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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 Reaction-Driven Restructuring of Bimetallic Nanoparticle Catalysts Print Wednesday, 28 January 2009 00:00...

2

Cleaner water using bimetallic nanoparticle catalysts  

SciTech Connect

Groundwater contaminated by hazardous chlorinated compounds, especially chlorinated ethenes, continues to be a significant environmental problem in industrialized nations. The conventional treatment methods of activated carbon adsorption and air-stripping successfully remove these compounds by way of transferring them from the water phase into the solid or gas phase. Catalysis is a promising approach to remove chlorinated compounds completely from the environment, by converting them into safer, non-chlorinated compounds. Palladium-based materials have been shown to be very effective as hydrodechlorination catalysts for the removal of chlorinated ethenes and other related compounds. However, relatively low catalytic activity and a propensity for deactivation are significant issues that prevent their widespread use in groundwater remediation. Palladium-on-gold bimetallic nanoparticles, in contrast, were recently discovered to exhibit superior catalyst activity and improved deactivation resistance. This new type of material is a significant next-step in the development of a viable hydrodechlorination catalysis technology.

Wong, Michael S.; Alvarez, Pedro J.J.; Fang, Yu-Iun; Akçin, Nurgül; Nutt, Michael O.; Miller, Jeffrey T.; Heck, Kimberly N.

2010-10-22T23:59:59.000Z

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

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.

5

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.

6

Titania-Supported PdAu Bimetallic Catalysts Prepared from Dendrimer-Encapsulated Nanoparticle Precursors  

E-Print Network (OSTI)

Titania-Supported PdAu Bimetallic Catalysts Prepared from Dendrimer-Encapsulated Nanoparticle the synthesis and characteriza- tion of TiO2-supported PdAu bimetallic nanoparticle catalysts prepared using dendrimer-encapsulated nanoparticles (DENs).1 The key result is that the compositional fidelity

Goodman, Wayne

7

Composition-Controlled Synthesis of Bimetallic Gold-Silver Nanoparticl...  

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

Composition-Controlled Synthesis of Bimetallic Gold-Silver Nanoparticles. Composition-Controlled Synthesis of Bimetallic Gold-Silver Nanoparticles. Abstract: This paper reports...

8

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

E-Print Network (OSTI)

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

Zhu, Zhongwei

2014-01-01T23:59:59.000Z

9

Neutral bimetallic transition metal phenoxyiminato catalysts and related polymerization methods  

DOE Patents (OSTI)

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

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

2012-08-07T23:59:59.000Z

10

Glycerol Hydrogenolysis on Carbon-Supported PtRu and AuRu Bimetallic Catalysts  

SciTech Connect

Bimetallic PtRu and AuRu catalysts were prepared by a surface redox method in which Pt or Au was deposited onto the surface of carbon-supported Ru nanoparticles with an average diameter of 2-3 nm. Characterization by H2 chemisorption, analytical TEM, and X-ray absorption spectroscopy at the Ru K-edge, Pt LIII-edge, and Au LIII-edge confirmed that Pt and Au were successfully deposited onto Ru without disrupting the Ru particles. Depression of the ethane hydrogenolysis rate over Ru after addition of Au provided further evidence of successful deposition. The bimetallic particles were subsequently evaluated in the aqueous-phase hydrogenolysis of glycerol at 473 K and 40 bar H2 at neutral and elevated pH. Although monometallic Pt and Ru exhibited different activities and selectivities to products, the bimetallic PtRu catalyst functioned more like Ru. A similar result was obtained for the AuRu bimetallic catalyst. The PtRu catalyst appeared to be stable under the aqueous-phase reaction conditions, whereas the AuRu catalyst was altered by the harsh conditions. Gold appeared to migrate off the Ru and agglomerate on the carbon during the reaction in liquid water.

Maris,E.; Ketchie, W.; Murayama, M.; Davis, R.

2007-01-01T23:59:59.000Z

11

Synthesis and Characterization of Cluster-Derived Supported Bimetallic Catalysts  

SciTech Connect

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

Adams, Richard D; Amiridis, Michael D

2008-10-10T23:59:59.000Z

12

Novel bimetallic dispersed catalysts for temperature-programmed coal liquefaction. Final report  

SciTech Connect

Development of new catalysts is a promising approach to more efficient coal liquefaction. It has been recognized that dispersed catalysts are superior to supported catalysts for primary liquefaction of coals, because the control of initial coal dissolution or depolymerization requires intimate contact between the catalyst and coal. This research is a fundamental and exploratory study on catalytic coal liquefaction, with the emphasis on exploring novel bimetallic dispersed catalysts for coal liquefaction and the effectiveness of temperature-programmed liquefaction using dispersed catalysts. The primary objective of this research was to explore novel bimetallic dispersed catalysts from organometallic molecular precursors, that could be used in low concentrations but exhibit relatively high activity for efficient hydroliquefaction of coals under temperature-programmed conditions. We have synthesized and tested various catalyst precursors in liquefaction of subbituminous and bituminous coals and in model compound studies to examine how do the composition and structure of the catalytic precursors affect their effectiveness for coal liquefaction under different reaction conditions, and how do these factors affect their catalytic functions for hydrogenation of polyaromatic hydrocarbons, for cleavage of C-C bonds in polycyclic systems such as 4-(1-naphthylmethyl)bibenzyl, for hydrogenolysis of C-O bond such as that in dinaphthylether, for hydrodeoxygenation of phenolic compounds and other oxygen-containing compounds such as xanthene, and for hydrodesulfurization of polycyclic sulfur compounds such as dibenzothiophene. The novel bimetallic and monometallic precursors synthesized and tested in this project include various Mo- and Fe-based compounds.

Chunshan Song; Schobert, H.H.; Parfitt, D.P. [and others

1997-11-01T23:59:59.000Z

13

Insights into the reaction mechanism for 5-hydroxymethylfurfural oxidation to FDCA on bimetallic Pd–Au nanoparticles  

Science Journals Connector (OSTI)

Abstract This work deals with the oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA) in water using supported Pd–Au nanoparticles. The active phase composition was shown to be crucial for FDCA formation. Indeed, both Au and Pd monometallic nanoparticles formed 5-hydroxymethyl-2-furancarboxylic acid (HMFCA) under the studied conditions; however, with Pd nanoparticles HMFCA was not further transformed, while Au and bimetallic Pd–Au systems both catalysed its oxidation to FDCA. The thermal treatment of Pd–Au catalysts considerably modified their catalytic activity, because Pd atoms migrated and concentrated onto the outer part of bimetallic nanoparticles. The resulting active phase morphology showed a different reaction path for FDCA formation compared to the untreated catalyst, with an important contribution of the Cannizzaro reaction. PVP-protected Pd–Au nanoparticles with different structures (either alloy or core-shell morphology) were synthesized and their reactivity tested in order to confirm the presence of different mechanisms for HMF oxidation, depending on whether the active phase preferentially exposes either Pd or Au atoms.

Alice Lolli; Stefania Albonetti; Luca Utili; Rossella Amadori; Francesca Ospitali; Carlo Lucarelli; Fabrizio Cavani

2014-01-01T23:59:59.000Z

14

Bimetallic Pt-Ag and Pd-Ag nanoparticles  

SciTech Connect

We report studies of bimetallic nanoparticles with 15%-16% atomic crystal parameters size mismatch. The degree of alloying was probed in a 2-nm Pt core (smallest attainable core size) of Pt-Ag nanoparticles (completely immiscible in bulk) and 20-nm-diameter Pd-Ag nanowires (completely miscible in bulk). Particles were synthesized radiolytically, and depending on the initial parameters, they assume spherical or cylindrical (nanowire) morphologies. In all cases, the metals are seen to follow their bulk alloying characteristics. Pt and Ag segregate in both spherical and wire forms, which indicates that strain due to crystallographic mismatch overcomes the excess surface free energy in the small particles. The Pd-Ag nanowires alloy similar to previously reported spherical Pd-Ag particles of similar diameter and composition.

Lahiri, Debdutta; Bunker, Bruce; Mishra, Bhoopesh; Zhang, Zhenyuan; Meisel, Dan; Doudna, C.M.; Bertino, M. F.; Blum, Frank D.; Tokuhiro, A.T.; Chattopadhyay, Soma; Shibata, Tomohiro; Terry, Jeff [Department of Physics, University of Notre Dame, Notre Dame, Indiana 46556 (United States); Radiation Laboratory and Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556 (United States); Departments of Physics, Chemistry and Nuclear Engineering, University of Missouri-Rolla, Missouri 65409 (United States); Department of Biological, Chemical, and Physical Sciences (BCPS), Illinois Institute of Technology, Chicago, Illinois 60616 (United States)

2005-05-01T23:59:59.000Z

15

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

SciTech Connect

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

16

Structure and properties of bimetallic Ru-Fe/Al/sub 2/O/sub 3/ catalysts  

SciTech Connect

The authors studied the influence of the composition of Ru-Fe-/Al/sub 2/O/sub 3/-catalysts on adsorption and interaction of carbon monoxide and hydrogen. Moessbauer investigations were conducted. According to x-ray photoelectron spectra (XPS) bimetallic Ru-Fe/Al/sub 2/O/sub 3/ catalysts contain ruthenium mainly in the form of Ru/sup 0/ (E/sub b/ = 280.8 eV). Adsorption of carbon monoxide, hydrogen, and CO + H/sub 2/ mixture was studied by microcalorimetric and thermal-desorption methods.

Zakumbaeva, G.D.; Shapovalova, L.B.; Omarov, Zh.T.; Kuanyshev, A.Sh.; Yaskevich, V.I.

1988-08-20T23:59:59.000Z

17

Functionalized electrospun nanofibers impregnated with nanoparticles for degradation of chlorinated compounds .  

E-Print Network (OSTI)

??Supported bimetallic Fe/Ni nanoparticles have been used for years as catalysts for the dechlorination of organochlorine compounds in ground water remediation. However, their fate and… (more)

Mapazi, Odwa

2014-01-01T23:59:59.000Z

18

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

SciTech Connect

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

19

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

20

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

SciTech Connect

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

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

2011-06-01T23:59:59.000Z

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

Ordered Nanoparticle Catalysts article is an Energy Focus > Archived...  

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

Gruner's time at CHESS In This Section EMC2 News Archived News Stories Ordered Nanoparticle Catalysts article is an Energy Focus January 24th, 2013 A Nature Materials...

22

Infrared spectra of carbon monoxide adsorbed on SiO sub 2 -supported lanthanide-Ni bimetallic catalysts and their catalytic properties  

SciTech Connect

Recently the surface properties of the lanthanide (rare earth) - transition metal intermetallics and lanthanide metal overlayers have attracted a growing interest from the point of view of technical applications in catalyst and hydrogen storage. However, despite the intrinsic interest and considerable potential of these novel materials, very little detailed work has been carried out with a view to unveiling the specific properties upon interactions of lanthanides with transition metals. It has been shown that Eu and Yb metals dissolve in liquid ammonia to yield homogeneous solutions containing the ammoniated electrons. When the transition metal powders are added to this solution, the metal powders react with the dissolved lanthanide metals in liquid ammonia to form novel bimetallic catalysts. Such a system can be used as a catalyst probe for studying the catalytic actions induced by interactions between the lanthanide and transition metals. The present investigation was extended to include a SiO{sub 2}-supported bimetallic systems obtained when Eu or Yb dissolved in liquid ammonia reacts with silica-supported Ni. Using Fourier transform (FT)-IR studies of adsorbed carbon monoxide the authors provided information about the way the surface components were disposed in this bimetallic system. Adsorbed carbon monoxide was used as a molecular probe for the nature of bimetallic surface since the IR spectra of adsorbed probe molecules directly reflected variations in the surface.

Imamura, Hayao; Sugimoto, Hiromi; Sakata, Yoshihisa; Tsuchiya, Susumu (Yamaguchi Univ., Ube (Japan))

1992-07-01T23:59:59.000Z

23

Characterization of CeO2-Supported Cu-Pd Bimetallic Catalyst for the Oxygen-Assisted Water-Gas Shift Reaction  

SciTech Connect

This study was focused to investigate the roles of Cu and Pd in CuPd/CeO2 bimetallic catalysts containing 20-30 wt% Cu and 0.5-1 wt% Pd used in the oxygen-assisted water-gas shift (OWGS) reaction employing a combined bulk and surface characterization techniques such as XRD, TPR, CO chemisorption, and in-situ XPS. The catalytic activity for CO conversion and the stability of catalyst during on-stream operation increased by the addition of Cu to Pd/CeO2 or Pd to Cu/CeO2 monometallic catalysts, especially when the OWGS reaction was performed under low temperatures, below 200oC. The bimetallic catalyst after leaching with nitric acid retained about 60% of its original activity. The TPR of monometallic Cu/CeO2 showed reduction of CuO supported on CeO2 in two distinct regions, around 150 and 250oC. The high temperature peak disappeared and reduction occurred in a single step around 150oC upon Pd addition. The Pd dispersion decreased from 38.5% for Pd/CeO2 to below 1% for CuPd/CeO2 bimetallic catalyst. In-situ XPS studies showed a shift in Cu 2p peaks toward lower binding energy (BE) with concommitant shift in the Pd 3d peaks toward higher BE. Addition of Pd decreased the surface Cu concentration while the concentration of Pd remained unaltered. All these observations indicated the formation of Cu-Pd surface alloy. The valence band XP spectra collected below 10 eV corroborated the core level XP spectra and indicated that Cu is mainly involved in the catalytic reaction. The improved catalytic activity and stability of CuPd/CeO2 bimetallic catalyst was attributed to the alloy formation.

Fox, Elise; Velu, Subramani; Engelhard, Mark H.; Chin, Ya-Huei; Miller, Jeffrey T.; Kropf, Jeremy; Song, Chunshan

2008-12-10T23:59:59.000Z

24

Supported catalysts using nanoparticles as the support material  

DOE Patents (OSTI)

A process for making a porous catalyst, comprises a) providing an aqueous solution containing a nanoparticle precursor, b) forming a composition containing nanoparticles, c) adding a first catalytic component or precursor thereof and a pore-forming agent to the composition containing nanoparticles and allowing the first catalytic component, the pore-forming agent, and the nanoparticles form an organic-inorganic structure, d) removing water from the organic-inorganic structure; and e) removing the pore-forming agent from the organic-inorganic structure so as to yield a porous catalyst.

Wong, Michael S. (Houston, TX); Wachs, Israel E. (Bethlehem, PA); Knowles, William V. (Pearland, TX)

2010-11-02T23:59:59.000Z

25

Monodisperse Platinum and Rhodium Nanoparticles as Model Heterogeneous Catalysts  

SciTech Connect

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

Coble, Inger M

2008-08-15T23:59:59.000Z

26

Surface spectroscopic characterization of oxide thin films and bimetallic model catalysts  

E-Print Network (OSTI)

of the surface morphology and electronic/geometric structure of the following catalysts: SiO2/Mo(112), Ag/SiO2/Mo(112), Au–Pd/Mo(110), Au–Pd/SiO2/Mo(110), and Pd– Sn/Rh(100). Specifically, different types of oxide surface defects were directly identified by MIES...

Wei, Tao

2009-05-15T23:59:59.000Z

27

From First Principles Design to Realization of Bimetallic Catalysts for Enhanced Selectivity  

SciTech Connect

“Catalysis by design” has been a dream for decades. To specify the composition and structure of matter to effect a desired catalytic transformation with desired and predicted rate and selectivity remains a monumental challenge, especially in heterogeneous catalysis. Our research thrusts have been chosen not only for their practical and scientific relevance, e.g. for more efficient and sustainable chemicals and fuels production, but also because they provide a foundation for developing and exploring broadly applicable principles and strategies for catalyst design.

Lobo, Raul F.; Crooks, Richard M.; Mavrikakis, Manos

2014-04-08T23:59:59.000Z

28

Development of Ni–Fe bimetallic based catalysts for biomass tar cracking/reforming: Effects of catalyst support and co-fed reactants on tar conversion characteristics  

Science Journals Connector (OSTI)

Abstract Catalytic activities of Ni- and Ni–Fe bimetallic based catalysts supported by palygorskite, MgO–Al2O3, La0.8Ca0.2CrO3, and La0.8Ca0.2CrO3/MgO–Al2O3 toward the cracking and reforming of naphthalene and toluene (as biomass tar model compounds) as well as real biomass tar from pyrolysis of eucalyptus wood chips were studied. At 700-900 °C, the main products from the cracking of these hydrocarbons are H2, CH4, C2H4, C2H6, and C3H6. Among all catalysts, Ni–Fe supported by MgO–Al2O3 and La0.8Ca0.2CrO3/MgO–Al2O3 show the highest H2 yield values and good resistance toward carbon deposition. Additions of H2O and CO2 can promote steam and dry reforming, from which H2 and CO were the major products from the reaction and the amount of carbon formation was considerably reduced. Importantly, the H2O/tar and CO2/tar ratios strongly affect the H2 yield value, particularly for Ni–Fe/La0.8Ca0.2CrO3/MgO–Al2O3 due to the presence of perovskite-based La0.8Ca0.2CrO3. At proper H2O/tar and CO2/tar ratios, La0.8Ca0.2CrO3 behaves like the partly-reduced metal-oxide catalysts and promotes the reforming activity. Addition of O2 along with H2O and/or CO2 can further reduce the carbon formation and increase the H2 yield. Nevertheless, excess O2 could oxidize metal particles and combusted H2 to H2O, which causes lower H2 yield production.

N. Laosiripojana; W. Sutthisripok; S. Charojrochkul; S. Assabumrungrat

2014-01-01T23:59:59.000Z

29

Development Plus Kinetic and Mechanistic Studies of a Prototype Supported-Nanoparticle Heterogeneous Catalyst  

E-Print Network (OSTI)

-Nanoparticle Heterogeneous Catalyst Formation System in Contact with Solution: Ir(1,5-COD)Cl/ -Al2O3 and Its Reduction by H2 to prepare the next generation of improved, supported-nanoparticle heterogeneous catalysts. It is precisely are eight criteria defining a prototype system for supported-nanoparticle heterogeneous catalyst formation

Frenkel, Anatoly

30

Z. B. He et al., Nickel catalyst shape Etchant-induced shaping of nanoparticle  

E-Print Network (OSTI)

Z. B. He et al., Nickel catalyst shape - 1 - Etchant-induced shaping of nanoparticle catalysts al., Nickel catalyst shape - 2 - Abstract Carbon nanofibres (CNFs) obtained by plasma show in this paper that the shape of Ni nanoparticle catalysts, and in turn the CNF properties, can

Boyer, Edmond

31

Bimetallic Ni-Rh catalysts with low amounts of Rh for the steam and autothermal reforming of n-butane for fuel-cell applications.  

SciTech Connect

Mono-metallic nickel and rhodium catalysts and bimetallic Ni-Rh catalysts supported on La-Al{sub 2}O{sub 3}, CeZrO{sub 2} and CeMgOx were prepared and evaluated for catalyzing the steam and autothermal reforming of n-butane. The binary Ni-Rh supported on La-Al{sub 2}O{sub 3} catalysts with low weight loading of rhodium exhibited higher H{sub 2} yields than Ni or Rh alone. The Ni-Rh/CeZrO{sub 2} catalyst exhibited higher performance and no coke formation, compared to the same metals on other supports. A NiAl{sub 2}O{sub 4} spinel phase was obtained on all Ni and Ni-Rh catalysts supported on La-Al{sub 2}O{sub 3}. The presence of rhodium stabilized the spinel phase as well as NiOx species upon reforming while Ni alone was mostly reduced into metallic species. Extended X-ray absorption fine-structure analysis showed evidence of Ni-Rh alloy during preparation and even further after an accelerated aging at 900C in a H{sub 2}/H{sub 2}O atmosphere.

Ferrandon, M.; Kropf, A. J.; Krause, T.; Chemical Sciences and Engineering Division

2010-05-15T23:59:59.000Z

32

Developing electrochemical sensor for point-of-care diagnostics of oxidative stress marker using imprinted bimetallic Fe/Pd nanoparticle  

Science Journals Connector (OSTI)

Abstract A novel electrochemical-sensing platform based on imprinted bimetallic Fe/Pd (BI-Fe/Pd) nanoparticle has been fabricated for point-of-care diagnostics of oxidative stress marker (3-nitrotyrosine) in biological fluids. Herein, BI-Fe/Pd nanoparticles are used as a platform on which 3-nitrotyrosine imprinted cavities are created using acrylamide as monomer and N-N?-methylene bisacrylamide as cross-linker. The performance of the obtained imprinted sensor is investigated by cyclic, differential pulse, and square wave voltammetry in stripping mode. The imprinted sensor exhibits high recognition ability and affinity for 3-nitrotyrosine in comparison with the non-imprinted one. In addition, the proposed sensor is capable of measuring 3-nitrotyrosine in aqueous as well as in human blood serum, plasma, and urine samples within the range of 4.90–867.57 µg L?1 and 9.90–867.57 µg L?1 with detection limit of 1.20 µg L?1 and 3.25 µg L?1 by square wave and differential pulse stripping voltammetry, respectively. Imprinted BI-Fe/Pd nanoparticle modified sensor shows high affinity and no interference from blood or urine components. Modified sensor was stored for 45 days at room temperature without any detrimental effects to their binding properties. The high affinity of proposed sensor and the lack of requirement for cold chain logistics make them an attractive alternative to the enzyme-linked immunosorbent assay (ELISA) technique.

