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1

Reaction-Driven Restructuring of Bimetallic Nanoparticle Catalysts  

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

Reaction-Driven Restructuring of Bimetallic Nanoparticle Catalysts Print Reaction-Driven Restructuring of Bimetallic Nanoparticle Catalysts Print Catalytic systems based on bimetallic particles with controlled size, composition, and structure dispersed on a high-surface-area support are widely used for catalytic reforming, pollution control, alcohol oxidation, and electrocatalysis in fuel cells. Owing to the nanoscale size of the particles, the modification of the surface structure and composition that may occur when reaction conditions change can have dramatic effects on catalyst activity and selectivity. Working at the ALS, a University of California, Berkeley-Berkeley Lab group has used an ambient-pressure x-ray photoelectron spectroscopy (APXPS) apparatus to demonstrate that bimetallic nanoparticle catalysts can undergo profound structural and chemical changes in response to reactive environments at ambient pressures, thereby opening the way for engineering catalysts with enhanced activity and selectivity.

2

Reaction-Driven Restructuring of Bimetallic Nanoparticle Catalysts  

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

Reaction-Driven Restructuring of Bimetallic Nanoparticle Catalysts Print Reaction-Driven Restructuring of Bimetallic Nanoparticle Catalysts Print Catalytic systems based on bimetallic particles with controlled size, composition, and structure dispersed on a high-surface-area support are widely used for catalytic reforming, pollution control, alcohol oxidation, and electrocatalysis in fuel cells. Owing to the nanoscale size of the particles, the modification of the surface structure and composition that may occur when reaction conditions change can have dramatic effects on catalyst activity and selectivity. Working at the ALS, a University of California, Berkeley-Berkeley Lab group has used an ambient-pressure x-ray photoelectron spectroscopy (APXPS) apparatus to demonstrate that bimetallic nanoparticle catalysts can undergo profound structural and chemical changes in response to reactive environments at ambient pressures, thereby opening the way for engineering catalysts with enhanced activity and selectivity.

3

Reaction-Driven Restructuring of Bimetallic Nanoparticle Catalysts  

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

Reaction-Driven Restructuring of Bimetallic Nanoparticle Catalysts Print Reaction-Driven Restructuring of Bimetallic Nanoparticle Catalysts Print Catalytic systems based on bimetallic particles with controlled size, composition, and structure dispersed on a high-surface-area support are widely used for catalytic reforming, pollution control, alcohol oxidation, and electrocatalysis in fuel cells. Owing to the nanoscale size of the particles, the modification of the surface structure and composition that may occur when reaction conditions change can have dramatic effects on catalyst activity and selectivity. Working at the ALS, a University of California, Berkeley-Berkeley Lab group has used an ambient-pressure x-ray photoelectron spectroscopy (APXPS) apparatus to demonstrate that bimetallic nanoparticle catalysts can undergo profound structural and chemical changes in response to reactive environments at ambient pressures, thereby opening the way for engineering catalysts with enhanced activity and selectivity.

4

General Method for Determination of the Surface Composition in Bimetallic Nanoparticle Catalysts from the L Edge X-ray Absorption Near-Edge Spectra  

SciTech Connect

Bimetallic PtPd on silica nano-particle catalysts have been synthesized and their average structure determined by Pt L3 and Pd K-edge extended X-ray absorption finestructure (EXAFS) spectroscopy. The bimetallic structure is confirmed from elemental line scans by STEM for the individual 1-2 nm sized particles. A general method is described to determine the surface composition in bimetallic nanoparticles even when both metals adsorb, for example, CO. By measuring the change in the L3 X-ray absorption near-edge structure (XANES) spectra with and without CO in bimetallic particles and comparing these changes to those in monometallic particles of known size the fraction of surface atoms can be determined. The turnover rates (TOR) and neopentane hydrogenolysis and isomerization selectivities based on the surface composition suggest that the catalytic and spectroscopic properties are different from those in monometallic nano-particle catalysts. At the same neo-pentane conversion, the isomerization selectivity is higher for the PtPd catalyst while the TOR is lower than that of both Pt and Pd. As with the catalytic performance, the infrared spectra of adsorbed CO are not a linear combination of the spectra on monometallic catalysts. Density functional theory calculations indicate that the Pt-CO adsorption enthalpy increases while the Pd-CO bond energy decreases. The ability to determine the surface composition allows for a better understanding of the spectroscopic and catalytic properties of bimetallic nanoparticle catalysts.

Wu, Tiapin; Childers, David; Gomez, Carolina; Karim, Ayman M.; Schweitzer, Neil; Kropf, Arthur; Wang, Hui; Bolin, Trudy B.; Hu, Yongfeng; Kovarik, Libor; Meyer, Randall; Miller, Jeffrey T.

2012-10-31T23:59:59.000Z

5

Aqueous Phase Glycerol Reforming by PtMo Bimetallic Nano-Particle Catalyst: Product Selectivity and Structural Characterization  

Science Conference Proceedings (OSTI)

A carbon supported PtMo aqueous phase reforming catalyst for producing hydrogen from glycerol was characterized by analysis of the reaction products and pathway, TEM, XPS and XAS spectroscopy. Operando X-ray absorption spectroscopy (XAS) indicates the catalyst consists of bimetallic nano-particles with a Pt rich core and a Mo rich surface. XAS of adsorbed CO indicates that approximately 25% of the surface atoms are Pt. X-ray photoelectron spectroscopy indicates that there is unreduced and partially reduced Mo oxide (MoO{sub 3} and MoO{sub 2}), and Pt-rich PtMo bimetallic nano-particles. The average size measured by transmission electron microscopy of the fresh PtMo nano-particles is about 2 nm, which increases in size to 5 nm after 30 days of glycerol reforming at 31 bar and 503 K. The catalyst structure differs from the most energetically stable structure predicted by density functional theory (DFT) calculations for metallic Pt and Mo atoms. However, DFT indicates that for nano-particles composed of metallic Pt and Mo oxide, the Mo oxide is at the particle surface. Subsequent reduction would lead to the experimentally observed structure. The aqueous phase reforming reaction products and intermediates are consistent with both C-C and C-OH bond cleavage to generate H{sub 2}/CO{sub 2} or the side product CH{sub 4}. While the H{sub 2} selectivity at low conversion is about 75%, cleavage of C-OH bonds leads to liquid products with saturated carbon atoms. At high conversions (to gas), these will produced additional CH{sub 4} reducing the H{sub 2} yield and selectivity.

Stach E. A.; Dietrich, P.J.; Lobo-Lapidus, R.J.; Wu, T.; Sumer, A.; Akatay, M.C.; Fingland, B.R.; Guo, N.; Dumesic, J.A.; Marshall, C.L.; Jellinek, J.; Delgass, W.N.; Ribeiro, F.H.; Miller, J.T.

2012-03-01T23:59:59.000Z

6

Monte carlo simulations of segregation in Pt-Re catalyst nanoparticles  

E-Print Network (OSTI)

and design of Pt-Re catalyst nanoparticles. ACKNOWLEDGMENTSJ.H. Sinfelt, Bimetallic Catalysts: Discoveries, concepts,of segregation in Pt-Re catalyst nanoparticles Guofeng Wang

Wang, Guofeng; Van Hove, M.A.; Ross, P.N.; Baskes, M.I.

2004-01-01T23:59:59.000Z

7

Surface Structures of Cubo-octahedral Pt-Mo Catalyst Nanoparticles from Monte Carlo Simulations  

E-Print Network (OSTI)

of Cubo-octahedral Pt-Mo Catalyst Nanoparticles from Montefuel cells, new electrode catalysts that have less preciousto designing Pt bimetallic catalysts is knowledge of the

Wang, Guofeng; Van Hove, M.A.; Ross, P.N.; Baskes, M.I.

2005-01-01T23:59:59.000Z

8

Neutral bimetallic transition metal phenoxyiminato catalysts and related polymerization methods  

SciTech Connect

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

9

A Systematic Investigation of pNitrophenol Reduction by Bimetallic Dendrimer Encapsulated Nanoparticles  

E-Print Network (OSTI)

. The resulting dendrimer encapsulated nanoparticles (DENs) are monodisperse, and the size distribution does of the two constituents, whereas DENs containing metals with a lattice mismatch show a bimodal distribution in the Ni/Au bimetallic system in order to design a steam reforming catalyst with a higher efficiency.15

Henkelman, Graeme

10

Metallic and bimetallic catalysts for electrochemical reduction of problematic aqueous anions.  

E-Print Network (OSTI)

??Metallic and bimetallic systems are investigated voltammetrically as possible catalysts for the electrochemical reduction of nitrate. Iindium and palladium are the most thoroughly examined metals… (more)

Mahle, Thomas

2012-01-01T23:59:59.000Z

11

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

DOE Green Energy (OSTI)

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

Wu, Xi.

1990-09-21T23:59:59.000Z

12

Fundamental studies of hydrogen interaction with supported meta and bimetallic catalysts  

DOE Green Energy (OSTI)

The thesis is divided into 3 parts: interaction of H with silica supported Ru catalysts (high pressure in situ NMR), in situ NMR study of H interaction with supported Ru-group IB bimetallic catalysts, and in-situ NMR study of H effects on silica-supported Pt, Rh and Ru catalysts.

Bhatia, S.

1993-12-07T23:59:59.000Z

13

Adsorption studies of gases on Pt-Rh bimetallic catalysts by reversed-flow gas chromatography  

SciTech Connect

In the present work, the relatively new technique of reversed-flow gas chromatography was applied for the study of adsorption of carbon monoxide, oxygen, and carbon dioxide on Pt-Rh bimetallic catalysts. Using suitable mathematical analysis, equations were derived by means of which rate constants for adsorption, desorption, and disproportionation reaction were calculated. From the variation of these rate constants with temperature and the nature of the catalyst (Pt content), as well as from the finding that the CO adsorption is a dissociative process, useful conclusions concerning the mechanism for the CO oxidation reaction over Pt-Rh bimetallic catalysts were extracted. The catalytic fractional conversions for the CO disproportionation reaction were found to be higher for the Pt-RH bimetallic catalysts than those for the pure Pt catalyst, indicating the presence of beneficial Pt-Rh synergism.

Gavril, D.; Koliadima, A.; Karaiskakis, G. [Univ. of Patras (Greece). Dept. of Chemistry

1999-05-25T23:59:59.000Z

14

Pt-Co Bimetallic Catalyst Supported on Single-Walled Carbon Nanotubes: Effect of Alloy Formation and Oxygen Containing Groups †  

E-Print Network (OSTI)

Pt monometallic and Pt-Co bimetallic catalysts have been prepared on single-walled carbon nanotubes (SWNT) with and without HNO3 treatment. The HNO3 treatment introduced oxygen containing groups (OCGs), which affect both the structure and activity of the catalyst. The introduction of OCGs does not affect the structure of Pt monometallic catalysts but increased the dispersion in the bimetallic catalysts. The aqueous phase reforming (APR) activity of the bimetallic catalysts is also affected by the OCGs, because the local concentration of the reactant around the SWNT support with OCGs is less than the case without OCGs. The two effects act on activity in opposing directions so the bimetallic catalysts on the two supports give similar APR yields, but this discovery gives us direction and a basis for the future design and improvement of SWNT supported catalysts. 1.

Xiaoming Wang; Nan Li; Lisa D. Pfefferle; Gary L. Haller

2010-01-01T23:59:59.000Z

15

Fundamental studies of hydrogen chemisorption on supported monometallic and bimetallic catalysts using microcalorimetry  

DOE Green Energy (OSTI)

Highly dispersed transition metal catalysts are used in numerous commercial processes such as hydrocarbon conversions. For example, the use of Pt supported on acidic alumina or silica-alumina for reforming of naphtha in the production of gasoline is well known. Another use of supported catalysts is in automobile emission control where supported Pt-Rh bimetallic catalysts are used. Supported Ru can be used in Fischer-Tropsch synthesis for the production of higher hydrocarbons from synthesis gas. While many of these catalyst systems have been in commercial operation for several decades there is still a lack of consensus regarding the exact role of the catalyst on a molecular level. In particular, little is known about the mechanisms operating on the catalyst surface at the high pressure and high temperature conditions typically used in commercial operations. This report contains the general introduction and conclusions and an appendix containing the operating instructions for a microcalorimeter. Three chapters have been processed separately. They are: the effect of K on the kinetics and thermodynamics of hydrogen adsorption on Ru/SiO{sub 2}; hydrogen adsorption states on silica supported Ru-Ag and Ru-Cu bimetallic catalysts investigated via microcalorimetry; a comparative study of hydrogen chemisorption on silica supported Ru, Rh, and Pt.

Narayan, R.L.

1997-06-24T23:59:59.000Z

16

Experimental and computational investigations of sulfur-resistant bimetallic catalysts for reforming of biomass gasification products  

DOE Green Energy (OSTI)

A combination of density functional theory (DFT) calculations and experimental studies of supported catalysts was used to identify H{sub 2}S-resistant biomass gasification product reforming catalysts. DFT calculations were used to search for bimetallic, nickel-based (1 1 1) surfaces with lower sulfur adsorption energies and enhanced ethylene adsorption energies. These metrics were used as predictors for H{sub 2}S resistance and activity toward steam reforming of ethylene, respectively. Relative to Ni, DFT studies found that the Ni/Sn surface alloy exhibited enhanced sulfur resistance and the Ni/Ru system exhibited an improved ethylene binding energy with a small increase in sulfur binding energy. A series of supported bimetallic nickel catalysts was prepared and screened under model ethylene reforming conditions and simulated biomass tar reforming conditions. The observed experimental trends in activity were consistent with theoretical predictions, with observed reforming activities in the order Ni/Ru > Ni > Ni/Sn. Interestingly, Ni/Ru showed a high level of resistance to sulfur poisoning compared with Ni. This sulfur resistance can be partly explained by trends in sulfur versus ethylene binding energy at different types of sites across the bimetallic surface.

Rangan, Meghana; Yung, Matthew M.; Medlin, J. William (NREL); (Colorado)

2011-11-17T23:59:59.000Z

17

Structural characteristics of bimetallic catalysts supported on nano-ceria  

Science Conference Proceedings (OSTI)

Cu-Pt bimetal catalysts supported on nanocrystalline CeO2 (nano-ceria) are synthesized via the low-cost sol-gel approach followed by impregnation processing. The average particle size of the catalytic composites is 63 nm. Ceria nanopowders ...

J. F. Bozeman; H. Huang

2011-01-01T23:59:59.000Z

18

Final technical report. Bimetallic complexes as methanol oxidation catalysts  

DOE Green Energy (OSTI)

Our work on the electrocatalyzed oxidation of methanol was initially motivated by the interest in methanol as an anodic reactant in fuel cells. The literature on electrochemical oxidation of alcohols can be roughly grouped into two sets: fuel cell studies and inorganic chemistry studies. Work on fuel cells primarily focuses on surface-catalyzed oxidation at bulk metal anodes, usually Pt or Pt/Ru alloys. In the surface science/electrochemistry approach to these studies, single molecule catalysts are generally not considered. In contrast, the inorganic community investigates the electrooxidation of alcohols in homogeneous systems. Ruthenium complexes have been the most common catalysts in these studies. The alcohol substrates are typically either secondary alcohols (e.g., isopropanol) such that the reaction stops after 2 e{sup -} oxidation to the aldehyde and 4 e{sup -} oxidation to the carboxylic acid can be observed. Methanol, which can also undergo 6 e{sup -} oxidation to CO{sub 2}, rarely appears in the homogeneous catalysis studies. Surface studies have shown that two types of metal centers with different functions result in more effective catalysts than a single metal; however, application of this concept to homogeneous systems has not been demonstrated. The major thrust of the work is to apply this insight from the surface studies to homogeneous catalysis. Even though homogeneous systems would not be appropriate models for active sites on Pt/Ru anodes, it is possible that heterobimetallic catalysts could also utilize two metal centers for different roles. Starting from that perspective, this work involves the preparation and investigation of heterobinuclear catalysts for the electrochemical oxidation of methanol.

McElwee-White, Lisa

2002-01-21T23:59:59.000Z

19

CATALYSIS SCIENCE INITIATIVE: From First Principles Design to Realization of Bimetallic Catalysts for Enhanced Selectivity  

DOE Green Energy (OSTI)

In this project, we have integrated state-of-the-art Density Functional Theory (DFT) models of heterogeneous catalytic processes with high-throughput screening of bimetallic catalytic candidates for important industrial problems. We have studied a new class of alloys characterized by a surface composition different from the bulk composition, and investigated their stability and activity for the water-gas shift reaction and the oxygen reduction reaction. The former reaction is an essential part of hydrogen production; the latter is the rate-limiting step in low temperature H2 fuel cells. We have identified alloys that have remarkable stability and activity, while having a much lower material cost for both of these reactions. Using this knowledge of bimetallic interactions, we have also made progress in the industrially relevant areas of carbohydrate reforming and conversion of biomass to liquid alkanes. One aspect of this work is the conversion of glycerol (a byproduct of biodiesel production) to synthesis gas. We have developed a bifunctional supported Pt catalyst that can cleave the carbon-carbon bond while also performing the water-gas shift reaction, which allows us to better control the H2:CO ratio. Knowledge gained from the theoretical metal-metal interactions was used to develop bimetallic catalysts that perform this reaction at low temperature, allowing for an efficient coupling of this endothermic reaction with other reactions, such as Fischer-Tropsch or methanol synthesis. In our work on liquid alkane production from biomass, we have studied deactivation and selectivity in these areas as a function of metal-support interactions and reaction conditions, with an emphasis on the bifunctionality of the catalysts studied. We have identified a stable, active catalyst for this process, where the selectivity and yield can be controlled by the reaction conditions. While complete rational design of catalysts is still elusive, this work demonstrates the power of combining the insights gained from theoretical models and the work of experiments to develop new catalysts for current and future industrial challenges.

MAVRIKAKIS, MANOS

2007-05-03T23:59:59.000Z

20

Novel bimetallic dispersed catalysts for temperature-programmed coal liquefaction. Technical progress report, January--March 1993  

SciTech Connect

The ultimate goal of the present research is to develop novel catalytic hydroliquefaction process using highly active dispersed catalysts. The primary objective of this research is to develop novel bimetallic dispersed catalysts from organometallic molecular precursors, that can be used in low concentrations (bimetallic complexes that contain Mo, Co, and S in a single molecule. Three of them are bimetallic thiocubanes: Mo{sub 2}Co{sub 2}S{sub 4}(S{sub 2} CNEt{sub 2})2(CH{sub 3} CN){sub 2}(CO){sub 2} [designated as MoCo-TCl], Mo{sub 2}Co{sub 2}S{sub 4}Cp{sub 2}(CO){sub 2} [MoCo-TC2], and Mo{sub 2}Co{sub 2}S{sub 4}(Cp`){sub 2}(CO){sub 2} [MoCo-TC3], in which Et, Cp and Cp` represent ethyl, cyclopentadiene, and pentainethylcyclopentadiene, respectively. These thiocubanes were synthesized in our laboratory based on the procedures reported in literature. For comparative examination, the tdanionic bimetallic complex, (PPh{sub 4}){sub 3}Co(MoS{sub 4}){sub 2}, was also synthesized. This bimetallic sulfide complex contains cobalt bis-tetrathiomolybdate trianion, Co(MoS{sub 4}){sub 2}{sup 3{minus}}, and is designated as MoCo-S.

Parfitt, D.S.; Song, Chunshan; Schobert, H.H.

1993-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "bimetallic nanoparticle catalysts" 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

NiW and NiRu Bimetallic Catalysts for Ethylene Steam Reforming: Alternative Mechanisms for Sulfur Resistance  

SciTech Connect

Previous investigations of Ni-based catalysts for the steam reforming of hydrocarbons have indicated that the addition of a second metal can reduce the effects of sulfur poisoning. Two systems that have previously shown promise for such applications, NiW and NiRu, are considered here for the steam reforming of ethylene, a key component of biomass derived tars. Monometallic and bimetallic Al{sub 2}O{sub 3}-supported Ni and W catalysts were employed for ethylene steam reforming in the presence and absence of sulfur. The NiW catalysts were less active than Ni in the absence of sulfur, but were more active in the presence of 50 ppm H{sub 2}S. The mechanism for the W-induced improvements in sulfur resistance appears to be different from that for Ru in NiRu. To probe reasons for the sulfur resistance of NiRu, the adsorption of S and C{sub 2}H{sub 4} on several bimetallic NiRu alloy surfaces ranging from 11 to 33 % Ru was studied using density functional theory (DFT). The DFT studies reveal that sulfur adsorption is generally favored on hollow sites containing Ru. Ethylene preferentially adsorbs atop the Ru atom in all the NiRu (111) alloys investigated. By comparing trends across the various bimetallic models considered, sulfur adsorption was observed to be correlated with the density of occupied states near the Fermi level while C{sub 2}H{sub 4} adsorption was correlated with the number of unoccupied states in the d-band. The diverging mechanisms for S and C{sub 2}H{sub 4} adsorption allow for bimetallic surfaces such as NiRu that enhance ethylene binding without accompanying increases in sulfur binding energy. In contrast, bimetallics such as NiSn and NiW appear to decrease the affinity of the surface for both the reagent and the poison.

Rangan, M.; Yung, M. M.; Medlin, J. W.

2012-06-01T23:59:59.000Z

22

Novel bimetallic dispersed catalysts for temperature-programmed coal liquefaction. Technical progress report, January--March 1993  

Science Conference Proceedings (OSTI)

The ultimate goal of the present research is to develop novel catalytic hydroliquefaction process using highly active dispersed catalysts. The primary objective of this research is to develop novel bimetallic dispersed catalysts from organometallic molecular precursors, that can be used in low concentrations (TCl], Mo{sub 2}Co{sub 2}S{sub 4}Cp{sub 2}(CO){sub 2} [MoCo-TC2], and Mo{sub 2}Co{sub 2}S{sub 4}(Cp`){sub 2}(CO){sub 2} [MoCo-TC3], in which Et, Cp and Cp` represent ethyl, cyclopentadiene, and pentainethylcyclopentadiene, respectively. These thiocubanes were synthesized in our laboratory based on the procedures reported in literature. For comparative examination, the tdanionic bimetallic complex, (PPh{sub 4}){sub 3}Co(MoS{sub 4}){sub 2}, was also synthesized. This bimetallic sulfide complex contains cobalt bis-tetrathiomolybdate trianion, Co(MoS{sub 4}){sub 2}{sup 3{minus}}, and is designated as MoCo-S.

Parfitt, D.S.; Song, Chunshan; Schobert, H.H.

1993-07-01T23:59:59.000Z

23

Reaction-Driven Restructuring of Bimetallic Nanoparticle Catalysts  

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

for catalytic reforming, pollution control, alcohol oxidation, and electrocatalysis in fuel cells. Owing to the nanoscale size of the particles, the modification of the surface...

24

Biosupported Bimetallic Pd Au Nanocatalysts for Dechlorination of Environmental Contaminants  

SciTech Connect

Biologically produced monometallic palladium nanoparticles (bio-Pd) have been shown to catalyze the dehalogenation of environmental contaminants, but fail to efficiently catalyze the degradation of other important recalcitrant halogenated compounds. This study represents the first report of biologically produced bimetallic Pd/Au nanoparticle catalysts. The obtained catalysts were tested for the dechlorination of diclofenac and trichloroethylene. When aqueous bivalent Pd(II) and trivalent Au(III) ions were both added to concentrations of 50 mg L{sup -1} and reduced simultaneously by Shewanella oneidensis in the presence of H{sub 2}, the resulting cell-associated bimetallic nanoparticles (bio-Pd/Au) were able to dehalogenate 78% of the initially added diclofenac after 24 h; in comparison, no dehalogenation was observed using monometallic bio-Pd or bio-Au. Other catalyst-synthesis strategies did not show improved dehalogenation of TCE and diclofenac compared with bio-Pd. Synchrotron-based X-ray diffraction, (scanning) transmission electron microscopy and energy dispersive X-ray spectroscopy indicated that the simultaneous reduction of Pd and Au supported on cells of S. oneidensis resulted in the formation of a unique bimetallic crystalline structure. This study demonstrates that the catalytic activity and functionality of possibly environmentally more benign biosupported Pd-catalysts can be improved by coprecipitation with Au.

De Corte, S.; Fitts, J.; Hennebel, T.; Sabbe, T.; Bliznuk, V.; Verschuere, S.; van der Lelie, D.; Verstraete, W.; Boon, N.

2011-08-30T23:59:59.000Z

25

Monte Carlo Simulations of Segregation in Pt-Ni Catalyst Nanoparticles  

E-Print Network (OSTI)

of Segregation in Pt-Ni Catalyst Nanoparticles Guofengsurface chemistry of catalyst nanoparticles (also called "Pt-Ni alloy is an electro-catalyst of interest in the air

Wang, Guofeng; Van Hove, Michel A.; Ross, Philip N.; Baskes, M.I.

2004-01-01T23:59:59.000Z

26

Molecular Level Control Through Dual Site Participation Using Bimetallic Catalysts - Final Report  

DOE Green Energy (OSTI)

The overall goal of this research program was to explore the hypothesis that it is possible to design a bimetallic surface such that each metal catalyzes different elementary reaction steps in an overall reaction pathway. A corollary to this hypothesis is that the different ensemble size requirements for an elementary reaction step can be used to force an elementary reaction step to occur on only one of the metals. The research program involved a combination of materials synthesis, chemical kinetics experiments, spectroscopic studies and computational investigations. The major outcome of this research program was the development and dissemination of the Dual Site Model, for which chlorocarbon reactions in the presence of hydrogen were used as model systems.

d'Itri, Julie, L.; Kovalchuk, Vladimir, I.

2010-02-08T23:59:59.000Z

27

Carbon-Supported bimetallic Pd-Fe catalysts for vapor-phase hydrodeoxygenation of guaiacol  

Science Conference Proceedings (OSTI)

Abstract Carbon supported metal catalysts (Cu/C, Fe/C, Pd/C, Pt/C, PdFe/C and Ru/C) have been prepared, characterized and tested for vapor-phase hydrodeoxygenation (HDO) of guaiacol (GUA) at atmospheric pressure. Phenol was the major intermediate on all catalysts. Over the noble metal catalysts saturation of the aromatic ring was the major pathway observed at low temperature (250 °C), forming predominantly cyclohexanone and cyclohexanol. Substantial ring opening reaction was observed on Pt/C and Ru/C at higher reaction temperatures (e.g., 350 °C). Base metal catalysts, especially Fe/C, were found to exhibit high HDO activity without ring-saturation or ring-opening with the main products being benzene, phenol along with small amounts of cresol, toluene and trimethylbenzene (TMB). A substantial enhancement in HDO activity was observed on the PdFe/C catalysts. Compared with Fe/C, the yield to oxygen-free aromatic products (i.e., benzene/toluene/TMB) on PdFe/C increased by a factor of four at 350 °C, and by approximately a factor of two (83.2% versus 43.3%) at 450 °C. The enhanced activity of PdFe/C is attributed to the formation of PdFe alloy as evidenced by STEM, EDS and TPR.

Sun, Junming; Karim, Ayman M.; Zhang, He; Kovarik, Libor; Li, Xiaohong S.; Hensley, Alyssa; McEwen, Jean-Sabin; Wang, Yong

2013-10-01T23:59:59.000Z

28

Single-step Precipitation of Ni Nanoparticle Catalyst on Zeolite and ...  

Science Conference Proceedings (OSTI)

Abstract Scope, Ni nanoparticle catalyst was prepared on zeolite (pores size: 2 production rate from the methanol stream reforming reaction ...

29

Selectivity, activity, and metal-support interactions of Rh bimetallic catalysts. Progress report, 15 November 1981-15 August 1982  

DOE Green Energy (OSTI)

We report on a detailed investigation of the effect of TiO/sub 2/ support on Rh-Ag interaction as exhibited in catalytic activity. The temporal evolution of activity over Rh-Ag/TiO/sub 2/ for ethane hydrogenolysis and hydrogen chemisorption as a function of temperature, Ag to Rh ratio, the Rh particle size, Rh loading, and ambient gas were studied. Preliminary extended x-ray absorption fine structure (EXAFS) analysis of Rh/TiO/sub 2/ catalysts indicate that 100% exposed (dispersed) catalyst prepared by ion exchange may be atomically dispersed after low temperature reduction. 7 figures, 1 table.

Haller, G L

1982-08-01T23:59:59.000Z

30

The Reaction Specificity of Nanoparticles in Solution: Application to the Reaction of Nanoparticulate Iron and Iron-Bimetallic Compounds with Chlorinated Hydrocarbons and Oxyanions  

SciTech Connect

The prospect for better remediation technologies using nanoparticles of iron, iron oxides, and iron with catalytic metals (i.e., bimetallics) has potentially transformative implications for environmental management of DOE sites across the country. Of particular interest is the potential to avoid undesirable products from the degradation of chlorinated solvents by taking advantage of the potential selectivity of nanoparticles to produce environmentally benign products from CCl{sub 4}. Chlorinated solvents are the most frequently reported subsurface contaminants across the whole DOE complex, and carbon tetrachloride (CCl{sub 4}) is the chlorinated solvent that is of greatest concern at Hanford (U. S. Department Energy 2001). In evaluating technologies that might be used at the site, a critical concern will be that CCl{sub 4} reduction usually occurs predominantly by hydrogenolysis to chloroform (CHCl{sub 3}) and methylene chloride (CH{sub 2}Cl{sub 2}), both of which are nearly as problematic as CCl{sub 4} (National Research Council, 1978). Competing reaction pathways produce the more desirable products carbon monoxide (CO) and/or formate (HCOO{sup -}), and possibly CO{sub 2}, but the proportion of reaction that occurs by these pathways is highly variable. Iron-based metallic and oxide nanoparticles have been shown to have enhanced reactivity towards a variety of chemical species, including chlorinated hydrocarbons and reducible oxyanions. Possibly of greater importance is the ability of nanoparticles to select for specific reaction products, potentially facilitating the formation of more environmentally acceptable products. The purpose of this study is to develop a fundamental understanding of the mechanism responsible for the overall particle reactivity and reaction selectivity of reactive metal and oxide nanoparticles. To achieve this objective the project involves the synthesis (using solution and vacuum synthesis methods) and characterization of well-defined nanoparticles, measurements of particle reactivity in solution or vacuum environments, and theory and modeling efforts to rationalize particle structure and reactivity.

None

2005-06-01T23:59:59.000Z

31

Low-Temperature Solution-Phase Synthesis of NiAu Alloy Nanoparticles via Butyllithium Reduction: Influences of Synthesis Details and Application as the Precursor to Active Au0NiO/Si02 Catalysts Through Proper Pretreatments  

SciTech Connect

Bimetallic nanoparticles (NPs) have wide applications in electronics, photonics, and catalysis. However, it is particularly challenging to synthesize size-controllable alloy nanoparticles (e.g., NiAu) with bulk immiscible metals as the components. Here we report the synthesis of isolable NiAu alloy nanoparticles with tunable and relatively uniform sizes via a coreduction method employing butyllithium as the reducing agent and trioctylphosphine as the protecting agent. The influences of synthesis conditions (e.g., protecting agent, aging temperature, and the solvent used to wash the product) were investigated, and the synthesis mechanism was preliminarily surveyed. The NiAu alloy nanoparticles obtained were then used as the precursor to prepare an Au-NiO/SiO2 catalyst highly active in low-temperature CO oxidation, and the effects of pretreatment details and catalyst compositions on catalytic activity were studied. Relevant characterization employing XRD, TEM, UV-vis, TG/DTG, and FT-IR was conducted. In addition, the importance of the current synthesis of NiAu alloy NPs and the contribution of the catalyst design were discussed in the context of the literature.

Zhou, Shenghu [ORNL; Ma, Zhen [ORNL; Yin, Hongfeng [ORNL; Wu, Zili [ORNL; Eichhorn, Bryan [University of Maryland; Overbury, Steven {Steve} H [ORNL; Dai, Sheng [ORNL

2009-01-01T23:59:59.000Z

32

Monodisperse Platinum and Rhodium Nanoparticles as Model Heterogeneous Catalysts  

E-Print Network (OSTI)

R. Structure of Metallic Catalysts ; Academic Press: London,pretreatments of the Rh catalysts and analyzing thea Pt(octahedra)/SBA-15 catalyst increased from 0.01 to 28

Coble, Inger M

2008-01-01T23:59:59.000Z

33

Au-Pt heteroaggregate dendritic nanostructures and Au-Pt alloy nanoparticles and their use as catalysts  

DOE Patents (OSTI)

Au--Pt heteroaggregate dendritic nanostructures and AuPt alloy nanoparticles, and their use as anodic catalysts in fuel cells.

Eichhorn, Bryan W. (University Park, MD); Zhou, Shenghu (Greenbelt, MD); Jackson, Gregory Scott (University Park, MD)

2011-10-18T23:59:59.000Z

34

Rhodium Catalysts in the Oxidation of CO by O2 and NO: Shape, Composition, and Hot Electron Generation  

E-Print Network (OSTI)

ACTIVITY OF PLATINUM CATALYSTS. Journal of Catalysis 1966,SUPPORTED BIMETALLIC-CLUSTER CATALYSTS. Journal of Catalysisnanoparticle heterogeneous catalyst. Chem. Commun. 1999, (

Renzas, James Russell

2010-01-01T23:59:59.000Z

35

Hollow Nanoparticles as Active and Durable Catalysts - Energy ...  

Platinum is an excellent catalyst for many reactions. However, it is also very expensive. The catalytic activity per gram of platinum can be increased by using a ...

36

Synthesis of Ni-Al Intermetallic Nanoparticle Catalysts by Vacuum ...  

Science Conference Proceedings (OSTI)

... methanol decomposition and methane steam reforming, indicating a possibility to develop Ni-Al intermetallic compounds as catalysts for hydrogen production.

37

NOVEL PREPARATION AND MAGNETO CHEMICAL CHARACTERIZATION OF NANO-PARTICLE MIXED ALCOHOL CATALYSTS  

DOE Green Energy (OSTI)

We have developed effective nanoparticle incorporated heterogeneous F-T catalysts starting with the synthesis of Fe, Co, Cu nanoparticles using Fe(acac){sub 3}, Co(acac){sub 2}, and Cu(acac){sub 2} precursors and incorporating the nanoparticles into alumina sol-gel to yield higher alkanes production. SEM/EDX, XRD, BET, VSM and SQUID experimental techniques were used to characterize the catalysts, and GC/MS were used for catalytic product analysis. The nanoparticle oxide method gave the highest metal loading. In case of mixed metals it seems that Co or Cu interferes and reduces Fe metal loading. The XRD pattern for nanoparticle mixed metal oxides show alloy formation between cobalt and iron, and between copper and iron in sol-gel prepared alumina granules. The alloy formation is also supported by DTA and VMS data. The magnetization studies were used to estimate the catalyst activity in pre- and post-catalysts. A lower limit of {approx}40% for the reduction efficiency was obtained due to hydrogenation at 450 C for 4 hrs. About 85% of the catalyst has become inactive after 25 hrs of catalytic reaction, probably by forming carbides of Fe and Co. The low temperature (300 K to 4.2 K) SQUID magnetometer results indicate a superparamagnetic character of metal nanoparticles with a wide size distribution of < 20 nm nanoparticles. We have developed an efficient and economical procedure for analyzing the F-T products using low cost GC-TCD system with hydrogen as a carrier gas. Two GC columns DC 200/500 and Supelco Carboxen-1000 column were tested for the separation of higher alkanes and the non-condensable gases. The Co/Fe on alumina sol-gel catalyst showed the highest yield for methane among Fe, Co, Cu, Co/Fe, Cu/Co, Fe/Cu. The optimization of CO/H{sub 2} ratio indicated that 1:1 ratio gave more alkanes distribution in F-T process with Co/Fe (6% each) impregnated on alumina mesoporous catalyst.

Seetala V. Naidu; Upali Siriwardane

2005-01-14T23:59:59.000Z

38

Chemistry of bimetallic and alloys surfaces  

DOE Green Energy (OSTI)

We have continued our work on elucidating the underlying principles that govern chemical reactions occurring on bimetallic and alloy surfaces. Our goal is to aid in the atomic level explanation of the reactivity and selectivity of alloy and bimetallic cluster catalysts and to provide a fundamental basis for the design of new catalysts with improved performance. Our approach is to use a battery of surface science methods to obtain fundamental data on the thermochemistry and kinetics of the adsorption and reaction of molecules on extensively characterized, single-crystal bimetallic surfaces. We measure changes in chemisorption bond strength, adsorption site distributions, and hydrocarbon fragment stability and reactivity and correlate these results with the geometric and electronic structure of the metal atoms on the surface. Often, our aim is to carefully design experiments that isolate the several factors (e.g., ensemble and ligand effects) that control surface chemistry and catalysis on bimetallic and alloy surfaces in order to better understand the importance of each contribution. In the past 18 months, we have continued to study how alkali promoters strongly affect the reactions of hydrocarbons on Pt and Ni surfaces by altering the electronic structure and inducing significant site-blocking effects. We have shown that bismuth coadsorption provides benchmark data on ensemble sizes required for chemical reactions on Pt and Ni surfaces. Surface alloys of Sn/Pt are being used for detailed probing of ensemble sizes and also reactive site requirements. 22 refs.

Koel, B.E.

