FTS activity of Fe catalysts. Calculations using periodic, self-consistent Density Functional Theory (DFT) methods were performed on various realistic models of industrial, Fe-based FTS catalysts. Close-packed, most stable Fe(110) facet was analyzed and subsequently carbide formation was found to be facile leading to the choice of the FeC(110) model representing a Fe facet with a sub-surface C atom. The Pt adatom (Fe{sup Pt}(110)) was found to be the most stable model for our studies into Pt promotion and finally the role of steps was elucidated by recourse to the defected Fe(211) facet. Binding Energies(BEs), preferred adsorption sites and geometries for all FTS relevant stable species and intermediates were evaluated on each model catalyst facet. A mechanistic model (comprising of 32 elementary steps involving 19 species) was constructed and each elementary step therein was fully characterized with respect to its thermochemistry and kinetics. Kinetic calculations involved evaluation of the Minimum Energy Pathways (MEPs) and activation energies (barriers) for each step. Vibrational frequencies were evaluated for the preferred adsorption configuration of each species with the aim of evaluating entropy-changes, pre exponential factors and serving as a useful connection with experimental surface science techniques. Comparative analysis among these four facets revealed important trends in their relative behavior and roles in FTS catalysis. Overall the First Principles Calculations afforded us a new insight into FTS catalysis on Fe and modified-Fe catalysts.

Manos Mavrikakis; James Dumesic; Rahul Nabar; Calvin Bartholonew; Hu Zou; Uchenna Paul

2008-09-29T23:59:59.000Z

338

Oxygen reduction on a graphite paste and a catalyst loaded graphite paste electrode  

SciTech Connect

Oxygen reduction was studied in basic solution at a graphite paste electrode (GPE). The GPE was used as the disk of a rotating ring disk electrode (RRDE) and experiments were done using the voltage scan technique. The enhancements afforded by catalysts applied to the GPE were also studied. Oxygen reduction on a GPE was shown to be a two-electron process resulting in the formation of peroxide. The Tafel slope (plotted as potential versus log(i/sub l/ x i/(i/sub l/ - i))) was 180 mV. The presence of gold, silver, or platinum on the GPE shifted the oxygen reduction wave approximately 800 mV in the anodic direction. Comparison of the data on a metal catalyzed GPE to the solid metal electrode showed that the former electrode produced a greater fraction of peroxide as product than did the latter. Silver and gold catalyzed GPEs gave Tagel slopes of about 120 mV. The intermediate catalysis of iron and cobalt porphyrin was also examined. While the cobalt porphyrin catalyzed oxygen reduction at a more anodic potential than the iron porphyrin, the latter appeared more active in reacting the peroxide formed as the product of the disk reaction.

DiMarco, D.M.

1980-03-01T23:59:59.000Z

339

Non-Platinum Bimetallic Cathode Electrocatalysts  

E-Print Network (OSTI)

Non-Platinum Bimetallic Cathode Electrocatalysts Debbie Myers ­ Argonne National Laboratory-platinum cathode electrocatalyst for polymer electrolyte fuel cells to meet DOE targets that: ­ Promotes the direct not contain any proprietary or confidential information #12;Objective and Technical Targets Develop a non

340

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

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

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

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

NLE Websites -- All DOE Office Websites (Extended Search)

Contiguous Platinum Monolayer Oxygen Reduction Contiguous Platinum Monolayer Oxygen Reduction Electrocatalysts on High-Stability-Low-Cost Supports Co-PIs: Jia Wang, Miomir Vukmirovic, Kotaro Sasaki, Brookhaven National Laboratory Yang Shao-Horn Massachusetts Institute of Technology Rachel O'Malley, David Thompsett, Sarah Ball, Graham Hard Johnson Matthey Fuel Cells Radoslav Adzic Brookhaven National Laboratory DOE Projects Kickoff Meeting September 30 , 2009 2 Project Overview Project Overview 1. Objectives: Objectives: Developing high performance fuel cell electrocatalysts for the oxygen reduction reaction (ORR) comprising contiguous Pt monolayer Pt monolayer on stable, inexpensive metal or alloy nanorods, nanowires, nanobars and

342

NREL: Biomass Research - Chemical and Catalyst Science Projects  

NLE Websites -- All DOE Office Websites (Extended Search)

Chemical and Catalyst Science Projects Chemical and Catalyst Science Projects A photo of a large white tank the size of a water heater. Several metal fittings stick out of the sides of the tank. Thin tubes are attached to some of the fittings and lead to flow meters and other metal pipes. Researchers use experimental data from this four-inch fluidized bed reactor to develop and validate gasification process models. NREL uses chemical analysis to study biomass-derived products online during the conversion process. Catalysts are used in the thermochemical conversion process to convert tars (a byproduct of gasification) to syngas and to convert syngas to liquid transportation fuels. Among the chemical and catalyst science projects at NREL are: Catalyst Fundamentals NREL is working to develop and understand the performance of catalyst and

343

Stereospecific olefin polymerization catalysts  

DOE Patents (OSTI)

A metallocene catalyst system is described for the polymerization of {alpha}-olefins to yield stereospecific polymers including syndiotactic, and isotactic polymers. The catalyst system includes a metal and a ligand of the formula shown wherein: R{sup 1}, R{sup 2}, and R{sup 3} are independently selected from the group consisting of hydrogen, C{sub 1} to C{sub 10} alkyl, 5 to 7 membered cycloalkyl, which in turn may have from 1 to 3 C{sub 1} to C{sub 10} alkyls as a substituent, C{sub 6} to C{sub 15} aryl or arylalkyl in which two adjacent radicals may together stand for cyclic groups having 4 to 15 carbon atoms which in turn may be substituted, or Si(R{sup 8}){sub 3} where R{sup 8} is selected from the group consisting of C{sub 1} to C{sub 10} alkyl, C{sub 6} to C{sub 15} aryl or C{sub 3} to C{sub 10} cycloalkyl; R{sup 4} and R{sup 6} are substituents both having van der Waals radii larger than the van der Waals radii of groups R{sup 1} and R{sup 3}; R{sup 5} is a substituent having a van der Waals radius less than about the van der Waals radius of a methyl group; E{sup 1}, E{sup 2} are independently selected from the group consisting of Si(R{sup 9}){sub 2}, Si(R{sup 9}){sub 2}--Si(R{sup 9}){sub 2}, Ge(R{sup 9}){sub 2}, Sn(R{sup 9}){sub 2}, C(R{sup 9}){sub 2}, C(R{sup 9}){sub 2}--C(R{sup 9}){sub 2}, where R{sup 9} is C{sub 1} to C{sub 10} alkyl, C{sub 6} to C{sub 15} aryl or C{sub 3} to C{sub 10} cycloalkyl; and the ligand may have C{sub S} or C{sub 1}-symmetry. Preferred metals are selected from the group consisting of group III, group IV, group V or lanthanide group elements. The catalysts are used to prepare stereoregular polymers including polypropylene from {alpha}-olefin monomers.

Bercaw, J.E.; Herzog, T.A.

1998-01-13T23:59:59.000Z

344

Stereospecific olefin polymerization catalysts  

DOE Patents (OSTI)

A metallocene catalyst system for the polymerization of .alpha.-olefins to yield stereospecific polymers including syndiotactic, and isotactic polymers. The catalyst system includes a metal and a ligand of the formula ##STR1## wherein: R.sup.1, R.sup.2, and R.sup.3 are independently selected from the group consisting of hydrogen, C.sub.1 to C.sub.10 alkyl, 5 to 7 membered cycloalkyl, which in turn may have from 1 to 3 C.sub.1 to C.sub.10 alkyls as a substituent, C.sub.6 to C.sub.15 aryl or arylalkyl in which two adjacent radicals may together stand for cyclic groups having 4 to 15 carbon atoms which in turn may be substituted, or Si(R.sup.8).sub.3 where R.sup.8 is selected from the group consisting of C.sub.1 to C.sub.10 alkyl, C.sub.6 to C.sub.15 aryl or C.sub.3 to C.sub.10 cycloalkyl; R.sup.4 and R.sup.6 are substituents both having van der Waals radii larger than the van der Waals radii of groups R.sup.1 and R.sup.3 ; R.sup.5 is a substituent having a van der Waals radius less than about the van der Waals radius of a methyl group; E.sup.1, E.sup.2 are independently selected from the group consisting of Si(R.sup.9).sub.2, Si(R.sup.9).sub.2 --Si(R.sup.9).sub.2, Ge(R.sup.9).sub.2, Sn(R.sup.9).sub.2, C(R.sup.9).sub.2, C(R.sup.9).sub.2 --C(R.sup.9).sub.2, where R.sup.9 is C.sub.1 to C.sub.10 alkyl, C.sub.6 to C.sub.15 aryl or C.sub.3 to C.sub.10 cycloalkyl; and the ligand may have C.sub.S or C.sub.1 -symmetry. Preferred metals are selected from the group consisting of group III, group IV, group V or lanthanide group elements. The catalysts are used to prepare stereoregular polymers including polypropylene from .alpha.-olefin monomers.