Ekta Roy; Santanu Patra; Rashmi Madhuri; Prashant K. Sharma

2015-01-01T23:59:59.000Z

33

PUBLISHED ONLINE: 20 FEBRUARY 2014 | DOI: 10.1038/NMAT3872 Platinumcobalt bimetallic nanoparticles in hollow  

E-Print Network (OSTI)

nanoparticles in hollow carbon nanospheres for hydrogenolysis of 5-hydroxymethylfurfural Guang-Hui Wang, Jakob and Ferdi Schüth* The synthesis of 2,5-dimethylfuran (DMF) from 5-hydroxymethylfurfural (HMF) is a highly

Cai, Long

34

Hidden features of the catalyst nanoparticles favorable for single-walled carbon nanotube growth  

E-Print Network (OSTI)

Hidden features of the catalyst nanoparticles favorable for single-walled carbon nanotube growth Combining in situ studies of the catalyst activity during single-walled carbon nanotube SWCNT growth by mass the favorable features of small catalyst for SWCNT growth and their relationship with synthesis parameters

Curtarolo, Stefano

35

Improved Pd-on-Au bimetallic nanoparticle catalysts for aqueous-phase trichloroethene hydrodechlorination  

E-Print Network (OSTI)

organic contaminants found in ground- water [1­5]. Its use as a solvent to degrease metals and electronic Available online 17 July 2006 Abstract Groundwater remediation through the catalytic breakdown recently been shown to catalyze the hydrodechlorination of trichloroethene in water, at room temperature

Alvarez, Pedro J.

36

Preparation of highly stable bimetallic Ni–Cu catalyst for simultaneous production of hydrogen and fish-bone carbon nanofibers: Optimization, effect of catalyst preparation methods and deactivation  

Science Journals Connector (OSTI)

Abstract This paper presents the preparation of highly stable nano-porous Ni–Cu catalysts for simultaneous production of COx–free hydrogen and carbon nano-fibers. The main features of this work focuses on the optimization, methods of catalyst preparation and application of an experimental model for deactivation. The fresh catalysts and the deposited carbon were characterized by SEM, TEM, XRD and Raman spectroscopy. Whatever to be the preparation methods, performance tests showed that the presence of Cu as promoter in Ni–Cu–MgO catalysts, enhanced the catalytic activity, substantially at higher temperatures with the best result obtained for Ni–Cu–MgO catalyst prepared by one step sol- gel method, reaching a hydrogen concentration of 70 vol% (160.51 mol H2/mol Ni-1 h) and a smaller value of ID/IG (less imperfection) for produced carbon nano-fibers at 670 °C. Detailed rate-based model for deactivation of catalyst was found to be dependent on the time, reaction temperature and partial pressure of methane and indicated that the reaction of deactivation could be modeled by a simple hyperbolic model.

Nosrat Izadi; Ali Morad Rashidi; Ahmad Zeraatkar; Heshmatollah Varmazyar; Maryam Rashtchi

2014-01-01T23:59:59.000Z

37

Novel bimetallic dispersed catalysts for temperature-programmed coal liquefaction. Quarterly technical progress report, July--September 1995  

SciTech Connect

Coal liquefaction involves cleavage of methylene, dimethylene and ether bridges connecting polycyclic aromatic units and the reactions of various oxygen functional groups. Here in this quarterly, we report on the hydrocracking of 4-(l-naphthylmethyl)bibenzyl in the presence of iron (Fe) catalysts and sulfur and residual wall catalytic effect. Catalytic hydrocracking of 4-(1-naphthylmethyl)bibenzyl (NMBB) predominantly yielded naphthalene and 4-methylbibenzyl. Various iron compounds were examined as catalyst precursors. Sulfur addition to most catalyst precursors led to substantially higher catalyst activity and higher conversion. NMBB was also treated with sulfur in the absence of iron compounds, in concentrations of 1.2-3.4 wt%, corresponding to the conditions present in reactions with added iron compounds. Increasing sulfur concentrations led to higher NMBB conversions. Furthermore, sulfur had a permanent effect on the reactor walls. A black sulfide layer formed on the surface which could not be removed mechanically. The supposed non-catalytic reactions done in the same reactor but after experiments with added sulfur showed higher conversions than comparable experiments done in new reactors. This wall catalytic effect can be reduced by treating the sulfided reactors with hydrochloric acid. The results of this work demonstrate the significant effect of sulfur addition and sulfur-induced residual wall effects on carbon-carbon bond cleavage and hydrogenation of aromatics.

Song, Chunshan; Schmidt, E.; Schobert, H.H.

1996-01-01T23:59:59.000Z

38

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

E-Print Network (OSTI)

and a basis for the future design and improvement of SWNT supported catalysts. 1. Introduction The hydrogen fuel cell is of growing interest as an electrical power source.1-3 Although the fuel cell itself content in the product, which is highly desirable for fuel cell applications.1,3,12 APR has been carried

Haller, Gary L.

39

Novel bimetallic dispersed catalysts for temperature-programmed coal liquefaction. Technical progress report, October 1995--December 1995  

SciTech Connect

Coal liquefaction involves cleavage of methylene, dimethylene and ether bridges connecting polycyclic aromatic units and the reactions of various oxygen functional groups. Here in this quarterly, we report on the catalytic effects of several molybdenum-, cobalt-, and iron-containing compounds in the reactions of dibenzothiophene (DBT) with hydrogen under conditions related to coal liquefaction. The catalytic effects of several molybdenum-, cobalt-, and iron-containing compounds have been examined in the hydrogenation and hydrodesulfurization reactions of dibenzothiophene (DBT) under conditions related to coal liquefaction. The metal compounds are candidate catalyst precursors for direct coal liquefaction. The reactions were carried out in batch microautoclave reactors at 400{degrees}C for 30 minutes with 6.9 MPa (cold) hydrogen pressure, and tridecane solvent. A metal loading of 0.5 mol% resulted in low conversion and only hydrogenation. Addition of sulfur in 4:1 molar ratio led only to a minor increase in conversion and hydrodesulfurization. The use of a higher boiling solvent (octadecane vs. tridecane) was beneficial in providing increased conversion, hydrodesulfurization, and hydrogenation. An increase in metal compound loading to 36.2 mol% led to a dramatic increase in conversion, hydrodesulfurization, and hydrocracking. Molybdenum hexacarbonyl at 36 mol% loading, with added sulfur at 6:1 ratio and octadecane solvent, gave 100% conversion of dibenzothiophene to other products with 100% hydrodesulfurization. Ammonium tetrathiomolybdate and molybdenum(III) chloride are less active under similar conditions. A cobalt-molybdenum thiocubane complex gave unexpectedly low conversions. Iron and cobalt carbonyls also provided very low conversions, even with added sulfur.

Song, C.; Cooke, W.S.; Schmidt, E.; Schobert, H.H.

1996-02-01T23:59:59.000Z

40

BIMETALLIC NANOCATALYSTS IN MESOPOROUS SILICA FOR HYDROGEN PRODUCTION FROM COAL-DERIVED FUELS  

SciTech Connect

In steam reforming reactions (SRRs) of alkanes and alcohols to produce H{sub 2}, noble metals such as platinum (Pt) and palladium (Pd) are extensively used as catalyst. These metals are expensive; so, to reduce noble-metal loading, bi-metallic nanocatalysts containing non-noble metals in MCM-41 (Mobil Composition of Material No. 41, a mesoporous material) as a support material with high-surface area were synthesized using one-pot hydrothermal procedure with a surfactant such as cetyltrimethylammonium bromide (CTAB) as a template. Bi-metallic nanocatalysts of Pd-Ni and Pd-Co with varying metal loadings in MCM-41 were characterized by x-ray diffraction (XRD), N{sub 2} adsorption, and Transmission electron microscopy (TEM) techniques. The BET surface area of MCM-41 (~1000 m{sup 2}/g) containing metal nanoparticles decreases with the increase in metal loading. The FTIR studies confirm strong interaction between Si-O-M (M = Pd, Ni, Co) units and successful inclusion of metal into the mesoporous silica matrix. The catalyst activities were examined in steam reforming of methanol (SRM) reactions to produce hydrogen. Reference tests using catalysts containing individual metals (Pd, Ni and Co) were also performed to investigate the effect of the bimetallic system on the catalytic behavior in the SRM reactions. The bimetallic system remarkably improves the hydrogen selectivity, methanol conversion and stability of the catalyst. The results are consistent with a synergistic behavior for the Pd-Ni-bimetallic system. The performance, durability and thermal stability of the Pd-Ni/MCM-41 and Pd-Co/MCM-41 suggest that these materials may be promising catalysts for hydrogen production from biofuels. A part of this work for synthesis and characterization of Pd-Ni-MCM-41 and its activity for SRM reactions has been published (“Development of Mesoporous Silica Encapsulated Pd-Ni Nanocatalyst for Hydrogen Production” in “Production and Purification of Ultraclean Transportation Fuels”; Hu, Y., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 2011.)

Kuila, Debasish; Ilias, Shamsuddin

2013-02-13T23:59:59.000Z

Note: This page contains sample records for the topic "bimetallic nanoparticle catalysts" from the National Library of EnergyBeta (NLEBeta).
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they are not comprehensive nor are they the most current set.
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to obtain the most current and comprehensive results.


41

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

SciTech Connect

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

Somorjai, G.A.

2009-09-14T23:59:59.000Z

42

Phosphotungstic acid supported on magnetic nanoparticles as an efficient reusable catalyst for epoxidation of alkenes  

SciTech Connect

Highlights: ? Phosphotungstic acid supported on functionalized cobalt ferrite was prepared. ? Silica coated cobalt ferrite nanoparticles were used as support. ? This composite was successfully used as catalyst for epoxidation of alkenes. ? Oxidation reactions were carried out in the presence of t-BuOOH as oxidant. ? The catalyst can be readily separated from solution by magnetic field. -- Abstract: A new magnetically separable catalyst consisting of phosphotungstic acid supported on imidazole functionalized silica coated cobalt ferrite nanoparticles was prepared. The synthesized catalyst was characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), vibrating sample magnetometry (VSM), thermogravimetric analysis (TGA), Fourier transform infrared (FT-IR), and inductively coupled plasma atomic emission spectroscopy (ICP-AES). This immobilized phosphotungstic acid was shown to be an efficient heterogeneous catalyst for the epoxidation of various alkenes using tert-butylhydroperoxide (t-BuOOH) as oxidant. The catalyst is readily recovered by simple magnetic decantation and can be recycled several times with no significant loss of catalytic activity.

Kooti, M., E-mail: m_kooti@scu.ac.ir [Department of Chemistry, College of Science, Shahid Chamran University, Ahvaz 61357- 43169 (Iran, Islamic Republic of); Afshari, M. [Department of Chemistry, College of Science, Shahid Chamran University, Ahvaz 61357- 43169 (Iran, Islamic Republic of)] [Department of Chemistry, College of Science, Shahid Chamran University, Ahvaz 61357- 43169 (Iran, Islamic Republic of)

2012-11-15T23:59:59.000Z

43

Sub-Nanometer-Resolution Elemental Mapping of “Pt3Co” Nanoparticle Catalyst Degradation in Proton-Exchange Membrane Fuel Cells  

Science Journals Connector (OSTI)

However, the specific activity enhancement of “Pt3Co” NPs decreases during PEMFC operation, which has been attributed to the formation of a Pt-enriched shell near the NP surfaces. ... Rate Enhancements in Structural Transformations of Pt–Co and Pt–Ni Bimetallic Cathode Catalysts in Polymer Electrolyte Fuel Cells Studied by in Situ Time-Resolved X-ray Absorption Fine Structure ... In situ time-resolved X-ray absorption fine structure spectra of Pt/C, Pt3Co/C, and Pt3Ni/C cathode electrocatalysts in membrane electrode assemblies (catalyst loading: 0.5 mgmetal cm–2) were successfully measured every 100 ms for a voltage cycling ... ...

Christopher E. Carlton; Shuo Chen; Paulo J. Ferreira; Lawrence F. Allard; Yang Shao-Horn

2011-12-29T23:59:59.000Z

44

Kinetics and PEMFC performance of RuxMoySez nanoparticles as a cathode catalyst  

Science Journals Connector (OSTI)

Kinetics of RuxMoySez nanoparticles dispersed on carbon powder was studied in 0.5 M H2SO4 electrolyte towards the oxygen reduction reaction (ORR) and as cathode catalysts for a proton exchange membrane fuel cell (PEMFC). RuxMoySez catalyst was synthesized by decarbonylation of transition-metal carbonyl compounds for 3 h in organic solvent. The powder was characterized by X-ray diffraction (XRD), and transmission electron microscopy (TEM) techniques. Catalyst is composed of uniform agglomerates of nanocrystalline particles with an estimated composition of Ru6Mo1Se3, embedded in an amorphous phase. The electrochemical activity was studied by rotating disk electrode (RDE) and rotating ring-disk electrode (RRDE) techniques. Tafel slopes for the ORR remain invariant with temperature at ?0.116 V dec?1 with an increase of the charge transfer coefficient in d?/dT = 1.6 × 10?3, attributed to an entropy turnover contribution to the electrocatalytic reaction. The effect of temperature on the ORR kinetics was analyzed resulting in an apparent activation energy of 45.6 ± 0.5 kJ mol?1. The catalyst generates less than 2.5% hydrogen peroxide during oxygen reduction. The RuxMoySez nanoparticles dispersed on a carbon powder were tested as cathode electrocatalyst in a single fuel cell. The membrane-electrode assembly (MEA), included Nafion® 112 as polymer electrolyte membrane and commercial carbon supported Pt (10 wt%Pt/C-Etek) as anode catalyst. It was found that the maximum performance achieved for the electro-reduction of oxygen was with a loading of 1.0 mg cm?2 RuxMoySez 20 wt%/C, arriving to a power density of 240 mW cm?2 at 0.3 V and 80 °C.

K. Suárez-Alcántara; O. Solorza-Feria

2008-01-01T23:59:59.000Z

45

Structure-Property Relationship in Metal Carbides and Bimetallic Alloys  

SciTech Connect

The primary objective of our DOE/BES sponsored research is to use carbide and bimetallic catalysts as model systems to demonstrate the feasibility of tuning the catalytic activity, selectivity and stability. Our efforts involve three parallel approaches, with the aim at studying single crystal model surfaces and bridging the “materials gap” and “pressure gap” between fundamental surface science studies and real world catalysis. The utilization of the three parallel approaches has led to the discovery of many intriguing catalytic properties of carbide and bimetallic surfaces and catalysts. During the past funding period we have utilized these combined research approaches to explore the possibility of predicting and verifying bimetallic and carbide combinations with enhanced catalytic activity, selectivity and stability.

Chen, Jingguan [University of Delaware] [University of Delaware

2014-03-04T23:59:59.000Z

46

High PEMFC performance by applying Ir-V nanoparticles as a cathode catalyst  

Science Journals Connector (OSTI)

Very active catalysts Ir-V/C, as a novel suitable cathode catalyst in \\{PEMFCs\\} was synthesized using IrCl3 and NH4VO3 as the Ir and V precursors. By applying the ethylene glycol (EG) method, a well dispersion of Ir-V/C catalysts with mean particle size of 2 nm was obtained. The membrane–electrode assembly (MEA) fabricated with Ir-V nanoparticles exhibited the excellent catalytic activity toward the oxygen reduction reaction (ORR) and, reached 517 mW cm?2 at 0.43 V and 210 mW cm?2 at 0.30 V in a real fuel cell environment, H2/O2 and H2/air, respectively. In particular, promising results were obtained based on a low metal (Ir) loading of 0.4 mg cm?2 on the cathode which achieved 100 h durability at a constant current density of 1200 mA cm?2. The electrocatalytic effect related to a change in the electro-catalyst structure was discussed based on the XRD and TEM data. Also, for the first time, the electrochemical impedance spectra (EIS) and cyclic voltammetry (CV) techniques were used to assess the kinetics of oxygen reduction on the produced samples and the enhancement effect of V in-situ of fuel cells.

Jinli Qiao; Bing Li; Daijun Yang; Jianxin Ma

2009-01-01T23:59:59.000Z

47

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

48

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

SciTech Connect

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

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

1985-02-01T23:59:59.000Z

49

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

50

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

E-Print Network (OSTI)

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

Somorjai, Gabor A.

2009-01-01T23:59:59.000Z

51

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

E-Print Network (OSTI)

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

Somorjai, G.A.

2010-01-01T23:59:59.000Z

52

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

Science Journals Connector (OSTI)

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

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

2003-04-10T23:59:59.000Z

53

Pd and Pd–Ag Nanoparticles within a Macroreticular Basic Resin: An Efficient Catalyst for Hydrogen Production from Formic Acid Decomposition  

Science Journals Connector (OSTI)

Pd and Pd–Ag Nanoparticles within a Macroreticular Basic Resin: An Efficient Catalyst for Hydrogen Production from Formic Acid Decomposition ... Palladium nanoparticles were immobilized within the pores of metal organic frameworks MIL-125 and amine-functionalized NH2-MIL-125 using photoassisted and ion exchange deposition methods. ...

Kohsuke Mori; Masahiro Dojo; Hiromi Yamashita

2013-04-15T23:59:59.000Z

54

IMPROVED CATALYSTS FOR HEAVY OIL UPGRADING BASED ON ZEOLITE Y NANOPARTICLES ENCAPSULATED IN STABLE NANOPOROUS HOST  

SciTech Connect

The objectives of this project are to synthesis nanocrystals of highly acidic zeolite Y, encapsulate them within the channels of mesoporous (nanoporous) silicates or nanoporous organosilicates and evaluate the ''zeolite Y/Nanoporous host'' composites as catalysts for the upgrading of heavy petroleum feedstocks. Our results to date are summarized as follows. The synthesis of high surface ordered nanoporous silica of expanded pore diameter of 25 nm (larger than the standard size of 8.4 nm) using trimethylbenzene as a pore size expander was accomplished. The synthesis of zeolite Y nanoparticles with median pore size of approximately 50 nm (smaller than the 80 nm typically obtained with TMAOH) using combined TMABr/TMAOH as organic additives was also accomplished. The successful synthesis of zeoliteY/Nanoporous host composite materials by sequential combination of zeolite precursors and nanoporous material precursor mixtures was implied based on results from various characterization techniques such as X-Ray diffraction, infrared spectra, thermal analysis, porosimetry data. The resulting materials showed pore sizes up to 11 nm, and infrared band at 570 cm{sup -1} suggesting the presence of both phases. New results indicated that good quality highly ordered nanoporous silica host can be synthesized in the presence of zeolite Y seed precursor depending on the amount of precursor added. Preliminary research on the catalytic performance of the materials is underway. Probe acid catalyzed reactions, such as the cracking of cumene is currently being conducted. Work in the immediate future will be focused on the following three areas: (1) Further characterization of all-silica and aluminosilicate mesoporous materials with expanded pore sizes up to 30 nm will continue; (2) Research efforts to reduce the average particle size of zeolite nanoparticles down to 35-30 nm will continue; (3) Further synthesis of ZeoliteY/Nanoporous host composite catalysts of improved structural and physicochemical characteristics will be conducted by changing the amount and chemistry of the zeolitic precursors added; and (4) Investigation on the catalytic properties of the materials using probe catalytic reactions (such as cumene cracking), followed by catalytic testing for heavy oil conversion.

Conrad Ingram; Mark Mitchell

2005-03-31T23:59:59.000Z

55

IMPROVED CATALYSTS FOR HEAVY OIL UPGRADING BASED ON ZEOLITE Y NANOPARTICLES ENCAPSULATED STABLE NANOPOROUS HOST  

SciTech Connect

The objectives of this project are to synthesis nanocrystals of highly acidic zeolite Y, encapsulate them within the channels of mesoporous (nanoporous) silicates or nanoporous organosilicates and evaluate the ''zeolite Y/Nanoporous host'' composites as catalysts for the upgrading of heavy petroleum feedstocks. Our results to date are summarized as follows. The synthesis of high surface ordered nanoporous silica of expanded pore diameter of 25 nm (larger than the standard size of 8.4 nm) using trimethylbenzene as a pore size expander was accomplished. The synthesis of zeolite Y nanoparticles with median pore size of approximately 50 nm (smaller than the 80 nm typically obtained with TMAOH) using combined TMABr/TMAOH as organic additives was also accomplished. The successful synthesis of zeoliteY/Nanoporous host composite materials by sequential combination of zeolite precursors and nanoporous material precursor mixtures was implied based on results from various characterization techniques such as X-Ray diffraction, infrared spectra, thermal analysis, porosimetry data. The resulting materials showed pore sizes up to 11 nm, and infrared band at 570 cm{sup -1} suggesting the presence of both phases. Work in the immediate future will be focused on the following three areas: (1) Further characterization of all-silica and aluminosilicate mesoporous materials with expanded pore sizes up to 30 nm will continue; (2) Research efforts to reduce the average particle size of zeolite nanoparticles down to 35-30 nm will continue; (3) Further synthesis of polymer-SBA15 nanocomposites will be conducted by changing the amount and chemistry of the zeolitic precursors added; and (4) Investigation on the catalytic properties of the materials using probe catalytic reactions (such as cumene cracking), followed by catalytic testing for heavy oil conversion.