1991-10-18T23:59:59.000Z

39

NOVEL PREPARATION AND MAGNETO CHEMICAL CHARACTERIZATION OF NANOPARTICLE MIXED ALCOHOL CATALYSTS  

DOE Green Energy (OSTI)

We have developed and streamlined the experimental systems: (a) Laser-induced solution deposition (LISD) photosynthesis, ball-milling, and chemical synthesis of Fe, Co, and Cu nanoparticle catalysts; (b) Sol-gel method for mesoporous {gamma}-Al{sub 2}O{sub 3}, SiO{sub 2}, hybrid alumina/silica granular supports; (c) Three sol-gel/oil-drop catalyst preparation methods to incorporate metal nanoparticles into mesoporous 1 mm granular supports; (d) Low-cost GC-TCD system with hydrogen as carrier gas for the determination of wide spectrum of alkanes produced during the F-T reactions; and (e) Gas-flow reactor and microchannel reactor for fast screening of catalysts. The LISD method could produce Co, Cu, and Fe (5 nm) nanoparticles, but in milligram quantities. We could produce nanoparticles in gram quantities using high-energy ball milling and chemical synthesis methods. Ball milling gave wide particle size distribution compared to the chemical synthesis method that gave almost uniform size ({approx}5 nm) particles. Metal nanoparticles Cu, Co, Fe, Cu/Co, Cu/Fe and Co/Fe were loaded (2-12 wt%) uniformly into {gamma}-Al{sub 2}O{sub 3}, SiO{sub 2}, or alumina/silica hybrid supports by combined sol-gel/oil-drop methods followed by calcination and hydrogenation steps, prior to syngas FT reaction studies. The properties of metal loaded {gamma}-Al{sub 2}O{sub 3} granules were compared for the two precursors: aluminum tri-sec-butoxide (ALTSB) and aluminum tri-iso-propoxide (ALTIP). The effect of solgel supports alumina, silica, and alumina/silica hybrid were examined on catalytic properties. Metal loading efficiencies for pure metal catalysts increased in the order Co, Cu and Fe in agreement with solubility of metal hydroxides. In case of mixed metals, Co and Cu seams to interfere and reduce Fe metal loading when metal nitrate solutions are used. The solubility differences of metal hydroxides would not allow precise control of metal loading. We have overcome this problem by introducing a novel method of nanoparticle metal oxide co-entrapped sol-gel that gave the highest metal loading with precise control and reproducibility, and greater mechanical strength of granules than the metal nitrate solution co-entrapping and wet impregnation methods. Both, slurry-phase-batch and gas-phase-continuous-flow, reactors were used for syngas conversion reactions. Our investigations of Co and Fe thin film deposited micro-reactors showed higher CO/H{sub 2} conversion for Fe compared to Co. The catalytic activity for CO/H{sub 2} conversion was observed in the increasing order for the nanocatalysts Cu, Co, Fe, Co/Fe, Cu/Co and Cu/Fe in alumina sol-gel support, and Co/Fe showed the highest yield for methane. The optimization of CO/H{sub 2} ratio indicated that 1:1 ratio gave more alkanes distribution in F-T process with Co/Fe (6% each) impregnated on alumina. We could estimate the activity of catalysts (involving Co, Fe) during hydrogenation and after catalytic reaction using magnetization studies. In summary our accomplishments are: (1) Novel chemical methods for the synthesis of (5 nm) Fe, Co, Cu nanoparticles with narrow size distribution. (2) Developing a method of metal oxide nanoparticles addition to alumina/silica sol-gel to control metal loading of pure and mixed metal catalysts compositions in high yields. (3) A low-cost GC-TCD system to analyze wide spectrum of alkanes (F-T reaction products). (4) Fe/Co mixed metal alumina/silica mesoporous catalysts with higher FT activity. (5) Characterizing nanoparticle catalysts and supports for detail understanding of FT-process.

Seetala V. Naidu; Upali Siriwardane

2005-05-24T23:59:59.000Z

40

Dispersion enhanced metal/zeolite catalysts  

DOE Patents (OSTI)

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

Sachtler, Wolfgang M. H. (Evanston, IL); Tzou, Ming-Shin (Evanston, IL); Jiang, Hui-Jong (Evanston, IL)

1987-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "bimetallic nanoparticle catalysts" 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

NOVEL PREPARATION AND MAGNETO CHEMICAL CHARACTERIZATION OF NANO-PARTICLE MIXED ALCOHOL CATALYSTS  

DOE Green Energy (OSTI)

We have produced Co, Cu, and Fe nano-particles by Laser-induced solution deposition (LISD) as evidenced by TEM investigations. Sizes of the nano-particles created are in the order of 5 nm. The LISD system could generate nano-particles in quantities only in the order of a milligram. This may be mainly due to the limited photo induced reactions taking place on the surface of the solutions. We have designed experiments to use drop flow technique with LISD for nano-particle deposition on microreactors. Preliminary work has been done on Co and Fe thin film deposited microreactors. We are also investigating the catalytic properties of nano-particles of FeO and CoO prepared by ball milling and dispersed into sol-gel prepared alumina granules. We have continued our investigation of catalytic reactions of Cu, Co, Fe, Cu/Co, Cu/Fe and Co/Fe on alumina support. The metal oxides were first reduced with hydrogen and used for the conversion of CO/H{sub 2}. The surface area of the catalysts has been determined by nitrogen disorption. They are in the range of 200-300 m{sup 2}/g. Cu, Co, Fe, Co/Fe, Cu/Co and Cu/Fe showed increasing order of catalytic activity for CO/H{sub 2} conversion. We are also studying catalytic conversion rates for CO{sub 2}/H{sub 2} and CO/CO{sub 2}/H{sub 2} mixtures using these catalysts. Our investigations of Co and Fe thin film deposited microreactors showed higher CO/H{sub 2} conversion for Fe compared to Co. We have used vibrating sample magnetometer (VSM) to study the magnetic characteristics of as prepared, reduced, post-reaction catalysts. Comparative study of the ferromagnetic component of these samples gives the reduction efficiency and the changes in metal centers during catalytic reactions. Magnetic studies of post-reaction Co and Fe micro-reactors show that more carbide formation occurs for iron compared to cobalt.

Setala V. Naidu

2003-01-01T23:59:59.000Z

42

Studying Fischer-Tropsch catalysts using transmission electron microscopy and model systems of nanoparticles on planar supports.  

SciTech Connect

Nanoparticle model systems on planar supports form a versatile platform for studying morphological and compositional changes of catalysts due to exposure to realistic reaction conditions. We review examples from our work on iron and cobalt catalysts, which can undergo significant rearrangement in the reactive environment of the Fischer-Tropsch synthesis. The use of specially designed, silicon based supports with thin film SiO{sub 2} enables the application of transmission electron microscopy, which has furnished important insight into e.g. the mechanisms of catalyst regeneration.

Thune, P. C.; Weststrate, C. J.; Moodley, P.; Saib, A. M.; van de Loosdrecht, J.; Miller, J. T.; Niemantsverdriet, J. W. (Chemical Sciences and Engineering Division); (Eindhoven Univ. of Technology); (Sasol Technology)

2011-01-01T23:59:59.000Z

43

On the nature of the deactivation of supported palladium nanoparticle catalysts in the decarboxylation of fatty acids.  

SciTech Connect

Supported palladium catalysts are effective catalysts for the hydrogen-free decarboxylation of fatty acids. However, the catalysts deactivate severely after one use. Here, the recyclability of a well-defined, mesoporous silica-supported palladium nanoparticle catalyst is evaluated in the batch decarboxylation of stearic acid at 300 C under inert atmosphere, producing n-heptadecane. The nature of the catalyst deactivation is examined in detail via an array of characterization techniques. X-ray photoelectron spectroscopy (XPS) demonstrates that little palladium surface oxidation occurs over the course of the reaction, and a combination of X-ray absorption spectroscopy and transmission electron microscopy (TEM) suggests negligible particle sintering or agglomeration. Physisorption and chemisorption measurements demonstrate substantial loss in total surface area and porosity as well as accessible palladium surface area with these losses attributed to significant organic deposition on the catalyst, as verified via thermogravimetric analysis. High temperature calcination is applied to combust and remove these residues, but resultant nanoparticle agglomeration is significant. Solid state nuclear magnetic resonance spectroscopy (NMR), Fourier transform infrared spectroscopy (FT-IR) and solid dissolution followed by organic extraction methodologies demonstrate that the carbonaceous deposits are not coke but rather strongly adsorbed reactants and products. Detrimental coke formation, as suggested by prior literature, is verified to be absent, as extraction of the surface-deposited organic species yields nearly complete recovery of the total surface area, pore volume, and active palladium surface area. Furthermore, the regenerated catalyst exhibits a corresponding significant recovery of decarboxylation activity.

Ping, E. W.; Pierson, J.; Wallace, R.; Miller, J. T.; Fuller, T. F.; Jones, C. W. (Chemical Sciences and Engineering Division); (Georgia Institute of Technology)

2011-04-15T23:59:59.000Z

44

Synthesis of Silica Supported AuCu Nanoparticle Catalysts and the Effects of Pretreatment Conditions for the CO Oxidation Reaction  

SciTech Connect

Supported gold nanoparticles have generated an immense interest in the field of catalysis due to their extremely high reactivity and selectivity. Recently, alloy nanoparticles of gold have received a lot of attention due to their enhanced catalytic properties. Here we report the synthesis of silica supported AuCu nanoparticles through the conversion of supported Au nanoparticles in a solution of Cu(C{sub 2}H{sub 3}O{sub 2}){sub 2} at 300 C. The AuCu alloy structure was confirmed through powder XRD (which indicated a weakly ordered alloy phase), XANES, and EXAFS. It was also shown that heating the AuCu/SiO{sub 2} in an O{sub 2} atmosphere segregated the catalyst into a Au-CuO{sub x} heterostructure between 150 C to 240 C. Heating the catalyst in H{sub 2} at 300 C reduced the CuO{sub x} back to Cu{sup 0} to reform the AuCu alloy phase. It was found that the AuCu/SiO{sub 2} catalysts were inactive for CO oxidation. However, various pretreatment conditions were required to form a highly active and stable Au-CuO{sub x}/SiO{sub 2} catalyst to achieve 100% CO conversion below room-temperature. This is explained by the in situ FTIR result, which shows that CO molecules can be chemisorbed and activated only on the Au-CuOx/SiO{sub 2} catalyst but not on the AuCu/SiO{sub 2} catalyst.

J Bauer; D Mullins; M Li; Z Wu; E Payzant; S Overbury; S Dai

2011-12-31T23:59:59.000Z

45

Revealing Correlation of Valence State with Nanoporous Structure in Cobalt Catalyst Nanoparticles by In situ Environmental TEM  

SciTech Connect

Simultaneously probing the electronic structure and morphology of materials at the nanometer or atomic scale while a chemical reaction proceeds is significant for understanding the underlying reaction mechanisms and optimizing a materials design. This is especially important in the study of nanoparticle catalysts, yet such experiments have rarely been achieved. Utilizing an environmental transmission electron microscope equipped with a differentially pumped gas cell, we are able to conduct nanoscopic imaging and electron energy loss spectroscopy in situ for cobalt catalysts under reaction conditions. Studies reveal quantitative correlation of the cobalt valence states with the particles' nanoporous structures. The in situ experiments were performed on nanoporous cobalt particles coated with silica, while a 15 mTorr hydrogen environment was maintained at various temperatures (300-600 C). When the nanoporous particles were reduced, the valence state changed from cobalt oxide to metallic cobalt and concurrent structural coarsening was observed. In situ mapping of the valence state and the corresponding nanoporous structures allows quantitative analysis necessary for understanding and improving the mass activity and lifetime of cobalt-based catalysts, for example, for Fischer-Tropsch synthesis that converts carbon monoxide and hydrogen into fuels, and uncovering the catalyst optimization mechanisms.

Xin H. L.; Diaz R.; Pach, E.A.; Stach, E.A.; Salmeron, M.; Zheng, H.

2012-05-01T23:59:59.000Z

46

Revealing Correlation of Valence State with Nanoporous Structure in Cobalt Catalyst Nanoparticles by in Situ Environmental TEM  

E-Print Network (OSTI)

Simultaneously probing the electronic structure and morphology of materials at the nanometer or atomic scale while a chemical reaction proceeds is significant for understanding the underlying reaction mechanisms and optimizing a materials design. This is especially important in the study of nanoparticle catalysts, yet such experiments have rarely been achieved. Utilizing an environmental transmission electron microscope (ETEM) equipped with a differentially pumped gas cell, we are able to conduct nanoscopic imaging and electron energy loss spectroscopy (EELS) in situ for cobalt catalysts under reaction conditions. Analysis revealed quantitative correlation of the cobalt valence states to the particles' nanoporous structures. The in situ experiments were performed on nanoporous cobalt particles coated with silica while a 15 mTorr hydrogen environment was maintained at various temperatures (300-600\\degreeC). When the nanoporous particles were reduced, the valence state changed from cobalt oxide to metallic coba...

Xin, Huolin L; Diaz, Rosa E; Stach, Eric A; Salmeron, Miquel; Zheng, Haimei

2012-01-01T23:59:59.000Z

47

Surface Structures of Cubo-octahedral Pt-Mo Catalyst Nanoparticles from Monte Carlo Simulations  

DOE Green Energy (OSTI)

The surface structures of cubo-octahedral Pt-Mo nanoparticles have been investigated using the Monte Carlo method and modified embedded atom method potentials that we developed for Pt-Mo alloys. The cubo-octahedral Pt-Mo nanoparticles are constructed with disordered fcc configurations, with sizes from 2.5 to 5.0 nm, and with Pt concentrations from 60 to 90 at. percent. The equilibrium Pt-Mo nanoparticle configurations were generated through Monte Carlo simulations allowing both atomic displacements and element exchanges at 600 K. We predict that the Pt atoms weakly segregate to the surfaces of such nanoparticles. The Pt concentrations in the surface are calculated to be 5 to 14 at. percent higher than the Pt concentrations of the nanoparticles. Moreover, the Pt atoms preferentially segregate to the facet sites of the surface, while the Pt and Mo atoms tend to alternate along the edges and vertices of these nanoparticles. We found that decreasing the size or increasing the Pt concentration leads to higher Pt concentrations but fewer Pt-Mo pairs in the Pt-Mo nanoparticle surfaces.

Wang, Guofeng; Van Hove, M.A.; Ross, P.N.; Baskes, M.I.

2005-03-31T23:59:59.000Z

48

Chemistry of bimetallic and alloys surfaces. Progress report, June 1, 1990--November 30, 1991  

DOE Green Energy (OSTI)

We have continued our work on elucidating the underlying principles that govern chemical reactions occurring on bimetallic and alloy surfaces. Our goal is to aid in the atomic level explanation of the reactivity and selectivity of alloy and bimetallic cluster catalysts and to provide a fundamental basis for the design of new catalysts with improved performance. Our approach is to use a battery of surface science methods to obtain fundamental data on the thermochemistry and kinetics of the adsorption and reaction of molecules on extensively characterized, single-crystal bimetallic surfaces. We measure changes in chemisorption bond strength, adsorption site distributions, and hydrocarbon fragment stability and reactivity and correlate these results with the geometric and electronic structure of the metal atoms on the surface. Often, our aim is to carefully design experiments that isolate the several factors (e.g., ensemble and ligand effects) that control surface chemistry and catalysis on bimetallic and alloy surfaces in order to better understand the importance of each contribution. In the past 18 months, we have continued to study how alkali promoters strongly affect the reactions of hydrocarbons on Pt and Ni surfaces by altering the electronic structure and inducing significant site-blocking effects. We have shown that bismuth coadsorption provides benchmark data on ensemble sizes required for chemical reactions on Pt and Ni surfaces. Surface alloys of Sn/Pt are being used for detailed probing of ensemble sizes and also reactive site requirements. 22 refs.

Koel, B.E.

1991-10-18T23:59:59.000Z

49

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  

SciTech Connect

Recent breakthroughs in synthesis in nanosciences have achieved control of size and shapes of nanoparticles that are relevant for catalyst design. In this article, we review the advance of synthesis of nanoparticles, fabrication of two and three dimensional model catalyst system, characterization, and studies of activity and selectivity. The ability to synthesize monodispersed platinum and rhodium nanoparticles in the 1-10 nm range permitted us to study the influence of composition, structure, and dynamic properties of monodispersed metal nanoparticle on chemical reactivity and selectivity. We review the importance of size and shape of nanoparticles to determine the reaction selectivity in multi-path reactions. The influence of metal-support interaction has been studied by probing the hot electron flows through the metal-oxide interface in catalytic nanodiodes. Novel designs of nanoparticle catalytic systems are discussed.

Somorjai, Gabor A.; Park, Jeong Y.

2008-02-13T23:59:59.000Z

50

Design of a high activity and selectivity alcohol catalyst  

DOE Green Energy (OSTI)

In order to explore the secondary dehydration of methanol over [gamma]-Al[sub 2]O[sub 3] support and over bimetallic Rh-Mo/[gamma]- Al[sub 2]O[sub 3], a new series of K-doped Rh-Mo/[gamma]-Al[sub 2]O[sub 3] catalysts was synthesized. Work on synthesis of bimetallic Rh-Mo clusters is reported.

Foley, H.C.; Mills, G.A.

1992-06-04T23:59:59.000Z

51

Novel Pt/Mg(In)(Al)O catalysts for ethane and propane dehydrogenation  

Science Conference Proceedings (OSTI)

Catalysts for the dehydrogenation of light alkanes were prepared by dispersing Pt on the surface of a calcined hydrotalcite-like support containing indium, Mg(In)(Al)O. Upon reduction in H{sub 2} at temperatures above 673 K, bimetallic particles of PtIn are observed by TEM, which have an average diameter of 1 nm. Analysis of Pt LIII-edge extended X-ray absorption fine structure (EXAFS) data shows that the In content of the bimetallic particles increases with increasing bulk In/Pt ratio and reduction temperature. Pt LIII-edge X-ray absorption near edge structure (XANES) indicates that an increasing donation of electronic charge from In to Pt occurs with increasing In content in the PtIn particles. The activity and selectivity of the Pt/Mg(In)(Al)O catalysts for ethane and propane dehydrogenation reactions are strongly dependent on the bulk In/Pt ratio. For both reactants, maximum activity was achieved for a bulk In/Pt ratio of 0.48, and at this In/Pt ratio, the selectivity to alkene was nearly 100%. Coke deposition was observed after catalyst use for either ethane or propane dehydrogenation, and it was observed that the alloying of Pt with In greatly reduced the amount of coke deposited. Characterization of the deposit by Raman spectroscopy indicates that the coke is present as highly disordered graphite particles propane dehydrogenation are comparable, the effects on activity are dependent on reactant composition. Coke deposition had no effect on ethane dehydrogenation activity, but caused a loss in propane dehydrogenation activity. This difference is attributed to the greater ease with which coke produced on the surface of PtIn nanoparticles migrates to the support during ethane dehydrogenation versus propane dehydrogenation.

Sun, Pingping; Siddiqi, Georges; Vining, William C.; Chi, Miaofang; Bell, Alexis T. (UCB); (ORNL)

2011-10-28T23:59:59.000Z

52

Bismuth as a modifier of Au Pd catalyst: Enhancing selectivity in alcohol oxidation by suppressing parallel reaction  

SciTech Connect

Bi has been widely employed as a modifier for Pd and Pt based catalyst mainly in order to improve selectivity. We found that when Bi was added to the bimetallic system AuPd, the effect on activity in alcohol oxidation mainly depends on the amount of Bi regardless its position, being negligible when Bi was 0.1 wt% and detectably negative when the amount was increased to 3 wt%. However, the selectivity of the reactions notably varied only when Bi was deposited on the surface of metal nanoparticles suppressing parallel reaction in both benzyl alcohol and glycerol oxidation. After a careful characterization of all the catalysts and additional catalytic tests, we concluded that the Bi influence on the activity of the catalysts could be ascribed to electronic effect whereas the one on selectivity mainly to a geometric modification. Moreover, the Bi-modified AuPd/AC catalyst showed possible application in the production of tartronic acid, a useful intermediate, from glycerol.

Villa, Alberto [Universita di Milano, Italy; Wang, Di [Fritz Haber Institute of the Max Planck Society, Berlin, Germany; Veith, Gabriel M [ORNL; Prati, Laura [Universita di Milano, Italy

2012-01-01T23:59:59.000Z

53

Final Technical Report: First Principles Investigations for the Ensemble Effects of PdAu and PtAu Bimetallic Nanocatalysts  

DOE Green Energy (OSTI)

Bimetallic surfaces with tunable chemical properties have attracted broad attention in recent years due to their ample potential for heterogeneous catalysis applications. The local chemical properties of constituents are strongly altered from their parent metals by 'ligand effect', a term encompassing the influences of charge transfer, orbital rehybridization and lattice strain. In comparison to the aforementioned, the 'ensemble effect' associated with particular arrangements of the active constituents have received much less attention, despite their notable importance towards the determination of reactivity and selectivity of bimetallic catalysts. We performed theoretical studies for understanding the ensemble effects on bimetallic catalysis: (i) simulations for the formation of different ensembles on PdAu and PtAu nanoclusters; (ii) studies of the size, shape, and substrate dependence of their electronic properties; and (iii) simulations for model reactions such as CO oxidation, methanol, ethylene and water dehydrogenation on PdAu and PtAu nanoclusters. In close collaboration with leading experimental groups, our theoretical research elucidated the fundamentals of Au based bimetallic nanocatalysts.

Ruqian Wu

2012-05-18T23:59:59.000Z

54

Reactivity of Nanoparticle Catalysts  

Science Conference Proceedings (OSTI)

... These, in turn, will provide a sustainable source of clean energy with applications in transportation and portable power generation. ...

2013-08-27T23:59:59.000Z

55

Bimetallic steel/aluminum wire for overhead telecommunication lines  

Science Conference Proceedings (OSTI)

for power transmission and overhead telecommunication lines and other .... " Method of manufacture of bimetallic wire for, e.g., trolley-bus cable or rods, n Inven-.

56

Design of a high activity and selectivity alcohol catalyst. Seventh quarterly report, February 7, 1992--May 7, 1992  

DOE Green Energy (OSTI)

In order to explore the secondary dehydration of methanol over {gamma}-Al{sub 2}O{sub 3} support and over bimetallic Rh-Mo/{gamma}- Al{sub 2}O{sub 3}, a new series of K-doped Rh-Mo/{gamma}-Al{sub 2}O{sub 3} catalysts was synthesized. Work on synthesis of bimetallic Rh-Mo clusters is reported.

Foley, H.C.; Mills, G.A.

1992-06-04T23:59:59.000Z

57

Nanoparticles  

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

Benjamin Gilbert1, Feng Huang1, Hengzhong Zhang1, Glenn A. Waychunas2, and Benjamin Gilbert1, Feng Huang1, Hengzhong Zhang1, Glenn A. Waychunas2, and Jillian F. Banfield1,2 1Department of Earth and Planetary Sciences, University of California at Berkeley 2Earth Sciences Division, Lawrence Berkeley National Laboratory Using synchrotron techniques, Benjamin Gilbert and colleagues in Jill Banfield's group at the University of California - Berkeley and Glenn Waychunas at LBNL have determined how the equilibrium structure and lattice dynamics of zinc sulfide (ZnS) nanoparticles differ from bulk ZnS. They combined size and shape information from small-angle x-ray scattering (SAXS) with structure information from wide-angle x-ray scattering (WAXS) to analyze structural differences in the real-space pair distribution function (PDF). By combining SAXS and WAXS, they were able to remove the small-particle size contribution to x-ray diffraction peak broadening and quantify the excess disorder and strain in the nanoparticles relative to bulk ZnS.

58

BIMETALLIC LITHIUM BOROHYDRIDES TOWARD REVERSIBLE HYDROGEN STORAGE  

DOE Green Energy (OSTI)

Borohydrides such as LiBH{sub 4} have been studied as candidates for hydrogen storage because of their high hydrogen contents (18.4 wt% for LiBH{sub 4}). Limited success has been made in reducing the dehydrogenation temperature by adding reactants such as metals, metal oxides and metal halides. However, full rehydrogenation has not been realized because of multi-step decomposition processes and the stable intermediate species produced. It is suggested that adding second cation in LiBH{sub 4} may reduce the binding energy of B-H. The second cation may also provide the pathway for full rehydrogenation. In this work, several bimetallic borohydrides were synthesized using wet chemistry, high pressure reactive ball milling and sintering processes. The investigation found that the thermodynamic stability was reduced, but the full rehydrogenation is still a challenge. Although our experiments show the partial reversibility of the bimetallic borohydrides, it was not sustainable during dehydriding-rehydriding cycles because of the accumulation of hydrogen inert species.

Au, M.

2010-10-21T23:59:59.000Z

59

Oxidation catalyst  

DOE Patents (OSTI)

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

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

2010-11-09T23:59:59.000Z

60

Materials Design of Advanced Performance Metal Catalysts  

SciTech Connect

The contribution of materials design to the fabrication of advanced metal catalysts is highlighted, with particular emphasis on the construction of relatively complex contact structures surrounding metal nanoparticles. Novel advanced metal catalysts can be synthesized via encapsulation of metal nanoparticles into oxide shells, immobilization of metal oxide core-shell structures on solid supports, post-modification of supported metal nanoparticles by surface coating, and premodification of supports before loading metal nanoparticles. Examples on how these materials structures lead to enhanced catalytic performance are illustrated, and a few future prospects are presented.

Ma, Zhen [ORNL; Dai, Sheng [ORNL

2008-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "bimetallic nanoparticle catalysts" 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

Probing the interaction of cells-nanoparticles using Force-Distance  

Science Conference Proceedings (OSTI)

Microbial synthesis and fabrication of palladium nanoparticle catalysts by using the metal ion-reducing bacterium Shewanella algae · Micromechanical ...

62

Spectroscopic Elucidation of First Steps of Supported Bimetallic Cluster Formation  

DOE Green Energy (OSTI)

Initial steps of bimetallic Ru-Os cluster formation on MgO in the presence of H{sub 2} are analyzed by EXAFS and IR spectroscopy. Ru-Os bond formation takes place after decarbonylation of Ru{sub 3} clusters and subsequently, at higher temperatures, of Os{sub 3} clusters to generate coordinative unsaturation.

Kulkarni, A.; Gates, B.C.; (UCD)

2009-12-23T23:59:59.000Z

63

Laser Catalyst  

INL’s Laser Catalyst is a method for removing contaminant matter from a porous material. A polymer material is applied to a contaminated surface and ...

64

Oxyhydrochlorination catalyst  

DOE Patents (OSTI)

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

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

1992-01-01T23:59:59.000Z

65

Photo-oxidation catalysts  

DOE Patents (OSTI)

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

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

2009-07-14T23:59:59.000Z

66

Preferential CO Oxidation in Hydrogen: Reactivity of Core-Shell Nanoparticles  

Science Conference Proceedings (OSTI)

We report on the first-principles-guided design, synthesis, and characterization of core-shell nanoparticle (NP) catalysts made of a transition metal core (M ) Ru, Rh, Ir, Pd, or Au) covered with a ?1-2 monolayer thick shell of Pt atoms (i.e., a M@Pt core-shell NP). An array of experimental techniques, including X-ray diffraction, Fourier transform infrared spectroscopy, high resolution transmission electron microscopy, and temperature-programmed reaction, are employed to establish the composition of the synthesized NPs. Subsequent studies of these NPs’ catalytic properties for preferential CO oxidation in hydrogen-rich environments (PROX), combined with Density Functional Theory (DFT)-based mechanistic studies, elucidate important trends and provide fundamental understanding of the reactivity of Pt shells as a function of the core metal. Both the PROX activity and selectivity of several of these M@Pt core-shell NPs are significantly improved compared to monometallic and bulk nonsegregated bimetallic nanoalloys. Among the systems studied, Ru@Pt core-shell NPs exhibit the highest PROX activity, where the CO oxidation is complete by 30 °C (1000 ppm CO in H2). Therefore, despite their reduced Pt content, M@Pt core-shell NPs afford the design of more active PROX catalysts. DFT studies suggest that the relative differences in the catalytic activities for the various core-shell NPs originate from a combination of (i) the relative availability of CO-free Pt surface sites on the M@Pt NPs, which are necessary for O2 activation, and (ii) a hydrogen-mediated low-temperature CO oxidation process that is clearly distinct from the traditional bifunctional CO oxidation mechanism.

Nilekar, Anand U.; Alayoglu, Selim; Eichhorn, Bryan W.; Mavrikakis, Manos

2010-06-02T23:59:59.000Z

67

Nanoporous Au: an unsupported pure gold catalyst?  

Science Conference Proceedings (OSTI)

The unique properties of gold especially in low temperature CO oxidation have been ascribed to a combination of various effects. In particular, particle sizes below a few nm and specific particle-support interactions have been shown to play important roles. On the contrary, recent reports revealed that monolithic nanoporous gold (npAu) prepared by leaching a less noble metal, such as Ag, out of the corresponding alloy can also exhibit remarkably high catalytic activity for CO oxidation, even though no support is present. Therefore, it was claimed to be a pure and unsupported gold catalyst. We investigated npAu with respect to its morphology, surface composition and catalytic properties. In particular, we studied the reaction kinetics for low temperature CO oxidation in detail taking mass transport limitation due to the porous structure of the material into account. Our results reveal that Ag, even if removed almost completely from the bulk, segregates to the surface resulting in surface concentrations of up to 10 at%. Our data suggest that this Ag plays a significant role in activation of molecular oxygen. Therefore, npAu should be considered as a bimetallic catalyst rather than a pure Au catalyst.

Wittstock, A; Neumann, B; Schaefer, A; Dumbuya, K; Kuebel, C; Biener, M; Zielasek, V; Steinrueck, H; Gottfried, M; Biener, J; Hamza, A; B?umer, M

2008-09-04T23:59:59.000Z

68

Catalytic studies of supported Pd-Au catalysts  

E-Print Network (OSTI)

Although Pd-Au high-surface area catalysts are used in industry to improve activity and selectivity, a thorough understanding of the nature of these enhancements is lacking. A molecular-level understanding of catalytic reactions under actual reaction conditions is the ultimate goal. This thesis is mainly focused on the application of Pd-Au supported catalysts for vinyl acetate synthesis and CO oxidation reactions using highsurface area catalysts. We have attempted to improve the conventional Pd-Au based catalyst by synthesizing novel acetate-based and polymer-based catalysts. The corresponding catalytic reactivity and selectivity were measured and compared to conventional Pd-Au based catalyst systems. Subsequent characterization was performed using characterization techniques, such as, X-ray diffraction (XRD) and transmission electron microscopy (TEM). From our bimetallic catalytic studies, it was evident that the addition of Au to Pd leads to increased reactivity and selectivity. This surface modification is an important factor in the altered reaction kinetics for vinyl acetate (VA) synthesis and CO oxidation reactions. Promoted and unpromoted Pd-Au/SiO2/K+ catalyst were used for VA synthesis and the effect of pre-adsorbed O2, acetic acid and the role of oxygen were explored. The VA reaction rate of novel acetate-based Pd-Au/SiO2 catalyst was 3.5 times higher than conventional Pd-Au catalysts. Also, 100% selectivity was obtained for acetate-based Pd-Au/SiO2 at 130 oC and the VA formation rate was comparable to that of conventional Pd-Au catalysts. Therefore, the acetate-based Pd-Au/SiO2 catalyst seems very promising and can be explored further. Also, Pd(1):Au(4)/SiO2 catalysts demonstrate 100% CO conversion at much lower temperatures (90 oC) compared with other Pd-Au based catalysts. Furthermore, we were successful in obtaining sufficient CO oxidation activity with increased metal loading (5 wt%) and these catalysts did not deactivate under above-ambient reaction temperature conditions, which make 1:4 Pd- Au/SiO2 catalyst a good candidate for further exploration in CO oxidation reactions.

Boopalachandran, Praveenkumar

69

Rare Earth Oxide Fluoride Nanoparticles And Hydrothermal Method For Forming Nanoparticles  

DOE Patents (OSTI)

A hydrothermal method for forming nanoparticles of a rare earth element, oxygen and fluorine has been discovered. Nanoparticles comprising a rare earth element, oxygen and fluorine are also described. These nanoparticles can exhibit excellent refractory properties as well as remarkable stability in hydrothermal conditions. The nanoparticles can exhibit excellent properties for numerous applications including fiber reinforcement of ceramic composites, catalyst supports, and corrosion resistant coatings for high-temperature aqueous solutions.

Fulton, John L. (Richland, WA); Hoffmann, Markus M. (Richland, WA)

2003-12-23T23:59:59.000Z

70

Catalysis of methanol-air mixture using platinum nanoparticles for microscale combustion  

Science Conference Proceedings (OSTI)

High surface area, active catalysts containing dispersed catalytic platinum nanoparticles (dp ?11.6 nm) on a cordierite substrate were fabricated and characterized using TEM, XRD, and SEM. The catalyst activity was evaluated for ...

James R. Applegate; Howard Pearlman; Smitesh D. Bakrania

2012-01-01T23:59:59.000Z

71

Catalyst activator  

DOE Patents (OSTI)

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

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

2001-01-01T23:59:59.000Z

72

Chemistry of Bimetallic Linked Cyclopentadienyl Complexes: Progress Report, 1 December 1986 --30 November 1989  

DOE R&D Accomplishments (OSTI)

Research continued on the chemistry and preparation of bimetallic cyclopentadienyl complexes containing up to two tungsten or one tungsten and a cobalt, rhodium, or ruthenium. The general method for preparation and analysis of polyenes is also discussed. (CBS)

Schrock, R. R.

1989-00-00T23:59:59.000Z

73

A Facile Synthesis of MPd (M=Co, Cu) Nanoparticles and Their Catalysis for Formic Acid Oxidation  

SciTech Connect

Monodisperse CoPd nanoparticles (NPs) were synthesized and studied for catalytic formic acid (HCOOH) oxidation (FAO). The NPs were prepared by coreduction of Co(acac)2 (acac = acetylacetonate) and PdBr2 at 260 C in oleylamine and trioctylphosphine, and their sizes (5-12 nm) and compositions (Co10Pd90 to Co60Pd40) were controlled by heating ramp rate, metal salt concentration, or metal molar ratios. The 8 nm CoPd NPs were activated for HCOOH oxidation by a simple ethanol wash. In 0.1 M HClO4 and 2 M HCOOH solution, their catalytic activities followed the trend of Co50Pd50 > Co60Pd40 > Co10Pd90 > Pd. The Co50Pd50 NPs had an oxidation peak at 0.4 V with a peak current density of 774 A/gPd. As a comparison, commercial Pd catalysts showed an oxidation peak at 0.75 V with peak current density of only 254 A/gPd. The synthesis procedure could also be extended to prepare CuPd NPs when Co(acac)2 was replaced by Cu(ac)2 (ac = acetate) in an otherwise identical condition. The CuPd NPs were less active catalysts than CoPd or even Pd for FAO in HClO4 solution. The synthesis provides a general approach to Pd-based bimetallic NPs and will enable further investigation of Pd-based alloy NPs for electro-oxidation and other catalytic reactions.

Mazumder, Vismadeb [Brown University; Chi, Miaofang [ORNL; Mankin, Max [Brown University; Liu, Yi [Brown University; Metin, Onder [Ataturk University; Sun, Daohua [Xiamen University, China; More, Karren Leslie [ORNL; Sun, Shouheng [Brown University

2012-01-01T23:59:59.000Z

74

Graphene bimetallic-like cantilevers: probing graphene/substrate interactions  

SciTech Connect

The remarkable mechanical properties of graphene the thinnest, lightest, and strongest material in existence are desirable in applications ranging from composite materials to sensors and actuators. Here, we demonstrate that these mechanical properties are strongly affected by the interaction with the substrate onto which graphene is deposited. By measuring the temperature-dependent deflection of graphene/substrate bimetallic cantilevers we determine strain, thermal expansion coefficient, and the adhesion force acting on graphene films attached to a substrate. Graphene deposited on silicon nitride (SiNx) is under much larger strain, g 1.5 10 2, compared to graphene on gold (Au), g < 10 3. The thermal expansion coefficient g of graphene attached to SiNx is found to be negative, in the range from ( 5 . . . 1) 10 6K 1 and smaller in magnitude than g of suspended graphene. We also estimate the interfacial shear strength of the graphene/SiNx interface to be 1 GPa at room temperature.

Conley, Hiram J [ORNL; Lavrik, Nickolay V [ORNL; Prasai, Dhiraj [Vanderbilt University; Bolotin, Kirill I [ORNL

2011-01-01T23:59:59.000Z

75

EFFECT OF PRETREATMENT ON PT-CO/C CATHODE CATALYSTS FOR THE OXYGEN-REDUCTION REACTION  

DOE Green Energy (OSTI)

In order to reduce the precious metal loading without sacrificing activity and stability, a new method for the preparation of bimetallic catalysts is proposed. Currently, Pt-alloy particles, with 2 to 3 nm in diameter, are loaded on high surface area carbon supports. Of the Pt loaded, only the surface atoms interact with the reactants. In order to increase the Pt utilization per metal particle the new process for catalyst preparation will incorporate a non-noble transition metal core coated with a skin layer of Pt deposited on high surface area carbon. The effect of reducing agent strength during synthesis was also explored. It was determined that the Co addition has a higher impact on catalyst when used with NaBH4 as reducing agent as compared to NaCOOH.

Fox, E.

2009-05-13T23:59:59.000Z

76

Solid Catalyst – Alkylation  

This is a method used to reactivate solid/liquid catalysts used in INL’s super critical process to produce alkylates. The method brings the catalyst ...

77

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.

Silva, Laura J. (Richland, WA); Bray, Lane A. (Richland, WA)

1995-01-01T23:59:59.000Z

78

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

79

Charge Effects on the Cu Pyramidal Nanoparticle and It's ...  

Science Conference Proceedings (OSTI)

In the chemical reaction, the different adsorption trend and sites are found in ... on the Cu Pyramidal Nanoparticle and It's Application as a CO2 Conversion Catalyst ... Performance Evaluation, Technical and Environmental Aspects of Biomass ...

80

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

DOE Green Energy (OSTI)

We present a combined experimental and theoretical approach to demonstrate how lattice strain can be used to continuously tune the catalytic activity of the oxygen reduction reaction (ORR) on bimetallic nanoparticles that have been dealloyed. The sluggish kinetics of the ORR is a key barrier to the adaptation of fuel cells and currently limits their widespread use. Dealloyed Pt-Cu bimetallic nanoparticles, however, have been shown to exhibit uniquely high reactivity for this reaction. We first present evidence for the formation of a core-shell structure during dealloying, which involves removal of Cu from the surface and subsurface of the precursor nanoparticles. We then show that the resulting Pt-rich surface shell exhibits compressive strain that depends on the composition of the precursor alloy. We next demonstrate the existence of a downward shift of the Pt d-band, resulting in weakening of the bond strength of intermediate oxygenated species due to strain. Finally, we combine synthesis, strain, and catalytic reactivity in an experimental/theoretical reactivity-strain relationship which provides guidelines for the rational design of strained oxygen reduction electrocatalysts. The stoichiometry of the precursor, together with the dealloying conditions, provides experimental control over the resulting surface strain and thereby allows continuous tuning of the surface electrocatalytic reactivity - a concept that can be generalized to other catalytic reactions.

Strasser, Peter

2011-08-19T23:59:59.000Z

Note: This page contains sample records for the topic "bimetallic nanoparticle catalysts" 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

Structure sensitive adsorption of hydrogen on ruthenium and ruthenium-silver catalysts supported on silica  

DOE Green Energy (OSTI)

Supported metal catalysts typically consist of particles with sizes less than 10 nm, and because of the small crystallite size, low coordination number sites (edges and corners) represent a significant fraction of all surface sites. Furthermore, it has been demonstrated that adsorption rates can be much greater at these low coordination sites than on basal plane sites. What has not been generally appreciated, however, is that preferential adsorption at edge and corner sites may explain the mechanism by which a promoter, or the addition of a second metal to form a bimetallic, can alter the selectivity and rate of reaction. For example, the measurements of hydrogen adsorption onto supported Ru-Ag catalysts show marked decreases in the amount of hydrogen adsorbed relative to the amount adsorbed on Ru catalysts. Although it is known that Ag does not dissociatively adsorb hydrogen, this decrease cannot be explained by a simple one-to-one site blocking mechanism unless Ag preferentially populates edges and corners, thereby reducing the number of Ru edge sites. Indeed, Monte Carlo simulations of Ru-Group IB metal catalysts predict that Group IB metal atoms preferentially populate corner and edge sites of ruthenium crystals. This evidence, taken together, suggests that adsorption occurs preferentially at Ru corner and edge sites, which act as portals onto basal planes. A model based on this portal theory for hydrogen adsorption onto supported ruthenium bimetallic catalysts has been developed using a rate equation approach. Specifically, the model accounts for the following features: (1) preferential adsorption through portals, (2) basal plane site-energy multiplicity, and (3) hydrogen spillover onto the support. A comparison of model predictions with experiment is presented for different concentration of Ag in Ru-Ag catalysts. The portal model of hydrogen adsorption can explain the observed decreased in the amount of hydrogen adsorbed on Ru-Ag catalysts. The model can be applied to understand the kinetics of ethane hydrogenolysis on Ru-Ag catalysts. The model is able to explain the change in the apparent order of hydrogenolysis reaction with respect to hydrogen from {minus}1.4 to {minus}2.4 when Ag is added to Ru/SiO{sub 2} catalyst.