Bercaw, John E. (Pasadena, CA); Herzog, Timothy A. (Pasadena, CA)

1998-01-01T23:59:59.000Z

345

Why is a Noble Metal Catalytically Active? The Role of the O-Ag Interaction in the Function of Silver as an Oxidation Catalyst  

Science Journals Connector (OSTI)

Extensive density-functional theory calculations, and taking into account temperature and pressure, afford a comprehensive picture of the behavior and interaction of oxygen and Ag(111), and provides valuable insight into the function of silver as an oxidation catalyst. The obtained phase diagram reveals the most stable species present in a given environment and thus identifies (and excludes) possibly active oxygen species. In particular, for the conditions of ethylene epoxidation, a thin oxidelike structure is most stable, suggesting that such atomic O species are actuating the catalysis, in contrast to hitherto proposed molecularlike species.

Wei-Xue Li; Catherine Stampfl; Matthias Scheffler

2003-06-25T23:59:59.000Z

346

Platinum/Chromium-Based Stents Approved for Treatment of Peripheral Artery  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Platinum/Chromium-Based Stents Approved for Treatment of Peripheral Platinum/Chromium-Based Stents Approved for Treatment of Peripheral Artery Disease Platinum/Chromium-Based Stents Approved for Treatment of Peripheral Artery Disease November 14, 2012 - 12:00pm Addthis Washington, DC - A new stent that incorporates an innovative metal alloy developed by scientists at Boston Scientific Corporation and the U.S. Department of Energy (DOE) has received European approval for use in the treatment of certain peripheral arterial diseases. Initially developed for use as a coronary stent, the new PROMUS ELEMENT™ PLUS BTK drug-eluting stent system is designed for treatment of critical limb ischemia, a severe obstruction of arteries within the extremities which reduces blood flow and can damage tissues. Restoring and maintaining peripheral blood flow in

347

Nanoscale Chemical Imaging of a Working Catalyst  

NLE Websites -- All DOE Office Websites (Extended Search)

Nanoscale Chemical Imaging of a Working Catalyst Print Nanoscale Chemical Imaging of a Working Catalyst Print The heterogeneous catalysts used in most chemical processes typically consist of nanoscale metal or metal oxide particles dispersed on high-surface-area supports. While these particles are the active elements of the catalyst, the overall performance depends not only on their size and composition but also on their multiple interactions with the support, reactants, and products. Probing this chemical soup in real time under realistic reaction conditions is such a tall order that in some cases even the catalytically active chemical species is not known. A Dutch team working at the ALS has combined scanning transmission x-ray microscopy with a reaction chamber adapted from electron microscopy to identify the chemical species present for an iron-based Fischer-Tropsch synthesis catalyst and to image their distribution on the nanoscale. When developed further, this new tool may give chemists the ability to design and tailor catalysts for maximum selectivity and efficiency in a wide range of chemical processes.

348

Nanoscale Chemical Imaging of a Working Catalyst  

NLE Websites -- All DOE Office Websites (Extended Search)

Nanoscale Chemical Imaging of a Working Catalyst Print Nanoscale Chemical Imaging of a Working Catalyst Print The heterogeneous catalysts used in most chemical processes typically consist of nanoscale metal or metal oxide particles dispersed on high-surface-area supports. While these particles are the active elements of the catalyst, the overall performance depends not only on their size and composition but also on their multiple interactions with the support, reactants, and products. Probing this chemical soup in real time under realistic reaction conditions is such a tall order that in some cases even the catalytically active chemical species is not known. A Dutch team working at the ALS has combined scanning transmission x-ray microscopy with a reaction chamber adapted from electron microscopy to identify the chemical species present for an iron-based Fischer-Tropsch synthesis catalyst and to image their distribution on the nanoscale. When developed further, this new tool may give chemists the ability to design and tailor catalysts for maximum selectivity and efficiency in a wide range of chemical processes.

349

Nanoscale Chemical Imaging of a Working Catalyst  

NLE Websites -- All DOE Office Websites (Extended Search)

Nanoscale Chemical Imaging of a Nanoscale Chemical Imaging of a Working Catalyst Nanoscale Chemical Imaging of a Working Catalyst Print Wednesday, 28 January 2009 00:00 The heterogeneous catalysts used in most chemical processes typically consist of nanoscale metal or metal oxide particles dispersed on high-surface-area supports. While these particles are the active elements of the catalyst, the overall performance depends not only on their size and composition but also on their multiple interactions with the support, reactants, and products. Probing this chemical soup in real time under realistic reaction conditions is such a tall order that in some cases even the catalytically active chemical species is not known. A Dutch team working at the ALS has combined scanning transmission x-ray microscopy with a reaction chamber adapted from electron microscopy to identify the chemical species present for an iron-based Fischer-Tropsch synthesis catalyst and to image their distribution on the nanoscale. When developed further, this new tool may give chemists the ability to design and tailor catalysts for maximum selectivity and efficiency in a wide range of chemical processes.

350

Nanoscale Chemical Imaging of a Working Catalyst  

NLE Websites -- All DOE Office Websites (Extended Search)

Nanoscale Chemical Imaging of a Working Catalyst Print Nanoscale Chemical Imaging of a Working Catalyst Print The heterogeneous catalysts used in most chemical processes typically consist of nanoscale metal or metal oxide particles dispersed on high-surface-area supports. While these particles are the active elements of the catalyst, the overall performance depends not only on their size and composition but also on their multiple interactions with the support, reactants, and products. Probing this chemical soup in real time under realistic reaction conditions is such a tall order that in some cases even the catalytically active chemical species is not known. A Dutch team working at the ALS has combined scanning transmission x-ray microscopy with a reaction chamber adapted from electron microscopy to identify the chemical species present for an iron-based Fischer-Tropsch synthesis catalyst and to image their distribution on the nanoscale. When developed further, this new tool may give chemists the ability to design and tailor catalysts for maximum selectivity and efficiency in a wide range of chemical processes.

351

Nanoscale Chemical Imaging of a Working Catalyst  

NLE Websites -- All DOE Office Websites (Extended Search)

Nanoscale Chemical Imaging of a Working Catalyst Print Nanoscale Chemical Imaging of a Working Catalyst Print The heterogeneous catalysts used in most chemical processes typically consist of nanoscale metal or metal oxide particles dispersed on high-surface-area supports. While these particles are the active elements of the catalyst, the overall performance depends not only on their size and composition but also on their multiple interactions with the support, reactants, and products. Probing this chemical soup in real time under realistic reaction conditions is such a tall order that in some cases even the catalytically active chemical species is not known. A Dutch team working at the ALS has combined scanning transmission x-ray microscopy with a reaction chamber adapted from electron microscopy to identify the chemical species present for an iron-based Fischer-Tropsch synthesis catalyst and to image their distribution on the nanoscale. When developed further, this new tool may give chemists the ability to design and tailor catalysts for maximum selectivity and efficiency in a wide range of chemical processes.

352

Nanoscale Chemical Imaging of a Working Catalyst  

NLE Websites -- All DOE Office Websites (Extended Search)

Nanoscale Chemical Imaging of a Working Catalyst Print Nanoscale Chemical Imaging of a Working Catalyst Print The heterogeneous catalysts used in most chemical processes typically consist of nanoscale metal or metal oxide particles dispersed on high-surface-area supports. While these particles are the active elements of the catalyst, the overall performance depends not only on their size and composition but also on their multiple interactions with the support, reactants, and products. Probing this chemical soup in real time under realistic reaction conditions is such a tall order that in some cases even the catalytically active chemical species is not known. A Dutch team working at the ALS has combined scanning transmission x-ray microscopy with a reaction chamber adapted from electron microscopy to identify the chemical species present for an iron-based Fischer-Tropsch synthesis catalyst and to image their distribution on the nanoscale. When developed further, this new tool may give chemists the ability to design and tailor catalysts for maximum selectivity and efficiency in a wide range of chemical processes.

353

Nanoscale Chemical Imaging of a Working Catalyst  

NLE Websites -- All DOE Office Websites (Extended Search)

Nanoscale Chemical Imaging of a Working Catalyst Print Nanoscale Chemical Imaging of a Working Catalyst Print The heterogeneous catalysts used in most chemical processes typically consist of nanoscale metal or metal oxide particles dispersed on high-surface-area supports. While these particles are the active elements of the catalyst, the overall performance depends not only on their size and composition but also on their multiple interactions with the support, reactants, and products. Probing this chemical soup in real time under realistic reaction conditions is such a tall order that in some cases even the catalytically active chemical species is not known. A Dutch team working at the ALS has combined scanning transmission x-ray microscopy with a reaction chamber adapted from electron microscopy to identify the chemical species present for an iron-based Fischer-Tropsch synthesis catalyst and to image their distribution on the nanoscale. When developed further, this new tool may give chemists the ability to design and tailor catalysts for maximum selectivity and efficiency in a wide range of chemical processes.

354

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

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

355

Platinum Availability for Future Automotive Technologies  

Science Journals Connector (OSTI)

(3) The goals of this paper are both (1) to provide a best available statement of the state of platinum supply and demand, the projected interaction of the two, and the current and projected risks to platinum supply chain stakeholders and (2) to extend the previous discussions of availability risk to also include dynamic market characteristics that either positively or negatively reinforce market risk. ... The analysis presented here may be applied to inform the decision about making such an investment to model a given material system. ... Moreover, platinum production is highly concentrated in a single geographic region, increasing the risk of supply disruptions, inefficient management, and political interference. ...