Conrad Ingram; Mark Mitchell

2005-03-21T23:59:59.000Z

56

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

SciTech Connect

It is well known that the activity, selectivity, and deactivation behavior of heterogeneous catalysts are strongly affected by a wide variety of parameters, including but not limited to nanoparticle size, shape, composition, support, pretreatment conditions, oxidation state, and electronic state. Enormous effort has been expended in an attempt to understand the role of these factors on catalytic behavior, but much still remains to be discovered. In this work, we have focused on deepening the present understanding of the role of nanoparticle shape, nanoparticle composition, and hot electrons on heterogeneous catalysis in the oxidation of carbon monoxide by molecular oxygen and nitric oxide. These reactions were chosen because they are important for environmental applications, such as in the catalytic converter, and because there is a wide range of experimental and theoretical insight from previous single crystal work as well as experimental data on nanoparticles obtained using new state-of-the-art techniques that aid greatly in the interpretation of results on complex nanoparticle systems. In particular, the studies presented in this work involve three types of samples: {approx} 6.5 nm Rh nanoparticles of different shapes, {approx} 15 nm Rh1-xPdx core-shell bimetallic polyhedra nanoparticles, and Rh ultra-thin film ({approx} 5 nm) catalytic nanodiodes. The colloidal nanoparticle samples were synthesized using a co-reduction of metal salts in alcohol and supported on silicon wafers using the Langmuir-Blodgett technique. This synthetic strategy enables tremendous control of nanoparticle size, shape, and composition. Nanoparticle shape was controlled through the use of different organic polymer capping layers. Bimetallic core-shell nanoparticles were synthesized by careful choice of metal salt precursors. Rh/TiO{sub x} and Rh/GaN catalytic nanodiodes were fabricated using a variety of thin film device fabrication techniques, including reactive DC magnetron sputtering, electron beam evaporation, and rapid thermal annealing. The combination of these techniques enabled control of catalytic nanodiode morphology, geometry, and electrical properties.

Renzas, James R.

2010-03-08T23:59:59.000Z

57

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

Science Journals Connector (OSTI)

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

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

2011-01-01T23:59:59.000Z

58

Lattice-Matched Bimetallic CuPd-Graphene Nanocatalysts for Facile Conversion of Biomass-Derived Polyols to Chemicals  

Science Journals Connector (OSTI)

Lattice-Matched Bimetallic CuPd-Graphene Nanocatalysts for Facile Conversion of Biomass-Derived Polyols to Chemicals ... A bimetallic nanocatalyst with unique surface configuration displays extraordinary performance for converting biomass-derived polyols to chemicals, with potentially much broader applications in the design of novel catalysts for several reactions of industrial relevance. ... Dehydrogenated species are instantaneously converted to LA(37, 41) (with OH–) or alcoholic chemicals(15, 39) (by in situ formed hydrogen) in alkaline medium. ...

Xin Jin; Lianna Dang; Jessica Lohrman; Bala Subramaniam; Shenqiang Ren; Raghunath V. Chaudhari

2013-01-08T23:59:59.000Z

59

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

Science Journals Connector (OSTI)

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

Dasika Harshini; Yongchai Kwon; Jonghee Han…

2010-03-01T23:59:59.000Z

60

Nanostructured catalysts for cathodes of oxygen-hydrogen fuel cells  

Science Journals Connector (OSTI)

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

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

2007-01-01T23:59:59.000Z

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

Improved Catalysts for Heavy Oil Upgrading Based on Zeolite Y Nanoparticles Encapsulated Stable Nanoporous Host  

SciTech Connect

The addition of hydrothermally-aged zeolite Y precursor to an SBA-15 synthesis mixture under a mildly acidic condition resulted in the formation of mesoporous aluminosilicate catalyst, Al-SBA-15, containing strong Broensted acid sites and aluminum (Al) stabilized in a totally tetrahedral coordination. The physicochemical characteristics of the catalyst varied as a function of the synthesis conditions. The catalyst possessed surface areas ranging between 690 and 850 m{sup 2}/g, pore sizes ranging from 5.6 to 7.5 nm, and pore volumes up 1.03 cm{sup 3}, which were comparable to the parent SBA-15 synthesized under similar conditions. Two wt% Al was present in the catalyst that was obtained from the reaction mixture that contained the highest Al content. The Al remained stable in totally tetrahedral coordination after calcination at 550 C. The Al-SBA-15 mesoporous catalyst showed significant catalytic activity for cumene dealkylation, and the activity increased as the amount of zeolite precursor added to the SBA-15 mixture was increased. In preparation for the final phase of the project, the catalyst was embedded into psuedoboemite alumina (catapal B) matrix and then formed into pellets. In the final phase of the project, the pelletized catalyst will be evaluated for the conversion of heavy petroleum feedstocks to naphtha and middle distillates.

Conrad Ingram; Mark Mitchell

2006-09-30T23:59:59.000Z

62

Improved Catalysts for Heavy Oil Upgrading Based on Zeolite Y Nanoparticles Encapsulated Stable Nanoporous Host  

SciTech Connect

The addition of hydrothermally-aged zeolite Y precursor to an SBA-15 synthesis mixture under a mildly acidic condition resulted in the formation of a mesoporous aluminosilicate catalyst, AlSBA-15. The Al-SBA-15 mesoporous catalyst contains strong Br{umlt o}nsted acid sites and aluminum (Al) stabilized in a totally tetrahedral coordination. The physicochemical characteristics of the catalyst varied as a function of the synthesis conditions. The catalyst possessed surface areas ranging between 690 and 850 m{sup 2}/g, pore sizes ranging from 5.6 to 7.5 nm, and pore volumes up 1.03 cm{sup 3}, which were comparable to the parent SBA-15 synthesized under similar conditions. Two wt % Al was present in the catalyst that was obtained from the reaction mixture that contained the highest Al content. The Al remained stable in totally tetrahedral coordination after calcination at a temperature of 550 C. The Al-SBA-15 mesoporous catalyst showed significant catalytic activity for cumene dealkylation, and the activity increased as the amount of zeolite precursor added to the SBA-15 mixture was increased. In preparation for the final phase of the project, the catalyst was embedded into a psuedoboemite alumina (catapal B) matrix and then formed into pellets. In the final phase of the project, the pelletized catalyst is being evaluated for the conversion of a heavy petroleum feedstock to naphtha and middle distillates. This phase was significantly delayed during the past six months due to a serious malfunction of the fume hoods in the Clark Atlanta University's Research Center for Science and Technology, where the project is being conducted. The fume hood system was repaired and the catalyst evaluation is now underway.

Conrad Ingram; Mark Mitchell

2007-03-31T23:59:59.000Z

63

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

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

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

64

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

E-Print Network (OSTI)

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

Li, Yujing

2012-01-01T23:59:59.000Z

65

Bimetallic and Ternary Alloys for Improved Oxygen Reduction Catalysis...  

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

Bimetallic and Ternary Alloys for Improved Oxygen Reduction Catalysis . Bimetallic and Ternary Alloys for Improved Oxygen Reduction Catalysis . Abstract: The research described in...

66

ZnO nanoparticle catalysts for use in biodiesel production and method of making  

DOE Patents (OSTI)

A method of forming a biodiesel product and a heterogeneous catalyst system used to form said product that has a high tolerance for the presence of water and free fatty acids (FFA) in the oil feedstock is disclosed. This catalyst system may simultaneously catalyze both the esterification of FAA and the transesterification of triglycerides present in the oil feedstock. The catalyst system is comprised of a mixture of zinc oxide and a second metal oxide. The zinc oxide includes a mixture of amorphous zinc oxide and zinc oxide nanocrystals, the zinc nanocrystals having a mean grain size between about 20 and 80 nanometers with at least one of the nanocrystals including a mesopore having a diameter of about 5 to 15 nanometers. Preferably, the second metal oxide is a lanthanum oxide, the lanthanum oxide being selected as one from the group of La.sub.2CO.sub.5, LaOOH, and combinations or mixtures thereof.

Yan, Shuli; Salley, Steven O; Ng, K. Y. Simon

2014-11-25T23:59:59.000Z

67

Catalyst supports for polymer electrolyte fuel cells  

Science Journals Connector (OSTI)

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

2010-01-01T23:59:59.000Z

68

IMPROVED CATALYSTS FOR HEAVY OIL UPGRADING BASED ON ZEOLITE Y NANOPARTICLES ENCAPSULATED STABLE NANOPOROUS HOST  

SciTech Connect

Al-SBA-15 mesoporous catalysts with strong Broensted acid sites and Al stabilized in a totally tetrahedral coordination was synthesized from the addition of hydrothermally aged zeolite Y precursor to SBA-15 synthesis mixture under mildly acidic condition of pH 5.5. The materials possessed surface areas between 690 and 850 m{sup 2}/g, pore sizes ranging from 5.6 to 7.5 nm and pore volumes up 1.03 cm{sup 3}, which were comparable to parent SBA-15 synthesized under similar conditions. Up to 2 wt. % Al was present in the most aluminated sample that was investigated, and the Al remained stable in totally tetrahedral coordination, even after calcination at 550 C. The Al-SBA-15 mesoporous catalyst showed significant catalytic activity for cumene dealkylation, and activity increased as the amount of zeolite precursor added to the SBA-15 mixture was increased. The catalyst's activity was not affected by the aging time of the precursor for up to the 24 hr aging time investigated. This method of introducing Al and maintaining it in a total tetrahedral coordination is very effective, in comparison to other direct and post synthesis alumination methods reported. The catalytic performance of the zeolite Y/SBA-15 composite materials will be compared with that of pure SBA-15. The catalysts will then be evaluated for the conversion of heavy petroleum feedstocks.

Conrad Ingram; Mark Mitchell

2006-06-20T23:59:59.000Z

69

IMPROVED CATALYSTS FOR HEAVY OIL UPGRADING BASED ON ZEOLITE Y NANOPARTICLES ENCAPSULATED IN STABLE NANOPOROUS HOSTS  

SciTech Connect

The focus of this project is to improve the catalytic performance of zeolite Y for heavy petroleum hydrocracking by synthesizing nanoparticles of the zeolite ({approx}20-30 nm) inside nanoporous silicate or aluminosilicate hosts of similar pore diameters. The encapsulated zeolite nanoparticles are expected to possess pores of reduced diffusional path lengths, hence hydrocarbon substrates will diffuse in, are converted and the products quickly diffused out. This is expected to prevent over-reaction, hence minimizing pore blockage and active sites deactivation. In this phase of the project, research activities were focused on refining procedures to: (a) improve the synthesis of ordered, high surface area nanoporous silica, such as SBA-15, with expanded pore size using trimethylbenzene as additive to the parent SBA-15 synthesis mixture; and (b) reduce the particle size of zeolite Y such that they can be effectively incorporated into the nanoporous silicas. The synthesis of high surface ordered nanoporous silica containing enlarged pores of diameter of 25 nm (larger than the standard size of 8.4 nm) using trimethylbenzene as a pore size expander was accomplished. The synthesis of zeolite Y nanoparticles with median pore size of approximately 50 nm (smaller than the 80 nm typically obtained with TMAOH) using combined TMABr/TMAOH as organic additives was also accomplished.

Conrad Ingram; Mark Mitchell

2004-06-30T23:59:59.000Z

70

IMPROVED CATALYSTS FOR HEAVY OIL UPGRADING BASED ON ZEOLITE Y NANOPARTICLES ENCAPSULATED IN STABLE NANOPOROUS HOSTS  

SciTech Connect

The focus of this project is to improve the catalytic performance of zeolite Y for petroleum hydrocracking by synthesizing nanoparticles of the zeolite ({approx}20-25 nm) inside nanoporous silicate or aluminosilicate hosts. The encapsulated zeolite nanoparticles are expected to possess reduced diffusional path lengths, hence hydrocarbon substrates will diffuse in, are converted and the products quickly diffused out. This is expected to prevent over-reaction and the blocking of the zeolite pores and active sites will be minimized. In this phase of the project, procedures for the synthesis of ordered nanoporous silica, such as SBA-15, using block copolymers and nonionic surfactant were successful reproduced. Expansion of the pores sizes of the nanoporous silica using trimethylbenzene is suggested based on shift in the major X-Ray Diffraction peak in the products to lower 2 angles compared with the parent SBA-15 material. The synthesis of ordered nanoporous materials with aluminum incorporated in the predominantly silicate framework was attempted but is not yet successful, and the procedures needs will be repeated and modified as necessary. Nanoparticles of zeolite Y of particle sizes in the range 40 nm to 120 nm were synthesized in the presence of TMAOH as the particle size controlling additive.

Conrad Ingram

2003-09-03T23:59:59.000Z

71

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

SciTech Connect

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

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

2010-04-30T23:59:59.000Z

72

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

SciTech Connect

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

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

2010-01-01T23:59:59.000Z

73

Investigation into the molar feeding ratio and temperature dependence on the replacement reaction between platinum ions and silver nanoparticles  

E-Print Network (OSTI)

The deliberate structuring of bimetallic nanoparticles has useful applications in both fuel cell applications and biomedical research. This thesis studies the replacement reaction between platinum ions and silver nanoparticles, ...

Stuk, Archimedes

2010-01-01T23:59:59.000Z

74

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

SciTech Connect

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 <30 nm in diameter. While the amount of coke deposited during ethane and 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

75

Exhaust-catalyst development for methanol-fueled vehicles. II. Synergism between palladium and silver in methanol and carbon monoxide oxidation over an alumina-supported palladium-silver catalyst  

SciTech Connect

Methanol and carbon monoxide oxidation were examined over 0.01 Pd, 5% Ag, and 0.01% Pd/5% Ag catalysts - all supported on ..gamma..-alumina. The bimetallic catalyst showed greater CO and CH/sub 3/OH oxidation activity than either of the single-component catalysts; moreover, the Pd and Ag interacted synergistically in the bimetallic catalyst to produce greater CO and CH/sub 3/OH oxidation rates and lower yields of methanol partial oxidation products than expected from a mixture of the single-component catalysts. Temperature-programmed oxidation experiments and reactivity experiments involving changes in O/sub 2/ partial pressure both provided evidence that the Pd-Ag synergism results from Pd promoting the rate of O/sub 2/ adsorption and reaction with CO and CH/sub 3/OH on Ag. The data also indicate that virtually all of the Pd in the bimetallic catalyst is present in Pd-Ag crystallites.

McCabe, R.W.; Mitchell, P.J.

1987-02-01T23:59:59.000Z

76

Non-Platinum Bimetallic Cathode Electrocatalysts  

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

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

77

Magnetic Compensation in the Bimetallic Oxalates  

SciTech Connect

Bimetallic oxalates are layered molecule-based magnets with either ferromagnetic or antiferromagnetic interactions between transition metals M(II) and M'(III) on an open honeycomb lattice. Some Fe(II)Fe(III) bimetallic oxalates exhibit magnetic compensation (MC) at a compensation temperature Tcomp ? 30 K below the ferrimagnetic transition temperature Tc ? 45 K. To see if MC is possible in other bimetallic oxalates, we construct a theoretical model for bimetallic oxalates that exhibit antiferromagnetic interactions. By varying the M(II) and M'(III) average orbital angular momentum, which can be controlled by the choice of interlayer cations, we have found regions of MC in the families M(II)Mn(III) with M = Fe, Co, or Ni and V(II)M'(III) with M' = Cr or V but not in the family M(II)Ru(III) with M = Fe or Cu.

Reis, Peter L [ORNL; Fishman, Randy Scott [ORNL; Reboredo, Fernando A [ORNL; Moreno, Juana [University of North Dakota, Grand Forks

2008-01-01T23:59:59.000Z

78

Propane dehydrogenation over Al2O3 supported Pt nanoparticles: Effect of cerium addition  

Science Journals Connector (OSTI)

Abstract The catalyst of Pt nanoparticles loaded on Al2O3 support has been prepared by a facile liquid phase synthesis–ultrasonic vibration method. With propane dehydrogenation as a probe reaction, the influence of promoter cerium (Ce) on the catalyst was investigated by means of transmission electron microscope (TEM), X-ray diffraction (XRD), N2 adsorption–desorption, X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR) spectroscopy of CO adsorption, H2-temperature programmed reduction (H2-TPR), and catalytic properties for propane dehydrogenation. The results revealed that the Pt nanograins with diameter of 1.6–4.8 nm were evenly dispersed on the Ce-containing Al2O3 support. The introduction of a small amount Ce into Pt/Al2O3 results in a bimetallic surface interaction, enhancing the surface reducibility and dispersity of Pt nanoparticles. The study of propane dehydrogenation performance shows that Ce-containing Pt catalyst is more active and less coke deposition than Ce-free Pt/Al2O3 counterpart. This study can provide an insight into the design and development of new Pt-based catalyst, especially for the improvement of catalytic activity and stability towards alkane dehydrogenation.

Zhanhua Ma; Jun Wang; Jun Li; Ningning Wang; Changhua An; Lanyi Sun

2014-01-01T23:59:59.000Z

79

IMPROVED CATALYSTS FOR HEAVY OIL UPGRADING BASED ON ZEOLITE Y NANOPARTICLES ENCAPSULATED IN STABLE NANOPOROUS HOST  

SciTech Connect

Composite materials of SBA-15/zeolite Y were synthesized from zeolite Y precursor and a synthesis mixture of mesoporous silicate SBA-15 via a hydrothermal process in the presence of a slightly acidic media of pH 4-6 with 2M H{sub 2}SO{sub 4}. The SBA-15/ZY composites showed Type IV adsorption isotherms, narrow BJH average pore size distribution of 4.9 nm, surface areas up to 800 m{sup 2}2/g and pore volumes 1.03 cm{sup 3}, all comparable to pure SBA-15 synthesized under similar conditions. Chemical analysis revealed Si/Al ratio down to 8.5 in the most aluminated sample, and {sup 27}AlSS MAS NMR confirmed aluminum was in tetrahedral coordination. This method of introduction of Al in pure T{sub d} coordination is effective in comparison to other direct and post synthesis alumination methods. Bronsted acid sites were evident from a pyridinium peak at 1544 cm-1 in the FTIR spectrum after pyridine adsorption, and from NH{sub 3} -TPD experiments. SBA-15/ZY composites showed significant catalytic activities for the dealkylation of isopropylbenzene to benzene and propene, similar to those of commercial zeolite Y. It was observed that higher conversion for catalysts synthesized with high amount of ZY precursor mixture added to the SBA-15. Over all the composites has shown good catalytic activity. Further studies will be focused on gaining a better understand the nature of the precursor, and to characterize and to locate the acid sites in the composite material. The composite will also be evaluated for heavy oil conversion to naphtha and middle distillates.

Conrad Ingram; Mark Mitchell

2005-11-15T23:59:59.000Z

80

Aerosol-Derived Bimetallic Alloy Powders: Bridging the Gap  

SciTech Connect

We present aerosol-derived alloy powders as a uniquely useful platform for studying the contribution of the metal phase to multifunctional supported catalysts. Multimetallic heterogeneous catalysts made by traditional methods are usually nonhomogenous while UHV-based methods, such as mass selected clusters or metal vapor deposited on single crystals, lead to considerably more homogeneous, well-defined samples. However, these well-defined samples have low surface areas and do not lend themselves to catalytic activity tests in flow reactors under industrially relevant conditions. Bimetallic alloy powders derived by aerosol synthesis are homogeneous and single phase and can have surface areas ranging 1-10 m2/g, making them suitable for use in conventional flow reactors. The utility of aerosol-derived alloy powders as model catalysts is illustrated through the synthesis of single phase PdZn which was used to derive the specific reactivity of the L10 tetragonal alloy phase for methanol steam reforming. Turnover frequencies on unsupported PdZn were determined from the experimentally determined metal surface area to be 0.21 molecules of methanol reacted per surface Pd at 250 °C and 0.06 molecules of CO oxidized to CO2 per surface Pd at 185 °C. The experimentally measured activation energies for MSR and CO-oxidation on PdZn are 48 and 87 kJ/mol, respectively.

Halevi, Barr; Peterson, Eric; DelaRiva, Andrew; Jeroro, E.; Lebarbier, Vanessa MC; Wang, Yong; Vohs, John M.; Kiefer, Boris; Kunkes, Edward L.; Havecker , Michael; Behrens, Malte; Schlogl, Robert; Datye, Abhaya K.