Kumar, N.

1999-02-12T23:59:59.000Z

82

Tungsten Cathode Catalyst for PEMFC  

DOE Green Energy (OSTI)

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

Joel B. Christian; Sean P. E. Smith

2006-09-22T23:59:59.000Z

83

Glossary Term - Catalyst  

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

Bohr Radius Previous Term (Bohr Radius) Glossary Main Index Next Term (Ceres) Ceres Catalyst A catalyst is a substance that increases the speed of a chemical reaction without being...

84

Microbially Supported Synthesis of Catalytically Active Bimetallic Pd-Au Nanoparticles  

E-Print Network (OSTI)

(Spirulina) platensis nd + nd AAQ63961. Spirulina subsulsa nd + nd AAQ63962. Prochlorothrix hollandica nd be simplified so that the costs for producing the hydrogen are significantly below the price at which, especially oil, are depleted and the cost of fuel increases, the use of even relatively inefficient solar

Lovley, Derek

85

Reversible surface structural changes in Pt-based bimetallic nanoparticles during oxidation and reduction cycles  

E-Print Network (OSTI)

experiments were carried out under the conditions of catalytic reforming of kerosene in the same reactor

Bao, Xinhe

86

Catalyst Management Planning  

Science Conference Proceedings (OSTI)

Catalyst used in selective catalytic reduction (SCR) systems for NOx control in coal-fired power plants is susceptible to deactivation over time due to exposure to trace elements contained in the coal. In order to sustain the levels of NOx reduction needed to comply with regulatory requirements, periodic replacement of the catalyst modules with new or regenerated catalyst is an essential element in operating an SCR system. Catalyst management planning is a process whereby decisions are made about when ca...

2010-12-21T23:59:59.000Z

87

Surface Characterization of Heterogeneous Catalysts Using Low Energy Ion Scattering Spectroscopy Combined with Electrochemistry  

E-Print Network (OSTI)

Fundamental studies of heterogeneous catalysis were performed and presented in this dissertation to gain a better understanding of heterogeneous catalytic reactions at a molecular level. Surface science techniques were employed in achieving the goal. Low energy ion scattering spectroscopy (LEISS) is the main surface science technique which will be used in all the studies discussed throughout this dissertation. The main objectives of LEISS measurements are to: 1) obtain the information of surface composition of heterogeneous catalysts from the topmost layer; 2) observe the effects of reaction conditions on the surface composition of heterogeneous catalysts. The surface composition and morphology of Au-Pd clusters bimetallic model catalysts supported on SiO2 were characterized using LEISS, infrared reflection absorption spectroscopy (IRAS), and temperature programmed desorption (TPD). It is observed that relative to the bulk, the surface of the clusters is enriched in Au. Ethylene adsorption and dehydrogenation show a clear structure-reactivity correlation with respect to the structure/composition of these Au-Pd model catalysts. Fundamental studies of heterogeneous catalysis were performed and presented in this dissertation to gain a better understanding of heterogeneous catalytic reactions at a molecular level. Surface science techniques were employed in achieving the goal. Low energy ion scattering spectroscopy (LEISS) is the main surface science technique which will be used in all the studies discussed throughout this dissertation. The main objectives of LEISS measurements are to: 1) obtain the information of surface composition of heterogeneous catalysts from the topmost layer; 2) observe the effects of reaction conditions on the surface composition of heterogeneous catalysts. The surface composition and morphology of Au-Pd clusters bimetallic model catalysts supported on SiO2 were characterized using LEISS, infrared reflection absorption spectroscopy (IRAS), and temperature programmed desorption (TPD). It is observed that relative to the bulk, the surface of the clusters is enriched in Au. Ethylene adsorption and dehydrogenation show a clear structure-reactivity correlation with respect to the structure/composition of these Au-Pd model catalysts.

Axnanda, Stephanus R.

2009-12-01T23:59:59.000Z

88

DNA-guided nanoparticle assemblies  

DOE Patents (OSTI)

In some embodiments, DNA-capped nanoparticles are used to define a degree of crystalline order in assemblies thereof. In some embodiments, thermodynamically reversible and stable body-centered cubic (bcc) structures, with particles occupying <.about.10% of the unit cell, are formed. Designs and pathways amenable to the crystallization of particle assemblies are identified. In some embodiments, a plasmonic crystal is provided. In some aspects, a method for controlling the properties of particle assemblages is provided. In some embodiments a catalyst is formed from nanoparticles linked by nucleic acid sequences and forming an open crystal structure with catalytically active agents attached to the crystal on its surface or in interstices.

Gang, Oleg; Nykypanchuk, Dmytro; Maye, Mathew; van der Lelie, Daniel

2013-07-16T23:59:59.000Z

89

Method Development to Evaluate the Oxygen Reduction Activity of High-Surface-Area Catalysts for Li-Air Batteries  

E-Print Network (OSTI)

This study presents a new method to quantitatively determine the electrocatalytic activity of Vulcan carbon and Vulcan-supported Au nanoparticles, dispersed as catalyst thin films on glass carbon, for oxygen reduction in ...

Lu, Yi-Chun

90

System for reactivating catalysts  

DOE Patents (OSTI)

A method of reactivating a catalyst, such as a solid catalyst or a liquid catalyst is provided. The method comprises providing a catalyst that is at least partially deactivated by fouling agents. The catalyst is contacted with a fluid reactivating agent that is at or above a critical point of the fluid reactivating agent and is of sufficient density to dissolve impurities. The fluid reactivating agent reacts with at least one fouling agent, releasing the at least one fouling agent from the catalyst. The at least one fouling agent becomes dissolved in the fluid reactivating agent and is subsequently separated or removed from the fluid reactivating agent so that the fluid reactivating agent may be reused. A system for reactivating a catalyst is also disclosed.

Ginosar, Daniel M. (Idaho Falls, ID); Thompson, David N. (Idaho Falls, ID); Anderson, Raymond P. (Idaho Falls, ID)

2010-03-02T23:59:59.000Z

91

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 and compared to that on pure Pt surfaces. Reactivity is evaluated on the basis of the adsorption strength of oxygenated compounds which are intermediate species of the four-electron oxygen reduction reaction, separating the effect of the first electron-proton transfer from that of the three last electron-proton transfer steps. It is found that most homogeneous distribution PtxM catalysts thermodynamically favor the dissociation of adsorbed OOH in comparison with pure Platinum and adsorb strongly O and OH due to the strong oxyphilicity of the M elements. On the other hand, in all cases skin Platinum surfaces catalysts do not favor the dissociation of adsorbed OOH and do favor the reduction of M-O and M-OH with respect to Platinum. Considering the overall pathway of the reactions to catalyze the ORR most of the skin Platinum monolayer catalysts provide more negative free energy changes and should behave at least in a similar way than Platinum in following order: Pt3V (skin Pt) > Pt3Co (skin Pt) > Pt3Ni (skin Pt) > Pt > PtPd (skin) > Pt4Rh (skin Pt) > PtPd3 (skin ). In all cases, the reactivity is shown to be not only sensitive to the overall composition of the catalyst, but most importantly to the surface atomic distribution. Proposed electrochemical dissolution reactions of the catalyst atoms are also analyzed for the ORR catalysts, by computing the free energy changes of Platinum and bimetallic Pt-X (X: Co, Pd, Ni, and Rh) catalysts. It is found that Platinum is thermodynamically more stable than Pt-alloys in Pt3Co, Pt3Pd, Pt3Ni and Pt4Rh.

Calvo, Sergio Rafael

2007-12-01T23:59:59.000Z

92

Methods of making textured catalysts  

SciTech Connect

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

93

Validation of Two Hydrocodes with a Bi-Metallic Shaped Charge Experiment  

SciTech Connect

Staggered grid (SGH) and cell-centered (CCH) Lagrangian Hydro are two approaches to modeling high explosives (HE) experiments. HE experiments involve complex flows. For example, the discontinuity in the tangential velocity across a frictionless contact surface. In this work, the SGH and CCH schemes with a contact surface algorithm are used to simulate a bimetallic shaped charge experiment using FLAG. Experiment will be performed at LANL in the coming year and used to validate the SGH and CCH schemes results.

Ingraham, Daniel J. [Los Alamos National Laboratory

2012-08-16T23:59:59.000Z

94

METHOD OF PURIFYING CATALYSTS  

DOE Patents (OSTI)

It has been fuund that the presence of chlorine as an impurity adversely affects the performance of finely divided platinum catalysts such as are used in the isotopic exchange process for the production of beavy water. This chlorine impurity may be removed from these catalysts by treating the catalyst at an elevated temperature with dry hydrogen and then with wet hydrogen, having a hydrogen-water vapor volume of about 8: 1. This alternate treatment by dry hydrogen and wet hydrogen is continued until the chlorine is largely removed from the catalyst.

Joris, G.G.

1958-09-01T23:59:59.000Z

95

Tuning the porosity of bimetallic nanostructures by a soft templating approach  

E-Print Network (OSTI)

We use hexagonal mesophases made of oil-swollen surfactant-stabilized tubes arranged on a triangular lattice in water and doped with metallic salts as templates for the radiolytic synthesis of nanostructures. The nanostructures formed in this type of soft matrix are bimetallic palladium-platinum porous nanoballs composed of 3D-connected nanowires, of typical thickness 2.5 nm, forming hexagonal cells. We demonstrate using electron microscopy and small-angle X-ray scattering that the pore size of the nanoballs is directly determined by the diameter of the oil tube of the doped mesophases, which we have varied in a controlled fashion from 10 to 55 nm. Bimetallic nanostructures comprising various proportions of palladium and platinum can be synthesized. Their alloy structure was evidenced by X-ray photoelectron spectroscopy, energy-dispersive X-ray spectroscopy, and high-angular dark field scanning transmission electron microscopy experiments. Our templating approach allows therefore the synthesis of bimetallic nanoballs of tunable porosity and composition.

Anaïs Lehoux; Laurence Ramos; Patricia Beaunier; Daniel Bahena Uribe; Philippe Dieudonné; Fabrice Audonnet; Arnaud Etcheberry; Miguel José-Yacaman; Hynd Remita

2012-12-05T23:59:59.000Z

96

Nanoparticle Metrology  

Science Conference Proceedings (OSTI)

... Demonstrated more than an order of magnitude improvement in the ability to trap and manipulate nanoparticles while enhancing positioning ...

2013-04-19T23:59:59.000Z

97

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

98

Final Technical Report on DE-SC00002460 [Bimetallic or trimetallic materials with structural metal centers based on Mn, Fe or V  

DOE Green Energy (OSTI)

Bimetallic or trimetallic materials with structural metal centers based on Mn, Fe or V were investigated under this project. These metal centers are the focus of this research as they have high earth abundance and have each shown success as cathode materials in lithium batteries. Silver ion, Ag{sup +}, was initially selected as the displacement material as reduction of this center should result in increased conductivity as Ag{sup 0} metal particles are formed in-situ upon electrochemical reduction. The in-situ formation of metal nanoparticles upon electrochemical reduction has been previously noted, and more recently, we have investigated the resulting increase in conductivity. Layered materials as well as materials with tunnel or channel type structures were selected. Layered materials are of interest as they can provide 2-dimensional ion mobility. Tunnel or channel structures are also of interest as they provide a rigid framework that should remain stable over many discharge/charge cycles. We describe some examples of materials we have synthesized that demonstrate promising electrochemistry.

Takeuchi, Esther Sans [Stony Brook University; Takeuchi, Kenneth James [Stony Brook University; Marschilok, Amy Catherine [Stony Brook University

2013-07-26T23:59:59.000Z

99

Balance of Nanostructure and Bimetallic Interactions in Pt Model Fuel Cell Catalysts: An in Situ XAS and DFT Study  

DOE Green Energy (OSTI)

We have studied the effect of nanostructuring in Pt monolayer model electrocatalysts on a Rh(111) single-crystal substrate on the adsorption strength of chemisorbed species. In situ high energy resolution fluorescence detection X-ray absorption spectroscopy at the Pt L(3) edge reveals characteristic changes of the shape and intensity of the 'white-line' due to chemisorption of atomic hydrogen (H(ad)) at low potentials and oxygen-containing species (O/OH(ad)) at high potentials. On a uniform, two-dimensional Pt monolayer grown by Pt evaporation in ultrahigh vacuum, we observe a significant destabilization of both H(ad) and O/OH(ad) due to strain and ligand effects induced by the underlying Rh(111) substrate. When Pt is deposited via a wet-chemical route, by contrast, three-dimensional Pt islands are formed. In this case, strain and Rh ligand effects are balanced with higher local thickness of the Pt islands as well as higher defect density, shifting H and OH adsorption energies back toward pure Pt. Using density functional theory, we calculate O adsorption energies and corresponding local ORR activities for fcc 3-fold hollow sites with various local geometries that are present in the three-dimensional Pt islands.

Friebel, Daniel; Viswanathan, Venkatasubramanian; Miller, Daniel James; Anniyev, Toyli; Ogasawara, Hirohito; Larsen, Ask Hjorth; O'Grady, Christopher P.; Norskov, Jens K.; Nilsson, Anders

2012-05-31T23:59:59.000Z

100

MgO-Supported Cluster Catalysts with Pt-Ru Interactions Prepared from Pt3Ru6(CO)21(u3-H)(u-H)3  

Science Conference Proceedings (OSTI)

Bimetallic MgO-supported catalysts were prepared by adsorption of Pt{sub 3}Ru{sub 6}(CO){sub 21}({mu}{sub 3}-H)({mu}-H){sub 3} on porous MgO. Characterization of the supported clusters by infrared (IR) spectroscopy showed that the adsorbed species were still in the form of metal carbonyls. The supported clusters were decarbonylated by treatment in flowing helium at 300 C, as shown by IR and extended X-ray absorption fine structure (EXAFS) data, and the resulting supported PtRu clusters were shown by EXAFS spectroscopy to have metal frames that retained Pt-Ru bonds but were slightly restructured relative to those of the precursor; the average cluster size was almost unchanged as a result of the decarbonylation. These are among the smallest reported bimetallic clusters of group-8 metals. The decarbonylated sample catalyzed ethylene hydrogenation with an activity similar to that reported previously for {gamma}-Al{sub 2}O{sub 3}-supported clusters prepared in nearly the same way and having nearly the same structure. Both samples were also active for n-butane hydrogenolysis, with the MgO-supported catalyst being more active than the {gamma}-Al{sub 2}O{sub 3}-supported catalyst.

Chotisuwan,S.; Wittapyakun, J.; Lobo-Lapidus, R.; Gates, B.

2007-01-01T23:59:59.000Z

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


101

Degradation of Bimetallic Model Electrocatalysts ___ an in situ XAS Study  

DOE Green Energy (OSTI)

One of the major challenges in the development of clean energy fuel cells is the performance degradation of the electrocatalyst, which, apart from poisoning effects, can suffer from corrosion due to its exposure to a harsh environment under high potentials. In this communication, we demonstrate how interactions of Pt with a transition metal support affect not only, as commonly intended, the catalytic activity, but also the reactivity of Pt towards oxide formation or dissolution. We use two well-defined single-crystal model systems, Pt/Rh(111) and Pt/Au(111) and a unique x-ray spectroscopy technique with enhanced energy resolution to monitor the potential-dependent oxidation state of Pt, and find two markedly different oxidation mechanisms on the two different substrates. This information can be of great significance for future design of more active and more stable catalysts. We have studied the potential-induced degradation of Pt monolayer model electrocatalysts on Rh(111) and Au(111) single-crystal substrates. The anodic formation of Pt oxides was monitored using in situ high energy resolution fluorescence detection x-ray absorption spectroscopy (HERFD XAS). Although Pt was deposited on both substrates in a three-dimensional island growth mode, we observed remarkable differences during oxide formation that can only be understood in terms of strong Pt-substrate interactions throughout the Pt islands. Anodic polarization of Pt/Rh(111) up to +1.6 V vs. RHE (reversible hydrogen electrode) leads to formation an incompletely oxidized passive layer, whereas formation of PtO2 and partial Pt dissolution is observed for Pt/Au(111).

Friebel, Daniel

2011-06-22T23:59:59.000Z

102

1: Redox chemistry of bimetallic fulvalene complexes; 2: Oligocyclopentadienyl complexes  

Science Conference Proceedings (OSTI)

The electrochemistry of the heterobimetallic complexes (fulvalene)WFe(CO){sub 5} (30) and (fulvalene)WRu(CO){sub 5} (31) has been investigated. Compound 30 is reduced in two one-electron processes, and this behavior was exploited synthetically to prepare a tetranuclear dimer by selective metal reduction. Complex 31 displayed a distinction between the metals upon reoxidation of the dianion, allowing the formation of a dimer by selective metal anion oxidation. The redox behavior of 30 led to an investigation of the use of electrocatalysis to effect metal-specific ligand substitution. It was found that reduction of 30 with a catalytic amount of CpFe(C{sub 6}Me{sub 6}) (97) in the presence of excess P(OMe){sub 3} or PMe{sub 3} led to the formation of the zwitterions (fulvalene)[W(CO){sub 3}{sup {minus}}][Fe(CO)PR{sub 3}{sup +}] (107, R = P(OMe){sub 3}; 108, R = PMe{sub 3}). Compound 31 also displayed unique behavior with different reducing agents, as the monosubstituted zwitterion (fulvalene)[W(CO){sub 3}{sup {minus}}][Ru(CO){sub 2}(PMe{sub 3}){sup +}] was obtained when 97 was used while the disubstituted complex (fulvalene) [W(CO){sub 3}{sup {minus}}] [Ru(CO)(PMe{sub 3}){sub 2}{sup +}] was produced when Cp*Fe(C{sub 6}Me{sub 6}) was the catalyst. Potential synthetic routes to quatercyclopentadienyl complexes were also explored. Various attempts to couple heterobimetallic fulvalene compounds proved to be unsuccessful. 138 refs.

Brown, D.S. [Univ. of California, Berkeley, CA (United States). Dept. of Chemistry]|[Lawrence Berkeley Lab., CA (United States). Chemical Sciences Div.

1993-11-01T23:59:59.000Z

103

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

104

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

105

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)

2010-06-29T23:59:59.000Z

106

Uranium-Based Catalysts  

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

Uranium-Based Catalysts S. H. Overbury, Cyrus Riahi-Nezhad, Zongtao Zhang, Sheng Dai, and Jonathan Haire Oak Ridge National Laboratory* P.O. Box 2008 Oak Ridge, Tennessee...

107

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

108

Catalysts and method  

DOE Patents (OSTI)

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

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

1991-01-01T23:59:59.000Z

109

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, hydrosilation, olefin oxidation, isomerization, hydrocyanation, 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.

Angelici, Robert J. (Ames, IA); Gao, Hanrong (Ames, IA)

1998-08-04T23:59:59.000Z

110

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, Rayford G. (Bryan, TX); Dosch, Robert G. (Albuquerque, NM)

1993-01-01T23:59:59.000Z

111

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.

1991-12-31T23:59:59.000Z

112

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

113

Plasmatron-catalyst system  

DOE Patents (OSTI)

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

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

2007-10-09T23:59:59.000Z

114

Catalytic reforming catalyst  

Science Conference Proceedings (OSTI)

An improved catalyst, having a reduced fouling rate when used in a catalytic reforming process, said catalyst comprising platinum disposed on an alumina support wherein the alumina support is obtained by removing water from aluminum hydroxide produced as a by-product from a ziegler higher alcohol synthesis reaction, and wherein the alumina is calcined at a temperature of 1100-1400/sup 0/F so as to have a surface area of 165 to 215 square meters per gram.

Buss, W.C.; Kluksdahl, H.E.

1980-12-09T23:59:59.000Z

115

Catalyst Modeling and CLEERS - Emissions & Emission Controls...  

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

Catalyst Modeling and CLEERS A large part of ORNL's efforts in catalyst research are geared toward model development of catalyst devices and engine systems. Experimental data...

116

Design of graphene sheets-supported Pt catalyst layer in PEM fuel cells  

DOE Green Energy (OSTI)

A series of cathodes using Pt supported onto graphene sheets with different contents of carbon black in the catalyst layer were prepared and characterized. Carbon black was added as a spacer between two-dimensional graphene sheets in the catalyst layer to study its effect on the performances of proton exchange membrane fuel cell. Electrochemical properties and surface morphology of the cathodes with and without carbon black were characterized using cyclic voltammetry, ac-impedance spectroscopy, electrochemical polarization technique, and scanning electron microscopy. The results indicated that carbon black effectively modifies the array of graphene supports, resulting in more Pt nanoparticles available for electrochemical reaction and better mass transport in the catalyst layer.

Park, Seh K.; Shao, Yuyan; Wan, Haiying; Rieke, Peter C.; Viswanathan, Vilayanur V.; Towne, Silas A.; Saraf, Laxmikant V.; Liu, Jun; Lin, Yuehe; Wang, Yong

2011-03-01T23:59:59.000Z

117

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

Science Conference Proceedings (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

P. K. Gupta

2013-01-01T23:59:59.000Z

118

Supported organoiridium catalysts for alkane dehydrogenation  

DOE Patents (OSTI)

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

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

2013-09-03T23:59:59.000Z

119

Size Effect of Ruthenium Nanoparticles in Catalytic Carbon Monoxide Oxidation  

Science Conference Proceedings (OSTI)

Carbon monoxide oxidation over ruthenium catalysts has shown an unusual catalytic behavior. Here we report a particle size effect on CO oxidation over Ru nanoparticle (NP) catalysts. Uniform Ru NPs with a tunable particle size from 2 to 6 nm were synthesized by a polyol reduction of Ru(acac){sub 3} precursor in the presence of poly(vinylpyrrolidone) stabilizer. The measurement of catalytic activity of CO oxidation over two-dimensional Ru NPs arrays under oxidizing reaction conditions (40 Torr CO and 100 Torr O{sub 2}) showed an activity dependence on the Ru NP size. The CO oxidation activity increases with NP size, and the 6 nm Ru NP catalyst shows 8-fold higher activity than the 2 nm catalysts. The results gained from this study will provide the scientific basis for future design of Ru-based oxidation catalysts.

Joo, Sang Hoon; Park, Jeong Y.; Renzas, J. Russell; Butcher, Derek R.; Huang, Wenyu; Somorjai, Gabor A.

2010-04-04T23:59:59.000Z

120

Stabilization of Electrocatalytic Metal Nanoparticles at Metal-Metal Oxide-Graphene Triple Junction Points  

DOE Green Energy (OSTI)

Carbon-supported metal catalysts are widely used in heterogeneous catalysis and electrocatalysis. In this paper, we report a novel method to deposit metal catalysts and metal oxide nanoparticles on two-dimensional graphene sheets to improve the catalytic performance and stability of the catalyst materials. The new synthesis method allows indium tin oxide (ITO) nanocrystals to be directly grown on functionalized graphene sheets forming the ITO-graphene hybrids. Pt nanoparticles are then deposited to form a special triple-junction structure (Pt-ITO-graphene). Both experimental study and periodic density functional theory calculations show that the supported Pt nanoparticles are stable at Pt-ITO-graphene triple junction points. The new catalyst materials were tested for oxygen reduction for potential applications in polymer electrolyte membrane fuel cells, and they exhibited greatly enhanced stability and activity. The reasons for the high stability and activity of Pt-ITO-graphene are analyzed.

Kou, Rong; Shao, Yuyan; Mei, Donghai; Nie, Zimin; Wang, Donghai; Wang, Chong M.; Viswanathan, Vilayanur V.; Park, Seh K.; Aksay, Ilhan A.; Lin, Yuehe; Wang, Yong; Liu, Jun

2011-03-02T23:59:59.000Z

Note: This page contains sample records for the topic "bimetallic nanoparticle catalysts" 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

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

2002-08-27T23:59:59.000Z

122

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

123

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)

2004-07-13T23:59:59.000Z

124

Partial oxidation catalyst  

DOE Patents (OSTI)

A two-part catalyst comprising a dehydrogenation portion and an oxide-ion conducting portion. The dehydrogenation portion is a group VIII metal and the oxide-ion conducting portion is selected from a ceramic oxide crystallizing in the fluorite or perovskite structure. There is also disclosed a method of forming a hydrogen rich gas from a source of hydrocarbon fuel in which the hydrocarbon fuel contacts a two-part catalyst comprising a dehydrogenation portion and an oxide-ion conducting portion at a temperature not less than about 400.degree. C. for a time sufficient to generate the hydrogen rich gas while maintaining CO content less than about 5 volume percent. There is also disclosed a method of forming partially oxidized hydrocarbons from ethanes in which ethane gas contacts a two-part catalyst comprising a dehydrogenation portion and an oxide-ion conducting portion for a time and at a temperature sufficient to form an oxide.

Krumpelt, Michael (Naperville, IL); Ahmed, Shabbir (Bolingbrook, IL); Kumar, Romesh (Naperville, IL); Doshi, Rajiv (Downers Grove, IL)

2000-01-01T23:59:59.000Z

125

Intermittency on catalysts  

E-Print Network (OSTI)

The present paper provides an overview of results obtained in four recent papers by the authors. These papers address the problem of intermittency for the Parabolic Anderson Model in a \\emph{time-dependent random medium}, describing the evolution of a ``reactant'' in the presence of a ``catalyst''. Three examples of catalysts are considered: (1) independent simple random walks; (2) symmetric exclusion process; (3) symmetric voter model. The focus is on the annealed Lyapunov exponents, i.e., the exponential growth rates of the successive moments of the reactant. It turns out that these exponents exhibit an interesting dependence on the dimension and on the diffusion constant.

J. Gaertner; F. den Hollander; G. Maillard

2007-06-08T23:59:59.000Z

126

Intermittency on catalysts  

E-Print Network (OSTI)

The present paper provides an overview of results obtained in four recent papers by the authors. These papers address the problem of intermittency for the Parabolic Anderson Model in a \\emph{time-dependent random medium}, describing the evolution of a 'reactant'' in the presence of a ``catalyst''. Three examples of catalysts are considered: (1) independent simple random walks; (2) symmetric exclusion process; (3) symmetric voter model. The focus is on the annealed Lyapunov exponents, i.e., the exponential growth rates of the successive moments of the reactant. It turns out that these exponents exhibit an interesting dependence on the dimension and on the diffusion constant.

Gärtner, J; Maillard, G

2007-01-01T23:59:59.000Z

127

Process of making supported catalyst  

DOE Patents (OSTI)

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

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

1992-01-01T23:59:59.000Z

128

Structural and Electrocatalytic Properties of PtIrCo/C Catalysts for Oxygen Reduction Reaction  

Science Conference Proceedings (OSTI)

This paper describes the results of an investigation of the synthesis of PtIrCo nanoparticles (2-3 nm) for electrocatalytic oxygen reduction reaction. The carbon-supported PtIrCo catalysts (PtIrCo/C) were thermally treated at temperatures ranging from 400 to 900 C. The size, composition, and atomic-scale structures of the PtIrCo/C catalysts were characterized for establishing their correlation with the electrocatalytic activity toward oxygen reduction reaction. The specific activity was found to increase by a factor of 3-5 for the PtIrCo/C catalysts in comparison with Pt/C catalysts. A correlation was identified between the specific activity and the nanoparticle's fcc-type lattice parameter. The specific activity increases whereas the fcc-type lattice parameter decreases with the thermal treatment temperature. This correlation was further substantiated by analyzing the interatomic spatial parameters in the trimetallic nanoparticles based on X-ray absorption fine structure spectroscopic and high-energy XRD experiments. Implications of these findings, along with the durability of the catalysts, to the design of active electrocatalysts were also discussed.

Loukrakpam, Rameshwori; Wanjala, Bridgid N.; Yin, Jun; Fang, Bin; Luo, Jin; Shao, Minhua; Protsailo, Lesia; Kawamura, Tetsuo; Chen, Yongsheng; Petkov, Valeri; Zhong, Chuan-Jian (CMU); (SUNY-Binghamton); (UTC Power); (Toyota); (Penn)

2011-08-29T23:59:59.000Z

129

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

130

Catalysts for hydrocarbon conversion  

Science Conference Proceedings (OSTI)

Catalyst, particularly useful in catalytic reforming and for producing highly pure aromatic hydrocarbons, comprising an alumina carrier and containing, expressed in proportion of the weight of the alumina carrier: 005 to 1% of platinum 01 to 4% of gallium, indium or thallium 01 to 2% of tungsten, and 1 to 10% of halogen.

Le P. J.; Malmaison, R.; Marcilly, C.; Martino, G.; Miquel, J.

1980-08-12T23:59:59.000Z

131

Sulfur condensation in Claus catalyst  

SciTech Connect

The heterogeneous reactions in which catalyst deactivation by pore plugging occur are listed and include: coke formation in petroleum processing, especially hydrocracking and hydrodesulfurization catalysts; steam reforming and methnation catalysts; ammonia synthesis catalyst; and automobile exhause catalysts. The authors explain how the Claus process converts hydrogen sulfide produced by petroleum desulfurization units and gas treatment processes into elemental sulfur and water. More than 15 million tons of sulfur are recovered annually by this process. Commercial Claus plants appear to operate at thermodynamic equilibrium. Depending on the H2S content of the feed and the number of reactors, total H2S conversion to elemental sulfur can exceed 95%.

Schoffs, G.R.

1985-02-01T23:59:59.000Z

132

Molybdenum sulfide/carbide catalysts  

DOE Patents (OSTI)

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

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

2007-05-29T23:59:59.000Z

133

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,

134

C47 Thermal Analysis of a Bi-Metallic Chill Vent for High Pressure ...  

Science Conference Proceedings (OSTI)

D14 Gold Nanoparticles in Red Ruby Glasses Used for Decoration in Thailand · D15 Soft Magnetic Properties of Nanocrystalline Fe-based P/M Cores Mixed ...

135

Binary ferrihydrite catalysts  

DOE Patents (OSTI)

A method of preparing a catalyst precursor comprises dissolving an iron salt and a salt of an oxoanion forming agent, in water so that a solution of the iron salt and oxoanion forming agent salt has a ratio of oxoanion/Fe of between 0.0001:1 to 0.5:1. Next is increasing the pH of the solution to 10 by adding a strong base followed by collecting of precipitate having a binary ferrihydrite structure. A binary ferrihydrite catalyst precursor is also prepared by dissolving an iron salt in water. The solution is brought to a pH of substantially 10 to obtain ferrihydrite precipitate. The precipitate is then filtered and washed with distilled water and subsequently admixed with a hydroxy carboxylic acid solution. The admixture is mixed/agitated and the binary ferrihydrite precipitate is then filtered and recovered. 3 figs.

Huffman, G.P.; Zhao, J.; Feng, Z.

1996-12-03T23:59:59.000Z

136

Fluorination process using catalysts  

DOE Patents (OSTI)

A process is given for converting an actinide compound selected from the group consisting of uranium oxides, plutonium oxides, uranium tetrafluorides, plutonium tetrafluorides and mixtures of said oxides and tetrafluorides, to the corresponding volatile actinide hexafluoride by fluorination with a stoichiometric excess of fluorine gas. The improvement involves conducting the fluorination of the plutonium compounds in the presence of a fluoride catalyst selected from the group consisting of CoF/sub 3/, AgF/sub 2/ and NiF/sub 2/, whereby the fluorination is significantly enhanced. The improvement also involves conducting the fluorination of one of the uranium compounds in the presence of a fluoride catalyst selected from the group consisting of CoF/sub 3/ and AgF/sub 2/, whereby the fluorination is significantly enhanced.

Hochel, R.C.; Saturday, K.A.

1983-08-25T23:59:59.000Z

137

Binary ferrihydrite catalysts  

DOE Patents (OSTI)

A method of preparing a catalyst precursor comprises dissolving an iron salt and a salt of an oxoanion forming agent, in water so that a solution of the iron salt and oxoanion forming agent salt has a ratio of oxoanion/Fe of between 0.0001:1 to 0.5:1. Next is increasing the pH of the solution to 10 by adding a strong base followed by collecting of precipitate having a binary ferrihydrite structure. A binary ferrihydrite catalyst precursor is also prepared by dissolving an iron salt in water. The solution is brought to a pH of substantially 10 to obtain ferrihydrite precipitate. The precipitate is then filtered and washed with distilled water and subsequently admixed with a hydroxy carboxylic acid solution. The admixture is mixed/agitated and the binary ferrihydrite precipitate is then filtered and recovered.

Huffman, Gerald P. (Lexington, KY); Zhao, Jianmin (Lexington, KY); Feng, Zhen (Lexington, KY)

1996-01-01T23:59:59.000Z

138

Fluorination process using catalyst  

DOE Patents (OSTI)

A process for converting an actinide compound selected from the group consisting of uranium oxides, plutonium oxides, uranium tetrafluorides, plutonium tetrafluorides and mixtures of said oxides and tetrafluorides, to the corresponding volatile actinide hexafluoride by fluorination with a stoichiometric excess of fluorine gas. The improvement involves conducting the fluorination of the plutonium compounds in the presence of a fluoride catalyst selected from the group consisting of CoF.sub.3, AgF.sub.2 and NiF.sub.2, whereby the fluorination is significantly enhanced. The improvement also involves conducting the fluorination of one of the uranium compounds in the presence of a fluoride catalyst selected from the group consisting of CoF.sub.3 and AgF.sub.2, whereby the fluorination is significantly enhanced.

Hochel, Robert C. (Aiken, SC); Saturday, Kathy A. (Aiken, SC)

1985-01-01T23:59:59.000Z

139

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

140

Oxygen-reducing catalyst layer  

DOE Patents (OSTI)

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

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

2011-03-22T23:59:59.000Z

Note: This page contains sample records for the topic "bimetallic nanoparticle catalysts" 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

Catalyst Renewables | Open Energy Information  

Open Energy Info (EERE)

Zip 75204 Product Pursue projects with low technical risk, stable fuel supply and prices, and long-term power purchase agreements References Catalyst Renewables1 LinkedIn...

142

Mixed Alcohol Synthesis Catalyst Screening  

DOE Green Energy (OSTI)

National Renewable Energy Laboratory (NREL) and Pacific Northwest National Laboratory (PNNL) are conducting research to investigate the feasibility of producing mixed alcohols from biomass-derived synthesis gas (syngas). PNNL is tasked with obtaining commercially available or preparing promising mixed-alcohol catalysts and screening them in a laboratory-scale reactor system. Commercially available catalysts and the most promising experimental catalysts are provided to NREL for testing using a slipstream from a pilot-scale biomass gasifier. From the standpoint of producing C2+ alcohols as the major product, it appears that the rhodium catalyst is the best choice in terms of both selectivity and space-time yield (STY). However, unless the rhodium catalyst can be improved to provide minimally acceptable STYs for commercial operation, mixed alcohol synthesis will involve significant production of other liquid coproducts. The modified Fischer-Tropsch catalyst shows the most promise for providing both an acceptable selectivity to C2+ alcohols and total liquid STY. However, further optimization of the Fischer-Tropsch catalysts to improve selectivity to higher alcohols is highly desired. Selection of a preferred catalyst will likely entail a decision on the preferred coproduct slate. No other catalysts tested appear amenable to the significant improvements needed for acceptable STYs.

Gerber, Mark A.; White, James F.; Stevens, Don J.

2007-09-03T23:59:59.000Z

143

Water Uptake in PEMFC Catalyst Layers  

E-Print Network (OSTI)

Water Uptake in PEMFC Catalyst Layers H. P. Gunterman, a A.membrane fuel-cell catalyst layers are characterized in thecurves indicate that the catalyst layers tested are highly

Gunterman, Haluna P.

2013-01-01T23:59:59.000Z

144

Cisco Catalyst 4503-E, Catalyst 4506-E, Catalyst 4507R-E ...  

Science Conference Proceedings (OSTI)

... The following figures illustrate the installation of the opacity shields for each platform. Figure 5: Catalyst 4503-E Opacity Shield Installation Page 23. ...

2013-07-18T23:59:59.000Z

145

Novel Reforming Catalysts  

Science Conference Proceedings (OSTI)

Aqueous phase reforming is useful for processing oxygenated hydrocarbons to hydrogen and other more useful products. Current processing is hampered by the fact that oxide based catalysts are not stable under high temperature hydrothermal conditions. Silica in the form of structured MCM-41 is thermally a more stable support for Co and Ni than conventional high surface area amorphous silica but hydrothermal stability is not demonstrated. Carbon nanotube supports, in contrast, are highly stable under hydrothermal reaction conditions. In this project we show that carbon nanotubes are stable high activity/selectivity supports for the conversion of ethylene glycol to hydrogen.

Pfefferle, Lisa D; Haller, Gary L

2012-10-16T23:59:59.000Z

146

Molecular water oxidation catalyst  

DOE Patents (OSTI)

A dimeric composition of the formula: ##STR1## wherein L', L", L'", and L"" are each a bidentate ligand having at least one functional substituent, the ligand selected from bipyridine, phenanthroline, 2-phenylpyridine, bipyrimidine, and bipyrazyl and the functional substituent selected from carboxylic acid, ester, amide, halogenide, anhydride, acyl ketone, alkyl ketone, acid chloride, sulfonic acid, phosphonic acid, and nitro and nitroso groups. An electrochemical oxidation process for the production of the above functionally substituted bidentate ligand diaqua oxo-bridged ruthenium dimers and their use as water oxidation catalysts is described.

Gratzel, Michael (St. Sulpice, CH); Munavalli, Shekhar (Bel Air, MD); Pern, Fu-Jann (Lakewood, CO); Frank, Arthur J. (Lakewood, CO)

1993-01-01T23:59:59.000Z

147

Water Uptake in PEMFC Catalyst Layers  

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

Water Uptake in PEMFC Catalyst Layers Title Water Uptake in PEMFC Catalyst Layers Publication Type Journal Article LBNL Report Number LBNL-5322E Year of Publication 2011 Authors...

148

Non-Noble Metal Water Electrolysis Catalysts  

This invention comprises an inexpensive catalyst system for water electrolyzers by replacing the noble-metal catalysts that are typically used in ...