Elisa Alonso; Frank R. Field; Randolph E. Kirchain

2012-10-22T23:59:59.000Z

356

Decomposition of nitrous oxide on AlFe-PILC catalyst  

Science Journals Connector (OSTI)

Two AlFe-PILC catalysts were prepared with different OH/metal...2O) decomposition reactions. The 100% conversion of N2O with NH3into N2and H2O was achieved below 500oC with both applied catalysts. However, the ac...

Ern? E. Kiss; Tatjana J Vuli?…

2005-11-01T23:59:59.000Z

357

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

358

Tungsten Cathode Catalyst for PEMFC  

SciTech Connect

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

359

Molecularly engineering homogenous catalysts  

E-Print Network (OSTI)

have developed new strategies for homogeneous catalyst recovery. Poly (N-isopropylacrylamide) and poly (N-octadecylacrylamide) supports, for example, yield recoverable catalysts that are selectively soluble in the lower (polar) phase and the upper (non...

Hughes, Reagan Rebekah

2013-02-22T23:59:59.000Z

360

Catalysts via First Principles  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

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....

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.


361

Vanadium catalysts break down biomass for fuels  

NLE Websites -- All DOE Office Websites (Extended Search)

Vanadium catalysts break down biomass for fuels Vanadium catalysts break down biomass for fuels Vanadium catalysts break down biomass into useful components Breaking down biomass could help in converting biomass to fuels. March 26, 2012 Biomass Due to diminishing petroleum reserves, non-food biomass (lignocellulose) is an attractive alternative as a feedstock for the production of renewable chemicals and fuels. Get Expertise Researcher Susan Hanson Inorganic Isotope & Actinide Chem Email Researcher Ruilian Wu Bioenergy & Environmental Science Email Researcher Louis "Pete" Silks Bioenergy & Environmental Science Email Vanadium is an inexpensive, earth-abundant metal that is well suited for promoting oxidations in air. Vanadium catalysts break down biomass into useful components Due to diminishing petroleum reserves, non-food biomass (lignocellulose) is

362

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

SciTech Connect

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

363

Patterned Growth of High-quality Single-walled Carbon Nanotubes from Dip-coated Catalyst  

E-Print Network (OSTI)

1 Patterned Growth of High-quality Single-walled Carbon Nanotubes from Dip-coated Catalyst Rong the sintering of catalyst into Si at high temperature, the difference in surface wettability between Si and SiO2. The conventional way to pattern CNT growth involves selective sputtering (evaporation) of metal catalyst through

Maruyama, Shigeo

364

Molten Gallium as a Catalyst for the Large-Scale Growth of Highly Aligned Silica Nanowires  

E-Print Network (OSTI)

Molten Gallium as a Catalyst for the Large-Scale Growth of Highly Aligned Silica Nanowires Zheng a small size (5-100 nm in diameter), high melting point metal (such as gold and iron) catalyst particle as an effective catalyst for the large-scale growth of highly aligned, closely packed silica nanowire bunches

Wang, Zhong L.

365

Patterned growth of single-walled carbon nanotube arrays from a vapor-deposited Fe catalyst  

E-Print Network (OSTI)

Patterned growth of single-walled carbon nanotube arrays from a vapor-deposited Fe catalyst H. B deposition using low-coverage vacuum-deposited iron as a catalyst. Ordered arrays of suspended nanotubes constructed directly on contacting metal electrodes of Pt/Cr patterned with catalysts. Patterning with solid

Golovchenko, Jene A.

366

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

367

Catalyst Manufacturing Science and  

E-Print Network (OSTI)

Catalyst Manufacturing Science and Engineering Consortium (CMSEC) Rutgers University New Jersey, U, automotive, and energy industries makes and/or uses catalysts, there has been no academic program focusing on the operations required to make catalytic materials. Thus, catalyst manufacturing processes are often designed

368

Non-Platinum Bimetallic Cathode Electrocatalysts  

Energy.gov (U.S. Department of Energy (DOE))

This presentation, which focuses on non-platinum bimetallic cathode electrocatalysts, was given by Debbie Myers of Argonne National Laboratory at a February 2007 meeting on new fuel cell projects.

369

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

370

Suppression of carbon formation in steam reforming of methane by addition of Co into Ni/ZrO2 catalysts  

Science Journals Connector (OSTI)

We investigated the steam reforming of methane (SRM) over various NiCo bimetallic catalysts...2...to determine whether the addition of Co on the Ni catalyst suppressed carbon formation. The effect of metal loadin...

Dasika Harshini; Yongchai Kwon; Jonghee Han…

2010-03-01T23:59:59.000Z

371

Development of the 2011MY Ford Super Duty Catalyst System  

Energy.gov (U.S. Department of Energy (DOE))

Efforts leading to medium-duty truck aftertreatment system development, issues addressed, including catalyst layout to maximize NOx conversion and balance of precious metals for oxidation function during cold-start and filter regeneration

372

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

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

373

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

374

What Makes a Good Catalyst for the Deacon Process?  

Science Journals Connector (OSTI)

The catalytic activity is to a large extent determined by the binding strength of the reaction intermediates to the catalyst’s surface (Sabatier principle). ... Therefore, a single metal oxide catalyst may not be improved according to the calculations performed in Norskov’s group. ... Reactor parameters that we have investigated in detail include the oxidizer and chlorinator temps., the catalyst circulation rate and its residence time in each fluidized-bed reactor, the HCl/O2 ratio in the oxidizer feed, and the fluid velocities in both reactors. ...

Herbert Over; Reinhard Schomäcker

2013-04-04T23:59:59.000Z

375

ETEM observation of Pt/C electrode catalysts in a moisturized cathode atmosphere  

Science Journals Connector (OSTI)

There have been reports of challenges in designing platinum carbon (Pt/C) electrode catalysts for PEMFC. Pt/C electrode catalysts deactivate much faster on the cathode (in moisturized O2) than on the anode (in H2). To understand influences of moisture and oxygen on the deactivation of the Pt/C catalysts in proton-exchange-membrane fuel cells (PEMFCs), spherical-aberration-corrected environmental transmission electron microscopy (AC-ETEM) was applied with a high-speed CCD camera. Structural changes of the Pt/C electrode catalysts were dynamically recorded in moisturized nitrogen, oxygen and hydrogen. The mass spectrometry confirmed the moisture content (between 5 to 30 %) of nitrogen driving gas through a humidifier. Coalescence of platinum nanoparticles (D = 3.24 nm) was carefully evaluated in pure N2 and moisturized N2 atmosphere. The Pt/C showed considerable structural weakness in a moisturized N2 atmosphere. Comparable results obtained by AC-ETEM in different gas atmospheres also suggested ways to improve the oxygen reduction reaction (ORR). In this paper, the deactivation process due to moisture (hydroxylation) of carbon supports is discussed using for comparison the movement of platinum nanoparticles measured in moisturized nitrogen and pure nitrogen atmospheres.

K Yoshida; X Zhang; N Tanaka; E D Boyes; P L Gai

2014-01-01T23:59:59.000Z

376

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

377

Los Alamos catalyst could jumpstart e-cars, green energy  

NLE Websites -- All DOE Office Websites (Extended Search)

Catalyst could jumpstart e-cars, green energy Catalyst could jumpstart e-cars, green energy Los Alamos catalyst could jumpstart e-cars, green energy The new material has the highest oxygen reduction reaction (ORR) activity in alkaline media of any non-precious metal catalyst developed to date. June 4, 2013 A high-resolution microscopic image of a new type of nanostructured-carbon-based catalyst developed at Los Alamos National Laboratory that could pave the way for reliable, economical next-generation batteries and alkaline fuel cells. (Photo credit: Los Alamos National Laboratory) A high-resolution microscopic image of a new type of nanostructured-carbon-based catalyst developed at Los Alamos National Laboratory that could pave the way for reliable, economical next-generation batteries and alkaline fuel cells. (Photo credit: Los Alamos National

378

Los Alamos catalyst could jumpstart e-cars, green energy  

NLE Websites -- All DOE Office Websites (Extended Search)

Catalyst could jumpstart e-cars, green energy Catalyst could jumpstart e-cars, green energy Los Alamos catalyst could jumpstart e-cars, green energy The new material has the highest oxygen reduction reaction (ORR) activity in alkaline media of any non-precious metal catalyst developed to date. June 4, 2013 A high-resolution microscopic image of a new type of nanostructured-carbon-based catalyst developed at Los Alamos National Laboratory that could pave the way for reliable, economical next-generation batteries and alkaline fuel cells. (Photo credit: Los Alamos National Laboratory) A high-resolution microscopic image of a new type of nanostructured-carbon-based catalyst developed at Los Alamos National Laboratory that could pave the way for reliable, economical next-generation batteries and alkaline fuel cells. (Photo credit: Los Alamos National

379

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

SciTech Connect

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

380

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

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

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

382

Effect of Fuel Cell System Contaminants on the Pt Catalyst  

SciTech Connect

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

383

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

SciTech Connect

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

384

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

385

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

386

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.

387

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

SciTech Connect

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

388

Hydrogenation of Aromatics in Synthetic Crude Distillates Catalyzed by Platinum Supported in Molecular Sieves  

Science Journals Connector (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. ... Pillared interlayered clay (PILC) was prepared using Accofloc 350, a sodium montmorillonite supplied by American Colloid Co. with a cation-exchange capacity (cec) of 80 mequiv/100 g. ... After stirring overnight, the suspension was cooled and the PILC was centrifuged, washed repeatedly until free of chloride ion, air dried, and ground to <200 mesh. ...