2010-09-03T23:59:59.000Z

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

Cu doped CdS nanoparticles: A versatile and recoverable catalyst for chemoselective synthesis of indolo[2,3-b]quinoxaline derivatives under microwave irradiation  

Science Journals Connector (OSTI)

Abstract CdS and Cu doped CdS \\{NPs\\} has been obtained successfully using safe agents through a simple aqueous chemical method and characterized by XRD, TEM, SEM, EDAX, UV/VIS and ICP-AES. These investigations revealed that the particle size of the synthesized materials were uniformly distributed in the range of 2–4 nm and confirm the Cu doping in the lattice of CdS NPs. These nanoparticles were exploited to study their catalytic activities toward the chemoselective synthesis of indolo[2,3-b]quinoxalines by the reaction of isatins with 1,2-diamines in ethylene glycol under microwave irradiation. The method showed remarkable selectivity for indolo[2,3-b]quinoxalines over 3-imino-isatin, spirobenzimidazole, and ring-opened quinoxalinone derivatives. The catalytic activity of Cu doped CdS \\{NPs\\} was found to be about 18-fold higher under microwave irradiation (MW) as compared to the conventional method. Nanocatalyst plays a dual role of catalyst as well as susceptor, and enhances the overall capacity to absorb MW in the reaction mixture. Doping of Cu promotes the activity and selectivity of CdS nanoparticles indicated by high TOF value with good chemoselectivity. The surface acidity of \\{NPs\\} was measured by FTIR spectra of chemisorbed pyridine. Simple workup, mild reaction conditions, low cost, easy separation, and reusability of the catalyst are some advantages of this method.

Anshu Dandia; Vijay Parewa; Shuchi Maheshwari; Kuldeep S. Rathore

2014-01-01T23:59:59.000Z

82

Nanoparticle  

Science Journals Connector (OSTI)

Nanoparticles are submicron particles covering the size range 20–200 nm (diameter). Two general methods are applied for production of nanoparticles: the top–down approach, where one starts with the bulk material ...

Prof. Tharwat Tadros

2013-01-01T23:59:59.000Z

83

Surface spectroscopic studies of mono- and bimetallic model catalysts  

E-Print Network (OSTI)

dipole theory....................................46 14 Calibration of Pd coverage on Au(111). ..............................................................49 15 IRAS of CO adsorbed on Cu(100) between 23 and 180 K.... .................................52 16 IRAS of NO adsorbed on Cu(100) at the indicated NO exposure. ......................54 x FIGURE 17 Comparison of 14NO, 15NO, and a mixture of 14NO and 15NO adsorbed onto Cu(100...

Yi, Cheol-Woo

2007-04-25T23:59:59.000Z

84

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

SciTech Connect

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

85

Non-Platinum Bimetallic Cathode Electrocatalysts  

E-Print Network (OSTI)

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

86

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

Science Journals Connector (OSTI)

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

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

2012-10-12T23:59:59.000Z

87

Matching between Reaction and Catalyst Conditions in Growing VA-SWNTs by ACCVD  

E-Print Network (OSTI)

Matching between Reaction and Catalyst Conditions in Growing VA-SWNTs by ACCVD Hisashi Sugime1 of the catalyst nanoparticles is a crucial issue. Co-Mo binary catalysts effectively grow SWNTs either from CO [1/3 for the former [1] and 1.6/1 for the latter [2]. The structure of catalyst nanoparticles should be determined

Maruyama, Shigeo

88

Detection of triphenylmethane drugs in fish muscle by surface-enhanced raman spectroscopy coupled with Au-Ag core-shell nanoparticles  

Science Journals Connector (OSTI)

Silver -coated gold bimetallic nanoparticles were synthesized and used as substrates for surface-enhanced Raman spectroscopy (SERS) in detecting prohibited triphenylmethane drugs (including crystal violet and malachite green) in fish muscle. The optical ...

Lu Pei, Yiqun Huang, Chunying Li, Yuanyuan Zhang, Barbara A. Rasco, Keqiang Lai

2014-01-01T23:59:59.000Z

89

General Method for Determination of the Surface Composition in...  

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

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

90

Pt5Gd as a Highly Active and Stable Catalyst for Oxygen Electroreduction  

Science Journals Connector (OSTI)

Furthermore, these novel bimetallic electrocatalysts are highly stable, which, in combination with their enhanced activity, makes them very promising for the development of new cathode catalysts for fuel cells. ... Despite these very promising results, the stability of the catalyst will ultimately need to be tested in nanoparticulate form in a PEMFC. ... For all these reasons, we expect that alloying Pt with Gd and other rare earths will be a fruitful strategy toward the development of highly active and durable cathodes for PEMFCs. ...

María Escudero-Escribano; Arnau Verdaguer-Casadevall; Paolo Malacrida; Ulrik Grønbjerg; Brian P. Knudsen; Anders K. Jepsen; Jan Rossmeisl; Ifan E. L. Stephens; Ib Chorkendorff

2012-09-21T23:59:59.000Z

91

BIMETALLIC LITHIUM BOROHYDRIDES TOWARD REVERSIBLE HYDROGEN STORAGE  

SciTech Connect

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

92

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.

93

Natta catalyst  

Science Journals Connector (OSTI)

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

2007-01-01T23:59:59.000Z

94

Natta Catalyst  

Science Journals Connector (OSTI)

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

Jan W. Gooch

2011-01-01T23:59:59.000Z

95

Creating Precise 3D Microstructures Using Laser Direct-write Bimetallic Thermal Resist Grayscale Photomasks  

E-Print Network (OSTI)

research demonstrated Sn/In and Bi/In bimetallic thermal resists are promising new materials for direct/In bimetallic thermal resists as a masking material, we used a modified form of interference lithographyCreating Precise 3D Microstructures Using Laser Direct-write Bimetallic Thermal Resist Grayscale

Chapman, Glenn H.

96

Effect of mass transfer on the oxygen reduction reaction catalyzed by platinum dendrimer encapsulated nanoparticles  

Science Journals Connector (OSTI)

...agglomeration of Pt/C catalyst on hydrogen peroxide formation...2009 ) Importance of catalyst stability vis-a-vis hydrogen...2 O 2 production in PEMFC cathode conditions . J Appl Electrochem...AuPt alloy nanoparticle catalysts in electrocatalytic reduction...

Ioana Dumitrescu; Richard M. Crooks

2012-01-01T23:59:59.000Z

97

Non-Platinum Bimetallic Cathode Electrocatalysts  

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

alloy Pt Pd Rh Ir 5 6 Base metal increased ORR activity of palladium 20 nm 50 nm Nano-particles formed by co-impregnation, reduction in hydrogen -300 -250 -200 -150 -100 -50...

98

Spin-waves in Antiferromagnetically-Coupled Bimetallic Oxalates  

SciTech Connect

Bimetallic oxalates are molecule-based magnets with transition-metal ions M(II) and M (III) arranged on an open honeycomb lattice. Performing a Holstein-Primakoff expansion, we obtain the spin-wave spectrum of antiferromagnetically-coupled bimetallic oxalates as a function of the crystal-field angular momentum L2 and L3 on the M(II) and M (III) sites. Our results are applied to the Fe(II)Mn(III), Ni(II)Mn(III) and V(II)V(III) bimetallic oxalates, where the spin-wave gap varies from 0 meV for quenched angular momentum to as high as 15 meV. The presence or absence of magnetic compensation appears to have no effect on the spin-wave gap.

Reis, Peter L [ORNL; Fishman, Randy Scott [ORNL

2009-01-01T23:59:59.000Z

99

Scalable Parallel Screening of Catalyst Activity at the Single-Particle Level and Subdiffraction Resolution  

E-Print Network (OSTI)

Scalable Parallel Screening of Catalyst Activity at the Single-Particle Level and Subdiffraction ABSTRACT: High-throughput and quantitative screening of catalyst activity is crucial for guiding the work cycles of catalyst improvements and optimizations. For nanoparticle catalysts, their inherent

Chen, Peng

100

E-Print Network 3.0 - anode catalysts prepared Sample Search...  

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

fuel cells, by modifying both the anode and the cathode catalysts that will enable PEM fuel cell... catalyst as a separate phase - as nanoparticles. 2. ... Source: DOE Office of...

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

Chelating agent assisted heat treatment of carbon supported cobalt oxide nanoparticle for use as cathode catalyst of polymer electrolyte membrane fuel cell (PEMFC)  

Science Journals Connector (OSTI)

Cobalt-based catalysts for the oxygen reduction reaction (ORR) in polymer electrolyte membrane fuel cell (PEMFC) have been successfully incorporated cobalt oxide (Co3O4) onto Vulcan XC-72 carbon powder by thermal decomposition of Co–ethylenediamine complex (ethylenediamine, NH2CH2CH2NH2, denoted en) at 850 °C. The catalysts were prepared by adsorbing the cobalt complexes [Co(en)(H2O)4]3+, [Co(en)2(H2O)2]3+ and [Co(en)3]3+ on commercial XC-72 carbon black supports, loading amount of Co with respect to carbon black was about 2%, the resulting materials have been pyrolyzed under nitrogen atmosphere to create CoOx/C catalysts, donated as E1, E2, and E3, respectively. The composite materials were characterized using X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM) and X-ray photoelectron spectroscopy (XPS). Chemical compositions of prepared catalysts were determined using inductively-coupled plasma-atomic emission spectroscopy (ICP-AES). The catalytic activities for ORR have been analyzed by cyclic voltammetry (CV) and linear sweep voltammetry (LSV). The electrocatalytic activity for oxygen reduction of E2 is superior to that of E1 and E3. Membrane electrode assemblies (MEAs) containing the synthesized CoOx/C cathode catalysts were fabricated and evaluated by single cell tests. The E2 cathode performed better than that of E1 and E3 cathode. This can be attributed to the enhanced activity for ORR, in agreement with the composition of the catalyst that CoO co-existed with Co3O4. The maximum power density 73 mW cm?2 was obtained at 0.3 V with a current density of 240 mA cm?2 for E2 and the normalized power density of E2 is larger than that that of commercial 20 wt.% Pt/C-ETEK.

Chia-Hung Huang; Shyh-Jiun Liu; Weng-Sing Hwang

2011-01-01T23:59:59.000Z

102

Oxygen Reduction Kinetics on Electrodeposited PtCo as a Model Catalyst for Proton Exchange Membrane Fuel Cell Cathodes: Stability as a Function of PtCo Composition  

Science Journals Connector (OSTI)

Oxygen Reduction Kinetics on Electrodeposited PtCo as a Model Catalyst for Proton Exchange Membrane Fuel Cell Cathodes: Stability as a Function of PtCo Composition ... When the focus is at reducing cost and improving durability, the PEMFC cathode deserves special attention. ... (4-7) Mukerjee et al. investigated various Pt bimetallic alloys supported on carbon and found a 2?3-fold increase in the oxygen reduction reaction (ORR) activity for the alloy catalysts under PEMFC operating conditions. ...

Kaushik Jayasayee; Van Anh T. Dam; Tiny Verhoeven; Serdar Celebi; Frank A. de Bruijn

2009-11-02T23:59:59.000Z

103

Perovskite Sr0.95Ce0.05CoO3d loaded with copper nanoparticles as a bifunctional catalyst for lithium-air batteries  

E-Print Network (OSTI)

could be used in a metal/air battery or a PEM fuel cell as an efficient and stable bifunctional catalyst for lithium-air batteries Wei Yang,ab Jason Salim,c Shuai Li,ab Chunwen Sun,*ab Liquan Chen,ab John B. 1. Introduction A requirement for the proton-exchange-membrane (PEM) H2/air fuel cell

104

Nano compartments may aid drug delivery, catalyst design > Archived...  

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

Nano compartments may aid drug delivery, catalyst design April 18th, 2013 By Bill Steele Spongelike nanoparticles whose pores can be filled with drugs offer the promise of drug...

105

Correlation of Theory and Function in Well-Defined Bimetallic Electrocatalysts - Final Report  

SciTech Connect

The objective of this research proposal was to correlate the structure of nanoparticles that are comprised of ~100-200 atoms to their electrocatalytic function. This objective was based on the growing body of evidence suggesting that catalytic properties can be tailored through controlled synthesis of nanoparticles. What has been missing from many of these studies, and what we are contributing, is a model catalyst that is sufficiently small, structurally well-defined, and well-characterized that its function can be directly predicted by theory. Specifically, our work seeks to develop a fundamental and detailed understanding of the relationship between the structure of nanoscopic oxygen-reduction catalysts and their function. We assembled a team with expertise in theory, synthesis, and advanced characterization methods to address the primary objective of this project. We anticipated the outcomes of the study to be: (1) a better theoretical understanding of how nanoparticle structure affects catalytic properties; (2) the development of advanced, in-situ and ex-situ, atomic-scale characterization methods that are appropriate for particles containing about 100 atoms; and (3) improved synthetic methods that produce unique nanoparticle structures that can be used to test theoretical predictions. During the project period, we have made excellent progress on all three fronts.

Crooks, Richard M.

2014-06-05T23:59:59.000Z

106

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

SciTech Connect

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

Kliewer, Christopher J.

2009-06-30T23:59:59.000Z

107

Manipulating the architecture of bimetallic nanostructures and their plasmonic properties.  

E-Print Network (OSTI)

?? There has been much interest in colloidal noble metal nanoparticles due to their fascinating plasmonic and catalytic properties. These properties make noble metal nanoparticles… (more)

DeSantis, Christopher John

2015-01-01T23:59:59.000Z

108

Catalyst proximity effects on the growth rate of Si nanowires S. T. Boles,1,a  

E-Print Network (OSTI)

Catalyst proximity effects on the growth rate of Si nanowires S. T. Boles,1,a E. A. Fitzgerald,1 C-liquid-solid VLS mechanism were fabricated using Au-catalyst nanoparticles and silane SiH4 gas on Si substrates. Au, with the growth rate increasing with increasing concentrations of Au-catalyst particles on the wafer surface

109

Methanol-tolerant carbon aerogel-supported Pt–Au catalysts for direct methanol fuel cell  

Science Journals Connector (OSTI)

Pt–Au nanoparticles supported on carbon aerogel, namely 2:1 has been synthesized by the microwave-assisted polyol process. The structure of Pt–Au nanoparticles is characterized by transmission electron microscopy (TEM) and X-ray diffraction (XRD). The electrochemical property of Pt–Au catalysts for methanol oxidation is evaluated by cyclic voltammetry (CV). The results show that Au-modified Pt catalysts exhibit a high methanol tolerance and improved electrochemical catalytic activity, suggesting that carbon aerogel supported Pt–Au catalysts are better catalysts for the electrochemical oxidation of methanol than conventional Pt catalysts.

Hong Zhu; Zhijun Guo; Xinwei Zhang; Kefei Han; Yubao Guo; Fanghui Wang; Zhongming Wang; Yongsheng Wei

2012-01-01T23:59:59.000Z

110

Thermally stable nanoparticles on supports  

DOE Patents (OSTI)

An inverse micelle-based method for forming nanoparticles on supports includes dissolving a polymeric material in a solvent to provide a micelle solution. A nanoparticle source is dissolved in the micelle solution. A plurality of micelles having a nanoparticle in their core and an outer polymeric coating layer are formed in the micelle solution. The micelles are applied to a support. The polymeric coating layer is then removed from the micelles to expose the nanoparticles. A supported catalyst includes a nanocrystalline powder, thin film, or single crystal support. Metal nanoparticles having a median size from 0.5 nm to 25 nm, a size distribution having a standard deviation .ltoreq.0.1 of their median size are on or embedded in the support. The plurality of metal nanoparticles are dispersed and in a periodic arrangement. The metal nanoparticles maintain their periodic arrangement and size distribution following heat treatments of at least 1,000.degree. C.

Roldan Cuenya, Beatriz; Naitabdi, Ahmed R.; Behafarid, Farzad

2012-11-13T23:59:59.000Z

111

Physical and Numerical Analysis of Extrusion Process for Production of Bimetallic Tubes  

SciTech Connect

Bimetallic tubes are used for very specific applications where one of the two metals provides strength and the other provides specific properties such as aqueous corrosion and carburization, coking resistance, and special electrical and thermal properties. Bimetallic tubes have application in pulp and paper industry for heat-recovery boilers, in the chemical industry for ethylene production, and in the petrochemical industry for deep oil well explorations. Although bimetallic tubes have major applications in energy-intensive industry, they often are not used because of their cost and manufacturing sources in the United States. This project was intended to address both of these issues.

Misiolek, W.Z.; Sikka, V.K.

2006-08-10T23:59:59.000Z

112

Spectroscopic investigation of palladium-copper bimetallic systems for PEM fuel cell catalysts.  

E-Print Network (OSTI)

??One of the main barriers to commercialization of polymer electrolyte membrane fuel cells systems is cost, which is largely due to the need of platinum… (more)

Hofmann, Timo

2009-01-01T23:59:59.000Z

113

Aerosol-Derived Bimetallic Alloy Powders: Bridging the Gap. ...  

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

heterogeneous catalysts made by traditional methods are usually nonhomogenous while UHV-based methods, such as mass selected clusters or metal vapor deposited on single...

114

Advanced Cathode Catalysts  

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

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

115

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

116

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

SciTech Connect

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

117

Lithium phosphate catalyst, III. New supported catalyst  

Science Journals Connector (OSTI)

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

A. M. Delgado; J. V. Sinisterra

1992-07-01T23:59:59.000Z

118

Sol?Gel Synthesis, Electrochemical Characterization, and Stability Testing of Ti0.7W0.3O2 Nanoparticles for Catalyst Support Applications in Proton-Exchange Membrane Fuel Cells  

Science Journals Connector (OSTI)

Generally, a material with activity for hydrogen evolution can also catalyze hydrogen oxidation; hence, the sample was tested for activity toward hydrogen oxidation. ... The Pt/TiO2 cathode catalyst exhibited excellent fuel cell performance and ultrahigh stability under accelerated stress test conditions and can be considered as a promising alternative for improving the reliability and durability of polymer electrolyte membrane fuel cells. ... Durability of the catalysts in proton exchange membrane fuel cells (PEMFC) is one of the major issues as the oxidn. of carbon catalyst supports causes degrdn. in catalyst performance during cycling in PEMFC. ...

Chinmayee V. Subban; Qin Zhou; Anthony Hu; Thomas E. Moylan; Frederick T. Wagner; Francis J. DiSalvo

2010-11-19T23:59:59.000Z

119

Nanoengineering Catalyst Supports via Layer-by Layer Surface Functionalization  

SciTech Connect

Recent progress in the layer-by-layer surface modification of oxides for the preparation of highly active and stable gold nanocatalysts is briefly reviewed. Through a layer-by-layer surface modification approach, the surfaces of various catalyst supports including both porous and nonporous silica materials and TiO{sub 2} nanoparticles were modified with monolayers or multilayers of distinct metal oxide ultra-thin films. The surface-modified materials were used as supports for Au nanoparticles, resulting in highly active nanocatalysts for low-temperature CO oxidation. Good stability against sintering under high-temperature treatment was achieved for a number of the Au catalysts through surface modification of the support material. The surface modification of supports can be a viable route to control both the composition and structure of support and nanoparticle interfaces, thereby tailoring the stability and activity of the supported catalyst systems.

Yan, Wenfu [ORNL; Mahurin, Shannon Mark [ORNL; Overbury, Steven {Steve} H [ORNL; Dai, Sheng [ORNL

2006-01-01T23:59:59.000Z

120

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

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

The kinetics of CO poisoning in simulated reformate and effect of Ru island morphology on PtRu fuel cell catalysts as determined by operando XANES  

SciTech Connect

In situ X-ray absorption spectroscopy (XAS) measurements, including both X-ray absorption near edge spectroscopy (XANES) and extended X-ray absorption fine structure (EXAFS), were carried out on commercially produced Pt and PtRu bimetallic electrocatalysts as well as on a mechanically mixed PtRu bimetallic electrocatalyst in an operating fuel cell in H{sub 2} doped with 150 ppm CO. By use of the novel {Delta}XANES technique, the coverages of CO and ontop and n-fold H (overpotential deposited and underpotential deposited hydrogen) are obtained and compared for the three catalysts, and the results are correlated with PtRu cluster morphology. The mechanical mixing process used to create the bimetallic PtRu catalyst is found to maximize CO tolerance, although the PtRu commercial electrocatalyst exhibits an increased electronic effect, most probably due to the presence of Ru(O){sub x} islands at the catalyst surface. The mobility of the CO on both Ru and Pt is found to be sharply dependent on the CO coverage, decreasing dramatically beyond 0.4 fractional coverage.

Scott, F.; Roth, C; Ramaker, D

2007-01-01T23:59:59.000Z

122

Tungsten Cathode Catalyst for PEMFC  

SciTech Connect

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

Joel B. Christian; Sean P. E. Smith

2006-09-22T23:59:59.000Z

123

Molecularly engineering homogenous catalysts  

E-Print Network (OSTI)

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

Hughes, Reagan Rebekah

2013-02-22T23:59:59.000Z

124

Catalyst Manufacturing Science and  

E-Print Network (OSTI)

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

125

Strategies for Probing Nanometer-Scale Electrocatalysts: From Single Particles to Catalyst-Membrane Architectures  

SciTech Connect

The project primary objectives are to prepare and elucidate the promoting properties of materials that possess high activity for the conversion of hydrogen and related small molecules (water, oxygen, carbon monoxide and methanol) in polymer electrolyte fuel cells. One area of research has focused on the study of catalyst materials. Protocols were developed for probing the structure and benchmarking the activity of Pt and Pt bimetallic nanometer-scale catalyst against Pt single crystal electrode standards. A second area has targeted fuel cell membrane and the advancement of simple methods mainly based on vibrational spectroscopy that can be applied broadly in the study of membrane structure and transport properties. Infrared and Raman methods combined with least-squares data modeling were applied to investigate and assist the design of robust, proton conductive membranes, which resist reactant crossover.