149

Transition metal sulfide loaded catalyst  

DOE Patents (OSTI)

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

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

1994-04-26T23:59:59.000Z

150

Transition metal sulfide loaded catalyst  

DOE Patents (OSTI)

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

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

1994-01-01T23:59:59.000Z

151

Gold-Copper Nanoparticles: Nanostructural Evolution and Bifunctional Catalytic Sites  

Science Conference Proceedings (OSTI)

Understanding of the atomic-scale structure is essential for exploiting the unique catalytic properties of any nanoalloy catalyst. This report describes novel findings of an investigation of the nanoscale alloying of gold-copper (AuCu) nanoparticles and its impact on the surface catalytic functions. Two pathways have been explored for the formation of AuCu nanoparticles of different compositons, including wet chemical synthesis from mixed Au- and Cu-precursor molecules, and nanoscale alloying via an evolution of mixed Au- and Cu-precursor nanoparticles near the nanoscale melting temperatures. For the evolution of mixed precursor nanoparticles, synchrotron x-ray based in-situ real time XRD was used to monitor the structural changes, revealing nanoscale alloying and reshaping towards an fcc-type nanoalloy (particle or cube) via a partial melting–resolidification mechanism. The nanoalloys supported on carbon or silica were characterized by in-situ high-energy XRD/PDFs, revealing an intriguing lattice "expanding-shrinking" phenomenon depending on whether the catalyst is thermochemically processed under oxidative or reductive atmosphere. This type of controllable structural changes is found to play an important role in determining the catalytic activity of the catalysts for carbon monoxide oxidation reaction. The tunable catalytic activities of the nanoalloys under thermochemically oxidative and reductive atmospheres are also discussed in terms of the bifunctional sites and the surface oxygenated metal species for carbon monoxide and oxygen activation.

Yin, Jun; Shan, Shiyao; Yang, Lefu; Mott, Derrick; Malis, Oana; Petkov, Valeri; Cai, Fan; Ng, Mei; Luo, Jin; Chen, Bing H.; Engelhard, Mark H.; Zhong, Chuan-Jian

2012-12-12T23:59:59.000Z

152

Materials - Catalysts for Diesel Engines  

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

Argonne's deNOx Catalyst Begins Extensive Diesel Engine Exhaust Testing Argonne's deNOx Catalyst Begins Extensive Diesel Engine Exhaust Testing denox monolith Argonne's deNOx catalyst can be prepared as a powder or a monolith. chris marshall Principal investigator Chris Marshall shows the monolith form of the Argonne deNOx catalyst with a sensor inserted for testing. doug longman Mechanical engineer Doug Longman inserts the instrumented deNOx catalyst monolith into the aftertreatment chamber of Argonne's heavy-duty Caterpillar diesel test engine. Background Diesel engines, while efficient, produce many undesirable combustion byproducts in their exhaust. While we tend to think of the sooty exhaust products we see as the bad stuff, it is the less-visible exhaust products such as nitrogen oxides (NOx) that create bigger problems.

153

Multilayered and complex nanoparticle architectures through plasma synthesis  

Science Conference Proceedings (OSTI)

Using the Aerosol Through Plasma (ATP) method in conjunction with simple chemical techniques a variety of complex and novel nanoparticle architectures were created. A TP was used to make metal-core/carbon shell nanoparticles (ca. 50 nm diameter) of SnlCarbon and AI/Carbon. These have, respectively, potential for application as battery anode (for hybrid and electric vehicles) and high energy fuel In one example of post processing, the Sn-core/carbon-shell material is treated in acidic solution and yields a true nano-sized hollow carbon shell. These shells have potential application as catalyst supports, gas storage, a neutral buoyancy material for applications as varied as proppants, and slow release capsules for pharmaceutical or agricultural applications. A different set of post-A-T-P processes were used to make three layer nanoparticles with a metal core, graphite inner shell and ceramic outer shell. This method extends the range of achievable nanoparticles architectures, hence enabling new applications.

Phillips, Jonathan [Los Alamos National Laboratory; Wakeland, Stephen [UNM MECH.ENG.; Cui, Yuehua [UNM MECH.ENG.; Knapp, Angela [TOYOTA USA; Richard, Monique [TOYOTA USA; Luhrs, Claudia [UNM MECH.ENG.

2009-01-01T23:59:59.000Z

154

NiO as a peculiar support for metal nanoparticles in polyols oxidation  

SciTech Connect

The peculiar influence of a NiO support was studied by preparing gold catalysts supported on NiO(1-x) TiO2(x) mixed oxides. PVA protected Au nanoparticles showed high activity when supported on NiO for the selective oxidation of glycerol and ethan-1,2-diol. A detailed characterization of the resulting Au catalysts revealed a preferential deposition of the metal nanoparticles on the NiO phase. However, the activity of Au on NiO(1-x)-TiO2(x) decreased with respect to pure NiO and the selectivity evolved with changes to the support.

Villa, Alberto [Universita di Milano, Italy; Veith, Gabriel M [ORNL; Ferri, Davide [EMPA, Laboratory for High Performance Ceramics, Duebendorf, Switzerland; Weidenkaff, Anke [EMPA, Laboratory for High Performance Ceramics, Duebendorf, Switzerland; Perry, Kelly A [ORNL; Campisi, Sebastiano [University of Milan and INFN, Milano, Italy; Prati, Laura [Universita di Milano, Italy

2013-01-01T23:59:59.000Z

155

Highly Active and Lower Cost Nanoparticle Catalyst for Producing ...  

stock chemical for conversion into biofuels and other value-added chemicals. While HMF synthesis from cellulose has already been realized at laboratory scale,

156

Highly Active and Lower Cost Nanoparticle Catalyst for ...  

Biofuels such as ethanol are already in use as alternatives to fossil fuels. These man-made fuels help to offset carbon dioxide emissions and are a sustainable source ...

157

In-Situ Observations Reveal How Nanoparticle Catalysts ...  

Science Conference Proceedings (OSTI)

... nickel and the PDC as a function of temperature in an atmosphere of dry hydrogen at 130 Pa, mimicking the partial pressure of hydrogen in a SOFC ...

2012-04-10T23:59:59.000Z

158

Catalytic Properties of Ni-Al Intermetallic Nanoparticle Catalysts for ...  

Science Conference Proceedings (OSTI)

In order to pursue high catalytic performance of Ni-Al intermetallic ... very high catalytic activity for methanol decomposition and methane steam reforming.

159

Textured Metal Catalysts for Heterogeneous Catalysis ...  

Biomass and Biofuels Advanced Materials Textured Metal Catalysts for Heterogeneous Catalysis Pacific Northwest National Laboratory. Contact ...

160

Stabilization of Nickel Metal Catalysts for Aqueous ...  

Biomass and Biofuels Stabilization of Nickel Metal Catalysts for Aqueous Processing Systems Pacific Northwest National Laboratory.

Note: This page contains sample records for the topic "bimetallic nanoparticle catalysts" 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

Chemical interactions in multimetal/zeolite catalysts  

SciTech Connect

This report treats four subject areas: PtCu/NaY and Pd/Cu/NaY catalysts; reducibility of Ni in PdNi/NaY catalysts; CO hydrogenation over PdNi/NaY catalysts; and PdFe/NaY, Ga/H-ZSM5 and PtGa/H-ZSM5 catalysts.

Sachtler, W.M.H.

1992-02-07T23:59:59.000Z

162

Chalcogen catalysts for polymer electrolyte fuel cell  

DOE Patents (OSTI)

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

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

2010-08-24T23:59:59.000Z

163

Rh-Based Mixed Alcohol Synthesis Catalysts: Characterization and Computational Report  

Science Conference Proceedings (OSTI)

The U.S. Department of Energy is conducting a program focused on developing a process for the conversion of biomass to bio-based fuels and co-products. Biomass-derived syngas is converted thermochemically within a temperature range of 240 to 330°C and at elevated pressure (e.g., 1200 psig) over a catalyst. Ethanol is the desired reaction product, although other side compounds are produced, including C3 to C5 alcohols; higher (i.e., greater than C1) oxygenates such as methyl acetate, ethyl acetate, acetic acid and acetaldehyde; and higher hydrocarbon gases such as methane, ethane/ethene, propane/propene, etc. Saturated hydrocarbon gases (especially methane) are undesirable because they represent a diminished yield of carbon to the desired ethanol product and represent compounds that must be steam reformed at high energy cost to reproduce CO and H2. Ethanol produced by the thermochemical reaction of syngas could be separated and blended directly with gasoline to produce a liquid transportation fuel. Additionally, higher oxygenates and unsaturated hydrocarbon side products such as olefins also could be further processed to liquid fuels. The goal of the current project is the development of a Rh-based catalyst with high activity and selectivity to C2+ oxygenates. This report chronicles an effort to characterize numerous supports and catalysts to identify particular traits that could be correlated with the most active and/or selective catalysts. Carbon and silica supports and catalysts were analyzed. Generally, analyses provided guidance in the selection of acceptable catalyst supports. For example, supports with high surface areas due to a high number of micropores were generally found to be poor at producing oxygenates, possibly because of mass transfer limitations of the products formed out of the micropores. To probe fundamental aspects of the complicated reaction network of CO with H2, a computational/ theoretical investigation using quantum mechanical and ab initio molecular dynamics calculations was initiated in 2009. Computational investigations were performed first to elucidate understanding of the nature of the catalytically active site. Thermodynamic calculations revealed that Mn likely exists as a metallic alloy with Rh in Rh-rich environments under reducing conditions at the temperatures of interest. After determining that reduced Rh-Mn alloy metal clusters were in a reduced state, the activation energy barriers of numerous transition state species on the catalytically active metal particles were calculated to compute the activation barriers of several reaction pathways that are possible on the catalyst surface. Comparison of calculations with a Rh nanoparticle versus a Rh-Mn nanoparticle revealed that the presence of Mn enabled the reaction pathway of CH with CO to form an adsorbed CHCO species, which was a precursor to C2+ oxygenates. The presence of Mn did not have a significant effect on the rate of CH4 production. Ir was observed during empirical catalyst screening experiments to improve the activity and selectivity of Rh-Mn catalysts. Thus, the addition of Ir to the Rh-Mn nanoparticles also was probed computationally. Simulations of Rh-Mn-Ir nanoparticles revealed that, with sufficient Ir concentrations, the Rh, Mn and Ir presumably would be well mixed within a nanoparticle. Activation barriers were calculated for Rh-Mn-Ir nanoparticles for several C-, H-, and O-containing transitional species on the nanoparticle surface. It was found that the presence of Ir opened yet another reactive pathway whereby HCO is formed and may undergo insertion with CHx surface moieties. The reaction pathway opened by the presence of Ir is in addition to the CO + CH pathway opened by the presence of Mn. Similar to Mn, the presence of Ir was not found to not affect the rate of CH4 production.

Albrecht, Karl O.; Glezakou, Vassiliki Alexandra; Rousseau, Roger J.; Engelhard, Mark H.; Varga, Tamas; Colby, Robert J.; Jaffe, John E.; Li, Xiaohong S.; Mei, Donghai; Windisch, Charles F.; Kathmann, Shawn M.; Lemmon, Teresa L.; Gray, Michel J.; Hart, Todd R.; Thompson, Becky L.; Gerber, Mark A.

2013-08-01T23:59:59.000Z

164

COMPARISON OF PLASMA-CATALYST AND ACTIVE LEAN NOx CATALYST  

DOE Green Energy (OSTI)

A number of NO{sub x} control systems are being discussed for potential application to diesel engines. Unfortunately, it can be difficult to compare systems on an equal basis because data are run under different conditions, or reported against different test cycles, or not shown over a range of operating conditions. In addition, the fuel consumption penalty associated with the NO{sub x} control technologies is not always reported. In this paper, we compare two diesel NO{sub x} aftertreatment systems: (1) Plasma-Catalyst (PC): a nonthermal plasma followed by a catalyst; and (2) Active Lean NO{sub x} Catalyst (ALNC): a NO{sub x} catalyst designed to selectively reduce NO{sub x} using hydrocarbon (HC) in the form of diesel fuel. Fuel is added to the exhaust to increase HC above normal diesel levels. These systems will be described in more detail in this report.

Hoard, John

2000-08-20T23:59:59.000Z

165

Near-Monodisperse Ni-Cu Bimetallic Nanocrystals of Variable Composition: Controlled Synthesis and Catalytic Activity for H2 Generation  

SciTech Connect

Near-monodisperse Ni{sub 1-x}Cu{sub x} (x = 0.2-0.8) bimetallic nanocrystals were synthesized by a one-pot thermolysis approach in oleylamine/1-octadecene, using metal acetylacetonates as precursors. The nanocrystals form large-area 2D superlattices, and display a catalytic synergistic effect in the hydrolysis of NaBH{sub 4} to generate H{sub 2} at x = 0.5 in a strongly basic medium. The Ni{sub 0.5}Cu{sub 0.5} nanocrystals show the lowest activation energy, and also exhibit the highest H{sub 2} generation rate at 298 K.

Zhang, Yawen; Huang, Wenyu; Habas, Susan E.; Kuhn, John N.; Grass, Michael E.; Yamada, Yusuke; Yang, Peidong; Somorjai, Gabor A.

2008-07-22T23:59:59.000Z

166

High Temperature Membrane & Advanced Cathode Catalyst Development  

DOE Green Energy (OSTI)

Current project consisted of three main phases and eighteen milestones. Short description of each phase is given below. Table 1 lists program milestones. Phase 1--High Temperature Membrane and Advanced Catalyst Development. New polymers and advanced cathode catalysts were synthesized. The membranes and the catalysts were characterized and compared against specifications that are based on DOE program requirements. The best-in-class membranes and catalysts were downselected for phase 2. Phase 2--Catalyst Coated Membrane (CCM) Fabrication and Testing. Laboratory scale catalyst coated membranes (CCMs) were fabricated and tested using the down-selected membranes and catalysts. The catalysts and high temperature membrane CCMs were tested and optimized. Phase 3--Multi-cell stack fabrication. Full-size CCMs with the down-selected and optimized high temperature membrane and catalyst were fabricated. The catalyst membrane assemblies were tested in full size cells and multi-cell stack.

Protsailo, Lesia

2006-04-20T23:59:59.000Z

167

Necessary conditions on entanglement catalysts  

E-Print Network (OSTI)

Given a pure state transformation $\\psi\\mapsto\\phi$ restricted to entanglement-assisted local operations with classical communication, we determine a lower bound for the dimension of a catalyst allowing that transformation. Our bound is stated in terms of the generalised concurrence monotones (the usual concurrence of two qubits is one such monotone). We further provide tools for deriving further conditions upon catalysts of pure state transformations.

Sanders, Yuval

2009-01-01T23:59:59.000Z

168

Necessary conditions on entanglement catalysts  

E-Print Network (OSTI)

Given a pure state transformation $\\psi\\mapsto\\phi$ restricted to entanglement-assisted local operations with classical communication, we determine a lower bound for the dimension of a catalyst allowing that transformation. Our bound is stated in terms of the generalised concurrence monotones (the usual concurrence of two qubits is one such monotone). We further provide tools for deriving further conditions upon catalysts of pure state transformations.

Yuval Sanders; Gilad Gour

2009-04-14T23:59:59.000Z

169

Electrocatalysts on Carbon Nanoparticles  

Carbon nanostructures offer extremely high surface areas and so are attractive candidates to support dispersed catalysts. These nanostructures, ...

170

Creating a culture of assessment: A catalyst for organizational change  

E-Print Network (OSTI)

Culture of Assessment: A Catalyst for Organizational ChangeCulture of Assessment: A Catalyst for Organizational ChangeCulture of Assessment: A Catalyst for Organizational Change

Lakos, Amos; Phipps, Shelley

2004-01-01T23:59:59.000Z

171

Catalyst-infiltrated supporting cathode for thin-film SOFCs  

E-Print Network (OSTI)

LBNL-55226 Catalyst-Infiltrated Supporting Cathode for Thin-demonstrate that cobalt catalyst-infiltrated LSM can beinfiltrating nano- sized catalyst particles into its pores

Yamahara, Keiji; Jacobson, Craig P.; Visco, Steven J.; De Jonghe, Lutgard C.

2004-01-01T23:59:59.000Z

172

Studies of Various Hydrocarbon Conversion Reactions on Pt Catalysts  

E-Print Network (OSTI)

observed after reduction on tetrahedral and cubic catalysts.Prepared catalysts………..…….……………………. ………………..……..35reactions on shape controlled catalysts………………………………22 3.1.

Kaneko, Shinji

2011-01-01T23:59:59.000Z

173

Business Case Slide 22: High-Value: Catalysts - Description  

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

Catalysts - Description Graduate student examining candidate DU-bearing catalyst Graduate student examining candidate DU-bearing catalyst Description Use DUO2 to catalyze chemical...

174

Business Case Slide 24: High-Value: Catalysts - Program Focus  

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

Catalysts - Program Focus Program Focus Off-gas cleanup catalysts (ORNL) Best form and substrate, effect of impurities Desulfurization catalyst (Rutgers) Proof-of-principle...

175

Standard practice for evaluation of disbonding of bimetallic stainless alloy/steel plate for use in high-pressure, high-temperature refinery hydrogen service  

E-Print Network (OSTI)

1.1 This practice covers a procedure for the evaluation of disbonding of bimetallic stainless alloy/steel plate for use in refinery high-pressure/high-temperature (HP/HT) gaseous hydrogen service. It includes procedures to (1) produce suitable laboratory test specimens, (2) obtain hydrogen charging conditions in the laboratory that are similar to those found in refinery HP/HT hydrogen gas service for evaluation of bimetallic specimens exposed to these environments, and (3) perform analysis of the test data. The purpose of this practice is to allow for comparison of data among test laboratories on the resistance of bimetallic stainless alloy/steels to hydrogen-induced disbonding (HID). 1.2 This practice applies primarily to bimetallic products fabricated by weld overlay of stainless alloy onto a steel substrate. Most of the information developed using this practice has been obtained for such materials. The procedures described herein, may also be appropriate for evaluation of hot roll bonded, explosive bonded...

American Society for Testing and Materials. Philadelphia

2001-01-01T23:59:59.000Z

176

CO HYDROGENATION OVER CLEAN AND OXIDIZED RHODIUM FOIL AND SINGLE CRYSTAL CATALYSTS. CORRELATIONS OF CATALYST ACTIVITY, SELECTIVITY AND SURFACE COMPOSITION  

E-Print Network (OSTI)

AND OXIDIZED RHODIUM FOIL AND SINGLE CRYSTAL CATALYSTS.CORRELATIONS OF CATALYST ACTIVITY, SELECTIVITY AND SURFACEobserved over the clean Rh catalysts during the catalyzed

Castner, D.G.

2012-01-01T23:59:59.000Z

177

The Chemical Composition and Structure of Supported Sulfated Zirconia with Regulated Size Nanoparticles  

Science Conference Proceedings (OSTI)

A set of model skeletal isomerization catalysts - sulfated zirconia nanoparticles of controlled thickness anchored on different supports - was prepared using colloidal solutions of Zr salt on titania as support. The nanoparticles of zirconia (1-5 nm) are epitaxially connected to the support surface, with S/Zr ratio equals to 1.3-1.5. It was shown by EXAFS that nanoparticles of non-stoichiometric zirconium sulfate Zr(SO4)1+x, where xbutane isomerisation at 150 deg. C, one can suggest that these species behave as the active component of sulfated zirconia. They are formed in subsurface layers as zirconium hydroxide undergoes sulfation followed by thermal treatment.

Kanazhevskiy, V. V. [Novosibirsk State University, 2 - Pirogova st. 630090 Novosibirsk (Russian Federation); Shmachkova, V. P.; Kotsarenko, N. S.; Kochubey, D. I. [Boreskov Institute of Catalysis, 5 - Lavrentev av. 630090 Novosibirsk (Russian Federation); Vedrine, J. C. [Laboratoire de Physico-Chimie des Surfaces, ENSCP, 11 - Rue P. and M. Curie, F-75005, Paris, (France)

2007-02-02T23:59:59.000Z

178

Catalyst for coal liquefaction process  

SciTech Connect

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

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

1984-01-01T23:59:59.000Z

179

Novel platinum/carbon catalysts with cluster size control for...  

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

Project overview - Cluster chemistry - Catalysts and supports * Experimental - Novel catalyst preparation * Results - Metal cluster size - Electrochemical properties * Summary...

180

Catalyst containing oxygen transport membrane  

Science Conference Proceedings (OSTI)

A composite oxygen transport membrane having a dense layer, a porous support layer and an intermediate porous layer located between the dense layer and the porous support layer. Both the dense layer and the intermediate porous layer are formed from an ionic conductive material to conduct oxygen ions and an electrically conductive material to conduct electrons. The porous support layer has a high permeability, high porosity, and a high average pore diameter and the intermediate porous layer has a lower permeability and lower pore diameter than the porous support layer. Catalyst particles selected to promote oxidation of a combustible substance are located in the intermediate porous layer and in the porous support adjacent to the intermediate porous layer. The catalyst particles can be formed by wicking a solution of catalyst precursors through the porous support toward the intermediate porous layer.

Christie, Gervase Maxwell; Wilson, Jamie Robyn; van Hassel, Bart Antonie

2012-12-04T23:59:59.000Z

Note: This page contains sample records for the topic "bimetallic nanoparticle catalysts" 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

Catalysts for improved fuel processing  

DOE Green Energy (OSTI)

This report covers our technical progress on fuel processing catalyst characterization for the specific purpose of hydrogen production for proton-exchange-membrane (PEM) fuel cells. These development efforts support DOE activities in the development of compact, transient capable reformers for on-board hydrogen generation starting from candidate fuels. The long-term objective includes increased durability and lifetime, in addition to smaller volume, improved performance, and other specifications required meeting fuel processor goals. The technical barriers of compact fuel processor size, transient capability, and compact, efficient thermal management all are functions of catalyst performance. Significantly, work at LANL now tests large-scale fuel processors for performance and durability, as influenced by fuels and fuel constituents, and complements that testing with micro-scale catalyst evaluation which is accomplished under well controlled conditions.

Borup, R.L.; Inbody, M.A. [and others

2000-09-01T23:59:59.000Z

182

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

183

Bimetallic IrNi Core Platinum Monolayer Shell Electrocatalysts for the Oxygen Reduction Reaction  

DOE Green Energy (OSTI)

We synthesized a low-Pt content electrocatalyst consisting of a Pt monolayer placed on carbon-supported thermally treated IrNi core-shell structured nanoparticles using galvanic displacement of a Cu monolayer deposited at underpotentials. The Pt mass activity of the Pt{sub ML}/IrNi/C electrocatalyst obtained in a scale-up synthesis is approximately 3 times higher than that of the commercial Pt/C electrocatalyst. The electronic and geometrical effects of the IrNi substrate on the Pt monolayer result in its higher catalytic activity than that of Pt nanoparticles. The structure and composition of the core-shell nanoparticles were verified using transmission electron microscopy and in situ X-ray absorption spectroscopy, while a potential cycling test was employed to confirm the stability of the electrocatalyst. Our experimental results, supported by the density functional calculations using a sphere-like model, demonstrate an effective way of using Pt that can resolve key problems of cathodic oxygen reduction hampering fuel cell commercialization.

Kuttiyiel K. A.; Sasaki, K.; Choi, Y.M.; Su, D.; Liu, P.; Adzic, R.R.

2012-01-01T23:59:59.000Z

184

Magnetic Nanoparticle Metrology  

Science Conference Proceedings (OSTI)

... T2 relaxation times, hysteretic energy loss, etc ... Optimization of magnetic nanoparticle synthesis for ... competition between lattice energies and dipolar ...

2012-12-03T23:59:59.000Z

185

On-line regeneration of hydrodesulfurization catalyst  

DOE Patents (OSTI)

A hydrotreating catalyst is regenerated as it concurrently hydrotreats a hydrocarbon fuel by introducing a low concentration of oxygen into the catalyst bed either continuously or periodically. At low oxygen concentrations the carbon deposits on the catalyst are burned off without harming the catalyst and without significantly affecting the hydrotreating process. In a preferred embodiment the hydrotreating process is hydrodesulfurization, and regenerating is done periodically with oxygen concentrations between 0.1 and 0.5 volume percent.

Preston, Jr., John L. (Hebron, CT)

1980-01-01T23:59:59.000Z

186

Nanosegregated Surfaces as Catalysts for Fuel Cells  

limitations for the oxygen reduction reaction. The result is a catalyst particularly advantageous for use in polymer electrolyte fuel cells.

187

Database - Selective Catalytic Reduction Catalyst Deactivation Rates  

Science Conference Proceedings (OSTI)

Selective catalytic reduction (SCR) catalyst deactivation is a critical parameter controlling to a large extent achievable catalyst life, as well as overall SCR system performance. Accurate assessment and prediction of catalyst deactivation is required to adequately manage reactor potential. EPRI has on-going efforts underway aimed at better understanding the factors that affect catalyst deactivation, especially as a function of fuel, boiler design, and boiler operating conditions, in hopes of ...

2013-11-06T23:59:59.000Z

188

Biomass Catalyst Characterization Laboratory (Fact Sheet)  

DOE Green Energy (OSTI)

This fact sheet provides information about Biomass Catalyst Characterization Laboratory (BCCL) capabilities and applications at NREL's National Bioenergy Center.

Not Available

2011-07-01T23:59:59.000Z

189

Nanostructured Water Oxidation Catalysts - Energy Innovation ...  

Nanostructured Cobalt Oxide Clusters in Mesoporous Silica as Efficient Oxygen-Evolving Catalysts. Angewandte Chemie International Edition. Vol. 28: ...

190

Attrition Resistant Catalyst Materials for Fluid Bed ...  

Biomass and Biofuels Attrition Resistant Catalyst Materials for Fluid Bed Applications National Renewable Energy Laboratory. Contact NREL About This ...

191

Catalyst-assisted Probabilistic Entanglement Transformation  

E-Print Network (OSTI)

We are concerned with catalyst-assisted probabilistic entanglement transformations. A necessary and sufficient condition is presented under which there exist partial catalysts that can increase the maximal transforming probability of a given entanglement transformation. We also design an algorithm which leads to an efficient method for finding the most economical partial catalysts with minimal dimension. The mathematical structure of catalyst-assisted probabilistic transformation is carefully investigated.

Yuan Feng; Runyao Duan; Mingsheng Ying

2004-04-27T23:59:59.000Z

192

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

193

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

194

Selective Catalytic Reduction (SCR) Catalyst Reconditioning as Part of Catalyst Management  

Science Conference Proceedings (OSTI)

Previous EPRI work on catalyst reconditioning for selective catalytic reduction (SCR) systems sought to offer guidance to catalyst users as to the expected performance of reconditioned catalysts, both in the short term and long term, as well as to offer guidance as to the actual processes used for catalyst reconditioning. The present work seeks to compile these past efforts into a single document offering maximum utility to catalyst end users. In addition, the report updates previous findings where pract...

2009-12-21T23:59:59.000Z

195

Catalysts for coal liquefaction processes  

SciTech Connect

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

Garg, Diwakar (Macungie, PA)

1986-01-01T23:59:59.000Z

196

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

197

Catalysts for coal liquefaction processes  

DOE Patents (OSTI)

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

Garg, D.

1986-10-14T23:59:59.000Z

198

De-alloyed platinum nanoparticles  

DOE Patents (OSTI)

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

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

2011-08-09T23:59:59.000Z

199

Attrition and carbon formation on iron catalysts  

DOE Green Energy (OSTI)

A serious engineering problem that needs to be addressed in the scale-up of slurry-phase, Fischer-Tropsch reactors is attrition of the precipitated iron catalyst. Attrition, which can break down the catalyst into particles too small to filter, results from both mechanical and chemical forces. This study examines the chemical causes of attrition in iron catalysts. A bench-scale, slurry-phase CSTR is used to simulate operating conditions that lead to attrition of the catalyst. The average particle size and size distribution of the catalyst samples are used to determine the effect of slurry temperature, reducing gas, gas flow rate and time upon attrition of the catalyst. Carbon deposition, a possible contributing factor to attrition, has been examined using gravimetric analysis and TEM. Conditions affecting the rate of carbon deposition have been compared to those leading to attrition of the precipitated iron catalyst.

Kohler, S.D.; Harrington, M.S.; Jackson, N.B. [Sandia National Labs., Albuquerque, NM (United States); Shroff, M.; Kalakkad, D.S.; Datye, A.K. [New Mexico Univ., Albuquerque, NM (United States). Dept. of Chemical and Nuclear Engineering

1994-08-01T23:59:59.000Z

200

Membrane catalyst layer for fuel cells  

DOE Patents (OSTI)

A gas reaction fuel cell incorporates a thin catalyst layer between a solid polymer electrolyte (SPE) membrane and a porous electrode backing. The catalyst layer is preferably less than about 10 {mu}m in thickness with a carbon supported platinum catalyst loading less than about 0.35 mgPt/cm{sup 2}. The film is formed as an ink that is spread and cured on a film release blank. The cured film is then transferred to the SPE membrane and hot pressed into the surface to form a catalyst layer having a controlled thickness and catalyst distribution. The layer has adequate gas permeability so that cell performance is not affected and has a density and particle distribution effective to optimize proton access to the catalyst and electronic continuity for electron flow from the half-cell reaction occurring at the catalyst.

Wilson, M.S.

1991-02-19T23:59:59.000Z

Note: This page contains sample records for the topic "bimetallic nanoparticle catalysts" 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

Autothermal reforming catalyst having perovskite structure  

DOE Patents (OSTI)

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

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

2009-03-24T23:59:59.000Z

202

Model Catalysts: Simulating the Complexities of Heterogeneous Catalysts  

Science Conference Proceedings (OSTI)

Surface-science investigations have contributed significantly to heterogeneous catalysis in the past several decades. Fundamental studies of reactive systems on metal single crystals have aided researchers in understanding the effect of surface structure on catalyst reactivity and selectivity for a number of important reactions. Recently, model systems, consisting of metal clusters deposited on planar oxide surfaces, have facilitated the study of metal particle-size and support effects. These model systems not only are useful for carrying out kinetic investigations, but are also amenable to surface spectroscopic techniques, thus enabling investigations under realistic pressures and at working temperatures. By combining surface-science characterization methods with kinetic measurements under realistic working conditions, researchers are continuing to advance the molecular-level understanding of heterogeneous catalysis and are narrowing he pressure and material gap between model and real-world catalysts.

Gao, Feng; Goodman, D. W.

2012-05-01T23:59:59.000Z

203

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

DOE Patents (OSTI)

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

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

1986-01-01T23:59:59.000Z

204

Supported fischer-tropsch catalyst and method of making the catalyst  

DOE Patents (OSTI)

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

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

1987-01-01T23:59:59.000Z

205

Graphene decorated with PtAu alloy nanoparticles: facile synthesis and promising application for formic acid oxidation  

DOE Green Energy (OSTI)

PtAu alloy nanoparticles (~ 3.2 nm in diameter) are synthesized in poly(diallyldimethylammonium chloride) (PDDA) aqueous solution and uniformly dispersed on graphene nanosheets. PtAu/graphene exhibits high electrocatalytic activity and stability for formic acid oxidation, which is attributed to the high dispersion of PtAu nanoparticles and the specific interaction between PtAu and graphene, indicating a promising catalyst for direct formic acid fuel cells. The facile method can be readily extended to the synthesis of other alloy nanoparticles.

Zhang, Sheng; Shao, Yuyan; Liao, Honggang; Liu, Jun; Aksay, Ilhan A.; Yin, Geping; Lin, Yuehe

2011-03-01T23:59:59.000Z

206

Late transition metal bimetallics for photocatalytic hydrogen production, M-X and C-H bond activation  

E-Print Network (OSTI)

Broadly defined this thesis has focused on the design and study of molecular catalysts that engender multi-electron reactions and photoreactions on small molecule substrates relevant to solar energy conversion. Specifically ...

Esswein, Arthur J

2007-01-01T23:59:59.000Z

207

Catalyst regeneration apparatus with radial flow distribution  

Science Conference Proceedings (OSTI)

Apparatus is described for regenerating spent hydrocarbon conversion catalyst. Catalyst particles in a vertically-elongated movable tapered bed are contacted with a hot oxygen-containing gas stream in order to remove, by means of combustion, coke which accumulated on the catalyst particles while they were used in a hydrocarbon conversion zone. Catalyst moves downward under the influence of gravity. The catalyst bed is tapered such that the thickness of the bed, in a dimension which is transverse to the direction of catalyst movement, varies from a minimum at the top of the tapered bed to a maximum at the bottom of the tapered bed. Gas passes through the tapered bed in a direction which is substantially transverse to the direction of catalyst movement. Substantially, all of the catalyst in the bed is in contact with the flowing gas. The variation in bed thickness causes a varying gas flow rate through the bed, from a maximum flow rate at the top of the tapered bed to a minimum flow rate at the bottom of the tapered bed and reduces the time that catalyst is exposed to high temperature gases. This flow pattern results in the delivery of oxygen in a manner which more closely matches the oxygen requirement for combustion at each point in the tapered bed. Advantages of the invention include increased coke burning capacity and longer catalyst life. Catalytic reforming is an example of a hydrocarbon conversion process in which the invention may be advantageously employed. 9 figs.

Sechrist, P.A.; Koves, W.J.

1994-01-11T23:59:59.000Z

208

Intermittency on catalysts: voter model  

E-Print Network (OSTI)

In this paper we study intermittency for the parabolic Anderson equation with a space-time random potential describing the evolution of a "reactant" under the influence of a "catalyst", where the catalyst is given by the voter model with opinions 0 and 1 that are updated according to a random walk transition kernel starting from either the Bernoulli measure or the equilibrium measure. We show that the annealed Lyapunov exponents of the solution are trivial when the random walk is not strongly transient, but display an interesting dependence on the diffusion constant when the random walk is strongly transient. Compared with our earlier work, the main obstacle is the non-reversibility of the voter model dynamics, since this precludes the application of spectral techniques. The duality with coalescing random walks is key to our analysis, and leads to a representation formula for the Lyapunov exponents that allows for the application of large deviation techniques.

Gärtner, J; Maillard, G

2009-01-01T23:59:59.000Z

209

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

210

Ethanol oxidation on metal oxide-supported platinum catalysts  

SciTech Connect

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

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

2009-09-01T23:59:59.000Z

211

Copper-containing zeolite catalysts  

DOE Patents (OSTI)

A catalyst useful in the conversion of nitrogen oxides or in the synthesis of nitriles or imines from amines, is formed by preparing an intimate mechanical mixture of a copper (II)-containing species, such as CuO or CuCl{sub 2}, or elemental copper, with a zeolite having a pore mouth comprising 10 oxygen atoms, such as ZSM-5, converting the elemental copper or copper (II) to copper (I), and driving the copper (I) into the zeolite.

Price, G.L.; Kanazirev, V.

1996-12-10T23:59:59.000Z

212

Copper-containing zeolite catalysts  

DOE Patents (OSTI)

A catalyst useful in the conversion of nitrogen oxides or in the synthesis of nitriles or imines from amines, formed by preparing an intimate mechanical mixture of a copper (II)-containing species, such as CuO or CuCl.sub.2, or elemental copper, with a zeolite having a pore mouth comprising 10 oxygen atoms, such as ZSM-5, converting the elemental copper or copper (II) to copper (I), and driving the copper (I) into the zeolite.

Price, Geoffrey L. (Baton Rouge, LA); Kanazirev, Vladislav (Sofia, BG)

1996-01-01T23:59:59.000Z

213

Carbon Encapsulated Platinum Nanoparticles: Growth ...  

Science Conference Proceedings (OSTI)

Such patterned assembly of carbon encapsulated nanoparticles was further studied for .... Silica Nanoparticles for His-tagged Proteins Capture and Separation.

214

Templated synthesis of nickel nanoparticles: Toward heterostructured nanocomposites for efficient hydrogen storage  

SciTech Connect

The world is currently facing an energy and environmental crisis for which new technologies are needed. Development of cost-competitive materials for catalysis and hydrogen storage on-board motor vehicles is crucial to lead subsequent generations into a more sustainable and energy independent future. This thesis presents work toward the scalable synthesis of bimetallic heterostructures that can enable hydrogen to compete with carbonaceous fuels by meeting the necessary gravimetric and volumetric energy densities and by enhancing hydrogen sorption/desorption kinetics near ambient temperatures and pressures. Utilizing the well-known phenomenon of hydrogen spillover, these bimetallic heterostructures could work by lowering the activation energy for hydrogenation and dehydrogenation of metals. Herein, we report a novel method for the scalable synthesis of silica templated zero-valent nickel particles (Ni?SiO{sub 2}) that hold promise for the synthesis of nickel nanorods for use in bimetallic heterostructures for hydrogen storage. Our synthesis proceeds by chemical reduction of a nickel-hydrazine complex with sodium borohydride followed by calcination under hydrogen gas to yield silica encapsulated nickel particles. Transmission electron microscopy and powder X-ray diffraction were used to characterize the general morphology of the resultant nanocapsules as well as the crystalline phases of the incorporated Ni{sup 0} nanocrystals. The structures display strong magnetic behavior at room temperature and preliminary data suggests nickel particle size can be controlled by varying the amount of nickel precursor used in the synthesis. Calcination under different environments and TEM analysis provides evidence for an atomic migration mechanism of particle formation. Ni?SiO{sub 2} nanocapsules were used as seeds to induce heterogeneous nucleation and subsequent growth within the nanocapsule via electroless nickel plating. Nickel nanoparticle growth occurs under high temperature alkaline conditions, however silica nanocapsule integrity is not maintained due to the incompatibility of silica with the growth conditions. Silica nanocapsule integrity is maintained under low temperature neutral conditions, but nickel particle growth is not observed. Through FTIR and UV/Vis analysis, we show the degree of crosslinking and condensation increases in calcined silica compared to as-synthesized silica. We propose the increased density of the silica nanocapsule hinders mass transfer of the bulky nickel precursor complex from solution and onto the surface of the “catalytic” zero-valent nickel seed within the nanocapsule cavity. Decreasing the density of the silica nanocapsule can be achieved through co-condensation of tetraethylorthosilicate with an alkyl functionalized silane followed by calcination to remove the organic component or by chemical etching in alkaline solution, but will not be addressed in this thesis.

Nelson, Nicholas Cole [Ames Laboratory

2013-05-07T23:59:59.000Z

215

The Existence of Quantum Entanglement Catalysts  

E-Print Network (OSTI)

Without additional resources, it is often impossible to transform one entangled quantum state into another with local quantum operations and classical communication. Jonathan and Plenio [Phys. Rev. Lett. 83, 3566(1999)] presented an interesting example showing that the presence of another state, called a catalyst, enables such a transformation without changing the catalyst. They also pointed out that in general it is very hard to find an analytical condition under which a catalyst exists. In this paper we study the existence of catalysts for two incomparable quantum states. For the simplest case of $2\\times 2$ catalysts for transformations from one $4\\times 4$ state to another, a necessary and sufficient condition for existence is found. For the general case, we give an efficient polynomial time algorithm to decide whether a $k\\times k$ catalyst exists for two $n\\times n$ incomparable states, where $k$ is treated as a constant.