Naoto Kimbara; Jean-Pierre Charland; Michael F. Wilson

1996-11-07T23:59:59.000Z

389

Advanced Cathode Catalysts  

Energy.gov (U.S. Department of Energy (DOE))

This presentation, which focuses on advanced cathode catalysts, was given by Piotr Zelenay of Los Alamos National laboratory at a February 2007 meeting on new fuel cell projects.

390

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

SciTech Connect

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

391

Platinum-Coated Nickel Nanowires as Oxygen-Reducing Electrocatalysts  

SciTech Connect

Platinum (Pt)-coated nickel (Ni) nanowires (PtNiNWs) are synthesized by the partial spontaneous galvanic displacement of NiNWs, with a diameter of 150 250 nm and a length of 100 200 m. PtNiNWs are electrochemically characterized for oxygen reduction (ORR) in rotating disk electrode half-cells with an acidic electrolyte and compared to carbon-supported Pt (Pt/HSC) and a polycrystalline Pt electrode. Like other extended surface catalysts, the nanowire morphology yields significant gains in ORR specific activity compared to Pt/HSC. Unlike other extended surface approaches, the resultant materials have yielded exceptionally high surface areas, greater than 90 m2 gPt 1. These studies have found that reducing the level of Pt displacement increases Pt surface area and ORR mass activity. PtNiNWs produce a peak mass activity of 917 mA mgPt 1, 3.0 times greater than Pt/HSC and 2.1 times greater than the U.S. Department of Energy target for proton-exchange membrane fuel cell activity.

Alia, Shaun M [National Renewable Energy Laboratory (NREL); Larsen, Brian A [National Renewable Energy Laboratory (NREL); Pylypenko, Svitlana [ORNL; Cullen, David A [ORNL; Diercks, David R [Colorado School of Mines, Golden; Neyerlin, Kenneth C [National Renewable Energy Laboratory (NREL); Kocha, Shyam S [National Renewable Energy Laboratory (NREL); Pivovar, Bryan [Los Alamos National Laboratory (LANL)

2014-01-01T23:59:59.000Z

392

UV-vis spectroscopy of iodine adsorbed on alkali-metal-modified zeolite catalysts for addition of carbon dioxide to ethylene oxide  

SciTech Connect

The basicity of alkali-metal-exchange (Na, K, Cs) zeolites X and Y was probed by UV-vis diffuse reflectance spectroscopy of adsorbed iodine. The observed blue shift in the visible absorption spectrum of adsorbed iodine, compared to gaseous iodine, correlated well with the negative charge on the framework oxygen atoms calculated from the Sanderson electronegativity equalization principle. The blue shifts associated with iodine adsorbed on classical catalytic supports like silica, alumina, and magnesia suggest that the iodine adsorption technique for probing basicity is applicable to a wide variety of solids. Iodine was also adsorbed on X and Y zeolites containing occluded cesium oxide formed by decomposition of impregnated cesium acetate. However, the iodine appeared to irreversibly react on these strongly basic samples, possibly forming an adsorbed triiodide ions. As a complement to the adsorption studies, the activity of alkali-metal-containing zeolites for the base-catalyzed formation of ethylene carbonate from ethylene oxide and carbon dioxide was investigated. Among the ion-exchanged zeolites, the cesium form of zeolite X exhibited the highest activity for ethylene carbonate formation. The catalytic activity of a zeolite containing occluded cesium was even higher than that of a cesium-exchanged zeolite. The presence of water adsorbed in zeolite pores promoted the rate of ethylene carbonate formation for both cesium-exchanged and cesium-impregnated zeolite X.

Doskocil, E.J.; Bordawekar, S.V.; Kaye, B.G.; Davis, R.J. [Univ. of Virginia, Charlottesville, VA (United States). Dept. of Chemical Engineering] [Univ. of Virginia, Charlottesville, VA (United States). Dept. of Chemical Engineering

1999-07-29T23:59:59.000Z

393

Novel Fischer-Tropsch catalysts  

DOE Patents (OSTI)

Novel polymer-supported metal complexes of the formula: PS --R Me(CO).sub.n H.sub.m where: PS represents a divinylbenzene crosslinked polystyrene in which the divinylbenzene crosslinking is greater than 1% and less than about 18%; R represents a cycloalkadienyl radical of 4 through 6 carbon atoms; Me represents a Group VIII metal; CO represents a carbonyl radical; H represents hydrogen; n represents an integer varying from 0 through 3; m represents an integer varying from 0 through 2 inclusively with the further provision that 2n+m must total 18 when added to the electrons in R and Me, or n+m must total 0; are prepared by: brominating PS --H by treating same with bromine in the presence of a thallium salt in a partially or fully halogenated solvent to form PS --Br; treating said PS --Br so produced with a lithium alkyl of 1 through 12 carbon atoms in an aromatic solvent to produce PS --Li; substituting said PS-- Li so produced by reaction with a 2-cycloalkenone of 4 to 6 carbon atoms in the presence of an ether solvent and using a water work-up to form a cycloalkenylalcohol-substituted PS ; dehydrating said alcohol so produced by heating under a vacuum to produce a cycloalkadienyl-substituted PS ; reacting the cycloalkadienyl-substituted PS with metal carbonyl in the presence of a partially or fully halogenated hydrocarbon, aromatic hydrocarbon of 6 through 8 carbon atoms, ethers, or esters of 4 through 10 carbon atoms as a solvent to produce a polystyrene-supported cycloalkadienyl metal carbonyl. The novel compounds are used as improved Fischer-Tropsch catalysts particularly for the conversion of CO+H.sub.2 to gaseous and liquid hydrocarbons at milder conditions than with prior catalysts.

Vollhardt, Kurt P. C. (Kensington, CA); Perkins, Patrick (Berkeley, CA)

1981-01-01T23:59:59.000Z

394

Novel Fischer-Tropsch catalysts  

DOE Patents (OSTI)

Novel polymer-supported metal complexes of the formula: PS --R Me(CO).sub.n H.sub.m where: PS represents a divinylbenzene crosslinked polystyrene in which the divinylbenzene crosslinking is greater than 1% and less than about 18%; R represents a cycloalkadienyl radical of 4 through 6 carbon atoms; Me represents a Group VIII metal; CO represents a carbonyl radical; H represents hydrogen; n represents an integer varying from 0 through 3; m represents an integer varying from 0 through 2 inclusively with the further provision that 2n+m must total 18 when added to the electrons in R and Me, or n+m must total 0; are prepared by: brominating PS --H by treating same with bromine in the presence of a thallium salt in a partially or fully halogenated solvent to form PS --Br; treating said PS --Br so produced with a lithium alkyl of 1 through 12 carbon atoms in an aromatic solvent to produce PS --Li; substituting said PS-- Li so produced by reaction with a 2-cycloalkenone of 4 to 6 carbon atoms in the presence of an ether solvent and using a water work-up to form a cycloalkenylalcohol-substituted PS ; dehydrating said alcohol so produced by heating under a vacuum to produce a cycloalkadienyl-substituted PS ; reacting the cycloalkadienyl-substituted PS with metal carbonyl in the presence of a partially or fully halogenated hydrocarbon, aromatic hydrocarbon of 6 through 8 carbon atoms, ethers, or esters of 4 through 10 carbon atoms as a solvent to produce a polystyrene-supported cycloalkadienyl metal carbonyl. The novel compounds are used as improved Fischer-Tropsch catalysts particularly for the conversion of CO+H.sub.2 to gaseous and liquid hydrocarbons at milder conditions than with prior catalysts.

Vollhardt, Kurt P. C. (Kensington, CA); Perkins, Patrick (Berkeley, CA)

1980-01-01T23:59:59.000Z

395

Novel Fischer-Tropsch catalysts  

DOE Patents (OSTI)

Novel polymer-supported metal complexes of the formula PS -R Me(CO).sub.n H.sub.m where: PS represents a divinylbenzene crosslinked polystyrene in which the divinylbenzene crosslinking is greater than 1% and less than about 18%; R represents a cycloalkadienyl radical of 4 through 6 carbon atoms; Me represents a Group VIII metal; CO represents a carbonyl radical; H represents hydrogen; n represents an integer varying from 0 through 3; m represents an integer varying from 0 through 2 inclusively with the further provision that 2n+m must total 18 when added to the electrons in R and Me, or n+m must total 0; are prepared by: brominating PS -H by treating same with bromine in the presence of a thallium salt in a partially or fully halogenated solvent to form PS -Br; treating said PS -Br so produced with a lithium alkyl of 1 through 12 carbon atoms in an aromatic solvent to produce PS -Li; substituting said PS - Li so produced by reaction with a 2-cycloalkenone of 4 to 6 carbon atoms in the presence of an ether solvent and using a water work-up to form a cycloalkenylalcohol-substituted PS ; dehydrating said alcohol so produced by heating under a vacuum to produce a cycloalkadienyl-substituted PS ; reacting the cycloalkadienyl-substituted PS with metal carbonyl in the presence of a partially or fully halogenated hydrocarbon, aromatic hydrocarbon of 6 through 8 carbon atoms, ethers, or esters of 4 through 10 carbon atoms as a solvent to produce a polystyrene-supported cycloalkadienyl metal carbonyl. The novel compounds are used as improved Fischer-Tropsch catalysts particularly for the conversion of CO+H.sub.2 to gaseous and liquid hydrocarbons at milder conditions than with prior catalysts.