Korzeniewski, Carol

2014-01-20T23:59:59.000Z

126

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

127

Methods of making textured catalysts  

DOE Patents (OSTI)

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

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

2010-08-17T23:59:59.000Z

128

Advanced Cathode Catalysts  

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

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

129

nanoparticles | EMSL  

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

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

130

Numerical simulation of carbon arc discharge for nanoparticle synthesis  

SciTech Connect

Arc discharge with catalyst-filled carbon anode in helium background was used for the synthesis of carbon nanoparticles. In this paper, we present the results of numerical simulation of carbon arc discharges with arc current varying from 10 A to 100 A in a background gas pressure of 68 kPa. Anode sublimation rate and current voltage characteristics are compared with experiments. Distribution of temperature and species density, which is important for the estimation of the growth of nanoparticles, is obtained. The probable location of nanoparticle growth region is identified based on the temperature range for the formation of catalyst clusters.

Kundrapu, M.; Keidar, M. [Department of Mechanical and Aerospace Engineering, George Washington University, Washington, DC 20052 (United States)

2012-07-15T23:59:59.000Z

131

Catalyst Characterization | Department of Energy  

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

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

132

Catalyst Renewables | Open Energy Information  

Open Energy Info (EERE)

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

133

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

134

Method to prepare nanoparticles on porous mediums  

DOE Patents (OSTI)

A method to prepare porous medium decorated with nanoparticles involves contacting a suspension of nanoparticles in an ionic liquid with a porous medium such that the particles diffuse into the pores of the medium followed by heating the resulting composition to a temperature equal to or greater than the thermal decomposition temperature of the ionic liquid resulting in the removal of the liquid portion of the suspension. The nanoparticles can be a metal, an alloy, or a metal compound. The resulting compositions can be used as catalysts, sensors, or separators.

Vieth, Gabriel M. (Knoxville, TN) [Knoxville, TN; Dudney, Nancy J. (Oak Ridge, TN) [Oak Ridge, TN; Dai, Sheng (Knoxville, TN) [Knoxville, TN

2010-08-10T23:59:59.000Z

135

Catalyst regeneration: the business case  

SciTech Connect

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

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

2006-01-15T23:59:59.000Z

136

Modeling of Diesel Oxidation Catalyst  

Science Journals Connector (OSTI)

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

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

2005-09-30T23:59:59.000Z

137

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

138

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

139

Phase-Transfer Catalysts  

Science Journals Connector (OSTI)

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

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

1994-01-01T23:59:59.000Z

140

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

DOE Patents (OSTI)

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

Angelici, R.J.; Gao, H.

1998-08-04T23:59:59.000Z

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

Kinetics of Oxygen-enhanced Water Gas Shift on Bimetallic Catalysts and the Roles of Metals and Support.  

E-Print Network (OSTI)

??The post-processing of reformate is an important step in producing hydrogen (H2) with low carbon monoxide (CO) for low temperature fuel cells from syn-gas. However,… (more)

Kugai, Junichiro

2011-01-01T23:59:59.000Z

142

The effect of impregnation sequence on the hydrogenation activity and selectivity of supported Pt/Ni bimetallic catalysts  

E-Print Network (OSTI)

of acetylene in the presence of ethylene [22], and the selective hydrogenation of acrolein toward its

Frenkel, Anatoly

143

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

SciTech Connect

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

144

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

145

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

146

Comprehensive catalyst management  

SciTech Connect

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

Pritchard, S. [Cormetech (United States)

2007-05-15T23:59:59.000Z

147

Controlling proton source speeds catalyst | EMSL  

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

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

148

Exploration of catalysis activation emergency as a function of gold nanoparticle surface morphology  

E-Print Network (OSTI)

The application of rippled gold nanoparticles with bi-ligand surface morphology as a catalyst was tested. The hydrolysis of 2,4-dinitrophenyl acetate (DNPA) served as the catalytic reaction being analyzed and the bi-ligand ...

Stefanescu, Cristina F

2008-01-01T23:59:59.000Z

149

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

Science Journals Connector (OSTI)

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

N. M. Ostrovskii

2011-12-01T23:59:59.000Z

150

Method for forming thermally stable nanoparticles on supports  

DOE Patents (OSTI)

An inverse micelle-based method for forming nanoparticles on supports includes dissolving a polymeric material in a solvent to provide a micelle solution. A nanoparticle source is dissolved in the micelle solution. A plurality of micelles having a nanoparticle in their core and an outer polymeric coating layer are formed in the micelle solution. The micelles are applied to a support. The polymeric coating layer is then removed from the micelles to expose the nanoparticles. A supported catalyst includes a nanocrystalline powder, thin film, or single crystal support. Metal nanoparticles having a median size from 0.5 nm to 25 nm, a size distribution having a standard deviation .ltoreq.0.1 of their median size are on or embedded in the support. The plurality of metal nanoparticles are dispersed and in a periodic arrangement. The metal nanoparticles maintain their periodic arrangement and size distribution following heat treatments of at least 1,000.degree. C.

Roldan Cuenya, Beatriz; Naitabdi, Ahmed R.; Behafarid, Farzad

2013-08-20T23:59:59.000Z

151

Carbon Nanotube Film by Filtration as Cathode Catalyst Support for Proton-Exchange Membrane Fuel Cell  

Science Journals Connector (OSTI)

Carbon Nanotube Film by Filtration as Cathode Catalyst Support for Proton-Exchange Membrane Fuel Cell ... 1-10 Some early investigations found that by using the normal paste method and simply replacing carbon black particles with disordered multiwalled CNTs as the support for Pt catalyst nanoparticles higher PEMFC and DMFC performances were achieved. ... activity of the CNT cathode catalysts was measured in a direct methanol fuel cell by use of a Pt-Ru/C anode, and use of a Nafion-115 membrane. ...

Wenzhen Li; Xin Wang; Zhongwei Chen; Mahesh Waje; Yushan Yan

2005-09-08T23:59:59.000Z

152

Microstructure-Based Modeling of Aging Mechanisms in Catalyst Layers of Polymer Electrolyte Fuel Cells  

Science Journals Connector (OSTI)

Conventional CCLs are random heterogeneous media that consist of a solid phase comprised of carbon particles or agglomerates decorated with catalyst nanoparticles (typically Pt-based) for conducting electrons and catalyzing reactions, a proton-conducting network of Nafion ionomer, and a particular water-filled porous network for gas transport. ... Polymer electrolyte membranes were catalyzed by direct application of thin film layers cast from solns. of suspended Pt/C catalyst and solubilized Nafion ionomer. ... During normal operating conditions of the fuel cell, the PEMFC lifetime tends to be limited by coarsening of the cathode's Pt-based catalyst and by corrosion of the cathode's C black support. ...

Kourosh Malek; Alejandro A. Franco

2011-06-07T23:59:59.000Z

153

Modeling nanostructured catalyst layer in PEMFC and catalyst utilization  

Science Journals Connector (OSTI)

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

Jiejing Zhang; Pengzhen Cao; Li Xu…

2011-09-01T23:59:59.000Z

154

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

SciTech Connect

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

155

Degradation of Bimetallic Model Electrocatalysts ___ an in situ XAS Study  

SciTech Connect

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

156

THE UNIVERSITY OF SHEFFIELD CATALYST HIGHER EDUCATION  

E-Print Network (OSTI)

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

Dixon, Peter

157

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

158

Insoluble Phase-Transfer Catalysts  

Science Journals Connector (OSTI)

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

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

1994-01-01T23:59:59.000Z

159

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

160

SHAPE SELECTIVE NANO-CATALYSTS: TOWARD DIRECT METHANOL FUEL CELLS APPLICATIONS  

SciTech Connect

A series of bimetallic core-shell-alloy type Au-Pt nanomaterials with various morphologies, aspect ratios and compositions, were produced in a heterogenous epitaxial fashion. Gold nanoparticles with well-controlled particle size and shape, e.g. spheres, rods and cubes, were used as 'seeds' for platinum growth in the presence of a mild reducing agent, ascorbic acid and a cationic surfactant cethyltrimethyl ammonium bromide (CTAB). The reactions take place in air and water, and are quick, economical and amenable for scaling up. The synthesized nanocatalysts were characterized by electron microscopy techniques and energy dispersive X-ray analysis. Nafion membranes were embedded with the Au-Pt nanomaterials and analyzed by atomic force microscopy (AFM) and scanning electron microscopy (SEM) for their potential in direct methanol fuel cells applications.

Murph, S.

2010-06-16T23:59:59.000Z

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.


161

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,

162

CO Oxidation at the Au-Cu Interface of Bimetallic Nanoclusters Supported on CeO2(111)  

E-Print Network (OSTI)

of tunable interfaces, metal and oxide,9,12,15-18 metal and carbide,19 and oxide and oxide,2 of the structure of CeO2(111)-supported Au- based bimetallic nanoclusters (NCs) show that a strong support-metal Materials, and Catalysis The critical role of the interface between a supporting oxide and supported metal

Henkelman, Graeme

163

EMSL - nanoparticles  

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

nanoparticles en Carbon Mineralizability Determines Interactive Effects onMineralization of Pyrogenic Organic Matter and Soil Organic Carbon. http:www.emsl.pnl.govemslweb...

164

Gold Nanoparticles  

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

Science Perspective Chemistry World 16 December 2007 Structure of a Coated Gold Nanoparticle summary written by Amber Dance, SLAC Communication Office A team of scientists,...

165

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

166

Laser Catalyst - Energy Innovation Portal  

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

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

167

Catalyst Characterization | Department of Energy  

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

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

168

High Impact Technology (HIT) Catalyst  

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

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

169

Magnetic Nanoparticle NANOMATERIALS  

E-Print Network (OSTI)

Magnetic Nanoparticle Metrology NANOMATERIALS We are developing best practice metrology for characterization of magnetic nanoparticle systems (e.g. blocking temperature, anisotropy, property distributions, T nanoparticles and provide guidelines to the FDA to properly compare systems when approving nanoparticle systems

170

Preparation and evaluation of hydrotreating catalysts based on activated carbon derived from oil sand petroleum coke  

Science Journals Connector (OSTI)

Novel Ni–Mo/activated carbon (AC) hydrotreating catalysts were prepared and evaluated for upgrading heavy vacuum gas oil (HVGO). The AC supports were derived from Alberta oil sand petroleum coke, i.e. fluid coke and/or delayed coke, hereafter referred to as OSP coke, through a chemical process. The BET surface area was as high as 2194 m2/g for the fluid coke derived AC and 2357 m2/g for the delayed coke derived AC. Both \\{ACs\\} contained a large number of micropores with pore volume as high as 1.2 cm3/g. Ni and Mo based active component precursors could be easily loaded on the activated carbon supports by chemical impregnation of nickel nitrate and ammonium molybdate followed by calcination in nitrogen at 773 K without further modification or oxidation treatment to the activated carbons. Scanning electron microscopy (SEM) observation showed highly porous surface structure of the bare activated carbon supports and well dispersed metal (oxide) precursor nanoparticles of 30–50 nm loaded on the AC supports. For comparison, two reference catalysts were also prepared by the same procedure but using commercial activated carbon and porous alumina as supports. After catalyst activation by sulfiding, the hydrotreating performance of the prepared catalysts was evaluated in a magnetically stirred autoclave with a HVGO feedstock to examine their hydrodesulfurization (HDS) and hydrodenitrogenation (HDN) activities. Two commercial hydrotreating catalysts were also tested and compared under similar conditions with the same feed. The results showed that the catalysts based on the activated carbon supports prepared from OSP coke had better hydrotreating performance than the other catalysts. Scanning transmission electron microscopy (STEM) characterization of the catalysts after activation showed that small particles of nanostructure (2–5 nm in size) were evenly embedded in the carbon matrix except for some bigger particles that were located on the catalyst surface. Energy dispersive X-ray (EDX) spectroscopy revealed that these particles were composed of Ni, Mo and S elements. The dispersed nanoparticles formed the active sites and were responsible for the observed high HDS and HDN activity. Elemental analysis and surface characterization of the spent catalysts showed that the formation of coke precursors was favored on the alumina supported catalyst, which resulted in catalyst deactivation.

Yu Shi; Jinwen Chen; Jian Chen; Robb A. Macleod; Marek Malac

2012-01-01T23:59:59.000Z

171

Bismuth Nanoparticle Decorating Graphite Felt as a High-Performance Electrode for an All-Vanadium Redox Flow Battery  

Science Journals Connector (OSTI)

Bismuth Nanoparticle Decorating Graphite Felt as a High-Performance Electrode for an All-Vanadium Redox Flow Battery ... Employing electrolytes containing Bi3+, bismuth nanoparticles are synchronously electrodeposited onto the surface of a graphite felt electrode during operation of an all-vanadium redox flow battery (VRFB). ... Energy storage; redox flow battery; electrode; catalyst; vanadium ...

Bin Li; Meng Gu; Zimin Nie; Yuyan Shao; Qingtao Luo; Xiaoliang Wei; Xiaolin Li; Jie Xiao; Chongmin Wang; Vincent Sprenkle; Wei Wang

2013-02-11T23:59:59.000Z

172

Catalyst by Design - Theoretical, Nanostructural, and Experimental...  

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

Treatment The overlap among theory, structure, and fully formed catalysts form the foundation of this study deer09narula.pdf More Documents & Publications Catalyst by Design -...

173

CLEERS Coordination & Development of Catalyst Process Kinetic...  

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

CLEERS Coordination & Development of Catalyst Process Kinetic Data CLEERS Coordination & Development of Catalyst Process Kinetic Data 2009 DOE Hydrogen Program and Vehicle...

174

Characterization of Catalysts for Aftertreatment and Biomass...  

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

Catalysts for Aftertreatment and Biomass-derived Fuels: Success Stories from the High Temperature Materials Laboratory (HTML) User Program Characterization of Catalysts for...

175

Exhaust Phosphorous Chemistry and Catalyst Poisoning | Department...  

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

Chemistry and Catalyst Poisoning Exhaust Phosphorous Chemistry and Catalyst Poisoning 2004 Diesel Engine Emissions Reduction (DEER) Conference Presentation: Oak Ridge National...

176

Doped palladium containing oxidation catalysts  

DOE Patents (OSTI)

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

Mohajeri, Nahid

2014-02-18T23:59:59.000Z

177

Successfully cope with FCC catalyst  

SciTech Connect

The fluid catalytic cracking (FCC) process converts straight-run atmospheric gas oil, vacuum gas oils, certain atmospheric residues, and heavy stocks recovered from other operations into high-octane gasoline, light fuel oils, and olefin-rich light gases. The main features of the FCC processes are long-term reliability and operating adjustability, allowing the refinery to easily adapt their product yields to an ever changing market. The produced gasoline, for example, has an excellent front-end octane number and good overall octane characteristics. The cracking reactions are carried out in a vertical reactor vessel in which vaporized oil rises and carries along with it in intimate contact small fluidized catalyst particles. The reactions are very rapid, and a contact time of only a few seconds is enough for most applications. During the cracking a carbonaceous material of low hydrogen-to-carbon ratio, coke, forms and deposits on the catalyst. The coke blocks the access to the internal structure of the catalyst particle and thus reduces its activity. The spent catalyst is separated from the cracking products in a catalyst stripper/disengager, and the catalyst is transported to a separate vessel, the regenerator, where the coke is burned off reactivating the catalyst. The regenerated catalyst is then transported to the bottom of the reactor riser, where the cycle begins again.

Lindstrom, T.H.; Hashemi, R.

1993-08-01T23:59:59.000Z

178

Precision Nanoparticles  

ScienceCinema (OSTI)

A revolutionary technology that efficiently produces nanoparticles in uniform and prescribed sizes (1-100 nanometers) using supercritical fluids. INL researcher Robert Fox was joined by Idaho State University researchers Rene Rodriquez and Joshua Pak in d

John Hemminger

2010-01-08T23:59:59.000Z

179

Nanoparticle Fabrication  

Science Journals Connector (OSTI)

This implies the capability to build up tailored nanostructures and various properties for given functions by control at the molecular levels [1...]. Nanoparticles make up one of the most important nanomaterials ...

Y. Hayashi; M. Inoue; H. Takizawa; K. Suganuma

2008-01-01T23:59:59.000Z

180

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.

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

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

Science Journals Connector (OSTI)

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

Mehtap Oezaslan; Frédéric Hasché; Peter Strasser

2013-09-12T23:59:59.000Z

182

Stereospecific olefin polymerization catalysts  

DOE Patents (OSTI)

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

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

1998-01-13T23:59:59.000Z

183

Stereospecific olefin polymerization catalysts  

DOE Patents (OSTI)

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

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

1998-01-01T23:59:59.000Z

184

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

E-Print Network (OSTI)

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

Goodman, Wayne

185

An Oregon State University Publication Catalyst Staff  

E-Print Network (OSTI)

The Catalyst An Oregon State University Publication Volume 3 #12;The Catalyst Staff Editors Megan and remain flexible to the possibilities of new modes of thinking. As editors of the Catalyst, we encourage. Keep on discovering! Katy, Megan, and Carly The Catalyst * Scientific Articles * Creative Writing

Escher, Christine

186

High Temperature Membrane & Advanced Cathode Catalyst Development  

SciTech Connect

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

187

Nanoparticle "theranostic" platforms for applications in cancer  

E-Print Network (OSTI)

For DNA Nanoparticle Preparation . 15CALIFORNIA, SAN DIEGO Nanoparticle “Theranostic” Platforms4   1.4  Nanoparticle  

Steiner, Jason Michael

2011-01-01T23:59:59.000Z

188

as Catalyst in Public Health  

E-Print Network (OSTI)

Crisis as Catalyst in Public Health Immigration Reform and the Threat of Rhetorical Violence look at immigration reform and the impact of public discourse focused on this topic. The panel

Bushman, Frederic

189

Secret Lives of Catalysts Revealed  

ScienceCinema (OSTI)

Miquel Salmeron and Gabor Somorjai of Berkeley Lab's Materials Sciences Division discuss the first-ever glimpse of nanoscale catalysts in action. More information: http://newscenter.lbl.gov/press-relea...

Miquel Salmeron and Gabor Somorjai

2010-01-08T23:59:59.000Z

190

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

SciTech Connect

Low-cost graphite submicronparticles (GSP) are employed as a possible catalyst support for polymer electrolyte membrane (PEM) fuel cells. Platinum nanoparticles are deposited on Vulcan XC-72 carbon black (XC-72), carbon nanotubes (CNT), and GSP via ethylene glycol (EG) reduction method. The morphologies and the crystallinity of Pt/XC-72, Pt/CNT, and Pt/GSP are characterized with X-ray diffraction and transmission electron microscope, which shows that Pt nanoparticles (~ 3.5 nm) are uniformly dispersed on GSP support. Pt/GSP exhibits the highest activity towards oxygen reduction reactions. The durability study indicates that Pt/GSP is 2 ~ 3 times durable than Pt/CNT and Pt/XC-72. The enhanced durability of Pt/GSP catalyst is attributed to the higher corrosion resistance of graphite submicronparticles, which results from higher graphitization degree of GSP support. Considering its low production cost, graphite submicronparticles are promising electrocatalyst support for fuel cells.

Zhang, Sheng; Shao, Yuyan; Li, Xiaohong; Nie, Zimin; Wang, Yong; Liu, Jun; Yin, Geping; Lin, Yuehe

2010-01-01T23:59:59.000Z

191

Rational Catalyst Design Applied to Development of Advanced Oxidation...  

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

Catalyst Design Applied to Development of Advanced Oxidation Catalysts for Diesel Emission Control Rational Catalyst Design Applied to Development of Advanced Oxidation...

192

(Chemisorption and reactions studies on well-characterized bimetallic and alloy surfaces)  

SciTech Connect

The authors have investigated the following major areas important to understanding bimetallic and alloy surface chemistry and catalysis: (1) the influence of potassium on the interactions of ethylene and other hydrocarbon species with platinum, (2) the determination of ensemble size requirements for adsorption and reaction on platinum surfaces, (3) the influence of oxygen adatoms on the bonding of nitric oxide to platinum, and (4) the role of the electronic structure of the metal surface in controlling surface chemistry. All of these studies were carried out using surface science techniques on well-characterized metal surfaces. A major effort and a major achievement of work have been to study model systems designed to explain how changes in geometric and electronic structure of metal surfaces affect surface chemistry. Specifically, the influence of potassium and bismuth coadsorption with small molecules on a Pt(111) single crystal surface can be compared to separate electronic effects from those of ensemble size effects. We also report the first measurements of the heat of adsorption of carbon monoxide as a function of Pd film thickness for thin films which have dramatically altered geometric and electronic structure.