Xiaoming Sun; Runyao Duan; Mingsheng Ying

2003-11-19T23:59:59.000Z

216

Surfactant removal for colloidal nanoparticles from solution systhesis: the effect on catalytic performance  

SciTech Connect

Colloidal nanoparticles prepared by solution synthesis with robust control over particle size, shape, composition, and structure have shown great potential for catalytic applications. However, such colloidal nanoparticles are usually capped with organic ligands (as surfactants) and cannot be directly used as catalyst. We have studied the effect of surfactant removal on the electrocatalytic performance of Pt nanoparticles made by organic solution synthesis. Various methods were applied to remove the oleylamine surfactant, which included thermal annealing, acetic acid washing, and UV-Ozone irradiation, and the treated nanoparticles were applied as electrocatalysts for the oxygen reduction reaction. It was found that the electrocatalytic performance, including electrochemically active surface area and catalytic activity, was strongly dependent on the pretreatment. Among the methods studied here, low-temperature thermal annealing ({approx}185 C) in air was found to be the most effective for surface cleaning without inducing particle size and morphology changes.

Li, D.; Wang, C.; Tripkovic, D.; Sun, S.; Markovic, N. M.; Stamenkovic, V. R. (Materials Science Division); (Brown Univ.)

2012-01-01T23:59:59.000Z

217

Regenerated Plate Type SCR Catalyst Performance  

Science Conference Proceedings (OSTI)

Selective Catalytic Reduction (SCR) technology has become the technology of choice for meeting stringent nitrogen oxides (NOX) emission limits for many coal fired electric generating plants. With the aging of the domestic SCR fleet, the average age of catalysts currently in use has increased; and many facilities are now considering replacement or regeneration of the catalyst materials. Facilities planning to integrate SCR catalyst regeneration into their operations need to understand the overall performa...

2009-01-26T23:59:59.000Z

218

SCR Catalyst Management for Mercury Control  

Science Conference Proceedings (OSTI)

A number of EPRI projects conducted over the past several years have examined the effects of SCR catalyst on mercury speciation. These projects have focused on the various factors influencing mercury oxidation, related to both the flue gas conditions and the catalysts themselves. However, the majority of these studies have only examined the speciation at the SCR inlet and outlet. Much less is known about the interlayer speciation, however, which is very important when developing catalyst management ...

2012-11-16T23:59:59.000Z

219

Mercury Oxidation Performance of Advanced SCR Catalyst  

Science Conference Proceedings (OSTI)

The ability of selective catalytic reduction (SCR) catalysts to oxidize mercury is an important aspect of many utilities’ mercury control strategies. Improved SCR mercury oxidation will facilitate its capture in downstream wet–flue gas desulfurization systems and will generally result in lower emission rates. Recently, catalyst manufacturers have attempted to maximize mercury oxidation through advanced catalyst formulations.This study documents the performance of an advanced ...

2012-12-31T23:59:59.000Z

220

Hydrocarbon synthesis catalyst and method of preparation  

DOE Patents (OSTI)

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, Richard S. (Shoreham, NY); Sansone, Michael J. (Summit, NJ); Slegeir, William A. R. (Hampton Bays, NY)

1983-08-02T23:59:59.000Z

Note: This page contains sample records for the topic "bimetallic nanoparticle catalysts" 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

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

222

Process for coal liquefaction using electrodeposited catalyst  

DOE Patents (OSTI)

A process for the liquefaction of solid hydrocarbonaceous materials is disclosed. Particles of such materials are electroplated with a metal catalyst and are then suspended in a hydrocarbon oil and subjected to hydrogenolysis to liquefy the solid hydrocarbonaceous material. A liquid product oil is separated from residue solid material containing char and the catalyst metal. The catalyst is recovered from the solid material by electrolysis for reuse. A portion of the product oil can be employed as the hydrocarbon oil for suspending additional particles of catalyst coated solid carbonaceous material for hydrogenolysis.

Moore, Raymond H. (Richland, WA)

1978-01-01T23:59:59.000Z

223

Nanoscale Chemical Imaging of a Working Catalyst  

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

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...

224

Heterogeneous Catalyst for Improved Selectivity of Biomass ...  

Technology Marketing Summary. In today’s industrial processes, heterogeneous catalysts are widely used because of their stability and ease of ...

225

Available Technologies: Catalyst Patterning for Scalable CVD ...  

Nano- & Micro-technology; Software and IT ; Licensing Interest Form Receive Customized Tech Alerts. Catalyst Patterning for Scalable CVD Growth of Graphene Nanoribbon.

226

Information Technology Solutions Designer Catalysts for ...  

petroleum industry’s “workhorse” catalysts for upgrading heavy petroleum feed stocks and removing sulfur, nitrogen and other pollutants from fuels.

227

Attrition resistant fluidizable reforming catalyst - Energy ...  

A method of preparing a steam reforming catalyst characterized by improved resistance to attrition loss when used for cracking, reforming, water gas shift and ...

228

Polyfunctional catalyst for processiing benzene fractions  

SciTech Connect

A by-product of the coke industry is a raw benzene fraction benzene- 1 which may serve as for catalytic processes. The paper reports a study on the influence of the composition and temperatures on the activity and selectivity of NiO-V{sub 2}O{sub 6}-MoO{sub 3}/{gamma}-Al{sub 2}O{sub 3} catalysts and the corresponding binary and tertiary subsystems are studied by a pulse method in model reactions; the hydrodealkylating of toluene and the hydrodesulfurizing of thioprhene. The optimal catalyst composition is established. The new catalyst is compared with industrial catalysts.

G. Byakov; B.D. Zubitskii; B.G. Tryasunov; I.Ya. Petrov [Kuznetsk Basin State Technical University, Kemerovo (Russian Federation)

2009-05-15T23:59:59.000Z

229

X-ray Photoelectron Spectroscopy and Kinetic Study: Pt-Group Metals and Bimetallic Surfaces  

E-Print Network (OSTI)

Pt-group metals were some of the first metals to be studied as catalysts for industrial use. The goal of these studies was to ascertain a fundamental understanding of CO oxidation and acetylene cyclotrimerization reactions on Ptgroup metals. A further goal was to determine the optimal conditions for each reaction. CO oxidation on Rh(111),Pt(100), and Pd(100) was scrutinized on various oxide surfaces from chemisorbed to bulk metal oxides. Low pressure reactions on Rh(111) reveal the highest activity was a CO uninhibited surface with oxidation revealed that only oxidation reactions on Pd(100) show oxygen penetration after CO has been consumed; however, during the highest activity XPS found only chemisorbed species. The cyclotrimerization of acetylene to benzene is another reaction found in industry typically carried out on Pd. The active site is considered to be a 7 atom configuration with 6 atoms surrounding a central atom. By adding relatively catalytically inert Au atoms to the active Pd(111) surface the acetylene coupling activity is enhanced. Cyclization activity is a function of the surface composition and the surface structure. A single Pd atom surrounded by six Au atoms is found to have the highest activity at 300K for acetylene cyclotrimerization.

Gath, Kerrie K.

2008-12-01T23:59:59.000Z

230

Method for making nanotubes and nanoparticles  

DOE Patents (OSTI)

The present invention is an apparatus and method for producing nano-scale tubes and particles. The apparatus comprises novel electrodes for use in arc discharge techniques. The electrodes have interior conduits for delivery and withdrawal of material from the arc region where product is formed. In one embodiment, the anode is optionally made from more than one material and is termed a compound anode. The materials used in the compound anode assist in the reaction that forms product in the arc region of the apparatus. The materials assist either by providing reaction ingredients, catalyst, or affecting the reaction kinetics. Among other uses, the inventive apparatus is used to produce nanotubes and nanoparticles having a variety of electrical and mechanical properties.

Zettl, Alexander Karlwalter (Kensington, CA); Cohen, Marvin Lou (Piedmont, CA)

2000-01-01T23:59:59.000Z

231

Focussing the view on Nature's water-splitting catalyst  

E-Print Network (OSTI)

formation in synthetic Mn-catalyst. Inorg. Chem. 43, 264-Nature’s water-splitting catalyst Samir Zein 1,2 , Leonid V.Nature’s water splitting catalyst Abstract About 3 billion

Yano, Junko

2008-01-01T23:59:59.000Z

232

Roles of Surface Step on Pt Nanoparticles in Electro-oxidation of Carbon Monoxide and Methanol  

DOE Green Energy (OSTI)

Design of highly active nanoscale catalysts for electro-oxidation of small organic molecules is of great importance to the development of efficient fuel cells. Increasing steps on single-crystal Pt surfaces is shown to enhance the activity of CO and methanol electro-oxidation up to several orders of magnitude. However, little is known about the surface atomic structure of nanoparticles with sizes of practical relevance, which limits the application of fundamental understanding in the reaction mechanisms established on single-crystal surfaces to the development of active, nanoscale catalysts. In this study, we reveal the surface atomic structure of Pt nanoparticles supported on multiwall carbon nanotubes, from which the amount of high-index surface facets on Pt nanoparticles is quantified. Correlating the surface steps on Pt nanoparticles with the electrochemical activity and stability clearly shows the significant role of surface steps in enhancing intrinsic activity for CO and methanol electro-oxidation. Here, we show that increasing surface steps on Pt nanoparticles of {approx}2 nm can lead to enhanced intrinsic activity up to {approx}200% (current normalized to Pt surface area) for electro-oxidation of methanol.

Lee, S.W.; Vescovo, E.; Chen, S.; Sheng, W.; Yabuuchi, N.; Kim, Y.T.; Mitani, T.; Shao-Horn, Y.

2009-10-13T23:59:59.000Z

233

Nanoparticle toxicity testing  

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

Nanoparticle toxicity testing Nanoparticle toxicity testing 1663 Los Alamos science and technology magazine Latest Issue:November 2013 All Issues » submit Nanoparticle toxicity testing Assessing the potential health hazards of nanotechnology March 25, 2013 Robot In the search for more accurate and efficient techniques to evaluate the health hazards of nanoparticles, Los Alamos researchers are developing artificial human tissues and organs to replace animal test subjects. A new approach to toxicity testing under development at Los Alamos uses artificial tissue and artificial organs instead of animal testing Manufactured nanoparticles such as buckyballs and carbon nanotubes, used in products ranging from sunscreens to solar panels, are proliferating so quickly that safety testing for potential health hazards-similar to those

234

Formation of alcohol conversion catalysts  

DOE Patents (OSTI)

The method of the present invention involves a composition containing an intimate mixture of (a) metal oxide support particles and (b) a catalytically active metal oxide from Groups VA, VIA, or VIIA, its method of manufacture, and its method of use for converting alcohols to aldehydes. During the conversion process, catalytically active metal oxide from the discrete catalytic metal oxide particles migrates to the oxide support particles and forms a monolayer of catalytically active metal oxide on the oxide support particle to form a catalyst composition having a higher specific activity than the admixed particle composition.

Wachs, Israel E. (Bridgewater, NJ); Cai, Yeping (Louisville, KY)

2001-01-01T23:59:59.000Z

235

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

236

Methanol-Tolerant Cathode Catalyst Composite For Direct Methanol...  

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

Methanol-Tolerant Cathode Catalyst Composite For Direct Methanol Fuel Cells Methanol-Tolerant Cathode Catalyst Composite For Direct Methanol Fuel Cells A direct methanol fuel cell...

237

A Goldilocks Catalyst: Nanocluster 'just right' for Recycling...  

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

Goldilocks Catalyst A Goldilocks Catalyst Nanocluster 'just right' for recycling carbon dioxide February 21, 2011 | Tags: Chemistry, Energy Technologies, Franklin Contact: John...

238

Self-oscillations on a partially wetted catalyst pellet in ? ...  

Science Conference Proceedings (OSTI)

and the vapor–gas phases on wetted and dry catalyst pellets, respectively. ... perature and flooding states of the catalyst pellet was first observed, which were ...

239

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), ...

240

Novel metalloporphyrin catalysts for the oxidation of hydrocarbons  

DOE Green Energy (OSTI)

Work was done for developing biomimetic oxidation catalysts. Two classes of metalloporphyrin catalysts were studied. The first class of catalysts studied were a novel series of highly substituted metalloporphyrins, the fluorinated iron dodecaphenylporphyrins. These homogeneous metalloporphyrin catalysts were screened for activity as catalysts in the oxidation of hydrocarbons by dioxygen. Results are discussed with respect to catalyst structural features. The second type of catalysts studied were heterogeneous catalysts consisting of metalloporphyrins applied to inorganic supports. Preliminary catalytic testing results with these materials are presented.

Showalter, M.C.; Nenoff, T.M.; Shelnutt, J.A.

1996-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "bimetallic nanoparticle catalysts" 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

Hydrogen catalysis and scavenging action of Pd-POSS nanoparticles  

DOE Green Energy (OSTI)

Prompted by the need for a self-supported, chemically stable, and functionally flexible catalytic nanoparticle system, we explore a system involving Pd clusters coated with a monolayer of polyhedral oligomeric silsesquioxane (POSS) cages. With an initial theoretical focus on hydrogen catalysis and sequestration in the Pd-POSS system, we report Density Functional Theory (DFT) results on POSS binding energies to the Pd(110) surface, hydrogen storing ability of POSS, and possible pathways of hydrogen radicals from the catalyst surface to unsaturated bonds away from the surface.

Maiti, A; Gee, R H; Maxwell, R; Saab, A

2007-02-01T23:59:59.000Z

242

Membrane catalyst layer for fuel cells  

DOE Patents (OSTI)

A gas reaction fuel cell incorporates a thin catalyst layer between a solid polymer electrolyte (SPE) membrane and a porous electrode backing. The catalyst layer is preferably less than about 10 .mu.m in thickness with a carbon supported platinum catalyst loading less than about 0.35 mgPt/cm.sup.2. The film is formed as an ink that is spread and cured on a film release blank. The cured film is then transferred to the SPE membrane and hot pressed into the surface to form a catalyst layer having a controlled thickness and catalyst distribution. Alternatively, the catalyst layer is formed by applying a Na.sup.+ form of a perfluorosulfonate ionomer directly to the membrane, drying the film at a high temperature, and then converting the film back to the protonated form of the ionomer. The layer has adequate gas permeability so that cell performance is not affected and has a density and particle distribution effective to optimize proton access to the catalyst and electronic continuity for electron flow from the half-cell reaction occurring at the catalyst.

Wilson, Mahlon S. (Los Alamos, NM)

1993-01-01T23:59:59.000Z

243

Integrated current collector and catalyst support  

DOE Patents (OSTI)

An integrated current collecting electrode for a molten carbonate fuel cell includes a corrugated metal conductive strip positioned in contact with a catalyst layer. The corrugations of the metal strip form a plurality of gas channels immediately adjacent the surface of the catalyst through which a reactant gas flows. Each channel is filled with a particulate material to maintain separation between the metal strip and the catalyst in ensuring gas channel integrity. The catalyst may be in the form of a compacted, particulate material provided the particle size of the material within the gas channels is larger than that of the catalyst particles to prevent catalyst migration to the metal conductor and provide reactant gas access to the catalyst layer. The gas channels formed by the corrugations of the metal strip are arranged in an offset pattern along the direction of gas flow for improved reactant gas distribution to the catalyst layer. The particulate material positioned within the gas flow channels may be a ceramic conductor such as a perovskite or a spinel for enhanced current collection.

Bregoli, Lawrence J. (Southwick, MA)

1985-10-22T23:59:59.000Z

244

Ligand iron catalysts for selective hydrogenation  

SciTech Connect

Disclosed are iron ligand catalysts for selective hydrogenation of aldehydes, ketones and imines. A catalyst such as dicarbonyl iron hydride hydroxycyclopentadiene) complex uses the OH on the five member ring and hydrogen linked to the iron to facilitate hydrogenation reactions, particularly in the presence of hydrogen gas.

Casey, Charles P. (Madison, WI); Guan, Hairong (Cincinnati, OH)

2010-11-16T23:59:59.000Z

245

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

246

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

247

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

248

Nanostructured Basic Catalysts: Opportunities for Renewable Fuels  

SciTech Connect

This research studied and developed novel basic catalysts for production of renewable chemicals and fuels from biomass. We focused on the development of unique porous structural-base catalysts zeolites. These catalysts were compared to conventional solid base materials for aldol condensation, that were being commercialized for production of fuels from biomass and would be pivotal in future biomass conversion to fuels and chemicals. Specifically, we had studied the aldolpyrolysis over zeolites and the trans-esterification of vegetable oil with methanol over mixed oxide catalysts. Our research has indicated that the base strength of framework nitrogen in nitrogen substituted zeolites (NH-zeolites) is nearly twice as strong as in standard zeolites. Nitrogen substituted catalysts have been synthesized from several zeolites (including FAU, MFI, BEA, and LTL) using NH3 treatment.

Conner, William C; Huber, George; Auerbach, Scott

2009-06-30T23:59:59.000Z

249

Porosimetric study of catalyst layer of polymer electrolyte fuel cells.  

DOE Green Energy (OSTI)

The porosimetry of the catalyst layer made by the 'decal process' was studied using mercury porosirnetry. The comparison of the porosimetric profiles between the carbon powder and the catalyst supported on carbon suggests that the loading of the catalyst onto the Vulcan XC-72 carbon changes the porosimetry of the catalyst/carbon. The porosimetry of the catalyst layer depends on the catalyst used and the Nafion content. Boiling the catalyst layer effectively increases the pore area and the porosity of the catalyst layer. The correlation of porosimetric data with performance of catalyst layers suggests that the Nafion content in catalyst layers plays a vital role on the structure of catalyst layer such as pore size and pore distribution and further influences the performance of PE:FC.

Xie, J. (Jian); Wilson, K. V. (Kennard V.); Zawodzinski, T. A. (Thomas A.), Jr.

2002-01-01T23:59:59.000Z

250

Gold nanoparticle-catalyzed reduction in a model system: Quantitative determination of reactive heterogeneity of a supported nanoparticle surface  

Science Conference Proceedings (OSTI)

Kinetic poisoning experiments employing organic ligands were conducted using a gold nanoparticle–catalyzed reaction consisting of the reduction of resazurin to resorufin. The kinetic contributions of three distinct types of sites along with the number density of each of these site types during reaction were determined. The calculated number densities of each of the three types of sites, hypothesized to be corners, edges, and terraces, correlates well with atomic-resolution micrographs of the supported gold nanoparticles, obtained using aberration-corrected transmission electron microscopy and with predictions based on geometric models of idealized gold nanoparticles. The most active sites comprising 1% of the surface atoms exhibit at least 30% of the total activity of the catalyst for resazurin reduction. The selective mechanical blocking of surface sites on nanoparticles, particularly undercoordinated sites, paves the way for novel approaches utilizing organic ligands to quantify the activity of different active sites and control catalysis on metal surfaces. This work was supported in part by the Laboratory Directed Research and Development program at the Pacific Northwest National Laboratory (PNNL). The aberration-corrected electron microscopy was performed in the William R. Wiley Environmental Molecular Sciences Laboratory, a U.S. Department of Energy (DOE) national scientific user facility located at PNNL and funded by BER. PNNL is operated by Battelle for the U.S. DOE under contract DE-AC05-76RL01830.

Nigra, Michael M.; Arslan, Ilke; Katz, Alexander

2012-11-01T23:59:59.000Z

251

Selective methane oxidation over promoted oxide catalysts  

DOE Green Energy (OSTI)

Principal accomplishments have been achieved in all three areas of selective catalytic oxidation of methane that have been pursued in this research project. These accomplishments are centered on the development of catalyst systems that produce high space time yields of C{sub 2} hydrocarbon products, formaldehyde, and methanol from methane/air mixtures at moderate temperatures and at ambient pressure. The accomplishments can be summarized as the following: the SO{sub 4}{sup 2{minus}}/SrO/La{sub 2}O{sub 3} catalyst developed here has been further optimized to produce 2 kg of C{sub 2} hydrocarbons/kg catalyst/hr at 550C; V{sub 2}O{sub 5}SiO{sub 2} catalysts have been prepared that produce up to 1.5 kg formaldehyde/kg catalyst/hr at 630C with CO{sub 2} selectivities; and a novel dual bed catalyst system has been designed and tested that produces over 100 g methanol/kg catalyst/hr at 600C.

Klier, K.; Herman, R.G.

1995-06-01T23:59:59.000Z

252

Improving and inventing catalysts with computers  

Science Conference Proceedings (OSTI)

Catalytic aftertreatment emerged as the only promising technology. As no catalyst existed at that time, a new catalyst-process had to be developed. A major industry-wide research effort was mounted which, in the case of General Motors alone involved testing of over 1,500 catalyst formulations, submitted by some 82 prospective catalyst manufacturers, involving over 5,000 General Motors employees, and 22 million test miles before the catalyst was commercialized in the fall of 1974. Computational methods can provide major inroads. Deterministic modeling of kinetics and transport can be carried out with increasingly more detail as computational speed increases. At present, new catalyst design still must proceed through a stage of conceptualization and invention that is not readily modeled. It is driven by experts who successfully employ heuristics (a set of empirical rules gained through time and experience). Through inherently nondeterministic and provisional, heuristics can be addressed computationally with expert or knowledge-based systems. This is one way for the computer to help solve catalyst design problems.

Foley, H.C.; Lowenthal, E.E. (Univ. of Delaware, Newark, DE (United States). Center for Catalytic Science and Technology)

1994-08-01T23:59:59.000Z

253

Reducing fischer-tropsch catalyst attrition losses in high ...  

Reducing fischer-tropsch catalyst attrition losses in high agitation reaction systems United States Patent

254

The three way catalyst efficiency and the gas temperature difference  

Science Conference Proceedings (OSTI)

This work refers to the examination of the three way catalyst efficiency, testing the exhaust gases temperature difference (?T) at the inlet and outlet of the catalyst, using gasoline - ethanol mixtures for fuel, at a catalyst engine functioning ... Keywords: bioethanol, gas emissions, three way catalyst

Charalampos Arapatsakos; Panagiotis Lefakis

2009-02-01T23:59:59.000Z

255

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

256

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

257

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

258

Divalent metal nanoparticles  

E-Print Network (OSTI)

Metal nanoparticles hold promise for many scientific and technological applications, such as chemical and biological sensors, vehicles for drug delivery, and subdiffraction limit waveguides. To fabricate such devices, a ...

DeVries, Gretchen Anne

2008-01-01T23:59:59.000Z

259

Modified MTS MRB500 CATALYST PERFORMANCE TEST  

DOE Green Energy (OSTI)

An experiment was conducted to determine if the oxygen supply in a CuO catalyst considered for use in the TMIST-2 irradiation test would be sufficient to convert all the hydrogen isotopes coming from the irradiation test to water. A mixture of 2% H2 in Ar was supplied to a modified MRB 500 stack m onitor from Mound Techology Solutions, Miamisburg, OH. It was found that the catalyst could convert 3.75E-03 moles of H2 before losing its effectiveness. Conversion was found to begin at a catalyst temperature of about 220 deg C and to be fully effective at about 300 deg C.

Glen R. Longhurst; Robert J. Pawelko

2008-10-01T23:59:59.000Z

260

The Role of -Al2O3 Single Crystal Support to Pt Nanoparticles Construction Zhongfan Zhang*, Long Li*, Lin-lin Wang**, Sergio I. Sanchez***, Qi Wang****,  

E-Print Network (OSTI)

The Role of -Al2O3 Single Crystal Support to Pt Nanoparticles Construction Zhongfan Zhang*, Long Li the preparation of a model Pt/-Al2O3 catalyst and its characterization by a cross-sectional high-resolution electron microscopy (XHREM) method. Pt/-Al2O3 is the most important technologically-relevant heterogeneous

Frenkel, Anatoly

Note: This page contains sample records for the topic "bimetallic nanoparticle catalysts" 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

Protocol for Laboratory Testing of SCR Catalyst: 2nd Edition  

Science Conference Proceedings (OSTI)

With the widespread deployment of selective catalytic NOx reduction (SCR) throughout the U.S. fleet of coal fired utility boilers, there was a need to establish standardized protocols to test catalyst. In 2006, EPRI issued a protocol that provided a uniform basis for testing SCR catalyst. In 2007, a wide range of industry representatives, including members of the Post-Combustion NOx Control Program, catalyst vendors, an independent catalyst testing laboratory, a catalyst reconditioner, and a provider of ...

2007-12-21T23:59:59.000Z

262

Enhanced catalyst for conversion of syngas to liquid motor fuels  

DOE Patents (OSTI)

Synthesis gas comprising carbon monoxide and hydrogen is converted to C[sub 5][sup +] hydrocarbons suitable for use as liquid motor fuels by contact with a dual catalyst system capable of enhancing the selectivity of said conversion to motor fuel range hydrocarbons and the quality of the resulting motor fuel product. The catalyst composition employs a Fischer-Tropsch catalyst, together with a co-catalyst/support component comprising a SAPO silicoaluminophosphate, non-zeolitic molecular sieve catalyst.

Coughlin, P.K.; Rabo, J.A.

1985-12-03T23:59:59.000Z

263

Enhanced catalyst for conversion of syngas to liquid motor fuels  

DOE Patents (OSTI)

Synthesis gas comprising carbon monoxide and hydrogen is converted to C.sub.5.sup.+ hydrocarbons suitable for use as liquid motor fuels by contact with a dual catalyst system capable of enhancing the selectivity of said conversion to motor fuel range hydrocarbons and the quality of the resulting motor fuel product. The catalyst composition employs a Fischer-Tropsch catalyst, together with a co-catalyst/support component comprising SAPO silicoaluminophosphate, non-zeolitic molecular sieve catalyst.

Coughlin, Peter K. (Yorktown Heights, NY); Rabo, Jule A. (Armonk, NY)

1985-01-01T23:59:59.000Z

264

Catalyst Reaction (CatReact) Version 1.2  

Science Conference Proceedings (OSTI)

Catalyst Reaction (CatReact) is a spreadsheet-based software tool that helps operators of Selective Catalytic Reduction (SCR) Systems in coal-fired power plants make catalyst management decisions throughout the lifetime of the plant.   The program determines when future catalyst additions or replacements will be necessary and calculates the operations and maintenance costs of the SCR system. Cost elements include 1) catalyst purchases, 2) labor to add or replace catalyst, 3) reagent usage, ...

2012-12-04T23:59:59.000Z

265

The role of rare-earth dopants in nanophase zirconia catalysts for automotive emission control.  

DOE Green Energy (OSTI)

Rare earth (RE) modification of automotive catalysts (e.g., ZrO{sub 2}) for exhaust gas treatment results in outstanding improvement of the structural stability, catalytic functions and resistance to sintering at high temperatures. Owing to the low redox potential of nonstoichiometric CeO{sub 2}, oxygen release and intake associated with the conversion between the 3+ and 4+ oxidation states of the Ce ions in Ce-doped ZrO{sub 2} provide the oxygen storage capacity that is essentially to effective catalytic functions under dynamic air-to-fuel ratio cycling. Doping tripositive RE ions such as La and Nd in ZrO{sub 2}, on the other hand, introduces oxygen vacancies that affect the electronic and ionic conductivity. These effects, in conjunction with the nanostructure and surface reactivity of the fine powders, present a challenging problem in the development of better ZrO{sub 2}-containing three-way catalysts. We have carried out in-situ small-to-wide angle neutron diffraction at high temperatures and under controlled atmospheres to study the structural phase transitions, sintering behavior, and Ce{sup 3+} {leftrightarrow} Ce{sup 4+} redox process. We found substantial effects due to RE doping on the nature of aggregation of nanoparticles, defect formation, crystal phase transformation, and metal-support interaction in ZrO{sub 2} catalysts for automotive emission control.

Loong, C.-K.; Ozawa, M.

1999-07-16T23:59:59.000Z

266

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

267

Catalyst regeneration process including metal contaminants removal  

DOE Patents (OSTI)

Spent catalysts removed from a catalytic hydrogenation process for hydrocarbon feedstocks, and containing undesired metals contaminants deposits, are regenerated. Following solvent washing to remove process oils, the catalyst is treated either with chemicals which form sulfate or oxysulfate compounds with the metals contaminants, or with acids which remove the metal contaminants, such as 5-50 W % sulfuric acid in aqueous solution and 0-10 W % ammonium ion solutions to substantially remove the metals deposits. The acid treating occurs within the temperature range of 60.degree.-250.degree. F. for 5-120 minutes at substantially atmospheric pressure. Carbon deposits are removed from the treated catalyst by carbon burnoff at 800.degree.-900.degree. F. temperature, using 1-6 V % oxygen in an inert gas mixture, after which the regenerated catalyst can be effectively reused in the catalytic process.

Ganguli, Partha S. (Lawrenceville, NJ)

1984-01-01T23:59:59.000Z

268

Catalysts for Destruction of Air Pollutants  

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

Destruction of Air Pollutants Catalysts for Destruction of Air Pollutants U.S. industries and the U.S. Department of Energy must manage a variety of off-gas wastes consisting of...

269

Moderated ruthenium fischer-tropsch synthesis catalyst  

DOE Patents (OSTI)

The subject Fischer-Tropsch catalyst comprises moderated ruthenium on an inorganic oxide support. The preferred moderator is silicon. Preferably the moderator is effectively positioned in relationship to ruthenium particles through simultaneous placement on the support using reverse micelle impregnation.

Abrevaya, Hayim (Wilmette, IL)

1991-01-01T23:59:59.000Z

270

SLAC National Accelerator Laboratory - Designing Chemical Catalysts...  

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

Designing Chemical Catalysts: There's an App for That By Mike Ross January 19, 2012 A big reason for publishing scientific results is to inform others who can then use your data...

271

Clean gasoline reforming with superacid catalysts  

DOE Green Energy (OSTI)

The objectives of this project are to: (a) determine if a coal-derived naphtha can be hydrotreated to produce a product with a sufficiently low heteroatom content that can be used for reforming, (b) identify hydrocarbon compounds in the naphtha with concentrations greater than 0.5 wt %, (c) develop a Pt/Al[sub 2]O[sub 3] heavily chlorided catalyst and determine the activity, selectivity and deactivation of this catalyst using model compounds and the hydrotreated naphtha, and (d) develop both a sulfated Pt/ZrO[sub 2] and Fe/Mn/ZrO[sub 2] catalyst formulations and determine the activity, selectivity and deactivation of these catalysts using model compounds and d warranted, the hydrotreated naphtha.

Davis, B.H.

1992-01-01T23:59:59.000Z

272

Oxford Catalysts Group plc | Open Energy Information  

Open Energy Info (EERE)

Oxford Catalysts Group plc Oxford Catalysts Group plc Jump to: navigation, search Name Oxford Catalysts Group plc Place Oxford, United Kingdom Zip OX2 6UD Sector Hydro, Hydrogen Product Developer of catalysts for room-temperature hydrogen production, hot steam production and Fischer-Tropsch processes. Coordinates 43.781517°, -89.571699° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":43.781517,"lon":-89.571699,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

273

Pf/Zeolite Catalyst for Tritium Stripping  

DOE Green Energy (OSTI)

This report described promising hydrogen (protium and tritium) stripping results obtained with a Pd/zeolite catalyst at ambient temperature. Preliminary results show 90-99+ percent tritium stripping efficiency may be obtained, with even better performance expected as bed configuration and operating conditions are optimized. These results suggest that portable units with single beds of the Pd/zeolite catalyst may be utilized as ''catalytic absorbers'' to clean up both tritium gas and tritiated water. A cart-mounted prototype stripper utilizing this catalyst has been constructed for testing. This portable stripper has potential applications in maintenance-type jobs such as tritium line breaks. This catalyst can also potentially be utilized in an emergency stripper for the Replacement Tritium Facility.

Hsu, R.H.

2001-03-26T23:59:59.000Z

274

Selective methane oxidation over promoted oxide catalysts  

DOE Green Energy (OSTI)

Objective was to selectively oxidize methane to C{sub 2} hydrocarbons and to oxygenates, in particular formaldehyde and methanol, in high space time yields under relatively mild reaction conditions. Results in this document are reported under the headings: methane oxidation over silica, methane oxidation over Sr/La{sub 2}O{sub 3} catalysts, and oxidative coupling of methane over sulfate-doped Sr/La{sub 2}O{sub 3} catalysts. 24 refs, 10 figs, 4 tabs.

Klier, K.; Herman, R.G.

1993-12-31T23:59:59.000Z

275

Single-layer transition metal sulfide catalysts  

SciTech Connect

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

Thoma, Steven G. (Albuquerque, NM)

2011-05-31T23:59:59.000Z

276

Single-layer transition metal sulfide catalysts  

DOE Patents (OSTI)

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

Thoma, Steven G. (Albuquerque, NM)

2011-05-31T23:59:59.000Z

277

Catalyst and method for aqueous phase reactions  

DOE Patents (OSTI)

The present invention is a catalyst in the form of a plurality of porous particles wherein each particle is a support having nickel metal catalytic phase or reduced nickel deposited thereon in a first dispersed phase and an additional metal deposited onto the support in a second dispersed phase. The additional metal is effective in retarding or reducing agglomeration or sintering of the nickel metal catalytic phase without substantially affecting the catalytic activity, thereby increasing the life time of the catalyst.

Elliott, Douglas C. (Richland, WA); Hart, Todd R. (Kennewick, WA)

1999-01-01T23:59:59.000Z

278

Microfluidic Synthesis of Nickel Nanoparticles  

Science Conference Proceedings (OSTI)

In the current investigation, we aim at synthesizing nickel nanoparticles of ... A Novel Type of Carbon Coated Sulfur Nanoparticles for Li/S Batteries .... Production and Mechanical Properties of Nanostructured Copper and Copper Zinc Alloys.

279

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.

280

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.

Note: This page contains sample records for the topic "bimetallic nanoparticle catalysts" 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

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.

282

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.

283

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.

284

Low temperature catalysts for methanol production  

DOE Patents (OSTI)

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

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

1986-01-01T23:59:59.000Z

285

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.

286

Low temperature catalysts for methanol production  

DOE Patents (OSTI)

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

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

1985-03-12T23:59:59.000Z

287

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.

288

Effects of Membrane- and Catalyst-layer-thickness Nonuniformities in Polymer-electrolyte Fuel Cells  

E-Print Network (OSTI)

thicknesses for the membrane and catalyst layer. Figure 2.of dry membrane (a) and catalyst-layer (b) thickness (andhollow symbols) and catalyst-layer (filled symbols)

Weber, Adam Z.; Newman, John

2006-01-01T23:59:59.000Z

289

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

290

A Well-Defined, Silica-Supported Tungsten Imido Alkylidene Olefin Metathesis Catalyst  

E-Print Network (OSTI)

olefin metathesis catalyst. Bouchra Rhers, a Alain Salameh,active propene metathesis catalyst, which can achieve 16000W-based olefin metathesis catalyst through the reaction of [

2006-01-01T23:59:59.000Z

291

Extended Two Dimensional Nanotube and Nanowire Surfaces as Fuel Cell Catalysts  

E-Print Network (OSTI)

for a thinner electrode catalyst layer, thereby improvingmass transport and catalyst utilization. ReferencesSurfaces as Fuel Cell Catalysts A Dissertation submitted in

Alia, Shaun Michael

2011-01-01T23:59:59.000Z

292

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

293

Reaction selectivity studies on nanolithographically-fabricated platinum model catalyst arrays  

E-Print Network (OSTI)

Structure of Metallic Catalysts. Academic Press, London,R. Structure of Metallic Catalysts. Academic Press, London,Ethylene on Metallic Catalysts, National Standard Reference

Grunes, Jeffrey Benjamin

2004-01-01T23:59:59.000Z

294

Nanostructured Cobalt Oxide Clusters in Mesoporous Silica as Efficient Oxygen-Evolving Catalysts  

E-Print Network (OSTI)

as Efficient Oxygen- Evolving Catalysts Feng Jiao and Heinzof efficient and robust catalysts for the chemicaltransformations. Catalysts need to exhibit turnover

Jiao, Feng

2010-01-01T23:59:59.000Z

295

Bifunctional Solid Catalysts for the Selective Conversion of Fructose to 5-Hydroxymethylfurfural  

E-Print Network (OSTI)

Bifunctional Solid Catalysts for the Selective Conversion ofat Springerlink.com Abstract Solid catalysts based on SBA-15methylfurfural (HMF). The catalysts incorporate thioether

Crisci, Anthony J.; Tucker, Mark H.; Dumesic, James A.; Scott, Susannah L.

2010-01-01T23:59:59.000Z

296

Cyclohexene Photo-oxidation over Vanadia Catalyst Analyzed by Time Resolved ATR-FT-IR Spectroscopy  

E-Print Network (OSTI)

oxidation over Vanadia Catalyst Analyzed by Time Resolvedperformance of vanadia catalysts [5] even though hydrationabsorption spectrum of these catalysts into the visible [

Mul, Guido

2008-01-01T23:59:59.000Z

297

THE MECHANISM AND KINETICS OF FISCHER-TROPSCH SYNTHESIS OVER SUPPORTED RUTHENIUM CATALYSTS  

E-Print Network (OSTI)

Structure of Metallic Catalysts", Academic Press Inc. , Newselectivity of these catalysts. Several appendices dealingOver Supported Ruthenium Catalysts ABSTRACT The effects of

Kellner, Carl Stephen

2013-01-01T23:59:59.000Z

298

Intermittency on catalysts: symmetric exclusion  

E-Print Network (OSTI)

We continue our study of intermittency for the parabolic Anderson equation $\\partial u/\\partial t = \\kappa\\Delta u + \\xi u$, where $u\\colon \\Z^d\\times [0,\\infty)\\to\\R$, $\\kappa$ is the diffusion constant, $\\Delta$ is the discrete Laplacian, and $\\xi\\colon \\Z^d\\times [0,\\infty)\\to\\R$ is a space-time random medium. The solution of the equation describes the evolution of a ``reactant'' $u$ under the influence of a ``catalyst'' $\\xi$. In this paper we focus on the case where $\\xi$ is exclusion with a symmetric random walk transition kernel, starting from equilibrium with density $\\rho\\in (0,1)$. We consider the annealed Lyapunov exponents, i.e., the exponential growth rates of the successive moments of $u$. We show that these exponents are trivial when the random walk is recurrent, but display an interesting dependence on the diffusion constant $\\kappa$ when the random walk is transient, with qualitatively different behavior in different dimensions. Special attention is given to the asymptotics of the exponents for $\\kappa\\to\\infty$, which is controlled by moderate deviations of $\\xi$ requiring a delicate expansion argument. In G\\"artner and den Hollander \\cite{garhol04} the case where $\\xi$ is a Poisson field of independent (simple) random walks was studied. The two cases show interesting differences and similarities. Throughout the paper, a comparison of the two cases plays a crucial role.

J. Gaertner; F. den Hollander; G. Maillard

2006-05-24T23:59:59.000Z

299

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

300

Stepwise method determines source of FCC catalyst losses  

Science Conference Proceedings (OSTI)

A set of guidelines for fluid catalytic cracking unit (FCCU) monitoring and a logical, stepwise approach to troubleshooting FCC catalyst losses is discussed. This will help process or operations engineers find the causes of such losses. A thorough understanding of the entire catalyst stem during normal operations establishes the base line data necessary for troubleshooting. A comprehensive, ongoing analysis of catalyst losses include: catalyst balance, fresh catalyst physical properties, equilibrium catalyst properties, fine particle size distribution, pressure surveys, and line and restriction orifice records. The paper goes on to identify each step in monitoring these operations and properties.