Vollhardt, Kurt P. C. (Kensington, CA); Perkins, Patrick (Berkeley, CA)

1981-01-01T23:59:59.000Z

396

Catalyst Characterization | Department of Energy  

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

Catalyst Characterization Catalyst Characterization Vehicle Technologies Office Merit Review 2014: Biofuel Impacts on Aftertreatment Devices (Agreement ID:26463) Project ID:18519...

397

Catalyst Renewables | Open Energy Information  

Open Energy Info (EERE)

Catalyst Renewables Jump to: navigation, search Name: Catalyst Renewables Place: Dallas, Texas Zip: 75204 Product: Pursue projects with low technical risk, stable fuel supply and...

398

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

399

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

400

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

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

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

402

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

403

SBIR/STTR FY15 Release 1 Awards Announced—Includes Fuel Cell Catalyst and Hydrogen Contamination Detection R&D  

Energy.gov (U.S. Department of Energy (DOE))

The U.S. Department of Energy has announced the 2015 Small Business Innovation Research and Small Business Technology Transfer (SBIR/STTR) Phase I Release 1 Awards, including projects focusing on non-platinum catalysts for fuel cells and detection of contaminants in hydrogen.

404

Fuel Cell Technologies Office: Non-Platinum Electrocatalysts Workshop  

NLE Websites -- All DOE Office Websites (Extended Search)

Non-Platinum Electrocatalysts Workshop Non-Platinum Electrocatalysts Workshop The U.S. Department of Energy sponsored the Non-Platinum Electrocatalysts Workshop in New Orleans, Louisiana, March 21-22, 2003. Attendees included researchers, government officials, and industry members. The purpose of the workshop was to review the current status of electrocatalysts for PEM fuel cells, review the impact of platinum cost and availability on PEM fuel cell commercialization, identify potential non-platinum electrocatalysts, develop a strategy to explore the potential development of new, non-platinum electrocatalysts for PEM fuel cell applications. The presentations from the Non-Platinum Electrocatalysts Workshop are available as Adobe Acrobat PDFs. Download Adobe Reader. Overview (PDF 349 KB), Nancy Garland, DOE Fuel Cell Technologies Office

405

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

406

Phase-Transfer Catalysis-Transition Metal Cocatalyzed Reactions  

Science Journals Connector (OSTI)

Transition metals are active catalysts for a variety of organic reactions. Sometimes they are also useful in conjunction with phase-transfer catalysts, particularly when hydroxide anions and other inorganic sp...

Charles M. Starks; Charles L. Liotta; Marc E. Halpern

1994-01-01T23:59:59.000Z

407

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

408

Nickel Catalysts Supported on Barium Hexaaluminate for Enhanced CO Methanation  

Science Journals Connector (OSTI)

(4, 5) Since Sabatier and Senderens discovered that some metals such as Ni, Ru, Rh, Pt, Fe, and Co could be used in the methanation reaction in 1902,(6) many methanation catalysts have been developed. ... In short, although Ni/Al2O3 catalysts have been extensively explored, their thermal stability and resistance to carbon deposition still need to be improved. ... Meanwhile, the catalyst coatings on the walls of micro-channel reactor showed high activity and stability, having the excellent catalytic performance for methanation reaction in micro-channel reactors and the reliability in long-term use as well. ...

Jiajian Gao; Chunmiao Jia; Jing Li; Fangna Gu; Guangwen Xu; Ziyi Zhong; Fabing Su

2012-07-16T23:59:59.000Z

409

Modeling of Diesel Oxidation Catalyst  

Science Journals Connector (OSTI)

Modeling of Diesel Oxidation Catalyst ... Optimization of hydrocarbon (HC) oxidation over a diesel oxidation catalyst (DOC) requires consideration of (i) HC gas diffusion into the catalyst layer, (ii) HC gas adsorption and desorption from catalyst sites, and (iii) kinetics of the oxidation reaction. ... Mutagenicity of Diesel Engine Exhaust Is Eliminated in the Gas Phase by an Oxidation Catalyst but Only Slightly Reduced in the Particle Phase ...

Yasushi Tanaka; Takashi Hihara; Makoto Nagata; Naoto Azuma; Akifumi Ueno

2005-09-30T23:59:59.000Z

410

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

411

Catalyst for steam reforming of hydrocarbons and process of preparing the catalyst  

SciTech Connect

A catalyst is provided for the steam reforming of normally liquid hydrocarbons to produce carbon monoxide and hydrogen, which does not promote the deposition of carbonaceous materials upon the catalytic surfaces. The catalyst consists of nickel promoted with the oxides of iron and manganese within a specific manganese to iron ratio, said metal and metal oxides being supported upon a refractory support. The support is preferably aluminum oxide in its alpha phase having a surface area of less than 15 m2/gm. The metallic constituents are impregnated onto said refractory low surface area support as salts and are calcined at sufficiently high temperature to convert the salts to the oxide but at a sufficiently low temperature that they do not chemically react with the support.

Broughton, D.R.; Russ, K.J.

1980-06-10T23:59:59.000Z

412

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

413

Phase-Transfer Catalysts  

Science Journals Connector (OSTI)

In previous chapters we learned that a phase-transfer catalyst must have two particular chemical functions to be successful, that is, it must rapidly transfer one of the reactant species into the normal phase ...

Charles M. Starks; Charles L. Liotta; Marc E. Halpern

1994-01-01T23:59:59.000Z

414

Comprehensive catalyst management  

SciTech Connect

From January 2009, as SCR season expands from five months to year-round to meet new US Clean Air Interstate Rule standards, new catalyst strategies are increasingly important. Power plants will need a comprehensive management strategy that accounts for a wide range of old and new issues to achieve peak performance. An optimum plan is necessary for catalyst replacement or addition. SCR systems should be inspected and evaluated at least once a year. Levels of deactivation agents, most often arsenic and calcium oxide, need to match the particular coals used. Tools such as Cormetech's FIELD Guide are available to quantify the effect on catalyst life under various fuel-firing scenarios. Tests should be conducted to evaluate the NH{sub 3}/NOx distribution over time to maximise catalyst performance. The article gives a case study of catalyst management at the Tennessee Valley Authority Allen plant. Recent changes have created new variables to be considered in a catalyst management process, notably the expansion of the operating temperature range, mercury oxidation and SO{sub 3} emission limits. Cormetech has researched these areas. 5 figs., 2 photos.

Pritchard, S. [Cormetech (United States)

2007-05-15T23:59:59.000Z

415

Controlling proton source speeds catalyst | EMSL  

NLE Websites -- All DOE Office Websites (Extended Search)

Controlling proton source speeds catalyst Controlling proton source speeds catalyst Nickel-based catalyst three times faster with adjustments to key acid Research showing that...

416

Performance of hydrous titanium oxide-supported catalysts in coal-liquids upgrading  

SciTech Connect

Experimental tests were performed in a continuous-flow hydrotreating unit at Pittsburgh Energy Technology Center to evaluate the performance of hydrous titanium oxide-supported (HTO) catalysts as hydrotreating catalysts for use in two-stage coal liquefaction. Catalysts containing either a combination of Co, Ni, and Mo as the active metal components or Pd as the active metal component were tested with representative hydrotreater feed stocks from the Wilsonville Advanced Coal Liquefaction Research and Development Facility. Catalyst performance evaluation was based on desulfurization and denitrogenation activity, the conversion of cyclohexane-insoluble material, and hydrogenation activity, during 100-hour reactor runs. Results indicated that the HTO catalysts were comparable to a commercial Ni/Mo-alumina supported catalyst in the areas evaluated.

Cillo, D.L.; Smith, D.N.; Ruether, J.A.; Stephens, H.P.; Dosch, R.G. (Department of Energy, Pittsburgh, PA (USA))

1988-01-01T23:59:59.000Z

417

Performance of hydrous titanium oxide-supported catalysts in coal-liquids upgrading  

SciTech Connect

Experimental tests were performed in a continuous-flow hydrotreating unit at Pittsburgh Energy Technology Center to evaluate the performance of hydrous titanium oxide-supported (HTO) catalysts as hydrotreating catalysts for use in two-stage coal liquefaction. Catalysts containing either a combination of Co, Ni, and MO as the active metal components or Pd as the active metal component were tested with representative hydrotreater feed stocks from the Wilsonville Advanced Coal Liquefaction Resarch and Development Facility. Catalyst performance evaluation was based on desulfurization and denitrogenation activity, the conversion of cyclohexane-insoluble material, and hydrogenation activity during 100-hour reactor runs. Results indicated that the HTO catalysts were comparable to a commercial Ni/Mo-alumina supported catalyst in the areas evaluated.