Koel, B.E.

1990-01-01T23:59:59.000Z

193

UT of bimetallic welds by shear horizontal waves and electromagnetic ultrasonic (EMUS) probes  

SciTech Connect

Bimetallic transition welds include in most cases besides the austenitic weldment an austenitic buttering. Their inspection by ultrasound is strongly complicated by a high degree of elastic anisotropy. The elastic anisotropy results in phase and group velocities of the elastic wave-modes, which are functions of the propagation direction inside the weld metal and which cause skewing of the sound beams. The coarse grain structure leads to enhanced scattering. Furthermore, there exists a mismatch of the acoustical impedances between the weld metal and the base metal, which depends on the angle of incidence at the interface base metal/weld metal and weld metal/buttering. Due to these facts up to now using standard UT-techniques only the HAZ`s are inspected from both sides. In many cases dissimilar metal welds are only accessible from one side. Therefore, US-techniques are necessary which are capable to inspect the whole weld even if there is only access from one side. By improvement of the technology of the EMUS-probes and of the EMUS-instrumentation for the US-transduction of SH-waves a reliable technique for the ISI of dissimilar metal welds and also of austenitic welds is available. The contribution will shortly introduce into the physical basis of the SH-wave technique and present the results of test specimen measurements. The main part of the paper will report about the experiences and the results of field applications in different nuclear power plants.

Huebschen, G.; Salzburger, H.J.; Kroening, M. [Fraunhofer-Inst. fuer Zerstoerungsfreie Pruefverfahren, Saarbruecken (Germany)

1994-12-31T23:59:59.000Z

194

Chemical looping gasification of solid fuels using bimetallic oxygen carrier particles – Feasibility assessment and process simulations  

Science Journals Connector (OSTI)

Abstract The chemical looping gasification (CLG) process utilizes an iron-based oxygen carrier to convert carbonaceous fuels into hydrogen and electricity while capturing CO2. Although the process has the potential to be efficient and environmentally friendly, the activity of the iron-based oxygen carrier is relatively low, especially for solid fuel conversion. In the present study, we propose to incorporate a secondary oxygen carrying metal oxide, i.e. CuO, to the iron-based oxygen carrier. Using the “oxygen-uncoupling” characteristics of CuO, gaseous oxygen is released at a high temperature to promote the conversion of both Fe2O3 and coal. Experiments carried out using a Thermal-Gravimetric Analyzer (TGA) indicate that a bimetallic oxygen carrier consisting of a small amount (5% by weight) of CuO is more effective for coal char conversion when compared to oxygen carrier without copper addition. ASPEN Plus® simulations and mathematical modeling of the process indicate that the incorporation of a small amount of copper leads to increased hydrogen yield and process efficiency.

Feng He; Nathan Galinsky; Fanxing Li

2013-01-01T23:59:59.000Z

195

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

Science Journals Connector (OSTI)

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

P. K. Gupta

2013-01-01T23:59:59.000Z

196

Dynamic structural disorder in supported nanoscale catalysts  

SciTech Connect

We investigate the origin and physical effects of “dynamic structural disorder” (DSD) in supported nano-scale catalysts. DSD refers to the intrinsic fluctuating, inhomogeneous structure of such nano-scale systems. In contrast to bulk materials, nano-scale systems exhibit substantial fluctuations in structure, charge, temperature, and other quantities, as well as large surface effects. The DSD is driven largely by the stochastic librational motion of the center of mass and fluxional bonding at the nanoparticle surface due to thermal coupling with the substrate. Our approach for calculating and understanding DSD is based on a combination of real-time density functional theory/molecular dynamics simulations, transient coupled-oscillator models, and statistical mechanics. This approach treats thermal and dynamic effects over multiple time-scales, and includes bond-stretching and -bending vibrations, and transient tethering to the substrate at longer ps time-scales. Potential effects on the catalytic properties of these clusters are briefly explored. Model calculations of molecule-cluster interactions and molecular dissociation reaction paths are presented in which the reactant molecules are adsorbed on the surface of dynamically sampled clusters. This model suggests that DSD can affect both the prefactors and distribution of energy barriers in reaction rates, and thus can significantly affect catalytic activity at the nano-scale.

Rehr, J. J.; Vila, F. D. [Department of Physics, University of Washington, Seattle, Washington 98195 (United States)] [Department of Physics, University of Washington, Seattle, Washington 98195 (United States)

2014-04-07T23:59:59.000Z

197

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

Science Journals Connector (OSTI)

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

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

2014-01-01T23:59:59.000Z

198

Identification of bimetallic electrocatalysts for ethanol and acetaldehyde oxidation: Probing C2-pathway and activity for hydrogen oxidation for indirect hydrogen fuel cells  

Science Journals Connector (OSTI)

Abstract Hydrogen, in the ethanol molecule, can be utilized in indirect hydrogen fuel cells. In this device, ethanol can be dehydrogenated producing H2 and acetaldehyde in an external fuel processor, and the H2 molecules are electro-oxidized in the anode. The anode electrocatalyst can, additionally, be active for the electro-oxidation of residual ethanol or acetaldehyde, but must catalyze the reaction via the C2-pathway (intact CC bond), in order to avoid the formation poisoning species. This work investigated potential materials that are active for H2 and catalyze the selective electro-oxidation of ethanol and acetaldehyde via the C2-pathway. The bimetallic electrocatalysts were formed by W, Ru and Sn-modified Pt nanoparticles. The reaction products were followed by on-line differential electrochemical mass spectrometry (DEMS) experiments. The results showed that Ru/Pt/C and Sn/Pt/C presented higher overall reaction rate when compared to the other studied materials. However, they were non-selective, even at different atomic proportions, and catalyzed the reaction in parallel pathways producing CO2 and acetaldehyde, with Ru/Pt/C presenting the highest average current efficiency for CO2 formation (16.6%). On the other hand, W/Pt/C with high W content was more selective to the C2 route, evidenced by the absence of the DEMS signals for molecules with one carbon atom such as CH4 and CO2. Additionally, this material was active and stable for H2 electro-oxidation, even in the presence of acetaldehyde in solution, contrarily to what was observed for Pt/C, and this was associated to its activity for H2 oxidation and its inability for the CC dissociation, as evidenced by the DEMS measurements. The high selectivity obtained for the W/Pt/C material to the C2-pathway, and its capability for hydrogen electro-oxidation, is an important novelty in this work, as it turns into a potential electrocatalyst for application in the anode of indirect hydrogen fuel cells powered by ethanol, mainly for those that operates as auxiliary power units of internal combustion engine cars.

A.C. Queiroz; W.O. Silva; I.A. Rodrigues; F.H.B. Lima

2014-01-01T23:59:59.000Z

199

Pd-Pt Bimetallic Nanodendrites with High Activity for Oxygen Reduction  

Science Journals Connector (OSTI)

...ORR) is kinetically limited at the cathode (5–8), and the scale of the Pt...for improving the performance of an electrocatalyst for the ORR that involved alloying...approach provides a promising route to the development of next-generation catalysts with...

Byungkwon Lim; Majiong Jiang; Pedro H. C. Camargo; Eun Chul Cho; Jing Tao; Xianmao Lu; Yimei Zhu; Younan Xia

2009-06-05T23:59:59.000Z

200

Chemical Reactivity of Pd-Au Bimetallic Nanoclusters Grown via Amorphous Solid Water as Buffer Layer  

E-Print Network (OSTI)

grown via ASW buffer layer on silica, presumably due to suppression of the trimerization pathway of both, is often rather difficult to obtain. Model catalysis has been studied in recent decades by in an industrial catalyst.16-20 Intro- duction of weakly bound buffer layers to assist the growth of clusters

Asscher, Micha

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

Understanding nanoparticle aggregation.  

E-Print Network (OSTI)

??Nanoparticles form the fundamental building blocks for many exciting applications in various scientific disciplines. However, the problem of the large-scale synthesis of nanoparticles remains challenging.… (more)

Pranami, Gaurav

2009-01-01T23:59:59.000Z

202

Regeneration of Hydrotreating and FCC Catalysts  

SciTech Connect

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

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

1999-09-30T23:59:59.000Z

203

Catalyst containing oxygen transport membrane  

SciTech Connect

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

204

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

205

Chapter 13 - Heterogeneous Catalysts and Biomass Conversion  

Science Journals Connector (OSTI)

Abstract The application of heterogeneous catalysts to conversion processes based on biomasses is described and discussed. The role of heterogeneous catalysts in the development of renewable industrial chemistry is emphasized.

Guido Busca

2014-01-01T23:59:59.000Z

206

Quasi-ternary nanoparticle superlattices through nanoparticle design  

E-Print Network (OSTI)

nanoscale. Quasi-Ternary nanoparticle superlattices Elena V.No1. – Page No6. Quasi-ternary nanoparticle superlatticesthrough nanoparticle design .

Shevchenko, Elena V.

2008-01-01T23:59:59.000Z

207

Experts reveal catalyst-selection methodologies  

SciTech Connect

Refining catalyst selection procedure were discussed in detail at Oil and Gas Journal`s International Catalyst Conference, Feb. 1--2, in Houston. Marathon Oil Co.`s James P. Wick revealed details of Marathon`s program for review and optimization of fluid catalytic cracking (FCC) and hydrotreating catalysts. And renowned FCC expert Del Tolen outlined a step-by-step procedure for choosing an FCC catalyst. The paper describes Marathon`s program and Tolen`s selection process.

NONE

1996-10-14T23:59:59.000Z

208

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

209

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

210

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

211

New life for old catalyst  

SciTech Connect

Technology originally developed in Europe is now being optimized to make an attractive catalyst rejuvenation option even better. SCR-Tech undertook a study with American Electric Power (AEP) and Southern Company to quantify the primary effects of five independent factors in SCR-Tech's catalytic regeneration process on the rate of CO{sub 2} oxidation. The study demonstrated the process could minimise CO{sub 2} conversion while maximising the restoration of NOx reduction activity. The team developed statistically valid linear models for SO{sub 2} conversion (K{sub 23}) on both honeycomb and plate catalyst as a function of controlled regeneration process parameters. 1 fig., 1 photo.

Cooper, M. [SCR-Tech (United States)

2006-03-15T23:59:59.000Z

212

Gold catalyst Styrene Benzaldehyde Styrene oxide Acetophenone  

E-Print Network (OSTI)

O O O + + O2 Gold catalyst Styrene Benzaldehyde Styrene oxide Acetophenone studies. However, the study by Turner et al.1 seems to be the first to use Au55 in the synthesis of supported gold catalysts a very narrow and reproducible size distribution for the result- ing particles. Traditional catalyst

Rouyer, Francois

213

Diesel Oxidation Catalyst Combined to Non-Thermal Plasma: Effect on Activation Catalyst Temperature and by-products formation  

E-Print Network (OSTI)

Diesel Oxidation Catalyst Combined to Non-Thermal Plasma: Effect on Activation Catalyst Temperature efficiency together with the catalyst activation temperature when a Diesel Oxidation Catalyst (DOC) is placed the advantageous plasma catalyst coupling effect on the lowering of the catalyst activation temperature

Paris-Sud XI, Université de

214

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

215

A Bimetallic Aluminum(salen) Complex for the Synthesis of 1,3-Oxathiolane-2-thiones and 1,3-Dithiolane-2-thiones  

Science Journals Connector (OSTI)

The combined use of the bimetallic aluminum(salen) complex [Al(salen)]2O and tetrabutylammonium bromide (or tributylamine) is found to catalyze the reaction between epoxides and carbon disulfide. In most cases, at 50 °C, the reaction produces 1,3-...

William Clegg; Ross W. Harrington; Michael North; Pedro Villuendas

2010-08-23T23:59:59.000Z

216

Preparation of Cu nanoparticle loaded SBA-15 and their excellent catalytic activity in reduction of variety of dyes  

Science Journals Connector (OSTI)

Abstract In this paper, we report a simple aqueous solution based chemical method for preparation of Cu nanoparticle loaded mesoporous silica SBA-15 (Cu@SBA-15) catalysts. Synthesized catalysts were characterized by powder X-ray diffraction (XRD), atomic absorption spectroscopy (AAS), Fourier transform infrared spectroscopy (FTIR), high resolution transmission electron microscope (HRTEM), N2 adsorption–desorption surface area and pore size analyzer, and particle size analyzer. Catalytic activity of Cu nanoparticle loaded SBA-15 towards reduction of various dyes, such as 4-nitrophenol, Methyl Orange, Congo Red, Rhodamine B, Methylene Blue and mixture of dyes were investigated in the presence of excess NaBH4. Catalysis reactions were monitored by employing UV–vis spectroscopy. Catalysis reactions followed pseudo-first order rate equation. These catalysts exhibited excellent catalytic activity and convenient recycling. The high catalytic activity, cost effectiveness and simple preparation methodology make 12.5Cu@SBA-15 an attractive catalyst for decolorization of organic dyes.

Barun Kumar Ghosh; Subhenjit Hazra; Bhanudas Naik; Narendra Nath Ghosh

2015-01-01T23:59:59.000Z

217

Highly chiral-selective growth of single-walled carbon nanotubes with a simple monometallic Co catalyst  

Science Journals Connector (OSTI)

We report on the growth of single-walled carbon nanotubes from a monometallic Co catalyst on an oxidized Si wafer support by the most simple growth recipe (vacuum annealing, growth by undiluted C2H2). Nevertheless, multiwavelength Raman spectroscopy and transmission electron spectroscopy show a remarkable selectivity for chiral indices and thus, e.g., high abundance with a single chirality representing 58% of all semiconducting tubes. In situ x-ray photoelectron spectroscopy monitors the catalyst chemistry during carbon nanotube growth and shows interfacial Co-Si interactions that may help to stabilize the nanoparticle/nanotube diameter. We outline a two-mechanism model explaining the selective growth.

M. Fouquet; B. C. Bayer; S. Esconjauregui; R. Blume; J. H. Warner; S. Hofmann; R. Schlögl; C. Thomsen; J. Robertson

2012-06-06T23:59:59.000Z

218

Perovskite catalysts for oxidative coupling  

DOE Patents (OSTI)

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

Campbell, Kenneth D. (Charleston, WV)

1991-01-01T23:59:59.000Z

219

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

220

as Catalyst in Public Health  

E-Print Network (OSTI)

Crisis as Catalyst in Public Health Alex's Lemonade Stand and the Fight Against Childhood Cancer, Medical Director, Pediatric Advanced Care Team, Children's Hospital of Philadelphia For more information, survivorship, and palliative care. We will also explore the impact that individuals can make on medical

Bushman, Frederic

Note: This page contains sample records for the topic "bimetallic nanoparticle catalysts" from the National Library of EnergyBeta (NLEBeta).
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221

Novel Surface Architecture Synthesis for Gas Separation and Fuel-Cell Catalyst Applications James Guthrie, Georgia Institute of Technology, SURF 2010 Fellow  

E-Print Network (OSTI)

Novel Surface Architecture Synthesis for Gas Separation and Fuel-Cell Catalyst Applications James-shell nanoparticle, Pt was deposited onto a flat surface substrate. Three separate substrates were used, Au(111 not significantly change over different voltages [3]. STM work was done using electrochemically etched tungsten tips

Li, Mo

222

Co-generation of electricity and chemicals from propane fuel in solid oxide fuel cells with anode containing nano-bimetallic catalyst  

E-Print Network (OSTI)

) produced from hydrocarbon in SOFCs. PAHs containing a benzene ring usually occur in oil, coal, and tar, PAHs are typically liquids at ambient temperature and pressure which make them convenient for capture

Frenkel, Anatoly

223

Supported fischer-tropsch catalyst and method of making the catalyst  

SciTech Connect

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

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

1987-01-01T23:59:59.000Z

224

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

SciTech Connect

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

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

1986-01-01T23:59:59.000Z

225

Impact of IrRu Oxygen Evolution Reaction Catalysts on Pt Nanostructured Thin Films under Start-Up/Shutdown Cycling  

SciTech Connect

Electron microscopy and X-ray photoelectron spectroscopy (XPS) methods have been utilized to study the role of oxygen evolution reaction (OER) catalysts in mitigating degradation arising from start-up/shutdown events. Pt nanostructured thin films (NSTF) were coated with a Ru0.1Ir0.9 OER catalyst at loadings ranging from 1 to 10 g/cm2 and submitted to 5,000 potential cycles within a membrane electrode assembly. Analysis of the as-deposited catalyst showed that Ir and Ru coating is primarily metallic, and further evidence is provided to support the previously reported interaction between Ru and the perylene-red support. Aberration-corrected scanning transmission electron microscopy and energy dispersive X-ray spectroscopy were used to observe the impact of the OER catalysts on Pt dissolution and migration through the membrane. Elemental mapping showed a high percentage of the Ir catalyst was maintained on the NSTF whisker surfaces following testing. The presence of the OER catalysts greatly reduced the smoothing of the Pt NSTF whiskers, which has been correlated with Pt dissolution and losses in electrochemically active surface area. The dissolution of both Ir and Pt led to the formation of IrPt nanoparticle clusters in the membrane close to the cathode, as well as the formation of a Pt band deeper in the membrane.

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

2014-01-01T23:59:59.000Z

226

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

227

Supercritical/Solid Catalyst (SSC)  

ScienceCinema (OSTI)

INL's patented, continuous-flow Supercritical/Solid Catalyst (SSC) produces the highest ASTM-quality B-100 biodiesel from waste fats, oils, and greases at the site of waste generation. SSC delivers low-cost transportation fuel, avoids significant landfill costs for municipalities, and reduces potent methane and other emissions produced in landfills from these wastes. You can learn more about INL's energy research programs at http://www.facebook.com/idahonationallaboratory.

None

2013-05-28T23:59:59.000Z

228

Catalysts for Fischer-Tropsch  

SciTech Connect

The slurry-phase Fischer-Tropsch (F-T) process has attracted considerable attention recently. The process can make liquid fuels by reacting hydrogen-lean synthesis gas produced from modern energy-efficient gasifiers. continuing assessment of Fischer-Tropsch Synthesis (FTS) has a high priority within an indirect liquefaction program, a part of the liquid fuels program sponsored by the U.S. Department of Energy (DOE) and executed by the Pittsburgh Energy Technology Center (PETC). Funding for the indirect liquefaction program in 1990:0090 is anticipated to be about $8.5 million compared to $6.6 million in 1989 and a like amount in the year before. The studies within the program are conducted by industry, universities, national laboratories and in-house PETC research and development. This article reviews preparation and properties of iron-based catalysts, including recent patent activities and in-depth process analysis of slurry-phase FTS. The review provides an analysis of Fischer-Tropsch catalyst research and development trends and describes options to increase selectivity for iron-based catalysts in a slurry phase.

Srivastava, R.D. (Burns and Roe Services Corp. (US)); Rao, V.U.S.; Cinquegrane, G.; Stiegel, G.J. (Pittsburgh Energy Technology Center, Pittsburgh, PA (US))

1990-02-01T23:59:59.000Z

229

Improved catalyst loading reduces guard reactor fouling  

SciTech Connect

A new catalyst-loading strategy reduced the fouling tendency of the gas oil hydrotreater guard reactors at Syncrude Canada Ltd.'s heavy-crude upgrading facilities. Studies conducted on the guard reactors were designed to determine the thermal stability of the coker gas oil and to understand the properties of the fouling material. Small particles (described as fines) were present in the upper section of the removed catalyst bed. This part of the bed was then replaced in one of three ways. One way was to replace the catalyst with used, nonregenerated catalyst, and cover the catalyst with nonactive support balls, 10 and 13 mm in diameter. The second way was to fill the entire space with nonactive support balls, and the third way was to fill with regenerated oxidic catalyst combined with semiactive support balls (unsulfided).

Sanford, E.C.; Kirchen, R.P. (Syncrude Canada Ltd., Edmonton (CA))

1988-12-19T23:59:59.000Z

230

Optimization of catalyst system reaps economic benefits  

SciTech Connect

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

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

1991-06-03T23:59:59.000Z

231

Polarization Losses under Accelerated Stress Test Using Multiwalled Carbon Nanotube Supported Pt Catalyst in PEM Fuel Cells  

SciTech Connect

The electrochemical behavior for Pt catalysts supported on multiwalled carbon nanotubes and Vulcan XC-72 in proton exchange membrane fuel cells under accelerated stress test was examined by cyclic voltammetry, electrochemical impedance spectroscopy, and polarization technique. Pt catalyst supported on multiwalled carbon nanotubes exhibited highly stable electrochemical surface area, oxygen reduction kinetics, and fuel cell performance at a highly oxidizing condition, indicating multiwalled carbon nanotubes show high corrosion resistance and strong interaction with Pt nanoparticles. The Tafel slope, ohmic resistances, and limiting current density determined were used to differentiate kinetic, ohmic, mass-transfer polarization losses from the actual polarization curve. Kinetic contribution to the total overpotential was larger throughout the stress test. However, the fraction of kinetic overpotential decreased and mass-transfer overpotential portion remained quite constant during accelerated stress test, whereas the fraction of ohmic overpotential primarily originating from severe proton transport limitation in the catalyst layer increased under the anodic potential hold.