Fletcher, R. [Akzo-Nobel Chemicals Inc., Houston, TX (United States)

1995-08-28T23:59:59.000Z

Note: This page contains sample records for the topic "bimetallic nanoparticle catalysts" 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

Method of depositing a catalyst on a fuel cell electrode  

DOE Patents (OSTI)

Fuel cell electrodes comprising a minimal load of catalyst having maximum catalytic activity and a method of forming such fuel cell electrodes. The method comprises vaporizing a catalyst, preferably platinum, in a vacuum to form a catalyst vapor. A catalytically effective amount of the catalyst vapor is deposited onto a carbon catalyst support on the fuel cell electrode. The electrode preferably is carbon cloth. The method reduces the amount of catalyst needed for a high performance fuel cell electrode to about 0.3 mg/cm.sup.2 or less.

Dearnaley, Geoffrey (San Antonio, TX); Arps, James H. (San Antonio, TX)

2000-01-01T23:59:59.000Z

302

Diesel Fuel Sulfur Effects on the Performance of Diesel Oxidation Catalysts  

DOE Green Energy (OSTI)

Research focus: - Impact of sulfur on: Catalyst performance; Short term catalyst durability. This presentation summarizes results from fresh catalyst performance evaluations - WVU contracted to conduct DOC and Lean NOx catalyst testing for DECSE DECSE program. (experimental details discussed previously)

Whitacre, Shawn D.

2000-08-20T23:59:59.000Z

303

Process and catalyst for carbonylating olefins  

DOE Patents (OSTI)

Disclosed is an improved catalyst system and process for preparing aliphatic carbonyl compounds such as aliphatic carboxylic acids, alkyl esters of aliphatic carboxylic acids and anhydrides of aliphatic carboxylic acids by carbonylating olefins in the presence of a catalyst system comprising (1) a first component selected from at least one Group 6 metal, i.e., chromium, molybdenum, and/or tungsten and (2) a second component selected from at least one of certain halides and tertiary and quaternary compounds of a Group 15 element, i.e., nitrogen, phosphorus and/or arsenic, and (3) as a third component, a polar, aprotic solvent. The process employing the improved catalyst system is carried out under carbonylating conditions of pressure and temperature discussed herein. The process constitutes and improvement over known processes since it can be carried out at moderate carbonylation conditions without the necessity of using an expensive noble metal catalyst, volatile, toxic materials such as nickel tetracarbonyl, formic acid or a formate ester. Further, the addition of a polar, aprotic solvent to the catalyst system significantly increases, or accelerates, the rate at which the carbonylation takes place.

Zoeller, Joseph Robert (Kingsport, TN)

1998-06-02T23:59:59.000Z

304

Method for dispersing catalyst onto particulate material  

DOE Patents (OSTI)

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

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

1992-01-01T23:59:59.000Z

305

Computational Design of Lignin Depolymerization Catalysts  

Science Conference Proceedings (OSTI)

Lignin is a major component of plant cell walls that is typically underutilized in selective conversion strategies for renewable fuels and chemicals. The mechanisms by which thermal and catalytic treatments deconstruct lignin remain elusive, for which quantum mechanical calculations can offer fundamental insights. In this work, a computational approach has been used to elucidate the reductive deconstruction pathway of a ruthenium-catalyzed system. Transition states have been computed to determine the rate-limiting steps for a catalyst that cleaves arylether linkages. Our calculations are supported by experimental synthesis and kinetic and thermodynamic measurements of the deconstruction of model lignin dimers by a ruthenium catalyst with the ultimate objective of designing new catalysts to eventually utilize lignin in biorefineries.

Kim, S.; Chmely, S. C.; Sturgeon, M.; Katahira, R.; Paton, R. S.; Beckham, G. T.

2012-01-01T23:59:59.000Z

306

Homogeneous catalyst formulations for methanol production  

DOE Patents (OSTI)

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

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

1991-02-12T23:59:59.000Z

307

Homogeneous catalyst formulations for methanol production  

DOE Patents (OSTI)

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

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

1990-01-01T23:59:59.000Z

308

Enhancement of alkylation catalysts for improved supercritical fluid regeneration  

DOE Patents (OSTI)

A method of modifying an alkylation catalyst to reduce the formation of condensed hydrocarbon species thereon. The method comprises providing an alkylation catalyst comprising a plurality of active sites. The plurality of active sites on the alkylation catalyst may include a plurality of weakly acidic active sites, intermediate acidity active sites, and strongly acidic active sites. A base is adsorbed to a portion of the plurality of active sites, such as the strongly acidic active sites, selectively poisoning the strongly acidic active sites. A method of modifying the alkylation catalyst by providing an alkylation catalyst comprising a pore size distribution that sterically constrains formation of the condensed hydrocarbon species on the alkylation catalyst or by synthesizing the alkylation catalyst to comprise a decreased number of strongly acidic active sites is also disclosed, as is a method of improving a regeneration efficiency of the alkylation catalyst.

Ginosar, Daniel M. (Idaho Falls, ID); Petkovic, Lucia M. (Idaho Falls, ID)

2010-12-28T23:59:59.000Z

309

Method of performing sugar dehydration and catalyst treatment  

Science Conference Proceedings (OSTI)

The invention includes a method of treating a solid acid catalyst. After exposing the catalyst to a mixture containing a sugar alcohol, the catalyst is washed with an organic solvent and is then exposed to a second reaction mixture. The invention includes a process for production of anhydrosugar alcohol. A solid acid catalyst is provided to convert sugar alcohol in a first sample to an anhydrosugar alcohol. The catalyst is then washed with an organic solvent and is subsequently utilized to expose a second sample. The invention includes a method for selective production of an anhydrosugar. A solid acid catalyst is provided within a reactor and anhydrosugar alcohol is formed by flowing a starting sugar alcohol into the reactor. The acid catalyst is then exposed to an organic solvent which allows a greater amount of additional anhydrosugar to be produced than would occur without exposing the acid catalyst to the organic solvent.

Hu, Jianli [Kennewick, WA; Holladay, Johnathan E [Kennewick, WA; Zhang, Xinjie [Burlington, MA; Wang, Yong [Richland, WA

2010-06-01T23:59:59.000Z

310

Enhancement of alkylation catalysts for improved supercritical fluid regeneration  

DOE Patents (OSTI)

A method of modifying an alkylation catalyst to reduce the formation of condensed hydrocarbon species thereon. The method comprises providing an alkylation catalyst comprising a plurality of active sites. The plurality of active sites on the alkylation catalyst may include a plurality of weakly acidic active sites, intermediate acidity active sites, and strongly acidic active sites. A base is adsorbed to a portion of the plurality of active sites, such as the strongly acidic active sites, selectively poisoning the strongly acidic active sites. A method of modifying the alkylation catalyst by providing an alkylation catalyst comprising a pore size distribution that sterically constrains formation of the condensed hydrocarbon species on the alkylation catalyst or by synthesizing the alkylation catalyst to comprise a decreased number of strongly acidic active sites is also disclosed, as is a method of improving a regeneration efficiency of the alkylation catalyst.

Ginosar, Daniel M. (Idaho Falls, ID); Petkovic, Lucia (Idaho Falls, ID)

2009-09-22T23:59:59.000Z

311

Los Alamos catalyst could jumpstart e-cars, green energy  

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

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...

312

Water Uptake of Fuel-Cell Catalyst Layers  

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

Water Uptake of Fuel-Cell Catalyst Layers Title Water Uptake of Fuel-Cell Catalyst Layers Publication Type Journal Article Year of Publication 2012 Authors Kusoglu, Ahmet, Anthony...

313

BSA 02-27: Catalysts for Hydrogenation and Hydrosilylation of ...  

... (30 mM) at 23 °C and 4 atm H 2 in CD 2 Cl 2. Homogeneous catalysts are usually more selective than heterogeneous catalysts, but they are often difficult to recycle.

314

Catalysts for oxidation of mercury in flue gas  

DOE Patents (OSTI)

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

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

2010-08-17T23:59:59.000Z

315

Catalyst dispersion and activity under conditions of temperature- staged liquefaction. [Catalyst precursors for molybdenum-based catalyst and iron-based catalyst  

DOE Green Energy (OSTI)

Two coals, a Texas subbituminous C and a Utah high volatile A bituminous, were used to examine the effects of solvent swelling and catalyst impregnation on liquefaction conversion behavior in temperature staged reactions for 30 minutes each at 275{degree} and 425{degree}C in H{sub 2} and 95:5 H{sub 2}:H{sub 2}S atmospheres. Methanol, pyridine, tetrahydrofuran, and tetrabutylammonium hydroxide were used as swelling agents. Molybdenum-based catalyst precursors were ammonium tetrathiomolybdate, molybdenum trisulfide, molybdenum hexacarbonyl, and bis(tricarbonylcyclopentadienyl-molybdenum). Ferrous sulfate and bis(dicarbonylcyclo-pentadienyliron) served as iron-based catalyst precursors. In addition, ion exchange was used for loading iron onto the subbituminous coal. For most experiments, liquefaction in H{sub 2}:H{sub 2}S was superior to that in H{sub 2}, regardless of the catalyst precursor. The benefit of the H{sub 2}S was greater for the subbituminous, presumably because of its higher iron content relative to the hvab coal. Tetrabutylammonium hydroxide was the only swelling agent to enhance conversion of the hvab coal significantly; it also caused a remarkable increase in conversion of the subbituminous coal. The combined application of solvent swelling and catalyst impregnation also improves liquefaction, mainly through increased oil yields from the hvab coal and increased asphaltenes from the subbituminous. A remarkable effect from use of ammonium tetrathiomolybdate as a catalyst precursor is substantial increase in pristane and phytane yields. Our findings suggest that these compounds are, at least in part, bound to the coal matrix.

Davis, A.; Schobert, H.H.; Mitchell, G.D.; Artok, L.

1992-07-01T23:59:59.000Z

316

Catalysts for lean burn engine exhaust abatement  

DOE Patents (OSTI)

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

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

2003-01-01T23:59:59.000Z

317

Catalysts For Lean Burn Engine Exhaust Abatement  

DOE Patents (OSTI)

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

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

2004-04-06T23:59:59.000Z

318

Method for producing iron-based catalysts  

DOE Patents (OSTI)

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

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

1999-01-01T23:59:59.000Z

319

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

320

Stabilization of Nickel Metal Catalysts for Aqueous Processing ...  

Search PNNL. PNNL Home; About; Research; Publications; Jobs; News; Contacts; Stabilization of Nickel Metal Catalysts for Aqueous Processing Systems. ...

Note: This page contains sample records for the topic "bimetallic nanoparticle catalysts" 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

Catalyst structure and method of fischer-tropsch synthesis  

Science Conference Proceedings (OSTI)

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

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

2002-12-10T23:59:59.000Z

322

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

323

Supercritical/Solid Catalyst (SSC) - Energy Innovation Portal  

Idaho National Laboratory. Contact INL About This Technology Technology Marketing Summary Supercritical/Solid Catalyst (SSC) is a tested ...

324

Numerical study of reaction in porous catalysts under composition modulation  

E-Print Network (OSTI)

in monolithic NOx storage and reduction catalyst." Topics in2007). "Model for NOx storage/reduction in the presence of

Hsiao, Hsu-Wen

2010-01-01T23:59:59.000Z

325

Substituted pyridine ligands and related water-soluble catalysts  

SciTech Connect

Versatile Group VIII metathesis catalysts, as can be used in a range of polymerization reactions and other chemical methodologies.

Emrick, Todd S. (Deerfield, MA)

2011-06-14T23:59:59.000Z

326

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

327

Cobalt Fischer-Tropsch catalysts having improved selectivity  

DOE Patents (OSTI)

The promoter(s) Mn oxide or Mn oxide and Zr oxide are added to a cobalt Fischer-Tropsch catalyst combined with the molecular sieve TC-103 or TC-123 such that the resultant catalyst demonstrates improved product selectivity, stability and catalyst life. The improved selectivity is evidenced by lower methane production, higher C5+ yield and increased olefin production.

Miller, James G. (Pearl River, NY); Rabo, Jule A. (Armonk, NY)

1989-01-01T23:59:59.000Z

328

Support Defined Novel Catalyst for Enhanced Fischer-Tropsch Activity.  

E-Print Network (OSTI)

??Four distinct Fisher-Tropsch catalysts were prepared through the incipient wetness technique. These catalysts were Fe-Zn-Ru/alumina, Fe-Zn-Ru/K/alumina, Fe-Zn-Ru/silica, and Fe-Zn-Ru/K/silica. The physical characterization of the catalysts… (more)

Lievers, Ashley Ann

2009-01-01T23:59:59.000Z

329

Recycling and Disposal of Spent Selective Catalytic Reduction Catalyst  

Science Conference Proceedings (OSTI)

Selective catalytic reduction (SCR) technology has become widespread within the utility industry as a means of controlling emissions of nitrogen oxides (NOx). The technology uses a solid catalyst that deactivates over time; and thus significant volumes of catalyst will need regeneration, recycle, or disposal. This study examined issues related to spent catalyst recycle and disposal.

2003-11-12T23:59:59.000Z

330

Separation of catalyst from Fischer-Tropsch slurry  

DOE Patents (OSTI)

This paper describes a process for the separation of catalysts used in Fischer-Tropsch synthesis. The separation is accomplished by extraction in which the organic compounds in the wax are dissolved and carried away from the insoluble inorganic catalyst particles that are primarily inorganic. The purified catalyst can be upgraded by various methods.

White, C.M.; Quiring, M.S.; Jensen, K.L.; Hickey, R.F.; Gillham, L.D.

1998-04-01T23:59:59.000Z

331

Nano Catalysts for Diesel Engine Emission Remediation  

DOE Green Energy (OSTI)

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

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

2012-06-01T23:59:59.000Z

332

Environmental Leaching of Nanoparticles from Consumer ...  

Science Conference Proceedings (OSTI)

... Nanoparticle-based consumer products are becoming available in the market at an increasing rate, but the safety of nanoparticles and the ...

2012-10-02T23:59:59.000Z

333

Evaluation of monolayer protected metal nanoparticle technology  

E-Print Network (OSTI)

Self assembling nanostructured nanoparticles represent a new class of synthesized materials with unique functionality. Such monolayer protected metal nanoparticles are capable of resisting protein adsorption, and if utilized ...

Wu, Diana J

2005-01-01T23:59:59.000Z

334

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

335

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

336

Water Uptake in PEMFC Catalyst Layers  

SciTech Connect

Water uptake profiles of proton-exchange-membrane fuel-cell catalyst layers are characterized in the form of capillary-pressure saturation (Pc-S) curves. The curves indicate that the catalyst layers tested are highly hydrophilic and require capillary pressures as low as -80 kPa to eject imbibed water. Comparison of materials made with and without Pt indicates a difference in water ejection and uptake phenomena due to the presence of Pt. The addition of Pt increases the tendency of the catalyst layer to retain water. Dynamic vapor sorption (DVS) is used to characterize the water-vapor sorption onto Nafion, Pt/C, and C surfaces. The DVS results align with the trends found from the Pc-S curves and show an increased propensity for water uptake in the presence of Pt. The effect of the ion in Nafion, sodium or protonated form, is also compared and demonstrates that although the protonation of the Nafion in the catalyst layer also increases hydrophilicity, the effect is not as great as that caused by Pt.

Gunterman, Haluna P.; Kwong, Anthony H.; Gostick, Jeffrey T.; Kusoglu, Ahmet; Weber, Adam Z.

2011-07-01T23:59:59.000Z

337

Nitrated metalloporphyrins as catalysts for alkane oxidation  

DOE Patents (OSTI)

Alkanes are oxidized by contact with oxygen-containing gas in the presence as catalyst of a metalloporphyrin in which hydrogen atoms in the porphyrin ring have been replaced with one or more nitro groups. Hydrogen atoms in the porphyrin ring may also be substituted with halogen atoms.

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

1992-01-01T23:59:59.000Z

338

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

339

Process of activation of a palladium catalyst system  

Science Conference Proceedings (OSTI)

Improved processes for activating a catalyst system used for the reduction of nitrogen oxides are provided. In one embodiment, the catalyst system is activated by passing an activation gas stream having an amount of each of oxygen, water vapor, nitrogen oxides, and hydrogen over the catalyst system and increasing a temperature of the catalyst system to a temperature of at least 180.degree. C. at a heating rate of from 1-20.degree./min. Use of activation processes described herein leads to a catalyst system with superior NOx reduction capabilities.

Sobolevskiy, Anatoly (Orlando, FL); Rossin, Joseph A. (Columbus, OH); Knapke, Michael J. (Columbus, OH)

2011-08-02T23:59:59.000Z

340

Catalysts for conversion of syngas to liquid motor fuels  

DOE Patents (OSTI)

Synthesis gas comprising carbon monoxide and hydrogen is converted to C.sub.5.sup.+ hydrocarbons suitable for use as liquid motor fuels by contact with a dual catalyst composition capable of ensuring the production of only relatively minor amounts of heavy products boiling beyond the diesel oil range. The catalyst composition, having desirable stability during continuous production operation, employs a Fischer-Tropsch catalyst, together with a co-catalyst/support component. The latter component is a steam-stabilized zeolite Y catalyst of hydrophobic character, desirably in acid-extracted form.

Rabo, Jule A. (Armonk, NY); Coughlin, Peter K. (Yorktown Heights, NY)

1987-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "bimetallic nanoparticle catalysts" 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

Catalyst Additives to Enhance Mercury Oxidation and Capture  

SciTech Connect

Preliminary research has shown that SCR catalysts employed for nitrogen-oxide reduction can effectively oxidize mercury. This report discusses initial results from fundamental investigations into the behavior of mercury species in the presence of SCR catalysts at Southern Research Institute. Three different SCR catalysts are being studied. These are honeycomb-type, plate-type, and a hybrid-type catalyst. The catalysts are manufactured and supplied by Cormetech Inc., Hitachi America Ltd., and Haldor-Topsoe Inc., respectively. Test methods and experimental procedures were developed for current and future testing. The methods and procedures equalize factors influencing mercury adsorption and oxidation (surface area, catalyst activity, and pore structure) that normally differ for each catalyst type. Initial testing was performed to determine the time necessary for each catalyst to reach surface-adsorption equilibrium. In addition, the fraction of Hg oxidized by each of the SCR catalyst types is being investigated, for a given amount of catalyst and flow rate of mercury and flue gas. The next major effort will be to examine the kinetics of mercury oxidation across the SCR catalysts with respect to changes in mercury concentration and with respect to HCl concentration. Hg-sorption equilibrium times will also be investigated with respect to ammonia concentration in the simulated flue gas.

Jared W. Cannon; Thomas K. Gale

2004-12-31T23:59:59.000Z

342

Hydrocarbon reforming catalyst material and configuration of the same  

DOE Patents (OSTI)

A hydrocarbon reforming catalyst material comprising a catalyst support impregnated with catalyst is provided for reforming hydrocarbon fuel gases in an electrochemical generator. Elongated electrochemical cells convert the fuel to electrical power in the presence of an oxidant, after which the spent fuel is recirculated and combined with a fresh hydrocarbon feed fuel forming the reformable gas mixture which is fed to a reforming chamber containing a reforming catalyst material, where the reforming catalyst material includes discrete passageways integrally formed along the length of the catalyst support in the direction of reformable gas flow. The spent fuel and/or combusted exhaust gases discharged from the generator chamber transfer heat to the catalyst support, which in turn transfers heat to the reformable gas and to the catalyst, preferably via a number of discrete passageways disposed adjacent one another in the reforming catalyst support. The passageways can be slots extending inwardly from an outer surface of the support body, which slots are partly defined by an exterior confining wall. According to a preferred embodiment, the catalyst support is non-rigid, porous, fibrous alumina, wherein the fibers are substantially unsintered and compressible, and the reforming catalyst support is impregnated, at least in the discrete passageways with Ni and MgO, and has a number of internal slot passageways for reformable gas, the slot passageways being partly closed by a containing outer wall. 5 figs.

Singh, P.; Shockling, L.A.; George, R.A.; Basel, R.A.

1996-06-18T23:59:59.000Z

343

Hydrocarbon reforming catalyst material and configuration of the same  

DOE Patents (OSTI)

A hydrocarbon reforming catalyst material comprising a catalyst support impregnated with catalyst is provided for reforming hydrocarbon fuel gases in an electrochemical generator. Elongated electrochemical cells convert the fuel to electrical power in the presence of an oxidant, after which the spent fuel is recirculated and combined with a fresh hydrocarbon feed fuel forming the reformable gas mixture which is fed to a reforming chamber containing a reforming catalyst material, where the reforming catalyst material includes discrete passageways integrally formed along the length of the catalyst support in the direction of reformable gas flow. The spent fuel and/or combusted exhaust gases discharged from the generator chamber transfer heat to the catalyst support, which in turn transfers heat to the reformable gas and to the catalyst, preferably via a number of discrete passageways disposed adjacent one another in the reforming catalyst support. The passageways can be slots extending inwardly from an outer surface of the support body, which slots are partly defined by an exterior confining wall. According to a preferred embodiment, the catalyst support is non-rigid, porous, fibrous alumina, wherein the fibers are substantially unsintered and compressible, and the reforming catalyst support is impregnated, at least in the discrete passageways with Ni and MgO, and has a number of internal slot passageways for reformable gas, the slot passageways being partly closed by a containing outer wall.

Singh, Prabhakar (Export, PA); Shockling, Larry A. (Plum Borough, PA); George, Raymond A. (Pittsburgh, PA); Basel, Richard A. (Plub Borough, PA)

1996-01-01T23:59:59.000Z

344

Near Critical Catalyst Reactant Branching Processes with Controlled Immigration  

E-Print Network (OSTI)

Near critical catalyst-reactant branching processes with controlled immigration are studied. The reactant population evolves according to a branching process whose branching rate is proportional to the total mass of the catalyst. The bulk catalyst evolution is that of a classical continuous time branching process; in addition there is a specific form of immigration. Immigration takes place exactly when the catalyst population falls below a certain threshold, in which case the population is instantaneously replenished to the threshold. Such models are motivated by problems in chemical kinetics where one wants to keep the level of a catalyst above a certain threshold in order to maintain a desired level of reaction activity. A diffusion limit theorem for the scaled processes is presented, in which the catalyst limit is described through a reflected diffusion, while the reactant limit is a diffusion with coefficients that are functions of both the reactant and the catalyst. Stochastic averaging principles under ...

Budhiraja, Amarjit

2012-01-01T23:59:59.000Z

345

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

346

Refiner details ``best practices`` approach to catalyst selection  

Science Conference Proceedings (OSTI)

Catalysts are critical to hydrocarbon processing in refineries. Refiners spend millions of dollars per year on catalysts. This cost, however, pales in comparison to the impact that catalysts can have. The lost opportunity from not using the right catalyst, or an unscheduled shutdown caused by a catalyst-related problem, can be an order of magnitude higher than the cost of the catalyst itself. Chevron Products Co. has adopted a best practices approach to addressing technical and operational issues in refining. A subset of the best-practices program includes the testing, selection, and monitoring of catalysts for Chevron`s fluid catalytic cracking (FCC), catalytic reforming, and hydroprocessing units. The paper discusses these practices.

Krishna, A.S. [Chevron Products Co., El Segundo, CA (United States); Arndt, J.H. [Chevron Products Co., Richmond, CA (United States); Kuehler, C.W.; Kramer, D.C. [Chevron Research and Technology Co., Richmond, CA (United States)

1996-10-14T23:59:59.000Z

347

Novel Attrition-Resistant Fischer Tropsch Catalyst  

DOE Green Energy (OSTI)

There is a strong national interest in the Fischer-Tropsch synthesis process because it offers the possibility of making liquid hydrocarbon fuels from reformed natural gas or coal and biomass gasification products. This project explored a new approach that had been developed to produce active, attrition-resistant Fischer-Tropsch catalysts that are based on glass-ceramic materials and technology. This novel approach represented a promising solution to the problem of reducing or eliminating catalyst attrition and maximizing catalytic activity, thus reducing costs. The technical objective of the Phase I work was to demonstrate that glass-ceramic based catalytic materials for Fischer-Tropsch synthesis have resistance to catalytic deactivation and reduction of particle size superior to traditional supported Fischer-Tropsch catalyst materials. Additionally, these novel glass-ceramic-based materials were expected to exhibit catalytic activity similar to the traditional materials. If successfully developed, the attrition-resistant Fischer-Tropsch catalyst materials would be expected to result in significant technical, economic, and social benefits for both producers and public consumers of Fischer-Tropsch products such as liquid fuels from coal or biomass gasification. This program demonstrated the anticipated high attrition resistance of the glass-ceramic materials. However, the observed catalytic activity of the materials was not sufficient to justify further development at this time. Additional testing documented that a lack of pore volume in the glass-ceramic materials limited the amount of surface area available for catalysis and consequently limited catalytic activity. However, previous work on glass-ceramic catalysts to promote other reactions demonstrated that commercial levels of activity can be achieved, at least for those reactions. Therefore, we recommend that glass-ceramic materials be considered again as potential Fischer-Tropsch catalysts if it can be demonstrated that materials with adequate pore volume can be produced. During the attrition resistance tests, it was learned that the glass-ceramic materials are very abrasive. Attention should be paid in any further developmental efforts to the potential for these hard, abrasive materials to damage reactors.

Weast, Logan, E.; Staats, William, R.

2009-05-01T23:59:59.000Z

348

Argonne CNM News: Hollow Iron Oxide Nanoparticles for Lithium...  

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

Hollow Iron Oxide Nanoparticles for Lithium-Ion Battery Applications Hollow iron oxide nanoparticles Transmission electron micrograph of hollow iron oxide nanoparticles....

349

Functionalized nanoparticles for sensor applications.  

Science Conference Proceedings (OSTI)

We will describe our work on functionalized arrays of nanoparticles crosslinked with short conducting molecules that contain sensing functionalities. These bridging ligands modulate their conductivity based on their interaction with analytes. This functionalized nanoparticles organic ligand composite material once it is assembled between nanogaps electrodes will provide nanosized sensors that can be easily interrogated. These nanogap sensors will be engineered so that they can be fabricated into arrays of different sensor elements. This project consists of a number of different requirements that must be met in order to enable the use of functionalized nanoparticles for sensor applications. The first requirement is the appropriately functionalized nanoparticle. The second is a method to assemble the particles. The third requirement is the generation of a nanogap to contain the nanoparticles. The successes in each of these areas will be discussed as will the sensing behavior of the final films.

Simonson, Robert Joseph; Childs, Kenton David; Howell, Stephen Wayne; Dirk, Shawn M.; Wheeler, David Roger

2005-09-01T23:59:59.000Z

350

STUDY OF SOLVENT AND CATALYST INTERACTIONS IN DIRECT COAL LIQUEFACTION  

SciTech Connect

Major objectives of the present project are to develop a better understanding of the roles of the catalyst and the liquefaction solvent in the coal liquefaction process. An open question concerning the role of the catalyst is whether intimate contact between the catalyst and the coal particles is important or required. To answer this question, it had been planned to coat an active catalyst with a porous silica coating which was found to retain catalyst activity while preventing actual contact between catalyst and coal. Consultation with people in DuPont who coat catalysts for increasing abrasion resistance have indicated that only portions of the catalyst are coated by their process (spray drying) and that sections of uncoated catalyst remain. For that reason, it was decided to suspend the catalyst in a basket separated from the coal in the reactor. The basket walls were to be permeable to the liquefaction solvent but not to the coal particles. Several such baskets were constructed of stainless steel with holes which would not permit passage of coal particles larger than 30 mesh. Liquefactions run with the coal of greater than 30 mesh size gave normal conversion of coal to liquid in the absence of catalyst in the basket, but substantially increased conversion when Ni/Mo on alumina catalyst was in the basket. While this result is interesting and suggestive of some kind of mass transfer of soluble material occurring between the catalyst and the coal, it does not eliminate the possibility of breakdown of the coal particle into particle sizes permeable to the basket. Indeed, a small amount of fine coal has been found inside the basket. To determine whether fine coal from breakdown of the coal particles is responsible for the conversion, a new basket is being prepared with 0.5{micro}m pore size.

Michael T. Klein

1998-10-01T23:59:59.000Z

351

Hydroprocessing of solvent-refined coal: catalyst-screening results  

SciTech Connect

This report presents the results of screening four catalysts for hydroprocessing a 50 wt% mixture of SRC-I in a prehydrogenated creosote oil using a continuous flow unit. All catalysts employed were nickel-molybdates with varying properties. Reaction conditions were 2000 psi, 8 SCFH of hydrogen, volume hourly space velocity of 0.6 to 1.0 cc of SRC-I/hr/cc of catalyst, and 48 hours at 750/sup 0/F followed by 72 hours at 780/sup 0/F. The results indicate that the Shell 324 catalyst is best for hydrogenation of the feedstock but only marginally better than CB 81-44 for denitrogenation. The CB 81-44 catalyst may be slightly better than Shell 324 for the conversion of the +850/sup 0/F fraction of the feedstock. Desulfurization was uniformly high for all catalysts. Catalysts with a bimodal pore size distribution (i.e., SMR7-6137(1)) appear to be better for denitrogenation than unimodal catalysts (i.e., SMR7-6137(4)) containing the same metals loading. Unimodal catalysts (i.e., Shell 324) with higher metals loadings are comparable to bimodal catalysts (i.e., CB 81-44) containing less metals. The results indicate that pore size distribution and metals loading are important parameters for high activity. Catalysts with a unimodal pore volume distribution are capable of being restored to their original state, while bimodal ones experience a loss in surface area and pore volume and an increase in pellet density. This is attributed to the more efficient use of the interior surface area of the catalyst, which results in higher accumulation of coke and metals. Since coke can be removed via controlled oxidation, the irreversible loss is due to the higher concentrations of metals in the catalyst.

Stiegel, G.J.; Tischer, R.E.; Polinski, L.M.

1982-03-01T23:59:59.000Z

352

Catalyst vendors take aim at emissions  

Science Conference Proceedings (OSTI)

Standards for emissions of air pollutants from stationary sources are expected to become more stringent under the 1990 U.S. Clean Air Act (CAA). For years, scrubbing, incineration and other end-of-pipe methods have been used to reduce nitrogen oxides (NO{sub x}) and volatile organic compounds (VOCs) from chemical and hydrocarbon processes. This paper reports that operating companies are now looking to catalyst manufacturers for technologies to meet higher standards. For the most part, development efforts have been centered on reducing emissions of carbon monoxide (CO) and VOCs for attainment of national ambient air quality standards for ozone under CAA's Title I. Now though, catalyst manufacturers are setting their sights on NO{sub x}.

Matthey, J.

1992-03-01T23:59:59.000Z

353

Intermediate Ethanol Blends Catalyst Durability Program  

Science Conference Proceedings (OSTI)

In the summer of 2007, the U.S. Department of Energy (DOE) initiated a test program to evaluate the potential impacts of intermediate ethanol blends (also known as mid-level blends) on legacy vehicles and other engines. The purpose of the test program was to develop information important to assessing the viability of using intermediate blends as a contributor to meeting national goals for the use of renewable fuels. Through a wide range of experimental activities, DOE is evaluating the effects of E15 and E20 - gasoline blended with 15% and 20% ethanol - on tailpipe and evaporative emissions, catalyst and engine durability, vehicle driveability, engine operability, and vehicle and engine materials. This report provides the results of the catalyst durability study, a substantial part of the overall test program. Results from additional projects will be reported separately. The principal purpose of the catalyst durability study was to investigate the effects of adding up to 20% ethanol to gasoline on the durability of catalysts and other aspects of the emissions control systems of vehicles. Section 1 provides further information about the purpose and context of the study. Section 2 describes the experimental approach for the test program, including vehicle selection, aging and emissions test cycle, fuel selection, and data handling and analysis. Section 3 summarizes the effects of the ethanol blends on emissions and fuel economy of the test vehicles. Section 4 summarizes notable unscheduled maintenance and testing issues experienced during the program. The appendixes provide additional detail about the statistical models used in the analysis, detailed statistical analyses, and detailed vehicle specifications.

West, Brian H; Sluder, Scott; Knoll, Keith; Orban, John; Feng, Jingyu

2012-02-01T23:59:59.000Z

354

Fuel cell applications for novel metalloporphyrin catalysts  

DOE Green Energy (OSTI)

This project utilized Computer-Aided Molecular Design (CAMD) to develop a new class of metalloporphyrin materials for use as catalysts for two fuel cell reactions. The first reaction is the reduction of oxygen at the fuel cell cathode, and this reaction was the main focus of the research. The second reaction we attempted to catalyze was the oxidation of methanol at the anode. Two classes of novel metalloporphyrins were developed. The first class comprised the dodecaphenylporphyrins whose steric bulk forces them into a non-planar geometry having a pocket where oxygen or methanol is more tightly bound to the porphyrin than it is in the case of planar porphyrins. Significant improvements in the catalytic reduction of oxygen by the dodecaphenyl porphyrins were measured in electrochemical cells. The dodecaphenylporphyrins were further modified by fluorinating the peripheral phenyl groups to varying degrees. The fluorination strongly affected their redox potential, but no effect on their catalytic activity towards oxygen was observed. The second class of porphyrin catalysts was a series of hydrogen-bonding porphyrins whose interaction with oxygen is enhanced. Enhancements in the interaction of oxygen with the porphyrins having hydrogen bonding groups were observed spectroscopically. Computer modeling was performed using Molecular Simulations new CERIUS2 Version 1.6 and a research version of POLYGRAF from Bill Goddard`s research group at the California Institute of Technology. We reoptimized the force field because of an error that was in POLYGRAF and corrected a problem in treatment of the metal in early versions of the program. This improved force field was reported in a J. Am. Chem. Soc. manuscript. Experimental measurements made on the newly developed catalysts included the electrochemical testing in a fuel cell configuration and spectroscopic measurements (UV-Vis, Raman and XPS) to characterize the catalysts.

Ryba, G.; Shelnutt, J.; Doddapaneni, N.; Zavadil, K.

1997-04-01T23:59:59.000Z

355

Dendrimer-encapsulated metal nanoparticles: synthesis, characterization, and applications to catalysis  

E-Print Network (OSTI)

The research in this dissertation examines the chemistry and applications of dendrimers in homogeneous catalysis. We examined interactions between dendrimers and charged probe molecules, prepared dendrimer-encapsulated metal nanoparticles in organic solvents, studied size-selectivity of dendrimer-encapsulted catalysts, and designed molecular rulers as in-situ probes to measure the location of dendrimer-encapsulted metal nanoparticles. The intrinsic proton binding constant and a constant that characterizes the strength of electrostatic interactions among occupied binding sites in poly(amidoamine) (PAMAM) dendrimers have been obtained by studying the effect of solution pH on the protonation of the dendrimers. The significant finding is that these two factors are greatly modulated by the unique and hydrophobic microenvironment in the dendrimer interior. Hydrophilic poly(propylene imine) (PPI) dendrimers were modified with various hydrophobic alkyl chains through an amide linkage and were then used as templates for preparing intradendrimer copper nanoclusters. The main driving force for encapsulating metal-ions was found to be the differences in metal-ion solubility between the solvent and the interior of the dendrimer. Nanometer-sized metal particles are synthesized and encapsulated into the interior of dendrimers by first mixing together the dendrimer and metal ion solution and then reducing the composite chemically, and the resulting dendrimer-encapsulated metal nanoparticles can then be used as catalysts. By controlling the packing density on the dendrimer periphery using either different dendrimer generations or dendrimer surface functionalities, it is possible to control access of substrates to the encapsulated catalytic nanoparticle. Molecular rulers consisting of a large molecular "stopper", a reactive probe and a linker were designed as in-situ probes for determining the average distance between the surface of dendrimer-encapsulated palladium nanoparticles and the periphery of their fourth-generation, hydroxyl-terminated PAMAM dendrimer hosts. By doing so, we avoid having to make assumptions about the nanoparticle size and shape. The results suggest that the surface of the encapsulated nanoparticle is situated 0.7 ± 0.2 nm from the surface of the dendrimer.

Niu, Yanhui

2003-05-01T23:59:59.000Z

356

Lloyd Crossing Sustainable Urban Design Plan and Catalyst Project - Portland, Oregon [2005 EDRA/Places Award -- Planning  

E-Print Network (OSTI)

Urban Design Plan and Catalyst Project—Portland, Oregonsensitivity. The associated Catalyst Project attempts toUrban Design Plan and Catalyst Project—Jury Comments Brager:

Hayter, Jason Alexander

2005-01-01T23:59:59.000Z

357

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

358

Engineering a cyanobacterium as the catalyst for the photosynthetic conversion of CO2 to 1,2-propanediol  

E-Print Network (OSTI)

a cyanobacterium as the catalyst for the photosynthetica cyanobacterium as the catalyst for the photosyntheticcan be engineered as a catalyst for the photosynthetic

Li, Han; Liao, James C

2013-01-01T23:59:59.000Z

359

Cationic Ruthenium Catalysts for Olefin Hydrovinylation  

E-Print Network (OSTI)

Stereoselective carbon?carbon bond formation is one of the most important types of bond construction in organic chemistry. A mild and acid free catalyst system for the hydrovinylation reaction utilizing a cationic, ruthenium center is described. A catalytic amount of RuHCl(CO)(PCy3)2 (2) activated with AgOTF or AgSbF6 at room temperature was found to be an effective catalyst system for the hydrovinylation of vinylarenes and the intramolecular hydrovinylation (IHV) of 1,6-dienes. Vinylarenes with both electron-donating and electron-withdrawing substituents reacted with ethylene at room temperature to provide the desired 3-arylbutenes in moderate to excellent yield (60-99%) under mild reaction conditions, while the IHV reaction of 1, 6 dienes provided greater than 90% of product conversion. We also developed the first hydrovinylation catalyst containing a chelating, bidentate phosphine ligand that provides the desired product. Our ruthenium-based catalytic system has also proven to give an appealing reactivity profile in favor of the desired arylbutenes without promoting undesirable oligomerization and isomerization.

Sanchez, Richard P., Jr

2009-08-01T23:59:59.000Z

360

Highly Dispersed Alloy Catalyst for Durability  

DOE Green Energy (OSTI)

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

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

2013-01-08T23:59:59.000Z

Note: This page contains sample records for the topic "bimetallic nanoparticle catalysts" 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

Characterization of active sites in zeolite catalysts  

DOE Green Energy (OSTI)

This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). Atomic-level details of the interaction of adsorbed molecules with active sites in catalysts are urgently needed to facilitate development of more effective and/or environmentally benign catalysts. To this end the authors have carried out neutron scattering studies combined with theoretical calculations of the dynamics of small molecules inside the cavities of zeolite catalysts. The authors have developed the use of H{sub 2} as a probe of adsorption sites by observing the hindered rotations of the adsorbed H{sub 2} molecule, and they were able to show that an area near the four-rings is the most likely adsorption site for H{sub 2} in zeolite A while adsorption of H{sub 2} near cations located on six-ring sites decreases in strength as Ni {approximately} Co > Ca > Zn {approximately} Na. Vibrational and rotational motions of ethylene and cyclopropane adsorption complexes were used as a measure for zeolite-adsorbate interactions. Preliminary studies of the binding of water, ammonia, and methylamines were carried out in a number of related guest-host materials.