Cillo, D.L.; Smith, D.N.; Ruether, J.A. (U.S. Dept. of Energy, Pittsburgh Energy Technology Center, P.O. Box 10940, Pittsburgh, PA (US)); Stephens, H.P.; Dosch, R.G. (Sandia National Labs., Albuquerque, NM (US))

1988-06-01T23:59:59.000Z

418

Performance of hydrous titanium oxide-supported catalysts in coal-liquids upgrading  

SciTech Connect

Experimental tests were performed in a continuous-flow hydrotreating unit at Pittsburgh Energy Technology Center to evaluate the performance of hydrous titanium-oxide supported (HTO) catalysts as hydrotreating catalysts for use in two-stage coal liquiefaction. Catalysts containing either a combination of CO, Ni, and Mo as the active metal components or Pd as the active metal componet were tested with representative hydrotreater feed stocks from the Wilsonville Advanced Coal Liquefaction Research and Development Facility. Catalyst performance evaluation was based on desulfurization and denitrogenation activity, the conversion of cyclohexane-insolbule material, and hydrogenation activity during 100-hour reactor runs. Results indicated that the HTO catalysts were comparable to a commercial Ni/Mo-alumina supported catalyst in the areas evaluated. 11 refs., 1 fig., 6 tabs.

Cillo, D.L.; Smith, D.N.; Ruether, J.A.; Stephens, H.P.; Dosch, R.G.

1988-01-01T23:59:59.000Z

419

Catalyst deactivation kinetics: An apparent delay in decreasing of catalyst activity, “inflection point” and data interpretation  

Science Journals Connector (OSTI)

Problems of catalyst deactivation kinetics and catalyst stability testing are considered. An apparent delay...

N. M. Ostrovskii

2011-12-01T23:59:59.000Z

420

Recent advances in activity and durability enhancement of Pt/C catalytic cathode in PEMFC: Part I. Physico-chemical and electronic interaction between Pt and carbon support, and activity enhancement of Pt/C catalyst  

Science Journals Connector (OSTI)

Carbon-supported platinum or platinum alloys are generally used as the cathodic electrocatalysts in polymer electrolyte membrane fuel cells (PEMFC) to enhance the oxygen reduction reaction (ORR). Main challenges to be addressed in this area are the high electrochemical activity and high stability maintenance for low-Pt-loading catalysts toward the feasibility for fuel cell operation and the reduction of the system cost. The interaction of Pt with carbon support, as well as the interaction of Pt precursor with carbon during the supported catalyst formation, are considered to be beneficial to the improvement of catalytic activity and durability of the electrocatalysts. This paper provides a review of recent advances related to the physico-chemical and electronic interactions at the catalyst–support interface and the catalyst activity enhancement through improved Pt–C interaction, especially focusing on the surface modification of the carbon support to form proper functional groups and chemical links at the Pt/C interface.

Xingwen Yu; Siyu Ye

2007-01-01T23:59:59.000Z

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.


421

In silico search for novel methane steam reforming catalysts  

Science Journals Connector (OSTI)

This paper demonstrates a method for screening transition metal and metal alloy catalysts based on their predicted rates and stabilities for a given catalytic reaction. This method involves combining reaction and activation energies (available to the public via a web-based application 'CatApp') with a microkinetic modeling technique to predict the rates and selectivities of a prospective material. This paper illustrates this screening technique using the steam reforming of methane to carbon monoxide and hydrogen as a test reaction. While catalysts are already commercially available for this process, the method demonstrated in this paper is very general and could be applied to a wide range of catalytic reactions. Following the steps outlined herein, such an analysis could potentially enable researchers to understand reaction mechanisms on a fundamental level and, on this basis, develop leads for new metal alloy catalysts.

Yue Xu; Adam C Lausche; Shengguang Wang; Tuhin S Khan; Frank Abild-Pedersen; Felix Studt; Jens K Nørskov; Thomas Bligaard

2013-01-01T23:59:59.000Z

422

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

423

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

1997-01-01T23:59:59.000Z

424

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

425

Mechanism of the Hydrogen/Platinum(111) Fuel Cell  

Science Journals Connector (OSTI)

Mechanism of the Hydrogen/Platinum(111) Fuel Cell† ... (5)?Marzari, N.; Blum, L.; Car, R. The Electroreduction of Hydrogen on Pt(111). ...

L. Blum; N. Marzari; R. Car

2004-11-12T23:59:59.000Z

426

Carbon Monoxide Tolerant Electrocatalyst with Low Platinum Loading...  

NLE Websites -- All DOE Office Websites (Extended Search)

particle. When used as an electrocatalyst for the oxidation of fuel at a fuel cell anode, this structure exhibits low platinum loading and elevated tolerance to carbon...

427

Science Magazine Highlight: Moving Towards Near Zero Platinum Fuel Cells  

Energy.gov (U.S. Department of Energy (DOE))

Slides presented at the Fuel Cell Technologies Office webinar "Science Magazine Highlight: Moving Towards Near Zero Platinum Fuel Cells" on April 25, 2011.

428

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

429

Octahedral PtNi Nanoparticle Catalysts: Exceptional Oxygen Reduction Activity by Tuning the Alloy Particle Surface Composition  

Science Journals Connector (OSTI)

The sluggish kinetics of the oxygen reduction reaction (ORR) on costly platinum cathode electrocatalysts represents a major obstacle to a more widespread use of the polymer electrolyte membrane fuel cell (PEMFC). ... Advancement in heterogeneous catalysis relies on the capability of altering material structures at the nanoscale, and that is particularly important for the development of highly active electrocatalysts with uncompromised durability. ... Moreover, after a long-term stability measurement, the ECSA of C2 catalysts can be restored to the initial value after another potential cycling treatment, and thus, this kind of electrocatalyst may be developed as next-generation restorable cathode fuel cell catalysts. ...

Chunhua Cui; Lin Gan; Hui-Hui Li; Shu-Hong Yu; Marc Heggen; Peter Strasser

2012-10-12T23:59:59.000Z

430

Development of active catalysts for low Pt loading cathodes of PEMFC by surface tailoring of nanocarbon materials  

Science Journals Connector (OSTI)

The use of novel nanocarbon supports—carbon nanofibers (CNF) and amorphous supermicroporous carbons (ASC) for synthesis of platinum cathode catalysts for proton exchange membrane fuel cells (PEMFC) was investigated. Different types of CNF—with “parallel” and “deck of cards” arrangement of graphitic planes and samples of ASC originating from different organic precursors were synthesized and characterized by XRD, electron microscopy and adsorption methods. Platinum catalysts for PEMFC cathodes on different structural types of CNF and one sample of ASC were synthesized and characterized by XRD, electron microscopy, CO adsorption and by studying characteristics of conventional membrane electrode assembly (MEA) cell with a low Pt loading level of 0.02–0.09 mg/cm2. The MEA testing showed that the Pt cathode catalysts on CNF exhibit inferior performance in comparison with a catalyst on conventional carbon black support Pt/Vulcan XC-72R. The cathode catalyst prepared on ASC support exhibits considerably better output in MEA, compared with Pt/Vulcan XC-72R even at a lower Pt loading.

Z.R. Ismagilov; M.A. Kerzhentsev; N.V. Shikina; A.S. Lisitsyn; L.B. Okhlopkova; Ch.N. Barnakov; Masao Sakashita; Takashi Iijima; Kenichiro Tadokoro

2005-01-01T23:59:59.000Z

431

THE UNIVERSITY OF SHEFFIELD CATALYST HIGHER EDUCATION  

E-Print Network (OSTI)

Page | 1 THE UNIVERSITY OF SHEFFIELD & CATALYST HIGHER EDUCATION (SHEFFIELD) PLC. UNIVERSITY of Sheffield / Catalyst Higher Education (Sheffield) plc Project Co Accommodation: Accommodation / Catalyst Higher Education (Sheffield) plc LLFM: Lend Lease Facilities Management Ltd Project Co: Catalyst

Dixon, Peter

432

Decomposition of Perfluorocompounds on Alumina-Based Catalyst  

SciTech Connect

The control of the atmospheric release of PFCs (perfluorocompounds) is an important environmental problem worldwide. PFCs are powerful greenhouse gases used by the semiconductor and liquid crystal industries as etching and cleaning agents. We developed a catalyst that decomposes PFCs with only water. Al2O3 was selected from the survey of some single metal-oxide catalysts. Addition of another metal-oxide improved the decomposition ratio and durability. The Al2O3-based catalyst decomposed CF4, C2F6, C3F8, C4F8, NF3 and SF6 by more than 99% at 750 degrees Celsius. Furthermore, our catalyst retained a high decomposition ratio as demonstrated by a continuous run for about 4000 hours at 700-750 degrees Celsius. The influence of chlorine as an impurity with regard to the SF6 decomposition ratio on the catalyst was examined. SF6 was decomposed at more than 99% during 8 hours in the presence of 400 ppm chlorine. Chlorine concentration in the outlet gas was less than TLV. No chlorine compounds were found by X-ray diffraction analysis of the used catalyst. That is, the hydrogenation of chlorine did not inhibit the surface catalytic reaction for PFC. Also, CF4 was decomposed at the condition of 1.4% of high concentration. The conversion remained higher than 99% throughout during a durability test. Furthermore, we investigated a large-scale decomposition system in the paper.