Park, Seh K.; Shao, Yuyan; Kou, Rong; Viswanathan, Vilayanur V.; Towne, Silas A.; Rieke, Peter C.; Liu, Jun; Lin, Yuehe; Wang, Yong

2011-03-01T23:59:59.000Z

232

Calcium Phosphate Nanoparticle Adjuvant  

Science Journals Connector (OSTI)

ARTICLE MICROBIAL IMMUNOLOGY Calcium Phosphate Nanoparticle Adjuvant Qing He Alaina R. Mitchell Stacy L. Johnson...to the surfaces on insect cells. . Calcium phosphate nanoparticle adjuvant. | Vaccination to protect against human infectious...

Qing He; Alaina R. Mitchell; Stacy L. Johnson; Claus Wagner-Bartak; Tulin Morcol; Steve J. D. Bell

2000-11-01T23:59:59.000Z

233

Steam reforming utilizing high activity catalyst  

SciTech Connect

High activity, sulfur tolerant steam reforming catalysts are described comprising rhodium or nickel supported on lanthanum stabilized alumina or magnesium promoted lanthanum stabilized alumina. The catalysts have improved activity over conventionally used catalysts in the presence of sulfur containing hydrocarbon fuel (such as No. 2 fuel oil) in a steam reforming environment. The material has particular utility in autothermal, tubular, cyclic and adiabatic steam reforming processes.

Setzer, H. J.

1985-03-05T23:59:59.000Z

234

Catalysts for Dehydrogenation of ammonia boranes  

SciTech Connect

Several effective homogeneous catalysts for the dehydrogenation of amine boranes have been developed. The best catalyst uses an iridium complex, and is capable of dehydrogenating H3NBH3 (AB) and CH3NH2BH3 (MeAB) at comparable rates. Thermodynamic measurements using this catalyst demonstrate that the dehydrogenation of AB and MeAB is substantially exothermic, which has important implications for regeneration.

Heinekey, Dennis M.

2014-12-19T23:59:59.000Z

235

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

236

Precursors of copper/zinc oxide catalysts  

Science Journals Connector (OSTI)

Recent results on hydroxycarbonate precursors of copper/zinc oxide catalysts for methanol synthesis are reinterpreted, taking into account earlier work on these systems.

M.S. Spencer

237

Bifunctional Catalysts for the Selective Catalytic Reduction...  

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

for the Selective Catalytic Reduction of NO by Hydrocarbons Development of Optimal Catalyst Designs and Operating Strategies for Lean NOx Reduction in Coupled LNT-SCR Systems...

238

Diffusion in Porous Catalysts and Adsorbents  

Science Journals Connector (OSTI)

Diffusion in Porous Catalysts and Adsorbents ... Single industrial adsorbent pellets of zeolites 5A and 13X were mounted with a polymer capable of withstanding high temperatures. ...

Jan Hoogschagen

1955-01-01T23:59:59.000Z

239

Low Temperature Catalyst for Fuel Injection System  

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

A low temperature oxidation catalyst applied to a DOC and DPF combined with a unique fuel injection system remove soot from a diesel exhaust system.

240

Highly Dispersed Alloy Cathode Catalyst for Durability  

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

This presentation, which focuses on alloy cathode catalysts, was given by T. D. Jarvi of UTC Power at a February 2007 meeting on new fuel cell projects.

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

CLEERS Coordination & Development of Catalyst Process Kinetic...  

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

Development of Catalyst Process Kinetic Data - Pres. 1: Coordination of CLEERS Project; Pres. 2: ORNL Research on LNT Sulfation & Desulfation CLEERS Coordination & Development of...

242

A SOLID CATALYST METHOD FOR BIODIESEL PRODUCTION.  

E-Print Network (OSTI)

??Biodiesel has considerable production potential as a renewable source of energy. The conventional processes use soluble alkali catalysts that contaminate the biodiesel and glycerol products,… (more)

Kannan, Dheeban Chakrvarthi

2009-01-01T23:59:59.000Z

243

Vanadium catalysts break down biomass for fuels  

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

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...

244

Steam reforming utilizing sulfur tolerant catalyst  

SciTech Connect

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

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

1987-09-15T23:59:59.000Z

245

New Catalyst Converts CO2 to Fuel  

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

New Catalyst Converts CO to Fuel Calculations Run at NERSC Help Confirm University of Illinois Breakthrough September 5, 2014 | Tags: Basic Energy Sciences (BES), Carver,...

246

New Catalyst Converts CO2 to Fuel  

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

offer better catalytic performance." The proportion of carbon monoxide to hydrogen in the syngas produced in the reaction can also be easily manipulated using the new catalyst,...

247

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

248

Sandia National Laboratories: fuel cell catalyst  

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

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

249

8, 27152744, 2008 Nanoparticle  

E-Print Network (OSTI)

ACPD 8, 2715­2744, 2008 Nanoparticle formation and evolution in the vehicle exhaust Hua Du the Creative Commons Attribution 3.0 License. Atmospheric Chemistry and Physics Discussions Nanoparticle­2744, 2008 Nanoparticle formation and evolution in the vehicle exhaust Hua Du and Fangqun Yu Title Page

Paris-Sud XI, Université de

250

Activation studies with promoted precipitated iron Fischer-Tropsch catalysts  

E-Print Network (OSTI)

the Ruhrchemie catalyst, the catalyst activity and stability changed markedly with reduction procedure. Hs reduction at 220'C was repeated since it gave very loiv activity. The reproducibility of this test ivas good. Hs reduction at 250 gave higher catalyst...

Manne, Rama Krishna

1991-01-01T23:59:59.000Z

251

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

252

Lean NOx Reduction with Dual Layer LNT/SCR Catalysts  

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

Results show that a series of dual layer catalysts with a bottom layer of LNT catalyst and a top layer of SCR catalyst can carry out coupled ammonia generation and NOx reduction, achieving high NOx conversion with minimal ammonia slip

253

Highly Active Steam Reforming Catalyst for Hydrogen and Syngas Production  

Science Journals Connector (OSTI)

Toyo Engineering Corporation developed a steam reforming catalyst, which is four times as active as conventional catalysts, for hydrogen and syngas production from light natural gas. The catalyst has...3 plant. B...

Toru Numaguchi

2001-11-01T23:59:59.000Z

254

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

255

E-Print Network 3.0 - aged catalyst extrudates Sample Search...  

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

catalyst extrudates Search Powered by Explorit Topic List Advanced Search Sample search results for: aged catalyst...

256

EXAFS Studies of Bimetallic Ag-Pt and Ag-Pd Nanorods  

SciTech Connect

Nanoparticles of Ag-Pt and Ag-Pd with high aspect ratios were synthesized using a radiolysis method. Gamma rays at dose rates below 0.5 kGy/h were used for irradiation. The nanoparticles were characterized by transmission electron microscopy (TEM), optical absorption spectroscopy and x-ray Absorption Fine Structure (XAFS) spectroscopy. Bright field micrographs show that Ag-Pt nanowires are composed of large particles with diameters ranging from 20-30 nm and joined by filaments of diameter between 2-5 nm. The Ag-Pd nanowires have diameters of 20-25 nm and lengths of 1.5 {micro}m. For XAFS measurements, the Pt L3 edge (11.564 keV), Ag K-edge (25.514 keV) and Pd K-edge (24.350 keV) were excited to determine the local structure around the respective atoms in the cluster. The Ag-Pt particles were found to possess a distinct core-shell structure with Pt in the core surrounded by Ag shell, with no indication of alloy formation. However, nanorods of Ag-Pd have formed an alloy for all the alloy compositions.

Lahiri, D.; Chattopadhyay, S.; Bunker, B.A.; Doudna, C.M.; Bertino, M.F.; Blum, F.; Tokuhiro, A.; Terry, J. (IIT); (UMR-MUST); (Notre)

2008-10-30T23:59:59.000Z

257

Thermodynamic Properties of Supported Catalysts  

SciTech Connect

The goals of this work were to develop Coulometric Titration as a method for characterizing the thermodynamic redox properties of oxides and to apply this technique to the characterization of ceria- and vanadia-based catalysts. The redox properties of ceria and vanadia are a major part of what makes these materials catalytically active but their properties are also dependent on their structure and the presence of other oxides. Quantifying these properties through the measurement of oxidation energetics was the goal of this work.

Gorte, Raymond J.

2014-03-26T23:59:59.000Z

258

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

259

Two Catalyst Formulations - One Solution for NOx After-treatment...  

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

Two Catalyst Formulations - One Solution for NOx After-treatment Systems Low-temperature SCR combined with standard high-temperature SCR catalyst formulation in one system provides...

260

Investigation of Sulfur Deactivation on Cu/Zeolite SCR Catalysts...  

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

of Sulfur Deactivation on CuZeolite SCR Catalysts in Diesel Application Investigation of Sulfur Deactivation on CuZeolite SCR Catalysts in Diesel Application Investigation of...

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

Development of Optimal Catalyst Designs and Operating Strategies...  

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

Optimal Catalyst Designs and Operating Strategies for Lean NOx Reduction in Coupled LNT-SCR Systems Development of Optimal Catalyst Designs and Operating Strategies for Lean NOx...

262

Transmural Catalysis - High Efficiency Catalyst Systems for NOx...  

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

Transmural Catalysis - High Efficiency Catalyst Systems for NOx Adsorbers and SCR Transmural Catalysis - High Efficiency Catalyst Systems for NOx Adsorbers and SCR Presentation...

263

Development of Optimal Catalyst Designs and Operating Strategies...  

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

Optimal Catalyst Designs and Operating Strategies for Lean NOx Reduction in Coupled LNT-SCR Systems Lean NOx Reduction with Dual Layer LNTSCR Catalysts Development of Optimal...

264

Understanding the Deactivation Mechanisms of Cu/Zeolite SCR Catalysts...  

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

Deactivation Mechanisms of CuZeolite SCR Catalysts in Diesel Application Understanding the Deactivation Mechanisms of CuZeolite SCR Catalysts in Diesel Application To understand...

265

Catalyst-Assisted Production of Olefins from Natural Gas Liquids...  

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

Catalyst-Assisted Production of Olefins from Natural Gas Liquids: Prototype Development and Full-Scale Testing, April 2013 Catalyst-Assisted Production of Olefins from Natural Gas...

266

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

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

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

267

Enhanced Activity and Stability of Pt catalysts on Functionalized...  

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

Enhanced Activity and Stability of Pt catalysts on Functionalized Graphene Sheets for Electrocatalytic Oxygen Reduction . Enhanced Activity and Stability of Pt catalysts on...

268

Active Hydrogenation Catalyst with a Structured, Peptide-Based...  

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

Hydrogenation Catalyst with a Structured, Peptide-Based Outer-Coordination Sphere. Active Hydrogenation Catalyst with a Structured, Peptide-Based Outer-Coordination Sphere....

269

Ultra-High Resolution Electron Microscopy for Catalyst Characterizatio...  

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

Ultra-High Resolution Electron Microscopy for Catalyst Characterization Ultra-High Resolution Electron Microscopy for Catalyst Characterization 2011 DOE Hydrogen and Fuel Cells...

270

Bond Energies in Models of the Schrock Metathesis Catalyst. ...  

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

Energies in Models of the Schrock Metathesis Catalyst. Bond Energies in Models of the Schrock Metathesis Catalyst. Abstract: Heats of formation, adiabatic and diabatic bond...

271

Defining Active Catalyst Structure and Reaction Pathways from...  

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

Active Catalyst Structure and Reaction Pathways from ab Initio Molecular Dynamics and Operando XAFS: Dehydrogenation of Defining Active Catalyst Structure and Reaction Pathways...

272

Ultra-high Resolution Electron Microscopy for Catalyst Characterizatio...  

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

high Resolution Electron Microscopy for Catalyst Characterization Ultra-high Resolution Electron Microscopy for Catalyst Characterization 2009 DOE Hydrogen Program and Vehicle...

273

Ultra-High Resolution Electron Microscopy for Catalyst Characterizatio...  

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

High Resolution Electron Microscopy for Catalyst Characterization Ultra-High Resolution Electron Microscopy for Catalyst Characterization 2010 DOE Vehicle Technologies and Hydrogen...

274

Cobalt discovery replaces precious metals as industrial catalyst  

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

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

275

Cobalt discovery replaces precious metals as industrial catalyst  

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

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

276

Expulsion Leads to a New Catalyst | The Ames Laboratory  

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

Expulsion Leads to a New Catalyst Locating a catalyst and reactants in confined spaces makes catalytic reactions go faster in the desired direction. Of course, the reaction...

277

Arginine-Containing Ligands Enhance H-2 Oxidation Catalyst Performance...  

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

Arginine-Containing Ligands Enhance H-2 Oxidation Catalyst Performance. Arginine-Containing Ligands Enhance H-2 Oxidation Catalyst Performance. Abstract: In H2 fuel cells,...

278

Bifunctional Anode Catalysts for Direct Methanol Fuel Cells....  

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

Anode Catalysts for Direct Methanol Fuel Cells. Bifunctional Anode Catalysts for Direct Methanol Fuel Cells. Abstract: Using the binding energy of OH* and CO* on close-packed...

279

Novel Approach to Advanced Direct Methanol Fuel Cell Anode Catalysts...  

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

Novel Approach to Advanced Direct Methanol Fuel Cell Anode Catalysts Novel Approach to Advanced Direct Methanol Fuel Cell Anode Catalysts Presented at the Department of Energy Fuel...

280

The Science And Engineering of Duralbe Ultralow PGM Catalysts...  

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

The Science And Engineering of Duralbe Ultralow PGM Catalysts The Science And Engineering of Duralbe Ultralow PGM Catalysts Presented at the Department of Energy Fuel Cell Projects...

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

Controlling Axial p-n Heterojunction Abruptness Through Catalyst...  

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

Axial p-n Heterojunction Abruptness Through Catalyst Alloying in Vapor-Liquid-Solid Grown Semiconductor Nanowires. Controlling Axial p-n Heterojunction Abruptness Through Catalyst...

282

The Electrode as Organolithium Reagent: Catalyst-Free Covalent...  

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

The Electrode as Organolithium Reagent: Catalyst-Free Covalent Attachment of Electrochemically Active Species to an Azide The Electrode as Organolithium Reagent: Catalyst-Free...

283

Three Hydrogen Bond Donor Catalysts: Oxyanion Hole Mimics and...  

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

Hydrogen Bond Donor Catalysts: Oxyanion Hole Mimics and Transition State Analogues. Three Hydrogen Bond Donor Catalysts: Oxyanion Hole Mimics and Transition State Analogues....

284

Advanced Cathode Catalysts and Supports for PEM Fuel Cells |...  

Energy Savers (EERE)

Advanced Cathode Catalysts and Supports for PEM Fuel Cells Advanced Cathode Catalysts and Supports for PEM Fuel Cells 2012 DOE Hydrogen and Fuel Cells Program and Vehicle...

285

New Catalysts for Green Diesel | The Ames Laboratory  

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

New Catalysts for Green Diesel A new economical and efficient catalyst for upgrading renewable feedstocks to green diesel has been created. Green diesel, produced by converting...

286

SISGR-Fundamental Experimental and Theoretical Studies on a Novel Family of Oxide Catalyst Supports for Water Electrolysis  

SciTech Connect

Identification and development of non-noble metal based electro-catalysts or electro-catalysts with significant reduction of expensive noble metal contents (E.g. IrO2, Pt) with comparable electrochemical performance as the standard noble metal/metal oxide for proton exchange membrane (PEM) based water electrolysis would constitute a major breakthrough in the generation of hydrogen by water electrolysis. Accomplishing such a system would not only result reduction of the overall capital costs of PEM based water electrolyzers, but also help attain the targeted hydrogen production cost [< $ 3.0 / gallon gasoline equivalent (gge)] comparable to conventional liquid fuels. In line with these goals, it was demonstrated that fluorine doped IrO2 thin films and nanostructured high surface area powders display remarkably higher electrochemical activity, and comparable durability as pure IrO2 electro-catalyst for the oxygen evolution reaction (OER) in PEM based water electrolysis. Furthermore, corrosion resistant SnO2 and NbO2 support has been doped with F and coupled with IrO2 or RuO2 for use as an OER electro-catalyst. A solid solution of SnO2:F or NbO2:F with only 20 - 30 mol.% IrO2 or RuO2 yielding a rutile structure in the form of thin films and bulk nanoparticles displays similar electrochemical activity and stability as pure IrO2/RuO2. This would lead to more than 70 mol.% reduction in the noble metal oxide content. Novel nanostructured ternary (Ir,Sn,Nb)O2 thin films of different compositions FUNDAMENTAL STUDY OF NANOSTRUCTURED ELECTRO-CATALYSTS WITH REDUCED NOBLE METAL CONTENT FOR PEM BASED WATER ELECTROLYSIS 4 have also been studied. It has been shown that (Ir0.40Sn0.30Nb0.30)O2 shows similar electrochemical activity and enhanced chemical robustness as compared to pure IrO2. F doping of the ternary (Ir,Sn,Nb)O2 catalyst helps in further decreasing the noble metal oxide content of the catalyst. As a result, these reduced noble metal oxide catalyst systems would potentially be preferred as OER electro-catalysts for PEM electrolysis. The excellent performance of the catalysts coupled with its robustness would make them great candidates for contributing to significant reduction in the overall capital costs of PEM based water electrolyzers. This s.thesis provides a detailed fundamental study of the synthesis, materials, characterization, theoretical studies and detailed electrochemical response and potential mechanisms of these novel electro-catalysts for OER processes.

Kumta, Prashant [University of Pittsburgh

2014-10-03T23:59:59.000Z

287

Method for reactivating catalysts and a method for recycling supercritical fluids used to reactivate the catalysts  

DOE Patents (OSTI)

A method of reactivating a catalyst, such as a solid catalyst or a liquid catalyst. 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)

2008-08-05T23:59:59.000Z

288

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

289

Long-term catalyst health care  

SciTech Connect

Now that many US selective catalytic reduction (SCR) systems are in their fifth or sixth year of operation, a number of utilities are shifting their attention from implementing the technology to operating and maintaining it. Catalyst management and performance are key to the successful operation of any SCR system. The article looks at the various stages of successful catalyst management. 7 figs.

Scot Pritchard [Cormetech Inc. (United States)

2006-01-15T23:59:59.000Z

290

Vanadium catalysts break down biomass for fuels  

E-Print Network (OSTI)

- 1 - Vanadium catalysts break down biomass for fuels March 26, 2012 Vanadium catalysts break down biomass into useful components Due to diminishing petroleum reserves, non-food biomass (lignocellulose biomass into high-value commodity chemicals. The journal Angewandte Chemie International Edition published

291

Advanced Cathode Catalysts and Supports for  

E-Print Network (OSTI)

;3 Objectives: Development of a durable, low cost, high performance cathode electrode (catalyst and support and Approach Approach: Development of advanced cathode catalysts and supports based on 3M's nanostructured thin Review (6/8/10) Water management for cool/wet transient operation (Task 5.2) Developed key strategy

292

Improved catalyst can clear the air  

SciTech Connect

Catalyst technology can make clean coal plants look as clean as they are. This article examines the need and available methods for SO{sub 2} control with a specific focus on a catalyst technology developed by Cormetech. It also presents the results of commercial operating experience. 1 fig., 2 tabs.

Pritchard, S. [Cormetech Inc. (United States)

2006-05-15T23:59:59.000Z

293

Hydrothermal Growth of Mesoporous SBA-15 Silica in the Presence of PVP-Stabilized Pt Nanoparticles: Synthesis,  

E-Print Network (OSTI)

Hydrothermal Growth of Mesoporous SBA-15 Silica in the Presence of PVP-Stabilized Pt Nanoparticles hydrothermal synthesis. Characterization of the Pt/SBA-15 catalysts suggests that Pt particles are located are responsible for ethane decomposition to surface carbon. The ability to design catalytic structures

Yang, Peidong

294

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

295

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

296

EXPERIMENTAL RESULTS ON DUAL-UEGO ACTIVE CATALYST CONTROL  

E-Print Network (OSTI)

EXPERIMENTAL RESULTS ON DUAL-UEGO ACTIVE CATALYST CONTROL Giovanni Fiengo Jessy W. Grizzle ignition engine equipped with a three-way catalyst and pre- and post-catalyst oxygen sensors. The control hydrocarbons. Linear exhaust gas oxygen sensors are used to measure pre- and post-catalyst air-fuel ratio

Grizzle, Jessy W.

297

CATALYST ENHANCED MICRO SCALE BATCHCATALYST ENHANCED MICRO SCALE BATCH ASSEMBLYASSEMBLY  

E-Print Network (OSTI)

CATALYST ENHANCED MICRO SCALE BATCHCATALYST ENHANCED MICRO SCALE BATCH ASSEMBLYASSEMBLY RajashreeCollection/Analysis Capabilities · Parts (800x800x50µmParts (800x800x50µm33 ) and catalysts (2x2x.5mm) and catalysts (2x2x.5mm33 non-participating millimeter scale parts that act as `catalysts'. We present experimental results

298

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

299

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

300

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

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

Adsorption of hydrogen on copper catalysts  

SciTech Connect

Copper catalysts display a high activity and selectivity in the hydrogenation of various carbonyl compounds, and copper is a component of the complex catalysts for the synthesis of methanol from CO and H/sub 2/. The adsorption of H/sub 2/ on copper catalysts has been studied by means of thermal desorption. The molecular form of adsorption of H/sub 2/ has been established, the thermal desorption parameters calculated, and the heat of adsorption of H/sub 2/ on a copper surface estimated.