Eckert, J. [Los Alamos National Lab., NM (United States); Bug, A. [Swarthmore Coll., PA (United States); Nicol, J.M. [MOLTECH (United States)] [and others

1997-11-01T23:59:59.000Z

362

Integrated model-based control and diagnostic monitoring for automotive catalyst systems  

Science Conference Proceedings (OSTI)

An integrated model-based automotive catalyst control and diagnostic monitoring system is presented. This system incorporates a simplified dynamic catalyst model that describes oxygen storage and release in the catalyst and predicts the post-catalyst ... Keywords: automotive catalyst, model predictive control, on-board diagnostic monitoring

Kenneth R. Muske; James C. Peyton Jones

2007-11-01T23:59:59.000Z

363

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

364

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

365

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,

366

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

367

Method for regeneration and activity improvement of syngas conversion catalyst  

DOE Patents (OSTI)

A method is disclosed for the treatment of single particle iron-containing syngas (synthes.s gas) conversion catalysts comprising iron, a crystalline acidic aluminosilicate zeolite having a silica to alumina ratio of at least 12, a pore size greater than about 5 Angstrom units and a constraint index of about 1-12 and a matrix. The catalyst does not contain promoters and the treatment is applicable to either the regeneration of said spent single particle iron-containing catalyst or for the initial activation of fresh catalyst. The treatment involves air oxidation, hydrogen reduction, followed by a second air oxidation and contact of the iron-containing single particle catalyst with syngas prior to its use for the catalytic conversion of said syngas. The single particle iron-containing catalysts are prepared from a water insoluble organic iron compound.

Lucki, Stanley J. (Runnemede, NJ); Brennan, James A. (Cherry Hill, NJ)

1980-01-01T23:59:59.000Z

368

Catalyst Additives to Enhance Mercury Oxidation and Capture  

SciTech Connect

Preliminary research has shown that SCR catalysts employed for nitrogen-oxide reduction can effectively oxidize mercury. Three different SCR catalysts are currently being studied in this project--honeycomb-type, plate-type, and a hybrid-type catalyst. The catalysts were manufactured and supplied by Cormetech Inc., Hitachi America Ltd., and Haldor-Topsoe Inc., respectively. Parametric testing was performed to investigate the contribution of flue-gas chemistry on mercury oxidation via SCR catalysts. Future work to characterize flue gas simulations typically derived from low and high sulfur bituminous coal are being performed in a stepwise manner, to avoid the constant interruptions in testing that occur when leaks in the system are generated during temperature transitions. Specifically, chlorine concentration vs. mercury oxidation correlations will be developed for each catalyst. The contributions of temperature are also being investigated. SO2 oxidation is also being investigated for each test condition.

Thomas K. Gale

2005-12-31T23:59:59.000Z

369

TECHNOLOGY DEVELOPMENT FOR IRON FISCHER-TROPSCH CATALYSTS  

DOE Green Energy (OSTI)

The goal of the proposed work described in this Final Report was the development of iron-based Fischer-Tropsch catalysts that combined high activity, selectivity and life with physical robustness for slurry phase reactors that will produce either low-alpha or high-alpha products. The work described here has optimized the catalyst composition and pretreatment operation for a low-alpha catalyst. In parallel, work has been conducted to design a high-alpha iron catalyst that is suitable for slurry phase synthesis. Studies have been conducted to define the chemical phases present at various stages of the pretreatment and synthesis stages and to define the course of these changes. The oxidation/reduction cycles that are anticipated to occur in large, commercial reactors have been studied at the laboratory scale. Catalyst performance has been determined for catalysts synthesized in this program for activity, selectivity and aging characteristics.

Davis, B.H.

1998-07-22T23:59:59.000Z

370

DYNAMOMETER EVALUATION OF PLASMA-CATALYST FOR DIESEL NOX REDUCTION  

DOE Green Energy (OSTI)

A three-stage plasma-catalyst system was developed and tested on an engine dynamometer. Previous laboratory testing suggested high NOx efficiency could be obtained. With hexene reductant added to the exhaust, over 90% NOx reduction was observed. However, with diesel or Fischer-Tropsch reductant the catalyst efficiency rapidly dropped off. Heating the catalyst in air removed brown deposit from the surface and restored conversion efficiency. Following the engine tests, the used catalysts were evaluated. BET surface area decreased, and TPD revealed significant storage. This storage appears to be partly unburned diesel fuel that can be removed by heating to around 250-300 C, and partly hydrocarbons bonded to the surface that remain in place until 450-500 C. Laboratory testing with propene reductant demonstrated that the catalyst regains efficiency slowly even when operating temperature does not exceed 300 C. This suggests that control strategies may be able to regenerate the catalyst by occasional moderate heating.

Hoard, J; Schmieg, S; Brooks, D; Peden, C; Barlow, S; Tonkyn, R

2003-08-24T23:59:59.000Z

371

Effect of Graphitic Content on Carbon Supported Catalyst Performance  

DOE Green Energy (OSTI)

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

372

Reforming with an improved platinum-containing catalyst  

Science Conference Proceedings (OSTI)

There is disclosed a catalyst, which catalyst comprises a physical particle-form mixture of a component A and a component B , said component A comprising one or more group VIII noble metals and a combined halogen deposed on a refractory inorganic oxide and said component B comprising a metal from group IVB or group VB of the periodic table of elements and a combined halogen deposed on a refractory inorganic oxide. Such catalyst is suitable for use in a hydrocarbon conversion reaction zone. The catalyst can be employed in a process for the reforming of a hydrocarbon stream, which process comprises contacting said stream in a reaction zone under reforming conditions and in the presence of hydrogen with said catalyst. The catalyst is not presulfided. A preferred process comprises contacting a hydrocarbon stream that contains a substantial amount of sulfur.

Bertolacini, R.J.; Lysholm, D.L.; Pellet, R.J.

1982-10-12T23:59:59.000Z

373

Methane ignition catalyzed by in situ generated palladium nanoparticles  

SciTech Connect

Catalytic ignition of methane over the surfaces of freely-suspended and in situ generated palladium nanoparticles was investigated experimentally and numerically. The experiments were conducted in a laminar flow reactor. The palladium precursor was a compound (Pd(THD){sub 2}, THD: 2,2,6,6-tetramethyl-3,5-heptanedione) dissolved in toluene and injected into the flow reactor as a fine aerosol, along with a methane-oxygen-nitrogen mixture. For experimental conditions chosen in this study, non-catalytic, homogeneous ignition was observed at a furnace temperature of {proportional_to}1123 K, whereas ignition of the same mixture with the precursor was found to be {proportional_to}973 K. In situ production of Pd/PdO nanoparticles was confirmed by scanning mobility, transmission electron microscopy and X-ray photoelectron spectroscopy analyses of particles collected at the reactor exit. The catalyst particle size distribution was log-normal. Depending on the precursor loading, the median diameter ranged from 10 to 30 nm. The mechanism behind catalytic ignition was examined using a combined gas-phase and gas-surface reaction model. Simulation results match the experiments closely and suggest that palladium nanocatalyst significantly shortens the ignition delay times of methane-air mixtures over a wide range of conditions. (author)

Shimizu, T.; Abid, A.D.; Poskrebyshev, G.; Wang, H. [Department of Aerospace and Mechanical Engineering, University of Southern California, Los Angeles, CA 90089 (United States); Nabity, J.; Engel, J.; Yu, J. [TDA Research, Inc., 12345 W. 52nd Ave, Wheat Ridge, CO 80033 (United States); Wickham, D. [Reaction Systems, LLC, 19039 E. Plaza Drive, Suite 290, Parker, CO 80134 (United States); Van Devener, B.; Anderson, S.L. [Department of Chemistry, University of Utah, Salt Lake City, UT 84112 (United States); Williams, S. [Air Force Research Laboratory, Mail Stop RZA, 1950 Fifth Street, WPAFB, OH 45433 (United States)

2010-03-15T23:59:59.000Z

374

Dendrimer-encapsulated metal nanoparticle thin films on solid surfaces: preparation, characterization, and applications to electrocatalysis  

E-Print Network (OSTI)

Dendrimer-encapsulated nanoparticles (DENs) were prepared, characterized, and immobilized on solid surfaces. The resulting films were applied as electrocatalysts for the oxygen reduction reaction (ORR). First, the synthesis, physical and chemical properties, and stability of Pd DENs prepared within poly(amidoamine) (PAMAM) dendrimers were studied in aqueous solution. In this part of the study, the following new findings were reported: (1) the maximum Pd ion loading in the dendrimer was correlated to the number of interior amines available for complexation; (2) Pd DENs could be synthesized within amine-terminated Pd DENs by controlling the solution pH; (3) the oxidative stability of Pd DENs was significantly improved by removing solution-phase impurities; (4) exposure to hydrogen gas reversibly converts partially oxidized Pd DENs back to the zerovalent state. Second, Pt and Pd DENs were prepared using amine-terminated PAMAM dendrimers, and then the free amine groups on the periphery were used to immobilize Pt and Pd DENs onto Au surfaces via an intermediate self-assembled monolayer. The resulting DEN films were more robust and had higher coverages of DENs compared to the DEN films prepared via physisorption. Third, Pt DENs were prepared and immobilized on glassy carbon electrodes using an electrochemical coupling method. The resulting films were electrochemically active for the ORR. These electrocatalytic monolayers were also robust, surviving up to 50 consecutive electrochemical scans for ORR and sonication in acid solution with no significant change in activity. Finally, PtPd bimetallic nanoparticles containing an average of 180 atoms (~1.8 nm in diameter) and composed of seven different Pt:Pd ratios were prepared within sixth-generation, hydroxyl-terminated PAMAM dendrimers. Transmission electron microscopy and single-particle energy dispersive spectroscopy confirmed the sizes and compositions of the particles. These DENs were immobilized on glassy carbon electrodes, and their electrocatalytic properties were evaluated as a function of composition using cyclic voltammetry and rotating disk voltammetry. The results showed that the maximum rate for the ORR occurs at a Pt:Pd ratio of 5:1, which corresponds to a relative mass activity enhancement of 2.5 compared to otherwise identical monometallic Pt nanoparticles.

Ye, Heechang

2006-12-01T23:59:59.000Z

375

Carbon-Supported IrNi Core-Shell Nanoparticles: Synthesis Characterization and Catalytic Activity  

Science Conference Proceedings (OSTI)

We synthesized carbon-supported IrNi core-shell nanoparticles by chemical reduction and subsequent thermal annealing in H{sub 2}, and verified the formation of Ir shells on IrNi solid solution alloy cores by various experimental methods. The EXAFS analysis is consistent with the model wherein the IrNi nanoparticles are composed of two-layer Ir shells and IrNi alloy cores. In situ XAS revealed that the Ir shells completely protect Ni atoms in the cores from oxidation or dissolution in an acid electrolyte under elevated potentials. The formation of Ir shell during annealing due to thermal segregation is monitored by time-resolved synchrotron XRD measurements, coupled with Rietveld refinement analyses. The H{sub 2} oxidation activity of the IrNi nanoparticles was found to be higher than that of a commercial Pt/C catalyst. This is predominantly due to Ni-core-induced Ir shell contraction that makes the surface less reactive for IrOH formation, and the resulting more metallic Ir surface becomes more active for H{sub 2} oxidation. This new class of core-shell nanoparticles appears promising for application as hydrogen anode fuel cell electrocatalysts.

K Sasaki; K Kuttiyiel; L Barrio; D Su; A Frenkel; N Marinkovic; D Mahajan; R Adzic

2011-12-31T23:59:59.000Z

376

Enhanced catalyst for converting synthesis gas to liquid motor fuels  

DOE Patents (OSTI)

The conversion of synthesis gas to liquid molar fuels by means of a cobalt Fischer-Tropsch catalyst composition is enhanced by the addition of molybdenum, tungsten or a combination thereof as an additional component of said composition. The presence of the additive component increases the olefinic content of the hydrocarbon products produced. 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

377

Status of the Development and Assessment of Advanced NOx Catalysts  

Science Conference Proceedings (OSTI)

This is an interim report summarizing the status of EPRI's advanced nitrogen oxides (NOx) reduction catalyst development efforts in 2000. Concepts for that are more effective, lower cost, and may not have the problems associated with the standard vanadium pentoxide - titanium dioxide (V2O5-TiO2) NOx selective catalytic reduction (SCR) catalysts that have been assessed under this program. The primary efforts in 2000 included further development of an ultra-high efficiency (UHE) catalyst, determining wheth...

2000-11-27T23:59:59.000Z

378

Enhanced catalyst stability for cyclic co methanation operations  

DOE Green Energy (OSTI)

Carbon monoxide-containing gas streams are passed over a catalyst to deposit a surface layer of active surface carbon thereon essentially without the formation of inactive coke. The active carbon is thereafter reacted with steam or hydrogen to form methane. Enhanced catalyst stability for long term, cyclic operation is obtained by the incorporation of an alkali or alkaline earth dopant in a silica binding agent added to the catalyst-support additive composition.

Risch, Alan P. (New Fairfield, CT); Rabo, Jule A. (Armonk, NY)

1983-01-01T23:59:59.000Z

379

Method of synthesizing tungsten nanoparticles  

DOE Patents (OSTI)

A method to synthesize tungsten nanoparticles has been developed that enables synthesis of nanometer-scale, monodisperse particles that can be stabilized only by tetrahydrofuran. The method can be used at room temperature, is scalable, and the product concentrated by standard means. Since no additives or stabilizing surfactants are required, this method is particularly well suited for producing tungsten nanoparticles for dispersion in polymers. If complete dispersion is achieved due to the size of the nanoparticles, then the optical properties of the polymer can be largely maintained.

Thoma, Steven G; Anderson, Travis M

2013-02-12T23:59:59.000Z

380

Attrition Resistant Fischer-Tropsch Catalysts Based on FCC Supports  

SciTech Connect

Commercial spent fluid catalytic cracking (FCC) catalysts provided by Engelhard and Albemarle were used as supports for Fe-based catalysts with the goal of improving the attrition resistance of typical F-T catalysts. Catalysts with the Ruhrchemie composition (100 Fe/5 Cu/4.2 K/25 spent FCC on mass basis) were prepared by wet impregnation. XRD and XANES analysis showed the presence of Fe{sub 2}O{sub 3} in calcined catalysts. FeC{sub x} and Fe{sub 3}O{sub 4} were present in the activated catalysts. The metal composition of the catalysts was analyzed by ICP-MS. F-T activity of the catalysts activated in situ in CO at the same conditions as used prior to the attrition tests was measured using a fixed bed reactor at T = 573 K, P = 1.38 MPa and H{sub 2}:CO ratio of 0.67. Cu and K promoted Fe supported over Engelhard provided spent FCC catalyst shows relatively good attrition resistance (8.2 wt% fines lost), high CO conversion (81%) and C{sub 5}+ hydrocarbons selectivity (18.3%).

Adeyinka Adeyiga

2010-02-05T23:59:59.000Z

Note: This page contains sample records for the topic "bimetallic nanoparticle catalysts" 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

Table III: Technical Targets for Catalyst Coated Membranes ...  

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

III: Technical Targets for Catalyst Coated Membranes (CCMs): Stationary All targets must be achieved simultaneously Characteristics Units Calendar year 2002 status a 2005 2010...

382

Table I: Technical Targets for Catalyst Coated Membranes (CCMs...  

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

I: Technical Targets for Catalyst Coated Membranes (CCMs): Automotive All targets must be achieved simultaneously Characteristics Units Calendar year 2002 status a 2005 2010...

383

Development of Ni-Fe Hydrogenation Catalyst from D. Gigas ...  

Development of Ni-Fe Hydrogenation Catalyst from D. Gigas Hydrogenase Note: The technology described above is an early stage opportunity. Licensing rights to this ...

384

TransForum v4n1 - Bifunctional Catalysts  

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

NEW BIFUNCTIONAL CATALYSTS PROMISE DRAMATIC NOx REDUCTIONS FOR HEAVY-DUTY DIESEL VEHICLES Truck manufacturers will need new technologies to help them meet EPA regulations that...

385

Novel catalyst for selective NOx reduction using hydrocarbons ...  

This invention discloses a catalyst and process for removing nitrogen oxides from exhaust streams under lean burn conditions using hydrocarbons as the reductant.

386

Pyrochlore-Based Catalysts for Syngas-Derived Alcohol Synthesis  

gas, coal, or biomass • Enhances the potential use of oxygenates as neat fuels or fuel additives • Develops a catalyst with high selectivity for ...

387

Multi-stage catalyst systems and uses thereof  

DOE Patents (OSTI)

Catalyst systems and methods provide benefits in reducing the content of nitrogen oxides in a gaseous stream containing nitric oxide (NO), hydrocarbons, carbon monoxide (CO), and oxygen (O.sub.2). The catalyst system comprises an oxidation catalyst comprising a first metal supported on a first inorganic oxide for catalyzing the oxidation of NO to nitrogen dioxide (NO.sub.2), and a reduction catalyst comprising a second metal supported on a second inorganic oxide for catalyzing the reduction of NO.sub.2 to nitrogen (N.sub.2).

Ozkan, Umit S. (Worthington, OH); Holmgreen, Erik M. (Columbus, OH); Yung, Matthew M. (Columbus, OH)

2009-02-10T23:59:59.000Z

388

Combined catalysts for the combustion of fuel in gas turbines  

Science Conference Proceedings (OSTI)

A catalytic oxidation module for a catalytic combustor of a gas turbine engine is provided. The catalytic oxidation module comprises a plurality of spaced apart catalytic elements for receiving a fuel-air mixture over a surface of the catalytic elements. The plurality of catalytic elements includes at least one primary catalytic element comprising a monometallic catalyst and secondary catalytic elements adjacent the primary catalytic element comprising a multi-component catalyst. Ignition of the monometallic catalyst of the primary catalytic element is effective to rapidly increase a temperature within the catalytic oxidation module to a degree sufficient to ignite the multi-component catalyst.

Anoshkina, Elvira V.; Laster, Walter R.

2012-11-13T23:59:59.000Z

389

Catalyst for selective NO.sub.x reduction using ...  

A method of preparing the two phase catalyst and using same to remediate NO.sub.x in combustion gases is also described. Skip to Content. Skip to ...

390

Heterogenization of Homogeneous Catalysts: the Effect of the Support  

DOE Green Energy (OSTI)

We have studied the influence of placing a soluble, homogeneous catalyst onto a solid support. We determined that such a 'heterogenized' homogeneous catalyst can have improved activity and selectivity for the asymmetric hydrogenation of enamides to amino acid derivatives. The route of heterogenization of RhDuPhos(COD){sup +} cations occurs via electrostatic interactions with anions that are capable of strong hydrogen bonding to silica surfaces. This is a novel approach to supported catalysis. Supported RhDuPhos(COD){sup +} is a recyclable, non-leaching catalyst in non-polar media. This is one of the few heterogenized catalysts that exhibits improved catalytic performance as compared to its homogeneous analog.

Earl, W.L.; Ott, K.C.; Hall, K.A.; de Rege, F.M.; Morita, D.K.; Tumas, W.; Brown, G.H.; Broene, R.D.

1999-06-29T23:59:59.000Z

391

Mercury Oxidation and Capture over SCR Catalysts in Simulated ...  

Science Conference Proceedings (OSTI)

The SCR catalysts were tested for oxidation and capture of elemental mercury ... EBSD Analysis of Complex Microstructures of CSP? Processed Low Carbon ...

392

The development of precipitated iron catalysts with improved stability  

DOE Green Energy (OSTI)

Precipitated iron catalysts are expected to be used in the next generation of slurry reactors for the large-scale production of transportation fuels from synthesis gas. These reactors may operate at higher temperatures and lower H {sub 2}: CO ratios relative to the Sasol Arge reactor. The feasibility of iron catalysts has been demonstrated under relatively mild Arge-type conditions but not under the more severe slurry conditions. The goal of this program is to identify the chemical principles governing the deactivation of precipitated iron catalysts during Fischer-Tropsch synthesis and to use these chemical principles in the design of catalysts suitable for slurry reactors.

Shah, P.P.

1990-01-01T23:59:59.000Z

393

The Science and Engineering of Durable Ultralow PGM Catalysts...  

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

the electroactive sites. Recent novel approaches include the nanoengineering of core shell catalysts and Pt particles of unusual geometries such as nanowireswhiskers. The...

394

Biomass-derived Hydrogen-evolution catalyst and electrode  

combination of biomass and earth-abundant metals has resulted in a durable catalyst for splitting water into oxygen and hydrogen, which can be used as ...

395

Taking Cues from Nature to Develop Better Biofuel Catalysts ...  

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

Taking Cues from Nature to Develop Better Biofuel Catalysts August 27, 2013 Printer-friendly version Scientists working at the Argonne Leadership Computing Facility (ALCF) are...

396

New Catalyst Opens Way to Next-Generation Fuel Cells  

DOE R&D Accomplishments (OSTI)

A new highly stable catalyst developed at Brookhaven Lab lowers barriers to commercial use of fuel cells in vehicles and stationary applications.

Snyder, Kendra

2011-03-28T23:59:59.000Z

397

ORNL-grown oxygen 'sponge' presents path to better catalysts...  

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

presents path to better catalysts, energy materials This schematic depicts a new ORNL-developed material that can easily absorb or shed oxygen atoms. This schematic depicts...

398

Method of distributing liquefaction catalysts in solid carbonaceous material  

DOE Patents (OSTI)

A method of dispersing a liquefaction catalyst within coal or other carbonaceous solids involves providing a suspension in oil of microcapsules containing the catalyst. An aqueous solution of a catalytic metal salt is emulsified in the water-immiscible oil and the resulting minute droplets microencapsulated in polymeric shells by interfacial polycondensation. The catalyst is subsequently blended and dispersed throughout the powdered carbonaceous material to be liquefied. At liquefaction temperatures the polymeric microcapsules are destroyed and the catalyst converted to minute crystallites in intimate contact with the carbonaceous material. 2 tables.

Weller, S.W.

1984-05-23T23:59:59.000Z

399

Supercomputers Help a Catalyst Reach its Full Potential  

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

by catalysts are crucial to many industrial processes. In fertilizer production, chemical companies combine copious amounts of molecular hydrogen with nitrogen to produce...

400

PROMOTED ZINC CHROMITE CATALYSTS FOR HIGHER ALCOHOL SYNTHESIS  

SciTech Connect

During this reporting period, a ''zinc chromite'' catalyst promoted with 6 wt.% cesium (Cs) was evaluated at the following operating conditions: Temperature - 375 C and 400 C; Total Pressure--13.6 MPa (2000 psig); Gas Hourly Space Velocity (GHSV) - 5000 standard liters/kg(cat)-hr; and H{sub 2}/CO feed ratio--0.5, 1.0 and 2.0 mole/mole. Decahydronaphthalene (DHN) was used as the slurry liquid. The experiment lasted for twelve days of continuous operation. Unpromoted zinc chromite catalyst then was re-examined under the same operating conditions. Reproducible data was achieved with a continuous liquid make-up. Compared with unpromoted zinc chromite catalyst, 6 wt.% Cs-promoted catalyst shifted the product distribution from methanol to higher alcohols, even though methanol was still the major product. The effect of operating conditions was less important than the addition of promoter. However, it was observed that higher temperature favors higher alcohol synthesis, and that a higher H{sub 2}/CO ratio leads to lower oxygenates selectivity and higher hydrocarbons selectivity. These trends showed clearly with the Cs-promoted catalyst, but were not as prominent with the unpromoted catalyst. The slurry liquid did not decompose or alkylate to a measurable extent during either continuous, 12 - day experiment, even with the higher reactor temperature (400 C). There was a relatively significant loss of catalyst surface area during the experiment with the promoted catalyst, but not with the unpromoted catalyst.

Ms. Xiaolei Sun; Professor George W. Roberts

2000-12-20T23:59:59.000Z

Note: This page contains sample records for the topic "bimetallic nanoparticle catalysts" 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

Toward Catalyst Design from Theoretical Calculations (464th Brookhaven Lecture)  

DOE Green Energy (OSTI)

Catalysts have been used to speed up chemical reactions as long as yeast has been used to make bread rise. Today, catalysts are used everywhere from home kitchens to industrial chemical factories. In the near future, new catalysts being developed at Brookhaven Lab may be used to speed us along our roads and highways as they play a major role in solving the world’s energy challenges. During the lecture, Liu will discuss how theorists and experimentalists at BNL are working together to formulate and test new catalysts that could be used in real-life applications, such as hydrogen-fuel cells that may one day power our cars and trucks.

Liu, Ping (BNL Chemistry Dept)

2010-12-15T23:59:59.000Z

402

Activation of molecular catalysts using semiconductor quantum dots  

DOE Patents (OSTI)

Photocatalytic materials based on coupling of semiconductor nanocrystalline quantum dots (NQD) and molecular catalysts. These materials have capability to drive or catalyze non-spontaneous chemical reactions in the presence of visible radiation, ultraviolet radiation, or both. The NQD functions in these materials as a light absorber and charge generator. Following light absorption, the NQD activates a molecular catalyst adsorbed on the surface of the NQD via transfer of one or more charges (either electrons or electron-holes) from the NQD to the molecular catalyst. The activated molecular catalyst can then drive a chemical reaction. A photoelectrolytic device that includes such photocatalytic materials is also described.

Meyer, Thomas J. (Chapel Hill, NC); Sykora, Milan (Los Alamos, NM); Klimov, Victor I. (Los Alamos, NM)

2011-10-04T23:59:59.000Z

403

Methanol-tolerant cathode catalyst composite for direct methanol fuel cells  

oxidation catalyst adjacent the anode electrode and the membrane, an oxidant reduction catalyst adjacent the cathode electrode and the membrane, comprises an oxidant reduction catalyst layer of a platinum-chromium alloy so that oxidation at the ...

404

COAL LIQUEFACTION USING ZINC CHLORIDE CATALYST IN AN EXTRACTING SOLVENT MEDIUM  

E-Print Network (OSTI)

Rate Data o a o u a a Catalyst Loading • . Reaction Time . •and Pressure Effect of CO-catalysts and Additives .Co-catalysts • • a. Zinc Metal • b. Nickel and Nickel

Gandhi, Shamim Ahmed

2013-01-01T23:59:59.000Z

405

High-Resolution Structure of the Photosynthetic Mn4Ca Catalyst from X-ray Spectroscopy  

E-Print Network (OSTI)

the Photosynthetic Mn 4 Ca Catalyst from X-ray Spectroscopystructure of the Mn 4 Ca catalyst at high-resolution whichthe structure of Mn 4 Ca catalyst as it cycles through the

Yano, Junko

2008-01-01T23:59:59.000Z

406

Break-up of Pt catalyst surfaces by high CO coverage  

E-Print Network (OSTI)

and atomic arrangement of catalyst surface under reactionof reactant molecules on the catalyst surfaces are the norm.Break-up of Pt catalyst surfaces by high CO coverage Feng

Tao, Feng

2010-01-01T23:59:59.000Z

407

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

E-Print Network (OSTI)

Loading Effects in Fuel-Cell Catalyst Layers Wonseok Yoon*CA 94720, USA The cathode catalyst layer within a proton-with low Pt-loading catalyst layers. Model results

Yoon, Wonseok

2013-01-01T23:59:59.000Z

408

A Multi-Ligand Based Pd Catalyst for C–N Cross-Coupling Reactions  

E-Print Network (OSTI)

An alternative approach to catalyst development, which led to a Pd catalyst based on two biarylphosphine ligands for C?N cross-coupling reactions, is reported. By effectively being able to take the form of multiple catalysts ...

Fors, Brett P.

409

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

E-Print Network (OSTI)

Promotion of iron-group catalysts by a calcium salt inet al. , Effects of metal catalysts on CO 2 gasificationbiomass tars with iron oxide catalysts, Fuel, 2008, 87, 451-

FAN, XIN

2012-01-01T23:59:59.000Z

410

Effect of catalyst structure on oxidative dehydrogenation of ethane and propane on alumina-supported vanadia  

E-Print Network (OSTI)

olefin yields are obtained on catalysts containing isolatededge energies for VO x /Al 2 O 3 catalysts Figure 2. Ramanspectra for VO x /Al 2 O 3 catalysts (obtained at 298 K in

Argyle, Morris D.; Chen, Kaidong; Bell, Alexis T.; Iglesia, Enrique

2001-01-01T23:59:59.000Z

411

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

E-Print Network (OSTI)

IR Absorption, Angewandte Chemie International Edition 11.Cheon, J. Angewandte Chemie-International Edition 2006 ,Skrabalak, S. E. Angewandte Chemie- International Edition

Li, Yujing

2012-01-01T23:59:59.000Z

412

Highly Active and Lower Cost Nanoparticle Catalyst for Producing Biofuel and Feedstock Chemicals  

Biofuels such as ethanol are already in use as alternatives to fossil fuels. These man-made fuels help to offset carbon dioxide emissions and are a ...

413

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

E-Print Network (OSTI)

and (5) solid oxide fuel cell (SOFC). The characteristics ofPEFC Electrolyte AFC PAFC MCFC SOFC Hydrated Polymeric Iondeveloped with AFC, MCFC, and SOFC configurations. The

Li, Yujing

2012-01-01T23:59:59.000Z

414

Nanoparticle Gas-Phase Electrophoresis  

Science Conference Proceedings (OSTI)

Page 1. Nanoparticle Gas-Phase Electrophoresis ... L f d f ? = L f /d f , f is the fraction of diffuse gas collisions with the cylinder -V + and where ? ? ...

2013-09-30T23:59:59.000Z

415

Review Article Activities of Heterogeneous Acid-Base Catalysts for Fragrances Synthesis: A Review  

E-Print Network (OSTI)

This paper reviews various types of heterogeneous acid-base catalysts for fragrances preparation. Catalytic activities of the various types of heterogeneous acid and base catalysts in fragrances preparation, i.e. nonzeolitic, zeolitic, and mesoporous molecular sieves, have been reported. Generally, heterogeneous acid catalysts are more commonly used in fragrance synthesis as compared to heterogeneous base catalysts. Heteropoly acids and hydrotalcites type catalysts are widely used as heterogeneous acid and base catalysts, respectively. © 2013 BCREC UNDIP. All rights reserved.

H. Hartati; Mardi Santoso; Sugeng Triwahyono; Didik Prasetyoko

2013-01-01T23:59:59.000Z

416

CATALYSTS NHI Thermochemical Systems FY 2009 Year-End Report  

DOE Green Energy (OSTI)

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

Daniel M. Ginosar

2009-09-01T23:59:59.000Z

417

Attrition Resistant Iron-Based Fischer-Tropsch Catalysts  

DOE Green Energy (OSTI)

The Fischer-Tropsch (F-T) reaction provides a way of converting coal-derived synthesis gas (CO+H{sub 2}) to liquid fuels. Since the reaction is highly exothermic, one of the major problems in control of the reaction is heat removal. Recent work has shown that the use of slurry bubble column reactors (SBCRS) can largely solve this problem. Iron-based (Fe) catalysts are preferred catalysts for F-T when using low CO/H{sub 2} ratio synthesis gases derived from modem coal gasifiers. This is because in addition to reasonable F-T activity, the FT catalysts also possess high water gas shift (WGS) activity. However, a serious problem with the use of Fe catalysts in a SBCR is their tendency to undergo attrition. This can cause fouling/plugging of downstream filters and equipment, making the separation of catalyst from the oil/wax product very difficult if not impossible, and results in a steady loss of catalyst from the reactor. The objectives of this research are to develop a better understanding of the parameters affecting attrition resistance of Fe F-T catalysts suitable for use in SBCRs and to incorporate this understanding into the design of novel Fe catalysts having superior attrition resistance. Catalyst preparations will be based on the use of spray drying and will be scalable using commercially available equipment. The research will employ among other measurements, attrition testing and F-T synthesis, including long duration slurry reactor runs in order to ascertain the degree of success of the various preparations. The goal is to develop an Fe catalyst which can be used in a SBCR having only an internal filter for separation of the catalyst from the liquid product, without sacrificing F-T activity and selectivity.

Jothimurugesan, K. [Hampton Univ., VA (United States). Dept. of Chemical Engineering; Goodwin, J.G. [Univ. of Pittsburgh, PA (United States). Chemical and Petroleum Engineering Dept.; Spivey, J.J.; Gangwal, S.K. [Research Triangle Inst., NC (United States)

1997-03-26T23:59:59.000Z

418

Selective catalyst reduction light-off strategy  

Science Conference Proceedings (OSTI)

An emissions control system includes a temperature determination module and an emissions control module. The temperature determination module determines a first temperature of a heater element of a diesel particulate filter (DPF) assembly in an exhaust system and determines a second temperature of a catalyst of the DPF assembly. The emissions control module selectively activates the heater element, selectively initiates a predefined combustion process in an engine based upon the first temperature, and selectively starts a reductant injection process based upon the second temperature.

Gonze, Eugene V [Pinckney, MI

2011-10-18T23:59:59.000Z

419

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

420

Hydrogen recombiner catalyst test supporting data  

DOE Green Energy (OSTI)

This is a data package supporting the Hydrogen Recombiner Catalyst Performance and Carbon Monoxide Sorption Capacity Test Report, WHC-SD-WM-TRP-211, Rev 0. This report contains 10 appendices which consist of the following: Mass spectrometer analysis reports: HRC samples 93-001 through 93-157; Gas spectrometry analysis reports: HRC samples 93-141 through 93-658; Mass spectrometer procedure PNL-MA-299 ALO-284; Alternate analytical method for ammonia and water vapor; Sample log sheets; Job Safety analysis; Certificate of mixture analysis for feed gases; Flow controller calibration check; Westinghouse Standards Laboratory report on Bois flow calibrator; and Sorption capacity test data, tables, and graphs.

Britton, M.D.

1995-01-19T23:59:59.000Z

Note: This page contains sample records for the topic "bimetallic nanoparticle catalysts" 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

Electrically heated particulate filter using catalyst striping  

DOE Patents (OSTI)

An exhaust system that processes exhaust generated by an engine is provided. The system generally includes a particulate filter (PF) that filters particulates from the exhaust wherein an upstream end of the PF receives exhaust from the engine. A grid of electrically resistive material is applied to an exterior upstream surface of the PF and selectively heats exhaust passing through the grid to initiate combustion of particulates within the PF. A catalyst coating is applied to the PF that increases a temperature of the combustion of the particulates within the PF.

Gonze, Eugene V; Paratore, Jr., Michael J; Ament, Frank

2013-07-16T23:59:59.000Z

422

Putting a Smiley Face on the Dragon: Wal-Mart as Catalyst to  

E-Print Network (OSTI)

the Dragon: Wal-Mart as Catalyst to U.S. -China Trade Emekthat Wal-Mart acts as a catalyst to greater imports and

Basker, Emek

2005-01-01T23:59:59.000Z

423

TransForum v8n2 - DeNOX Catalyst License  

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

Integrated Fuel Technologies Gets Worldwide License for Argonne-developed Diesel DeNOX Catalyst Argonne chemist Chris Marshall (front) displays a container of the catalyst while...

424

Catalysts for interconversion of CO2H2 and formic acid  

Catalyst compounds for the energetically feasible interconversion CO2 plus H2and formic acid are disclosed as are methods for using the catalysts for ...

425

Hydrogenation of Fats and Oils: Theory and PracticeChapter 7 Catalysts  

Science Conference Proceedings (OSTI)

Hydrogenation of Fats and Oils: Theory and Practice Chapter 7 Catalysts Processing eChapters Processing Press Downloadable pdf of Chapter 7 Catalysts from the book ...

426

Phosphorylated Mesoporous Carbon as a Solid Acid Catalyst  

Science Conference Proceedings (OSTI)

Mesoporous carbon catalyst supports are attractive due to their wide chemical stability while potentially increasing masstransport through and providing a path for larger molecules to access catalytic sites. Herein we report the synthesis of a 10 phosphorylated mesoporous carbon solid-acid catalyst characterized by NH3-TPD and isopropanol dehydration.

Dai, Sheng [ORNL; Mayes, Richard T [ORNL; Fulvio, Pasquale F [ORNL; Ma, Zhen [ORNL

2011-01-01T23:59:59.000Z

427

Effects of catalyst pretreatment for carbon nanotube growth  

E-Print Network (OSTI)

The effects of pretreatment of iron catalyst for carbon nanotube (CNT) growth was studied. CNTs were grown on Fe/A1203 (1/10 nm) thin-film catalyst deposited on silicon substrates via exposure to C2H4 in a thermal chemical ...

Morgan, Caitlin D

2007-01-01T23:59:59.000Z

428

IN SITU Device for Real-Time Catalyst Deactivation Measurements  

SciTech Connect

SCR catalyst management has become an important operations and maintenance activity for coal-fired utility boilers in the United States. To facilitate this activity, a method to determine Catalyst Activity in situ is being developed. This report describes the methodology and presents the results of a two ozone season demonstration conducted at Alabama Power Company's Gorgas Unit 10 during the 2005 and 2006 ozone seasons. The results showed that the in situ measurements are in good agreement with the laboratory measurements and the technique has some advantages over the traditional laboratory method of determining Catalyst Activity and Reactor Potential. SCR Performance is determined by the overall Reactor Potential (the product of the Catalyst Activity and the available surface area per unit of flue gas). The in situ approach provides a direct measurement of Reactor Potential under actual operating conditions, whereas laboratory measurements of Catalyst Activity need to be coupled with estimates of catalyst pluggage and flue gas flowrate in order to assess Reactor Potential. The project also showed that the in situ activity results can easily be integrated into catalyst management software to aid in making informed catalyst decisions.

Fossil Energy Research

2008-03-31T23:59:59.000Z

429

Hydrous metal oxide catalysts for oxidation of hydrocarbons  

DOE Green Energy (OSTI)

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

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

1993-07-01T23:59:59.000Z

430

Supported organometallic catalysts for hydrogenation and Olefin Polymerization  

DOE Patents (OSTI)

Novel heterogeneous catalysts for the which hydrogenation of olefins and arenes with high conversion rates under ambient conditions and the polymerization of olefins have been developed. The catalysts are synthesized from Ziegler-type precatalysts by supporting them on sulfate-modified zirconia.

Marks, Tobin J. (Evanston, IL); Ahn, Hongsang (Evanston, IL)

2001-01-01T23:59:59.000Z

431

Report of 1,000 Hour Catalyst Longevity Evaluation  

DOE Green Energy (OSTI)

This report presents the results of a 1,000 hour, high-pressure, catalyst longevity test for the decomposition of concentrated sulfuric acid. The reaction is used for both the sulfur-iodine (S-I) cycle and hybrid sulfur cycle. By the time of the delivery date of April 17, 2009, for project milestone no. 2NIN07TC050114, the 1% Pt/TiO2 catalyst had been in the reaction environment for 658 hours. During the first 480 hours of testing, the catalyst activity provided stable, near-equilibrium yields of 46.8% SO2 and 22.8% O2. However, product yields declined at sample exposure times >480 hours. At 658 hours of operation, catalyst activity (based on oxygen yield) declined to 57% relative to the stable period of catalyst activity. Thus, as of April 17, this catalyst did not provide the desired stability level of <10% degradation per 1,000 hours. The experiment was terminated on April 27, after 792 hours, when a fitting failed and the catalyst was displaced from the reactor such that the sample could not be recovered. Oxygen conversion at the end of the experiment was 12.5% and declining, suggesting that at that point, catalyst activity had decreased to 54% of the initial level.