Kanno, Shuichi; Tamata, Shin; Kurokawa, Hideaki

2004-03-31T23:59:59.000Z

433

Electrochemical performance of low temperature PEMFC with surface tailored carbon nanofibers as catalyst support  

Science Journals Connector (OSTI)

The present work is focused on the synthesis of new catalysts of platinum supported on carbon nanofibers and their use in PEMFC electrodes. Carbon nanofibers (CNF) and functionalized carbon nanofibers (CNF-f), synthesized via the thermocatalytic decomposition of CH4, were characterized, in the presence and the absence of deposited Pt, by porosimetric, SEM, TPD, and HRTEM analyses, and compared to commercial Vulcan® XC72R carbon black (CB). CNF and CNF-f show similar BET surface areas, but smaller than that of CB, which have a large quantity of micropores. On the contrary, the microporosity in CNF and CNF-f was negligible, and the mesopores were the dominant pore structure. A single cell characterization of three catalysts Pt/CNF, Pt/CNF-f and Pt/CB was carried out, measuring the relevant kinetic parameters. The power density given by the Pt/CNF catalyst in the cathode catalyst layer was 1.5 times higher than that given by the Pt/CB catalyst at 0.600 V. It is shown when using functionalized carbon nanofibers in the anode catalyst layer, that functionalization by chemically modifying the surface of the nanofibers significantly affects the PEMFC performance.

Garbiñe Álvarez; Francisco Alcaide; Pere L. Cabot; María J. Lázaro; Elena Pastor; José Solla-Gullón

2012-01-01T23:59:59.000Z

434

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

435

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

436

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

437

Towards improved iron-based catalysts for direct coal liquefaction  

SciTech Connect

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

438

Application of solid ash based catalysts in heterogeneous catalysis  

SciTech Connect

Solid wastes, fly ash, and bottom ash are generated from coal and biomass combustion. Fly ash is mainly composed of various metal oxides and possesses higher thermal stability. Utilization of fly ash for other industrial applications provides a cost-effective and environmentally friendly way of recycling this solid waste, significantly reducing its environmental effects. On the one hand, due to the higher stability of its major component, aluminosilicates, fly ash could be employed as catalyst support by impregnation of other active components for various reactions. On the other hand, other chemical compounds in fly ash such as Fe{sub 2}O{sub 3} could also provide an active component making fly ash a catalyst for some reactions. In this paper, physicochemical properties of fly ash and its applications for heterogeneous catalysis as a catalyst support or catalyst in a variety of catalytic reactions were reviewed. Fly-ash-supported catalysts have shown good catalytic activities for H{sub 2} production, deSOx, deNOx, hydrocarbon oxidation, and hydrocracking, which are comparable to commercially used catalysts. As a catalyst itself, fly ash can also be effective for gas-phase oxidation of volatile organic compounds, aqueous-phase oxidation of organics, solid plastic pyrolysis, and solvent-free organic synthesis. 107 refs., 4 figs., 2 tabs.

Shaobin Wang [Curtin University of Technology, Perth, WA (Australia). Department of Chemical Engineering

2008-10-01T23:59:59.000Z

439

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

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

More Documents & Publications Understanding the Deactivation Mechanisms of CuZeolite SCR Catalysts in Diesel Application Deactivation Mechanisms of Base MetalZeolite Urea...

440

Catalyst, method of making, and reactions using the catalyst  

DOE Patents (OSTI)

The present invention includes a catalyst having a layered structure with, (1) a porous support, (2) a buffer layer, (3) an interfacial layer, and optionally (4) a catalyst layer. The invention also provides a process in which a reactant is converted to a product by passing through a reaction chamber containing the catalyst.

Tonkovich, Anna Lee Y [Pasco, WA; Wang, Yong [Richland, WA; Gao, Yufei [Kennewick, WA

2009-03-03T23:59:59.000Z

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

Advanced Metal-Oxide based SCR Catalysts  

Energy.gov (U.S. Department of Energy (DOE))

SCR with ammonia as reductant is an effective strategy being utilized to reduce NOx emissions to meet regulated levels.

442

Chiral Metal Complexes as Discriminating Molecular Catalysts  

Science Journals Connector (OSTI)

...the efficient asymmetric catalyses. Names of the individuals are given in the references. Critical reviewing ofthis manuscript by Y. Hayakawa, M. Kitamura, W. D. Lubell, and M. Suzuki is also appreciated. ARTICLES II998 JUNE 1990

Ryoji Noyori

1990-06-08T23:59:59.000Z

443

Insoluble Phase-Transfer Catalysts  

Science Journals Connector (OSTI)

An important problem facing the designer of industrial phase-transfer catalysis (PTC) processes using soluble PTC catalysts concerns the removal of the catalyst from the reaction mixture, and its economic recy...

Charles M. Starks; Charles L. Liotta; Marc E. Halpern

1994-01-01T23:59:59.000Z

444

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

445

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

446

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

447

Electrocatalytic Measurement Methodology of Oxide Catalysts Using a Thin-Film Rotating Disk Electrode  

E-Print Network (OSTI)

Transition-metal oxides can exhibit high electrocatalytic activity for reactions such as the oxygen reduction reaction (ORR) in alkaline media. It is often difficult to measure and compare the activities of oxide catalysts ...

Suntivich, Jin

448

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

449

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

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Department's New Laboratory at NREL Earns LEED Platinum 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 Integrations Facility at the Energy Department’s National Renewable Energy Laboratory in Golden, Colorado has received a LEED® (Leadership in Energy and Environmental Design) Platinum designation for new construction by the U.S. Green Building Council. | Photo by Dennis Schroeder, National Renewable Energy Laboratory The Energy Systems Integrations Facility at the Energy Department's National Renewable Energy Laboratory in Golden, Colorado has received a LEED® (Leadership in Energy and Environmental Design) Platinum designation for new construction by the U.S. Green Building Council. | Photo by Dennis

450

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

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Energy Department's New Laboratory at NREL Earns LEED Platinum Energy 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 Integrations Facility at the Energy Department’s National Renewable Energy Laboratory in Golden, Colorado has received a LEED® (Leadership in Energy and Environmental Design) Platinum designation for new construction by the U.S. Green Building Council. | Photo by Dennis Schroeder, National Renewable Energy Laboratory The Energy Systems Integrations Facility at the Energy Department's National Renewable Energy Laboratory in Golden, Colorado has received a LEED® (Leadership in Energy and Environmental Design) Platinum designation for new construction by the U.S. Green Building Council. | Photo by Dennis

451

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

452

Catalysis Without Precious Metals  

SciTech Connect

Written for chemists in industry and academia, this ready reference and handbook summarizes recent progress in the development of new catalysts that do not require precious metals. The research thus presented points the way to how new catalysts may ultimately supplant the use of precious metals in some types of reactions, while highlighting the remaining challenges. This material is based upon work supported as part of the Center for Molecular Electrocatalysis, an Energy Frontier Research Center funded by the US Department of Energy, Office of Science, Office of Basic Energy Sciences.

Bullock, R. Morris

2010-11-01T23:59:59.000Z

453

Project Catalyst | Open Energy Information  

Open Energy Info (EERE)

Project Catalyst Project Catalyst Jump to: navigation, search Name Project Catalyst Agency/Company /Organization ClimateWorks, European Climate Foundation Sector Climate, Energy, Land Focus Area Energy Efficiency, Forestry Website http://www.project-catalyst.in References Project Catalyst[1] Project Catalyst Screenshot Contents 1 About 2 Resources 2.1 Tools 2.2 Programs 3 References About "Project Catalyst is an initiative of the ClimateWorks Foundation. ClimateWorks is a global, nonprofit philanthropic foundation headquartered in San Francisco, California with a network of affiliated foundations in China, India, the US, and the European Union. The ClimateWorks family of organizations focus on enacting policies that reduce greenhouse gas emissions through three general policy areas: energy efficiency standards,

454

Core-Protected Platinum Monolayer Shell High-Stability Electrocatalysts for Fuel-Cell Cathodes  

SciTech Connect

Platinum monolayers can act as shells for palladium nanoparticles to lead to electrocatalysts with high activities and an ultralow platinum content, but high platinum utilization. The stability derives from the core protecting the shell from dissolution. In fuel-cell tests, no loss of platinum was observed in 200,000 potential cycles, whereas loss of palladium was significant.

K Sasaki; H Naohara; Y Cai; Y Choi; P Liu; M Vukmirovic; J Wang; R Adzic

2011-12-31T23:59:59.000Z

455

Oxygen Reduction Catalyzed by Platinum Nanoparticles Supported on Graphene Quantum Dots  

Science Journals Connector (OSTI)

graphene quantum dot; platinum nanoparticle; oxygen reduction; defect; X-ray diffraction; XPS; Tafel plot ...

Guoqiang He; Yang Song; Ke Liu; Andrew Walter; Sophie Chen; Shaowei Chen

2013-03-19T23:59:59.000Z

456

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

SciTech Connect

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

457

Development of inexpensive metal macrocyclic complexes for use in fuel cells  

SciTech Connect

Several metal macrocyclic complexes were synthesized for use as catalysts in fuel cells. An initial evaluation of their ability to catalyze the fuel cell reactions were completed. Based on this initial evaluation, one metal macrocyclic catalyst was selected and long-term stability testing in a fuel cell was initiated. The fuel cell employing this catalyst was operated continuously for one year with little signs of catalyst degradation. The effect of synthetic reformates on the performance of the catalyst in the fuel cell environment also demonstrated high tolerance of this catalyst for common contaminants and poisons.