Daniel M. Ginosar

2009-06-01T23:59:59.000Z

432

Cobalt Fischer-Tropsch catalysts having improved selectivity  

DOE Patents (OSTI)

A cobalt Fischer-Tropsch catalyst having an improved steam treated, acid extracted LZ-210 support is taught. The new catalyst system demonstrates improved product selectivity at Fischer-Tropsch reaction conditions evidenced by lower methane production, higher C.sub.5.sup.+ yield and increased olefin production.

Miller, James G. (Pearl River, NY); Rabo, Jule A. (Armonk, NY)

1989-01-01T23:59:59.000Z

433

Research Approach for Aging and Evaluating Diesel Exhaust catalysts  

DOE Green Energy (OSTI)

To determine the impact of diesel fuel sulfur levels on emissions control devices that could lower emissions of oxides of nitrogen (NOX) and particulate matter (PM) from on-highway trucks and buses in the 2002-2004 model years. West Virginia University is evaluating: - Diesel Oxidation Catalysts - Lean NOX Catalysts

Wayne, Scott

2000-08-20T23:59:59.000Z

434

NOVEL SLURRY PHASE DIESEL CATALYSTS FOR COAL-DERIVED SYNGAS  

DOE Green Energy (OSTI)

This report describes research conducted to support the DOE program in novel slurry phase catalysts for converting coal-derived synthesis gas to diesel fuels. The primary objective of this research program is to develop attrition resistant catalysts that exhibit high activities for conversion of coal-derived syngas.

Dr. Dragomir B. Bukur; Dr. Ketil Hanssen; Alec Klinghoffer; Dr. Lech Nowicki; Patricia O'Dowd; Dr. Hien Pham; Jian Xu

2001-01-07T23:59:59.000Z

435

Development of a Desulfurization Strategy for a NOx Adsorber Catalyst  

DOE Green Energy (OSTI)

Improve NOx regeneration calibration developed in DECSE Phase I project to understand full potential of NOx adsorber catalyst over a range of operating temperatures. Develop and demonstrate a desulfurization process to restore NOx conversion efficiency lost to sulfur contamination. Investigate effect of desulfurization process on long-term performance of the NOx adsorber catalyst.

Tomazic, Dean

2000-08-20T23:59:59.000Z

436

Fixed-bed reforming with mid-cycle catalyst addition  

Science Conference Proceedings (OSTI)

A fixed-bed catalytic reforming process is described in which on-stream operation is begun with the catalyst retention volume in the first reactor less than 99% full and additional catalyst is added to said reactor while on-stream.

Houston, R.J.; McCoy, C.S.

1981-02-17T23:59:59.000Z

437

SCALEUP OF ALUMINUM PHOSPHATE CATALYST FOR PILOT PLANT LPDMEtm RUN  

SciTech Connect

The Liquid Phase Dimethyl Ether (LPDME{trademark}) process converts synthesis gas to dimethyl ether in a single slurry bubble column reactor. A mixed slurry of methanol synthesis catalyst and methanol dehydration catalyst in a neutral mineral oil simultaneously synthesizes methanol from syngas and converts some of it to dimethyl ether and water. The reaction scheme is: 2H{sub 2} + CO = CH{sub 3}OH 2CH{sub 3}OH = CH{sub 3}OCH{sub 3} + H{sub 2}O H{sub 2}O + CO = CO{sub 2} + H{sub 2}. Most of the water produced in this reaction is converted to hydrogen by reduction with carbon monoxide (water gas shift reaction). This synergy permits higher per pass conversion than methanol synthesis alone. The enhancement in conversion occurs because dehydration of the methanol circumvents the equilibrium constraint of the syngas-to-methanol step. The slurry bubble column reactor provides the necessary heat transfer capacity to handle the greater heat duty associated with high conversion. In order to improve the stability of the catalyst system, non-stoichiometric aluminum phosphate was proposed as the dehydration catalyst for the LPDME{trademark} process. This aluminum phosphate material is a proprietary catalyst. This catalyst system of a standard methanol catalyst and the aluminum phosphate provided stable process performance that met the program targets under our standard test process conditions in the laboratory. These targets are (1) an initial methanol equivalent productivity of 28 gmol/kg/hr, (2) a CO{sub 2}-free, carbon selectivity of 80% to dimethyl ether and (3) stability of both catalysts equivalent to that of the methanol catalyst in the absence of the aluminum phosphate. A pilot plant trial of the LPDME{trademark} process using the aluminum phosphate catalyst was originally planned for March 1998 at the DOE-owned, Air Products (APCI)-operated facility at LaPorte, Texas. Because the aluminum phosphate catalyst is not commercially available, we initiated a scaleup project with a commercial catalyst vendor. A total of 800 pounds of aluminum phosphate catalyst was ordered to provide two reactor charges and some additional material for testing. Although the scaleup was never completed, the effort yielded valuable information about the nature of the catalyst and the nature of the LPDME{trademark} process. This information is documented in this topical report.

Andrew W. Wang

2002-05-15T23:59:59.000Z

438

SCALEUP OF ALUMINUM PHOSPHATE CATALYST FOR PILOT PLANT LPDMEtm RUN  

SciTech Connect

The Liquid Phase Dimethyl Ether (LPDME{trademark}) process converts synthesis gas to dimethyl ether in a single slurry bubble column reactor. A mixed slurry of methanol synthesis catalyst and methanol dehydration catalyst in a neutral mineral oil simultaneously synthesizes methanol from syngas and converts some of it to dimethyl ether and water. The reaction scheme is shown below: 2H{sub 2} + CO = CH{sub 3}OH; 2CH{sub 3}OH = CH{sub 3}OCH{sub 3} + H{sub 2}O; H{sub 2}O + CO = CO{sub 2} + H{sub 2}. Most of the water produced in this reaction is converted to hydrogen by reduction with carbon monoxide (water gas shift reaction). This synergy permits higher per pass conversion than methanol synthesis alone. The enhancement in conversion occurs because dehydration of the methanol circumvents the equilibrium constraint of the syngas-to-methanol step. The slurry bubble column reactor provides the necessary heat transfer capacity to handle the greater heat duty associated with high conversion. In order to improve the stability of the catalyst system, non-stoichiometric aluminum phosphate was proposed as the dehydration catalyst for the LPDME{trademark} process. This aluminum phosphate material is a proprietary catalyst. This catalyst system of a standard methanol catalyst and the aluminum phosphate provided stable process performance that met the program targets under our standard test process conditions in the laboratory. These targets are (1) an initial methanol equivalent productivity of 28 gmol/kg/hr, (2) a CO{sub 2}-free, carbon selectivity of 80% to dimethyl ether and (3) stability of both catalysts equivalent to that of the methanol catalyst in the absence of the aluminum phosphate. A pilot plant trial of the LPDME{trademark} process using the aluminum phosphate catalyst was originally planned for March 1998 at the DOE-owned, Air Products (APCI)-operated facility at LaPorte, Texas. Because the aluminum phosphate catalyst is not commercially available, we initiated a scaleup project with a commercial catalyst vendor. A total of 800 pounds of aluminum phosphate catalyst was ordered to provide two reactor charges and some additional material for testing. Although the scaleup was never completed, the effort yielded valuable information about the nature of the catalyst and the nature of the LPDME{trademark} process. This information is documented in this topical report.

Andrew W. Wang

2002-01-01T23:59:59.000Z

439

Long life hydrocarbon conversion catalyst and method of making  

DOE Patents (OSTI)

The present invention includes a catalyst that has at least four layers, (1) porous support, (2) buffer layer, (3) interfacial layer, and optionally (4) catalyst layer. The buffer layer provides a transition of thermal expansion coefficient from the porous support to the interfacial layer thereby reducing thermal expansion stress as the catalyst is heated to high operating temperatures. The method of the present invention for making the at least three layer catalyst has the steps of (1) selecting a porous support, (2) solution depositing an interfacial layer thereon, and optionally (3) depositing a catalyst material onto the interfacial layer; wherein the improvement comprises (4) depositing a buffer layer between the porous support and the interfacial layer.

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

2002-11-12T23:59:59.000Z

440

Methods of Reforming Hydrocarbon Fuels Using Hexaaluminate Catalysts  

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

of Reforming Hydrocarbon Fuels Using of Reforming Hydrocarbon Fuels Using Hexaaluminate Catalysts Contact NETL Technology Transfer Group techtransfer@netl.doe.gov May 2012 Opportunity Research is currently active on the technology "Methods of Reforming Hydrocarbon Fuels Using Hexaaluminate Catalysts." The technology is available for licensing and/or further collaborative research from the U.S. Department of Energy's National Energy Technology Laboratory. Overview This invention discloses a method to reform hydrocarbon fuels using hexa- aluminate catalysts. In general, the method successfully disrupts the forma- tion of carbon that leads to the deactivation of the catalyst, a key element in the reforming of hydrocarbon fuels. When researchers are designing catalysts to reform hydrocarbon fuels, one

Note: This page contains sample records for the topic "bimetallic nanoparticle catalysts" 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

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

442

NREL: Biomass Research - Chemical and Catalyst Science Capabilities  

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

Chemical and Catalyst Science Capabilities Chemical and Catalyst Science Capabilities A photo of a man in a white lab coat and dark goggles looking at a microscope. A bright green light shines down from the microscope lens and illuminates a round glass tray containing small white beads. The Laser Raman Spectrometer is used to obtain phase and structural identification information for catalysts used in the thermochemical conversion process. NREL researchers use chemical and catalyst science to assess and improve biochemical and thermochemical conversion throughout the processes, from analyzing feedstocks to improving the yield of desired end products. Catalyst Science Syngas produced during gasification contains tars that are contaminants, but these tars can be reformed to more syngas using tar-reforming

443

ATTRITION RESISTANT IRON-BASED FISCHER-TROPSCH CATALYSTS  

DOE Green Energy (OSTI)

The Fischer-Tropsch (F-T) reaction provides a way of converting coal-derived synthesis gas (CO+H{sub 2}) to liquid fuels. Since the reaction is highly exothermic, one of the major problems in control of the reaction is heat removal. Recent work has shown that the use of slurry bubble column reactors (SBCRs) can largely solve this problem. Iron-based (Fe) catalysts are preferred catalysts for F-T when using low CO/H2 ratio synthesis gases derived from modern coal gasifiers. This is because in addition to reasonable F-T activity, the F-T catalysts also possess high water gas shift (WGS) activity. However, a serious problem with the use of Fe catalysts in a SBCR is their tendency to undergo attrition. This can cause fouling/plugging of downstream filters and equipment, making the separation of catalyst from the oil/wax product very difficult if not impossible, and results in a steady loss of catalyst from the reactor. The objectives of this research are to develop a better understanding of the parameters affecting attrition resistance of Fe F-T catalysts suitable for use in SBCRs and to incorporate this understanding into the design of novel Fe catalysts having superior attrition resistance. Catalyst preparations will be based on the use of spray drying and will be scalable using commercially available equipment. The research will employ among other measurements, attrition testing and F-T synthesis, including long duration slurry reactor runs in order to ascertain the degree of success of the various preparations. The goal is to develop an Fe catalyst which can be used in a SBCR having only an internal filter for separation of the catalyst from the liquid product, without sacrificing F-T activity and selectivity. The effect of silica addition via coprecipitation and as a binder to a doubly promoted Fischer-Tropsch synthesis iron catalyst (100 Fe/5 Cu/4.2 K) was studied. The catalysts were prepared by coprecipitation, followed by binder addition and drying in a 1 m diameter, 2 m tall spray dryer. The binder silica content was varied from 0 to 20 wt %. A catalyst with 12 wt % binder silica was found to have the highest attrition resistance. F-T reaction studies over 100 hours in a fixed-bed reactor showed that this catalyst maintained around 95 % CO conversion with a methane selectivity of less than 7 wt % and a C5 + selectivity of greater than 73 wt %. The effect of adding precipitated silica from 0 to 20 parts by weight to this catalyst (containing 12 wt % binder silica) was also studied. Addition of precipitated silica was found to be detrimental to attrition resistance and resulted in increased methane and reduced wax formation. An HPR series of proprietary catalysts was prepared to further improve the attrition resistance. Based on the experience gained, a proprietary HPR-43 catalyst has been successfully spray dried in 500 g quantity. This catalyst showed 95 % CO conversion over 125 h and had less than 4 % methane selectivity. Its attrition resistance was one of the highest among the catalyst tested.

James G. Goodwin, Jr.; James J. Spivey; K. Jothimurugesan; Santosh K. Gangwal

1999-03-29T23:59:59.000Z

444

Technology development for iron Fischer-Tropsch catalysts  

DOE Green Energy (OSTI)

Objective is to develop producing active, stable iron Fischer-Tropsch catalysts for use in slurry-phase synthesis reactors and to synthesize such catalysts on a large scale for process development and long-term testing in slurry bubble-column reactors. A mixed oxalate of Fe, Cu, and K was prepared; a catalyst will be prepared from this material. An evaluation run was performed on an Fe-based UCI catalyst, which was shown to produce low levels of C[sub 1] and C[sub 2] paraffins; e.g., at the end of the run, when the catalyst was converting 60% of the CO, the C[sub 1] and C[sub 2] paraffin selectivities were 4.2 and 1.0, respectively.

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

1992-12-22T23:59:59.000Z

445

Reforming with an improved platinum-containing catalyst  

Science Conference Proceedings (OSTI)

A catalyst is disclosed which comprises a physical particle-form mixture of a Component A and a Component B. Said Component A comprises one or more Group VIII noble metals and combined halogen deposed on a refractory inorganic oxide and said Component B comprising a metal from Group IVB or Group VB of the Periodic Table of Elements and a combined halogen deposed on a refrac inorganic oxide. Such catalyst is suitable for use in a hydrocarbon conversion reaction zone. The catalyst can be employed in a process for the reforming of a hydrocarbon stream, which process comprises contacting said stream in a reaction zone under reforming conditions and in the presence hydrogen with said catalyst. The catalyst is not presulfided. A preferred process comprises contacting a hydrocarbon stream that contains a substantial amount of sulfur.

Pellet, R.J.; Bertolacini, R.J.; Lysholm, D.L.

1983-08-30T23:59:59.000Z

446

Hydrothermal alkali metal catalyst recovery process  

DOE Patents (OSTI)

In a coal gasification operation or similar conversion process carried out in the presence of an alkali metal-containing catalyst wherein solid particles containing alkali metal residues are produced, alkali metal constituents are recovered from the particles primarily in the form of water soluble alkali metal formates by treating the particles with a calcium or magnesium-containing compound in the presence of water at a temperature between about 250.degree. F. and about 700.degree. F. and in the presence of added carbon monoxide. During the treating process the water insoluble alkali metal compounds comprising the insoluble alkali metal residues are converted into water soluble alkali metal formates. The resultant aqueous solution containing water soluble alkali metal formates is then separated from the treated particles and any insoluble materials formed during the treatment process, and recycled to the gasification process where the alkali metal formates serve as at least a portion of the alkali metal constituents which comprise the alkali metal-containing catalyst. This process permits increased recovery of alkali metal constituents, thereby decreasing the overall cost of the gasification process by reducing the amount of makeup alkali metal compounds necessary.

Eakman, James M. (Houston, TX); Clavenna, LeRoy R. (Baytown, TX)

1979-01-01T23:59:59.000Z

447

EFFLUENT TREATMENT FACILITY PEROXIDE DESTRUCTION CATALYST TESTING  

SciTech Connect

The 200 Area Effluent Treatment Facility (ETF) main treatment train includes the peroxide destruction module (PDM) where the hydrogen peroxide residual from the upstream ultraviolet light/hydrogen peroxide oxidation unit is destroyed. Removal of the residual peroxide is necessary to protect downstream membranes from the strong oxidizer. The main component of the PDM is two reaction vessels utilizing granular activated carbon (GAC) as the reaction media. The PDM experienced a number of operability problems, including frequent plugging, and has not been utilized since the ETF changed to groundwater as the predominant feed. The unit seemed to be underperforming in regards to peroxide removal during the early periods of operation as well. It is anticipated that a functional PDM will be required for wastewater from the vitrification plant and other future streams. An alternate media or methodology needs to be identified to replace the GAC in the PDMs. This series of bench scale tests is to develop information to support an engineering study on the options for replacement of the existing GAC method for peroxide destruction at the ETF. A number of different catalysts will be compared as well as other potential methods such as strong reducing agents. The testing should lead to general conclusions on the viability of different catalysts and identify candidates for further study and evaluation.

HALGREN DL

2008-07-30T23:59:59.000Z

448

Catalyst Additives to Enhance Mercury Oxidation and Capture  

SciTech Connect

Preliminary research has shown that SCR catalysts employed for nitrogen-oxide reduction can effectively oxidize mercury. This report discusses initial results from fundamental investigations into the behavior of mercury species in the presence of SCR catalysts at Southern Research Institute. The testing was performed at Southern Research's Catalyst Test Facility, a bench-scale reactor capable of simulating gas-phase reactions occurring in coal-fired utility pollution-control equipment. Three different SCR catalysts are currently being studied in this project - honeycomb-type, plate-type, and a hybrid-type catalyst. The catalysts were manufactured and supplied by Cormetech Inc., Hitachi America Ltd., and Haldor-Topsoe Inc., respectively. Parametric testing was performed to investigate the contribution of flue-gas chemistry on mercury oxidation via SCR catalysts. Methods and procedures for experimental testing continue to be developed to produce the highest quality mercury-oxidation data. Most experiments so far have focused on testing the catalysts in a simulated Powder River Basin (PRB) flue-gas environment, which contains lower sulfur and chlorine than produced by other coals. Future work to characterize flue gas simulations typically derived from low and high sulfur bituminous coal will be performed in a stepwise manner, to avoid the constant interruptions in testing that occur when leaks in the system are generated during temperature transitions. Specifically, chlorine concentration vs. mercury oxidation graph will be developed for each catalyst. The contributions of temperature and later sulfur will be investigated after this is complete. Also, last quarter's tests showed a potential linear relationship between SO3 conversion and mercury oxidation. As a result, SO3 samples will be taken more frequently to investigate each catalyst's ability to selectively oxidize mercury.

Alex J. Berry; Thomas K. Gale

2005-09-30T23:59:59.000Z

449

Nanoparticle Superlattices for Custom-designed ...  

Wind Energy; Partners (27) Visual Patent Search; Success Stories; News; Events; Industrial Technologies Nanoparticle Superlattices for Custom-designed ...

450

Alloy nanoparticle synthesis using ionizing radiation  

DOE Patents (OSTI)

A method of forming stable nanoparticles comprising substantially uniform alloys of metals. A high dose of ionizing radiation is used to generate high concentrations of solvated electrons and optionally radical reducing species that rapidly reduce a mixture of metal ion source species to form alloy nanoparticles. The method can make uniform alloy nanoparticles from normally immiscible metals by overcoming the thermodynamic limitations that would preferentially produce core-shell nanoparticles.

Nenoff, Tina M. (Sandia Park, NM); Powers, Dana A. (Albuquerque, NM); Zhang, Zhenyuan (Durham, NC)

2011-08-16T23:59:59.000Z

451

New Gold Nanoparticle RMs Support Nanotechnology ...  

Science Conference Proceedings (OSTI)

... Various types of nanoparticles (eg, dendrimers, quantum dots, gold nanospheres ... by a lack of comprehensive and accurate physical and chemical ...

2012-10-02T23:59:59.000Z

452

Mixed Alcohol Synthesis Catalyst Screening 2007 Progress Report  

DOE Green Energy (OSTI)

Pacific Northwest National Laboratory (PNNL) and National Renewable Energy Laboratory (NREL) are researching the feasibility of producing mixed alcohols from biomass-derived synthesis gas (syngas). PNNL is obtaining commercially available mixed alcohol or preparing promising mixed-alcohol catalysts and screening them in a laboratory-scale reactor system. The most promising catalysts are provided to NREL for testing using a slipstream from a pilot-scale biomass gasifier. After a review of the literature in 2006 and conversations with companies that produce catalysts, it was determined that no commercial mixed-alcohol synthesis catalysts were available. One manufacturer supplied a modified methanol catalyst that was tested in the PNNL laboratory-scale system and provided to NREL for further testing. PNNL also prepared and tested the behavior of 10 other catalysts representing the distinct catalyst classes for mixed alcohol syntheses. Based on those results,testing in 2007 focused on the performance of the rhodium-based catalysts. The effects of adding promoters to the rhodium catalysts in addition to the manganese already being used were examined. The iron and rhenium promoters both stood out as achieving higher carbon selectivities , followed by Cu. Iridium and Li, on the other hand, had low carbon selectivity ratios of 0.27 and 0.22, respectively. Although testing of candidate promoters is not complete, it appears that Ir and Li promoters warrant further optimization and possibly combination to further improve STYs and carbon selectivities to C2+ oxygenates. However, using these promoters, it will be necessary to incorporate a separate hydrogenation catalyst to improve the yield of C2+ alcohols with respect to the other oxygenates. Fe, Re, and Cu stand out as possible candidates in this respect, but additional research is needed to examine whether they can be combined with the other promoters on the Rh-based catalyst or need to be optimized on a separate catalyst support that is either physically mixed or used in series with the promoted Rh-based catalyst.

Gerber, Mark A.; White, J. F.; Gray, Michel J.; Stevens, Don J.

2007-11-01T23:59:59.000Z

453

DEVELOPMENT OF PRECIPITATED IRON FISCHER-TROPSCH CATALYSTS  

SciTech Connect

Despite the current worldwide oil glut, the US will ultimately require large-scale production of liquid (transportation) fuels from coal. Slurry phase Fischer-Tropsch (F-T) technology, with its versatile product slate, may be expected to play a major role in production of transportation fuels via indirect coal liquefaction. Some of the F-T catalysts synthesized and tested at Texas A and M University under DOE Contract No. DE-AC22-89PC89868 were more active than any other known catalysts developed for maximizing production of high molecular weight hydrocarbons (waxes). The objectives of the present contract were to demonstrate repeatability of catalyst performance and reproducibility of preparation procedures of two of these catalysts on a laboratory scale. Improvements in the catalyst performance were attempted through the use of: (a) higher reaction pressure and gas space velocity to maximize the reactor productivity; (b) modifications in catalyst preparation steps; and (c) different pretreatment procedures. Repeatability of catalyst performance and reproducibility of catalyst synthesis procedure have been successfully demonstrated in stirred tank slurry reactor tests. Reactor space-time-yield was increased up to 48% by increasing reaction pressure from 1.48 MPa to 2.17 MPa, while maintaining the gas contact time and synthesis gas conversion at a constant value. Use of calcination temperatures above 300 C, additional CaO promoter, and/or potassium silicate as the source of potassium promoter, instead of potassium bicarbonate, did not result in improved catalyst performance. By using different catalyst activation procedures they were able to increase substantially the catalyst activity, while maintaining low methane and gaseous hydrocarbon selectivities. Catalyst productivity in runs SA-0946 and SA-2186 was 0.71 and 0.86 gHC/g-Fe/h, respectively, and this represents 45-75% improvement in productivity relative to that achieved in Rheinpreussen's demonstration plant unit (the most successful bubble column slurry reactor performance to date), and sets new standards of performance for ''high alpha'' iron catalysts.

Dr. Dragomir B. Bukur; Dr. X. Lang; Dr. S. Chokkaram; Dr. L. Nowicki; G. Wei; Dr. Y. Ding; Dr. B. Reddy; Dr. S. Xiao

1999-07-22T23:59:59.000Z

454

80 HP PLASMA ASSISTED CATALYST SYSTEM  

DOE Green Energy (OSTI)

The US economy is linked to efficient heavy vehicle transportation and diesel remains the fuel of choice for mass transportation of goods and services. Diesel engines remain the most reliable and cost effective system for commerce. Recent deleterious effects of diesel exhaust on health and environment have led to an urgent need for cost effective technologies that would bring about reduction in NOx and PM. CARB estimates on-road diesel mobile source will contribute almost 50% NOx and 78% PM emissions by 2010. As a result recent Federal and State mandates have been adopted to reduce emissions from diesel exhaust to 1 Gm/bhp.-Hr of NOx and 0.05 Gm/bhp-hr of PM by the year 2007. The 2007 standard is to be achieved in a stepwise manner starting with the standards for 2002 namely 2 Gm/bhp-hr NOx and 0.1 Gm/bhp-hr of PM. 2002 standards are likely to be met by most engine manufacturer by some modified form of exhaust gas recirculation (EGR) system or by employing a sophisticated engine control system. Importance of cost effective technology requirement is further exaggerated by the fact that in recent years diesel engine production have increased dramatically see figure 1 and has out stripped the gasoline engine production almost 4:1 see figure 2. Currently gasoline engine employs a 3-way catalytic system for NOx and HC reduction and in order for the 3-way system to work the engine is run near stoichiometric air : fuel ratio so that exhaust has virtually no oxygen. This strategy has resulted in a poorer efficiency and hence less efficient utilization of our natural resources. By contrast diesel engine operate on a lean burn principals i.e. air rich and currently there are no commercial technologies available for treating NOx and PM. Technologies being considered for reducing NOx from lean burn (diesel) exhaust are; Lean NOx catalyst systems, NOx adsorber system, Selective Catalytic Reduction systems and plasma assisted catalyst system. Of all these technologies Plasma assisted catalyst system is probably the most attractive since it can use currently available fuel onboard.

Slone, Ralph

2001-08-05T23:59:59.000Z

455

Catalyst Additives to Enhance Mercury Oxidation and Capture  

SciTech Connect

Catalysis is the key fundamental ingredient to convert elemental mercury in coal-fired power stations into its oxidized forms that are more easily captured by sorbents, ESPs, baghouses, and wet scrubbers, whether the catalyst be unburned carbon (UBC) in the ash or vanadium pentoxide in SCR catalysts. This project has investigated several different types of catalysts that enhance mercury oxidation in several different ways. The stated objective of this project in the Statement of Objectives included testing duct-injection catalysts, catalyst-sorbent hybrids, and coated low-pressure-drop screens. Several different types of catalysts were considered for duct injection, including different forms of iron and carbon. Duct-injection catalysts would have to be inexpensive catalysts, as they would not be recycled. Iron and calcium had been shown to catalyze mercury oxidation in published bench-scale tests. However, as determined from results of an on-going EPRI/EPA project at Southern Research, while iron and calcium did catalyze mercury oxidation, the activity of these catalysts was orders of magnitude below that of carbon and had little impact in the short residence times available for duct-injected catalysts or catalyst-sorbent hybrids. In fact, the only catalyst found to be effective enough for duct injection was carbon, which is also used to capture mercury and remove it from the flue gas. It was discovered that carbon itself is an effective catalyst-sorbent hybrid. Bench-scale carbon-catalyst tests were conducted, to obtain kinetic rates of mercury adsorption (a key step in the catalytic oxidation of mercury by carbon) for different forms of carbon. All carbon types investigated behaved in a similar manner with respect to mercury sorption, including the effect of temperature and chlorine concentration. Activated carbon was more effective at adsorbing mercury than carbon black and unburned carbon (UBC), because their internal surface area of activated carbon was greater. Catalyst coating of low-pressure-drop screens was of particular interest as this project was being developed. However, it was discovered that URS was already heavily involved in the pursuit of this same technology, being funded by DOE, and reporting significant success. Hence, testing of SCR catalysts became a major focus of the project. Three different commercial SCR catalysts were examined for their ability to oxidize mercury in simulated flue-gas. Similar performance was observed from each of the three commercial catalysts, both in terms of mercury oxidation and SO{sub 3} generation. Ammonia injection hindered mercury oxidation at low HCl concentrations (i.e., {approx}2 ppmv), yet had little impact on mercury oxidation at higher HCl concentrations. On the other hand, SO{sub 2} oxidation was significantly reduced by the presence of ammonia at both low and high concentrations of HCl.

Thomas K. Gale

2006-06-30T23:59:59.000Z

456

Fischer-Tropsch Synthesis on Ceramic Monolith-Structured Catalysts  

SciTech Connect

This paper reports recent research results about impact of different catalyst bed configurations on FT reaction product distribution. A CoRe/?-alumina catalyst is prepared in bulk particle form and tested in the packed bed reactor at a size of 60 to 100 mesh. The same catalyst is ball milled and coated on a ceramic monolith support structure of channel size about 1mm. The monolith catalyst module is tested in two different ways, as a whole piece and as well-defined channels. Steady-state reaction conversion is measured at various temperatures under constant H2/CO feed ratio of 2 and reactor pressure of 25 bar. Detailed product analysis is performed. Significant formation of wax is evident with the packed particle bed and with the monolith catalyst that is improperly packed. By contrast, the wax formation is not detected in the liquid product by confining the reactions inside the monolith channel. This study presents an important finding about the structured catalyst/reactor system that the product distribution highly depends on the way how the structured reactor is set up. Even if the same catalyst and same reaction conditions (T, P, H2/oil ratio) are used, hydrodynamics (or flow conditions) inside a structured channel can have a significant impact on the product distribution.

Wang, Yong; Liu, Wei

2009-02-01T23:59:59.000Z

457

ATTRITION RESISTANT IRON-BASED FISCHER-TROPSCH CATALYSTS  

SciTech Connect

Fischer-Tropsch (FT) synthesis to convert syngas (CO + H{sub 2}) derived from natural gas or coal to liquid fuels and wax is a well-established technology. For low H{sub 2} to CO ratio syngas produced from CO{sub 2} reforming of natural gas or from gasification of coal, the use of Fe catalysts is attractive because of their high water gas shift activity in addition to their high FT activity. Fe catalysts are also attractive due to their low cost and low methane selectivity. Because of the highly exothermic nature of the FT reaction, there has been a recent move away from fixed-bed reactors toward the development of slurry bubble column reactors (SBCRs) that employ 30 to 90 {micro}m catalyst particles suspended in a waxy liquid for efficient heat removal. However, the use of FeFT catalysts in an SBCR has been problematic due to severe catalyst attrition resulting in fines that plug the filter employed to separate the catalyst from the waxy product. Fe catalysts can undergo attrition in SBCRs not only due to vigorous movement and collisions but also due to phase changes that occur during activation and reaction.

K. Jothimurugesan; James G. Goodwin, Jr.; Santosh K. Gangwal

1999-10-01T23:59:59.000Z

458

The generation of efficient supported (Heterogeneous) olefin metathesis catalysts  

Science Conference Proceedings (OSTI)

Over the past decade, a new family of homogeneous metathesis catalysts has been developed that will tolerate most organic functionalities as well as water and air. These homogeneous catalysts are finding numerous applications in the pharmaceutical industry as well as in the production of functional polymers. In addition the catalysts are being used to convert seed oils into products that can substitute for those that are now made from petroleum products. Seed oils are unsaturated, contain double bonds, and are a ready source of linear hydrocarbon fragments that are specifically functionalized. To increase the number of applications in the area of biomaterial conversion to petrol chemicals, the activity and efficiency of the catalysts need to be as high as possible. The higher the efficiency of the catalysts, the lower the cost of the conversion and a larger number of practical applications become available. Active supported catalysts were prepared and tested in the conversion of seed oils and other important starting materials. The outcome of the work was successful and the technology has been transferred to a commercial operation to develop viable applications of the discovered systems. A biorefinery that converts seed oils is under construction in Indonesia. The catalysts developed in this study will be considered for the next generation of operations.

Grubbs, Robert H

2013-04-05T23:59:59.000Z

459

JV 58-Effects of Biomass Combustion on SCR Catalyst  

DOE Green Energy (OSTI)

A portable slipstream selective catalytic reduction (SCR) reactor was installed at a biomass cofired utility boiler to examine the rates and mechanisms of catalyst deactivation when exposed to biomass combustion products. The catalyst was found to deactivate at a much faster rate than typically found in a coal-fired boiler, although this may have been the result of high ash loading rather than a general property of biomass combustion. Deactivation was mainly the result of alkali and alkaline-earth sulfate formation and growth in catalyst pores, apparently caused by alkaline-earth ash deposition on or near the pore sites. The high proportion of biomass in the fuel contributed to elevated levels of alkali and alkaline-earth material in the ash when compared to coal ash, and these higher levels provided more opportunity for sulfate formation. Based on laboratory tests, neither catalyst material nor ammonia contributed measurably to ash mass gains via sulfation. A model constructed using both field and laboratory data was able to predict catalyst deactivation of catalysts under subbituminous coal firing but performed poorly at predicting catalyst deactivation under cofiring conditions. Because of the typically higher-than coal levels of alkali and alkaline-earth elements present in biomass fuels that are available for sulfation at typical SCR temperatures, the use of SCR technology and biomass cofiring needs to be carefully evaluated prior to implementation.

Bruce C. Folkedahl; Christopher J. Zygarlicke; Joshua R. Strege; Donald P. McCollor; Jason D. Laumb; Lingbu Kong

2006-08-31T23:59:59.000Z

460

Low temperature steam-coal gasification catalysts  

SciTech Connect

Shrinking domestic supplies and larger dependence on foreign sources have made an assortment of fossil fuels attractive as possible energy sources. The high sulfur and mineral coals of Illinois would be an ideal candidate as possible gasification feedstock. Large reserves of coal as fossil fuel source and a projected shortage of natural gas (methane) in the US, have made development of technology for commercial production of high Btu pipeline gases from coal of interest. Several coal gasification processes exist, but incentives remain for the development of processes that would significantly increase efficiency and lower cost. A major problem in coal/char gasification is the heat required which make the process energy intensive. Hence, there is a need for an efficient and thermally neutral gasification process. Results are described for the gasification of an Illinois No. 6 coal with transition metal catalysts and added potassium hydroxide.

Hippo, E.J.; Tandon, D. [Southern Illinois Univ., Carbondale, IL (United States)

1996-12-31T23:59:59.000Z

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461

Octahedral molecular sieve sorbents and catalysts  

DOE Patents (OSTI)

Octahedral molecular sieve sorbents and catalysts are disclosed, including silver hollandite and cryptomelane. These materials can be used, for example, to catalyze the oxidation of CO.sub.x (e.g., CO), NO.sub.x (e.g., NO), hydrocarbons (e.g., C.sub.3H.sub.6) and/or sulfur-containing compounds. The disclosed materials also may be used to catalyze other reactions, such as the reduction of NO.sub.2. In some cases, the disclosed materials are capable of sorbing certain products from the reactions they catalyze. Silver hollandite, in particular, can be used to remove a substantial portion of certain sulfur-containing compounds from a gas or liquid by catalysis and/or sorption. The gas or liquid can be, for example, natural gas or a liquid hydrocarbon.

Li, Liyu [Richland, WA; King, David L [Richland, WA

2010-04-20T23:59:59.000Z

462

BSA 07-17: Synthesis of Metal-Metal Oxide Catalysts and ...  

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463

A carbon riveted Pt/Graphene catalyst with high stability for direct methanol fuel cell  

Science Conference Proceedings (OSTI)

Pt/Graphene catalyst was prepared by microwave-assisted polyol process, and carbonization was riveted onto the catalyst surface to enhance the catalyst stability. The physical properties of the obtained catalysts were characterized by X-ray diffraction ... Keywords: Direct methanol fuel cell, Methanol electrooxidation, Pt/Graphene, Stability

Xiaowei Liu, Jialin Duan, Hailong Chen, Yufeng Zhang, Xuelin Zhang

2013-10-01T23:59:59.000Z

464

Fabrication of transparent ceramics using nanoparticles  

DOE Patents (OSTI)

A method of fabrication of a transparent ceramic using nanoparticles synthesized via organic acid complexation-combustion includes providing metal salts, dissolving said metal salts to produce an aqueous salt solution, adding an organic chelating agent to produce a complexed-metal sol, heating said complexed-metal sol to produce a gel, drying said gel to produce a powder, combusting said powder to produce nano-particles, calcining said nano-particles to produce oxide nano-particles, forming said oxide nano-particles into a green body, and sintering said green body to produce the transparent ceramic.

Cherepy, Nerine J; Tillotson, Thomas M; Kuntz, Joshua D; Payne, Stephen A

2012-09-18T23:59:59.000Z

465

Scintillation of rare earth doped fluoride nanoparticles  

SciTech Connect

The scintillation response of rare earth (RE) doped core/undoped (multi-)shell fluoride nanoparticles was investigated under x-ray and alpha particle irradiation. A significant enhancement of the scintillation response was observed with increasing shells due: (i) to the passivation of surface quenching defects together with the activation of the REs on the surface of the core nanoparticle after the growth of a shell, and (ii) to the increase of the volume of the nanoparticles. These results are expected to reflect a general aspect of the scintillation process in nanoparticles, and to impact radiation sensing technologies that make use of nanoparticles.

Jacobsohn, L. G.; McPherson, C. L.; Sprinkle, K. B.; Ballato, J. [Center for Optical Materials Science and Engineering Technologies (COMSET), and School of Materials Science and Engineering, Clemson University, Clemson, South Carolina 29634 (United States); Yukihara, E. G. [Physics Department, Oklahoma State University, Stillwater, Oklahoma 74078-3072 (United States); DeVol, T. A. [Department of Environmental Engineering and Earth Sciences, Clemson University, Clemson, South Carolina 29634-0905 (United States)

2011-09-12T23:59:59.000Z

466

Energy and economic savings from improved catalysts: Executive summary  

SciTech Connect

The energy, economic costs and benefits of applying the materials-by-design concept to catalysts were estimated. Catalysts are of particular interest because of the competitive challenge from Japan, West Germany, and France. Initial estimates developed in this study reveal a potential capital cost savings of $31 billion and an operating cost savings of $69 billion for chemical and petroleum refining plants over a 15-year period. The findings of this study substantiate the claim that a major US effort to enhance materials-by-design technology is warranted, at least for catalyst materials. In addition, this technology would ensure pre-eminence by the US industry.

1986-11-01T23:59:59.000Z

467

HYBRID HETEROGENEOUS CATALYSTS FOR HYDROGENATION OF CARBON DIOXIDE  

DOE Green Energy (OSTI)

HYBRID HETEROGENEOUS CATALYSTS FOR HYDROGENATION OF CARBON DIOXIDE Lucia M. Petkovic, Harry W. Rollins, Daniel M. Ginosar, and Kyle C. Burch Idaho National Laboratory P.O. Box 1625 Idaho Falls, ID 83415-2208 Introduction Anthropogenic emissions of carbon dioxide, a gas often associated with global warming, have increased considerably since the beginning of the industrial age.1 In the U.S., stationary CO2 sources, such as electricity generation plants, produce about one-third of the anthropogenic CO2 generation. Reports2 indicate that the power required to recover 90% of the CO2 from an integrated coal-fired power-plant is about 10% of the power-plant capacity. This ener