Doddapaneni, N.; Ingersoll, D. [Sandia National Labs., Albuquerque, NM (United States). Lithium Battery Research and Development Dept.; Kosek, J.A.; Cropley, C.C.; Hamdan, M. [Giner, Inc., Waltham, MA (United States)

1998-01-01T23:59:59.000Z

458

Dispersed slurry catalysts for hydroconversion of carbonaceous materials  

SciTech Connect

Dispersed slurry catalysts, based upon the in situ sulfided forms of transition metals such as iron and molybdenum, have been developed and successfully employed in the multi-stage hydroconversion of various carbonaceous materials including coal, heavy petroleum resid, waste plastics, and different combinations of these feedstocks. For example, using HTI`s proprietary iron-based catalyst and commercial Molyvan-A additive, over 95% maf coal conversion has been obtained accompanied by over 90% maf conversion of 524{degrees}C+ residuum and over 65% maf yield of C{sub 4}-524{degrees}C distillate yield in a fully back-mixed high pressure reaction system. The use of an in-fine fixed-bed hydrotreater in such a hydroconversion process that relies only on dispersed slurry catalysts for conversion allows to selectively upgrade the light distillate products (IBP-400{degrees}C) from the process resulting in premium quality naphtha and mid-distillate products with less than 10 ppm nitrogen, an FUC ratio of 1.9, and about 20 ppm sulfur. The use of dispersed catalyst for such hydroconversion processes has a significant positive impact (as much as 20% cost potential reduction) on the process economics because the reactor throughput can be increased by as much as 70 % while maintaining the equivalent residence time and the cost associated with the expensive high pressure catalyst addition/withdrawal system, used for supported extrudate catalyst, and that associated with expensive ebullating pumps can be reduced or eliminated completely.

Lee, L.K.; Pradhan, V.R.; Popper, G.; Comolli, A.G. [Hydrocarbon Technologies, Inc., Lawrenceville, NJ (United States)

1996-12-31T23:59:59.000Z

459

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

460

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

E-Print Network (OSTI)

Si feature is exposed by a CF4 plasma etch. The poly-Si isthrough the SiO2 layers with CF4 plasma followed by HBr &

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).
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461

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

462

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

E-Print Network (OSTI)

that ultra-high vacuum (UHV) techniques be used [1-3].UHV offers two main advantages to atmospheric techniques.2 Figure 2.1 Schematic of UHV system coupled with high-

Contreras, A.M.

2006-01-01T23:59:59.000Z

463

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

464

Solution-mediated strategies for synthesizing metal oxides, borates and phosphides using nanocrystals as reactive precursors  

E-Print Network (OSTI)

substrates can be transformed into their corresponding phosphides. Furthermore, this strategy is applicable towards the conversion of supported metal nanocrystals into metal phosphides. Supported metal phosphides are used as hydrotreating catalysts...

Henkes, Amanda Erin

2009-05-15T23:59:59.000Z

465

Cobalt-ruthenium catalysts for Fischer-Tropsch synthesis  

SciTech Connect

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

466

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

467

A highly active and stable Co4N/?-Al2O3 catalyst for CO and CO2 methanation to produce synthetic natural gas (SNG)  

Science Journals Connector (OSTI)

Abstract Co4N/?-Al2O3 and Co/?-Al2O3 catalysts with different metal loadings were prepared by NH3 and H2-temperature programmed reaction method for the co-methanation of carbon oxides (CO and CO2). The catalysts were characterized by N2 adsorption–desorption, XRD, XPS, TEM-SAED, H2, CO, and CO2-TPD techniques. Results showed that the Co4N catalysts had higher activity than Co metal-supported catalysts due to their enhanced adsorption capacity, uniform metal dispersion, and superior metal-support interaction. Among the catalysts studied, 20Co4N/?-Al2O3 catalyst with 20 wt% metal loading showed the best performance. This catalyst achieved higher activity for CH4 formation between 200 and 300 °C and maintained high product selectivity (?98%). A 250 h stability test for 20Co4N/?-Al2O3 was also conducted at 350 °C and increased gas hourly space velocity (GHSV; 10,000 h?1). The spent catalyst was further characterized using XRD, TEM, and TGA analysis. Results revealed that the catalyst was highly resistant to metal sintering and carbon deposition, whereas high CO and CO2 conversion and CH4 selectivity were maintained even at a higher GHSV.

Rauf Razzaq; Chunshan Li; Muhammad Usman; Kenzi Suzuki; Suojiang Zhang

2015-01-01T23:59:59.000Z

468

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

469

Chemical solution deposition of ferroelectric yttrium-doped hafnium oxide films on platinum electrodes  

SciTech Connect

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

470

Laser Catalyst - Energy Innovation Portal  

NLE Websites -- All DOE Office Websites (Extended Search)

Industrial Technologies Industrial Technologies Find More Like This Return to Search Laser Catalyst Idaho National Laboratory Contact INL About This Technology Technology Marketing...

471

Catalyst Characterization | Department of Energy  

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

1 DOE Hydrogen and Fuel Cells Program, and Vehicle Technologies Program Annual Merit Review and Peer Evaluation pm028watkins2011p.pdf More Documents & Publications Catalyst...

472

High Impact Technology (HIT) Catalyst  

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

Impact Technology (HIT) Catalyst Images courtesy CREE, True Manufacturing, A.O. Smith, Bernstein Associates, Cambridge Engineering, Alliance Laundry Systems, NREL Commercial...

473

Iron-Phosphate/Platinum/Carbon Nanocomposites for Enhanced Electrocatalytic Stability  

E-Print Network (OSTI)

.23 V (Oxygen Reduction) PEMFC (1.23 V) DMFC (1.18 V) Hydrogen (PEMFC) CatalystsCatalysts #12;Laptop Membrane~ 10 m 0 50 100 %PtSurfaceArea Cathode 10 nm 10 nm #12;Instability of Pt Catalysts Pt Pt2+ + 2e- E O2- 1000 Ceramic (YSZ) SOFC (Solid Oxide Fuel Cell) WkW-WkWPower Pt, Pt-RuPtPtCatalyst H

Park, Byungwoo

474

Catalyst supports for polymer electrolyte fuel cells  

Science Journals Connector (OSTI)

...Bruce, Richard Catlow and Peter Edwards Catalyst supports for polymer electrolyte fuel...durability in fuel cells is to discover catalyst supports that do not corrode, or corrode...black support. fuel cells|oxides|catalyst supports|nanoparticles|conductivity...

2010-01-01T23:59:59.000Z

475

Low-cost and durable catalyst support for fuel cells: graphite submicronparticles  

SciTech Connect

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

476

Cu/Zn-based catalysts improved by adding magnesium for water–gas shift reaction  

Science Journals Connector (OSTI)

Ternary Cu/MeO/ZnO (Me: alkaline-earth metal, Mg, Ca, Sr and Ba) catalysts were prepared by homogeneous precipitation (hp) using urea hydrolysis. The structure and the activity for the water–gas shift reaction of these catalysts were studied compared with those of the catalysts prepared by coprecipitation (cp). The highest activity was obtained over hp-Cu/MgO/ZnO among the catalysts tested. The catalyst precursors after the precipitation contained mainly aurichalcite, (Cu,Zn)5(CO3)2(OH)16, while the decomposed products after the calcination contained apparently CuO and ZnO as crystalline phases, since the amount of Mg actually included in the catalyst was less than 1.0 at.%. The Cu metal surface area was larger and the particle size of Cu metal was smaller on the hp-catalysts than those on the cp-catalysts; nonetheless the BET surface area was sometimes larger on the latter than on the former. The addition of ?0.1 at.% of Mg was the most effective, resulting in the highest activity as well as the lowest activation energy. A good correlation was observed between the amount of Cu+ species and the activation energy of the shift reaction, suggesting that MgO significantly enhanced the formation of Cu+ species as the active sites. Even after the pre-reduction at the high temperature, 250 °C, hp-Cu/MgO/ZnO catalyst showed no significant decrease in the activity as well as no detectable sintering in the Cu metal particles during 50 h of the reaction. It was supposed that the shift reaction proceeds by a reduction–oxidation mechanism between Cu0 ? Cu+.

Tetsuya Shishido; Manabu Yamamoto; Ikuo Atake; Dalin Li; Yan Tian; Hiroyuki Morioka; Masahide Honda; Tsuneji Sano; Katsuomi Takehira

2006-01-01T23:59:59.000Z

477

Spotlights on Recent JACS Publications  

Science Journals Connector (OSTI)

Renewable Energy: Photochemical Hydrogen Production with Low-Cost Catalysts ... Here, the hydrogen is released via a hydrogen evolution reaction (HER), usually at high temperature, using costly, often platinum-based, metal catalysts. ...

2013-06-12T23:59:59.000Z

478

Performance and cost of automotive fuel cell systems with ultra-low platinum loadings.  

SciTech Connect

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

479

Synthesis of carbon nanocoil forests on BaSrTiO3 substrates with the aid of a Sn catalyst  

E-Print Network (OSTI)

Synthesis of carbon nanocoil forests on BaSrTiO3 substrates with the aid of a Sn catalyst Jingyu route for the Sn-assisted synthesis of carbon nanocoils (CNCs) by chemical vapor deposition of acetylene catalyst for CNC synthesis in conjunction with either perov- skite oxides (BST) or transition metals (Fe

Castell, Martin

480

In-situ X-ray diffraction activation study on an Fe/TiO2 pre-catalyst  

Science Journals Connector (OSTI)

It is well known that pre-treatment procedures affect catalyst performance. In situ X-ray diffraction was used in this study to monitor the changes in phase composition and crystallite size during the pre-treatment of Fe/TiO2 catalysts, yielding insight into crystalline and non-crystalline phase changes and metal-support interactions.