Pavlenko, N.V.; Tripol'skii, A.I.; Golodets, G.I.

1987-10-01T23:59:59.000Z

302

Steam reforming utilizing iron oxide catalyst  

SciTech Connect

High activity steam reforming iron oxide catalysts are described. Such catalysts can be unsupported utilizing at least 90% by weight iron oxide and various modifiers (Ai/sub 2/O/sub 3/, K/sub 2/O, CaO, SiO/sub 2/) or unmodified and supported on such things as alumina, CaO impregnated alumina, and lanthanum stabilized alumina. When used in steam reformers such as autothermal and tubular steam reformers, these catalysts demonstrate much improved resistance to carbon plugging.

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

1985-06-11T23:59:59.000Z

303

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

304

Watching nanoparticles grow | EMSL  

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

and the distribution of particle sizes, scientists can explain what they see when nanoparticle ensembles form via non-classical mechanisms. Doing a portion of their research at...

305

High-resolution chemical imaging of gold nanoparticles using hard x-ray ptychography  

SciTech Connect

We combine resonant scattering with (ptychographic) scanning coherent diffraction microscopy to determine the chemical state of gold nanoparticles with high spatial resolution. Ptychographic images of the sample are recorded for a series of energies around the gold L{sub 3} absorption edge. From these data, chemical information in the form of absorption and resonant scattering spectra is reconstructed at each location in the sample. For gold nanoparticles of about 100 nm diameter, a spatial resolution of about 20-30 nm is obtained. In the future, this microscopy approach will open the way to operando studies of heterogeneous catalysts on the nanometer scale.

Hoppe, R.; Patommel, J.; Schroer, C. G. [Institute of Structural Physics, Technische Universitaet Dresden, D-01062 Dresden (Germany)] [Institute of Structural Physics, Technische Universitaet Dresden, D-01062 Dresden (Germany); Reinhardt, J. [Institute of Structural Physics, Technische Universitaet Dresden, D-01062 Dresden (Germany) [Institute of Structural Physics, Technische Universitaet Dresden, D-01062 Dresden (Germany); Deutsches Elektronen-Synchrotron DESY, D-22607 Hamburg (Germany)] [Germany; Hofmann, G.; Grunwaldt, J.-D. [Institute for Chemical Technology and Polymer Chemistry, Karlsruhe Institute of Technology, D-76131 Karlsruhe (Germany)] [Institute for Chemical Technology and Polymer Chemistry, Karlsruhe Institute of Technology, D-76131 Karlsruhe (Germany); Damsgaard, C. D. [Center for Electron Nanoscopy and Department of Physics, Technical University of Denmark, DK-2800 Lyngby (Denmark)] [Center for Electron Nanoscopy and Department of Physics, Technical University of Denmark, DK-2800 Lyngby (Denmark); Wellenreuther, G.; Falkenberg, G. [Deutsches Elektronen-Synchrotron DESY, D-22607 Hamburg (Germany)] [Deutsches Elektronen-Synchrotron DESY, D-22607 Hamburg (Germany)

2013-05-20T23:59:59.000Z

306

Predicting the Effect of Catalyst Axial Active Site Distributions on a Diesel Oxidation Catalyst Performance.  

E-Print Network (OSTI)

??Zone-coated diesel oxidation catalysts (DOCs) can be used to obtain overall improved performance in oxidation reaction extents. However, why this occurs and under what conditions… (more)

Al-Adwani, Suad

2012-01-01T23:59:59.000Z

307

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

Science Journals Connector (OSTI)

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

Xingwen Yu; Siyu Ye

2007-01-01T23:59:59.000Z

308

Unraveling the Active Site in Copper-Ceria Systems for the Water-Gas Shift Reaction: In Situ Characterization of an Inverse Powder CeO2-x/CuO-Cu Catalyst  

SciTech Connect

An inverse powder system composed of CeO{sub 2} nanoparticles dispersed over a CuO-Cu matrix is proposed as a novel catalyst for the water-gas shift reaction. This inverse CeO{sub 2}/CuO-Cu catalyst exhibits a higher activity than standard Cu/CeO{sub 2} catalysts. In situ synchrotron characterization techniques were employed to follow the structural changes of CeO{sub 2}/CuO-Cu under reaction conditions. Time-resolved X-ray diffraction experiments showed the transformation of CuO to metallic Cu via a Cu{sub 2}O intermediate. Short-order structural changes were followed by pair distribution function analysis and corroborated the results obtained by diffraction. Moreover, X-ray absorption spectroscopy also revealed oxidation state changes from Cu{sup 2+} to Cu{sup 0} and the partial reduction of CeO{sub x} nanoparticles. The activity data obtained by mass spectrometry revealed that hydrogen production starts once the copper has been fully reduced. The strong interaction of ceria and copper boosted the catalytic performance of the sample. The inverse catalyst was active at low temperatures, stable to several reaction runs and to redox cycles. These characteristics are highly valuable for mobile fuel cell applications. The active phases of the inverse CeO{sub 2}/CuO-Cu catalyst are partially reduced ceria nanoparticles strongly interacting with metallic copper. The nature and structure of the ceria nanoparticles are of critical importance because they are involved in processes related to water dissociation over the catalyst surface.

Barrio, L.; Estrella, M; Zhou, G; Wen, W; Hanson, J; Hungria, A; Hornes, A; Fernandez-Garcia, M; Martinez-Arias, A; Rodriguez, J

2010-01-01T23:59:59.000Z

309

Unraveling the Active Site in Copper-ceria Systems for the Water Gas Shift Reaction: In-situ Characterization of an Inverse Powder CeO2-x/CuO-Cu Catalyst  

SciTech Connect

An inverse powder system composed of CeO{sub 2} nanoparticles dispersed over a CuO-Cu matrix is proposed as a novel catalyst for the water-gas shift reaction. This inverse CeO{sub 2}/CuO-Cu catalyst exhibits a higher activity than standard Cu/CeO{sub 2} catalysts. In situ synchrotron characterization techniques were employed to follow the structural changes of CeO{sub 2}/CuO-Cu under reaction conditions. Time-resolved X-ray diffraction experiments showed the transformation of CuO to metallic Cu via a Cu{sub 2}O intermediate. Short-order structural changes were followed by pair distribution function analysis and corroborated the results obtained by diffraction. Moreover, X-ray absorption spectroscopy also revealed oxidation state changes from Cu{sup 2+} to Cu{sup 0} and the partial reduction of CeOx nanoparticles. The activity data obtained by mass spectrometry revealed that hydrogen production starts once the copper has been fully reduced. The strong interaction of ceria and copper boosted the catalytic performance of the sample. The inverse catalyst was active at low temperatures, stable to several reaction runs and to redox cycles. These characteristics are highly valuable for mobile fuel cell applications. The active phases of the inverse CeO{sub 2}/CuO-Cu catalyst are partially reduced ceria nanoparticles strongly interacting with metallic copper. The nature and structure of the ceria nanoparticles are of critical importance because they are involved in processes related to water dissociation over the catalyst surface.

Rodriguez, J.A.; Barrio, L.; Estrella, M.; Zhou, G.; Wen, W.; Hanson, J.C.; Hungría, A.B.; Hornés, A.; Fernández-García, M.; Arturo Martínez-Arias, A.

2010-03-04T23:59:59.000Z

310

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

311

Catalyst for methanol synthesis: Preparation and activation  

Science Journals Connector (OSTI)

Phase composition and structure of the initial and reduced forms of the copper-zinc oxide catalysts for methanol synthesis are discussed. The mechanism of the process is discussed.

T. M. Yurieva

1995-06-01T23:59:59.000Z

312

Poisoning and Sulfation on Vanadia SCR Catalyst.  

E-Print Network (OSTI)

??Deactivation of titania-supported vanadia commercial SCR catalysts exposed to flue gases from both coal and coal-biomass co-firing boilers were investigated. BET surface area and average… (more)

Guo, Xiaoyu 1974-

2006-01-01T23:59:59.000Z

313

Poisoning and Sulfation on Vanadia SCR Catalyst.  

E-Print Network (OSTI)

?? Deactivation of titania-supported vanadia commercial SCR catalysts exposed to flue gases from both coal and coal-biomass co-firing boilers were investigated. BET surface area and… (more)

Guo, Xiaoyu

2006-01-01T23:59:59.000Z

314

Clay Minerals as Catalysts and Adsorbents  

Science Journals Connector (OSTI)

... largely devoted to a discussion on the use of clay minerals as catalysts and industrial adsorbents ; in the later part of the afternoon some general papers Were also given. ...

D. M. C. MACEWAN

1948-07-31T23:59:59.000Z

315

Cheap catalyst gets expensive accessory | EMSL  

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

catalyst and its ability to remove oxygen from m-cresol, which is a model compound for lignin, an integral part of cell walls in plants. The synergy between the palladium and iron...

316

Catalyst by Design - Theoretical, Nanostructural, and Experimental...  

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

Directions in Engine-Efficiency and Emissions Research (DEER) Conference in Detroit, MI, September 27-30, 2010. p-08narula.pdf More Documents & Publications Catalyst by Design...

317

Building Better Catalysts for Splitting Water  

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

Scientists are eagerly developing catalysts to lower the energy demands, and thus the cost, of H2 production. Yet, they still struggle with the basics, such as what structural...

318

Combustion Catalysts in Industry- An Update  

E-Print Network (OSTI)

applications of combustion catalysts for coal are presented. Combustion efficiency and calculations are discussed, followed by an explanation of the theories of combustion catalysis and a review of three case histories....

Merrell, G. A.; Knight, R. S.

319

Synthesis and Understanding of Novel Catalysts  

SciTech Connect

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

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

2013-07-09T23:59:59.000Z

320

Extended Platinum Nanotubes as Fuel Cell Catalysts  

SciTech Connect

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

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

2012-01-01T23:59:59.000Z

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

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":""}]}

322

Hydrogen catalysis and scavenging action of Pd-POSS nanoparticles  

SciTech Connect

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

323

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.

324

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.

325

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.

326

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.

327

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.

328

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.

329

Low Cost Autothermal Diesel Reforming Catalyst Development  

SciTech Connect

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

Shihadeh, J.; Liu, D.

2004-01-01T23:59:59.000Z

330

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.

331

SO2-induced stability of Ag-alumina catalysts in the SCR of NO with methane  

SciTech Connect

We report on a stabilization effect on the structure and activity of Ag/Al2O3 for the selective catalytic reduction (SCR) of NOx with CH4 imparted by the presence of SO2 in the exhaust gasmixture. The reaction is carried out at temperature above 600 8C to keep the surface partially free of sulfates. In SO2-free gases, catalyst deactivation is fast and measurable at these temperatures. Time-resolved TEM analyses of used samples have determined that deactivation is due to sintering of silver from well-dispersed clusters to nanoparticles to micrometer-size particles with time-on-stream at 625 8C. However, sintering of silver was dramatically suppressed by the presence of SO2 in the reaction gas mixture. The structural stabilization by SO2 was accompanied by stable catalyst activity for the NO reduction to N2. The direct oxidation of methane was suppressed, thus the methane selectivity was improved in SO2-laden gas mixtures. In tests with high-content silver alumina with some of the silver present in metallic form, an increase in the SCR activity was found in SO2-containing gas mixtures. This is attributed to redispersion of the silver particles by SO2, an unexpected finding. The catalyst performance was reversible over many cycles of operation at 625 8C with the SO2 switched on and off in the gas mixture.

She, Xiaoyan; Flytzani-Stephanopoulos, Maria; Wang, Chong M.; Wang, Yong; Peden, Charles HF

2009-04-29T23:59:59.000Z

332

Extended Two Dimensional Nanotube and Nanowire Surfaces as Fuel Cell Catalysts  

E-Print Network (OSTI)

the development of PEMFC cathode catalysts. The Pt content70] Conclusions PEMFC cathode catalysts were developed wereFor PEMFC development, highly active cathode catalysts are

Alia, Shaun Michael

2011-01-01T23:59:59.000Z

333

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

334

Single Bifunctional Ruthenium Catalyst for One-Pot Cyclization and Hydration giving Functionalized Indoles and Benzofurans  

E-Print Network (OSTI)

Soc. 2004, 126, 12232. Catalyst 1 is now available from7992 – 7995 Bifunctional Ruthenium Catalyst COMMUNICATIONuse of bifunctional catalyst 1 for hydration and cycliza-

Nair, Rejiâ??N.; Lee, Paulâ??J.; Rheingold, Arnoldâ??L.; Grotjahn, Douglasâ??B.

2010-01-01T23:59:59.000Z

335

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

336

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

337

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

338

E-Print Network 3.0 - alternative silp-scr catalysts Sample Search...  

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

by Ce 16 3. Catalysts based on alternative... .2 Catalytic activity of iron based PILC catalysts 24 4. Catalysts based on alternative support materials... , which deals with...

339

The Corrosion of PEM Fuel Cell Catalyst Supports and Its Implications...  

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

The Corrosion of PEM Fuel Cell Catalyst Supports and Its Implications for Developing Durable Catalysts. The Corrosion of PEM Fuel Cell Catalyst Supports and Its Implications for...

340

Subsurface Synthesis and Characterization of Ag Nanoparticles...  

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

Synthesis and Characterization of Ag Nanoparticles Embedded in MgO. Subsurface Synthesis and Characterization of Ag Nanoparticles Embedded in MgO. Abstract: Metal nanoparticles...

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

Nanoparticles > Complex Oxides > Research > The Energy Materials...  

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

Nanoparticles The nanoparticle synthesis efforts at EMC2 mostly take place in the Frank DiSalvo group, and focus on preparing useful fuel cell electrocatalysts in nanoparticle...

342

Inkjet printed electronics using copper nanoparticle ink  

E-Print Network (OSTI)

electronics using copper nanoparticle ink Jin Sung Kang •of electrode using copper nanoparticle ink is presented.of drop on demand copper nanoparticle inkjet printer system,

Kang, Jin Sung; Kim, Hak Sung; Ryu, Jongeun; Thomas Hahn, H.; Jang, Seonhee; Joung, Jae Woo

2010-01-01T23:59:59.000Z

343

Microstructural Characterization of Colloid-Derived Bimetallic Pd-Cu Nanocatalysts Supported on -Al2O3 for Nitrate Reduction  

E-Print Network (OSTI)

and Center of Advanced Materials for the Purification of Water with Systems, University of Illinois at Urbana of Advanced Materials for Purification of Water with Systems, University of Illinois at Urbana to develop heterogeneous catalysts as a viable water purification method. The rates of nitrate and nitrite

Frenkel, Anatoly

344

Nanoparticle Safety and Health Guidelines  

E-Print Network (OSTI)

disposal of nanoparticles utilized or generated during research projects. This document is intended to

unknown authors

2010-01-01T23:59:59.000Z

345

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

346

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

347

Molecular-level Design of Heterogeneous Chiral Catalysts  

SciTech Connect

Understanding and controlling selectivity is one of the key challenges in heterogeneous catalysis. Among problems in catalytic selectivity enantioselectivity is perhaps the most the most challenging. The primary goal of the project on “Molecular-level Design of Heterogeneous Chiral Catalysts” is to understand the origins of enantioselectivity on chiral heterogeneous surfaces and catalysts. The efforts of the project team include preparation of chiral surfaces, characterization of chiral surfaces, experimental detection of enantioselectivity on such surfaces and computational modeling of the interactions of chiral probe molecules with chiral surfaces. Over the course of the project period the team of PI’s has made some of the most detailed and insightful studies of enantioselective chemistry on chiral surfaces. This includes the measurement of fundamental interactions and reaction mechanisms of chiral molecules on chiral surfaces and leads all the way to rationale design and synthesis of chiral surfaces and materials for enantioselective surface chemistry. The PI’s have designed and prepared new materials for enantioselective adsorption and catalysis. Naturally Chiral Surfaces • Completion of a systematic study of the enantiospecific desorption kinetics of R-3-methylcyclohexanone (R-3-MCHO) on 9 achiral and 7 enantiomeric pairs of chiral Cu surfaces with orientations that span the stereographic triangle. • Discovery of super-enantioselective tartaric acid (TA) and aspartic acid (Asp) decomposition as a result of a surface explosion mechanism on Cu(643)R&S. Systematic study of super-enantiospecific TA and Asp decomposition on five enantiomeric pairs of chiral Cu surfaces. • Initial observation of the enantiospecific desorption of R- and S-propylene oxide (PO) from Cu(100) imprinted with {3,1,17} facets by L-lysine adsorption. Templated Chiral Surfaces • Initial observation of the enantiospecific desorption of R- and S-PO from Pt(111) and Pd(111) modified by a variety of chiral templates. • Demonstrated enantioselective separation of racemic PO on chemically synthesized chiral gold nanoparticles. • Discovery of zwitterionic adsorption states of amino acids on Pd(111). • First structure determinations of adsorbed amino acids and identification of tetrameric chiral template structures. • Exploration of the enantiospecific interaction of PO and R-3-MCHO adsorption on chirally modified Cu(100), Cu(110) and Cu(111). One-to-One Interactions • Determination of cinchona orientation on Pt surfaces in situ at the solid-liquid interface using FT-IRAS. • Systematic study of the influence of solution properties on the adsorption of modified cinchonas alkaloids onto Pt surfaces. • Correlation of cinchona adsorption with catalytic activity, as affected by concentration, the nature of the solvent, and dissolved gases in the liquid phase. • Measurement of enantioselective chemisorption on 1-(1-naphthyl) ethylamine (NEA) modified Pt(111) and Pd(111) surfaces. • Imaging of chiral docking complexes between NEA and methyl pyruvate on Pd(111). Chiral Catalyst Synthesis • Anchoring of cinchona alkaloid to surfaces • Synthesis of chiral Au nanoparticles and demonstration of their enantiospecific interactions with R- and S-PO. • Elucidation of the driving forces for chiral imprinting of Cu(100) by L- and D-lysine to form Cu(3,1,17)R&S facets.

Gellman, Andrew John [Carnegie Mellon University; Sholl, David S. [Georgia Institute of Technology; Tysoe, Wilfred T. [University of Wisconsin - Milwaukee; Zaera, Francisco [University of California at Riverside

2013-04-28T23:59:59.000Z

348

New applications of noble metal catalysts in hydrocracking  

SciTech Connect

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

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

1995-09-01T23:59:59.000Z

349

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

350

Ordered Hierarchical Nanostructured Carbon as a Highly Efficient Cathode Catalyst Support in Proton Exchange Membrane Fuel Cell  

Science Journals Connector (OSTI)

Ordered hierarchical nanostructured carbon (OHNC) has been fabricated through inverse replication of silica template and explored for the first time to support high loading of Pt nanoparticles as cathode catalyst in proton exchange membrane fuel cells (PEMFC). ... Ordered porous carbon materials with three-dimensionally interconnected pore structures and highly developed porosity have a variety of potential applications such as catalyst supports in low temperature fuel cells,(1, 2) electrode materials for electric double-layer capacitors(3, 4) and for lithium ion batteries,(5) adsorbents, and hydrogen storage materials. ... Carbon black Vulcan XC-72 (VC) is widely used as an electrocatalyst support in the PEMFCs due to its relatively large surface area and excellent chemical stability in the fuel cell environment. ...

Baizeng Fang; Jung Ho Kim; Minsik Kim; Jong-Sung Yu

2009-02-04T23:59:59.000Z

351

Homogeneous catalysts in hypersonic combustion  

SciTech Connect

Density and residence time both become unfavorably small for efficient combustion of hydrogen fuel in ramjet propulsion in air at high altitude and hypersonic speed. Raising the density and increasing the transit time of the air through the engine necessitates stronger contraction of the air flow area. This enhances the kinetic and thermodynamic tendency of H/sub 2/O to form completely, accompanied only by N/sub 2/ and any excess H/sub 2/(or O/sub 2/). The by-products to be avoided are the energetically expensive fragment species H and/or O atoms and OH radicals, and residual (2H/sub 2/ plus O/sub 2/). However, excessive area contraction raises air temperature and consequent combustion-product temperature by adiabatic compression. This counteracts and ultimately overwhelms the thermodynamic benefit by which higher density favors the triatomic product, H/sub 2/O, over its monatomic and diatomic alternatives. For static pressures in the neighborhood of 1 atm, static temperature must be kept or brought below ca. 2400 K for acceptable stability of H/sub 2/O. Another measure, whose requisite chemistry we address here, is to extract propulsive work from the combustion products early in the expansion. The objective is to lower the static temperature of the combustion stream enough for H/sub 2/O to become adequately stable before the exhaust flow is massively expanded and its composition ''frozen.'' We proceed to address this mechanism and its kinetics, and then examine prospects for enhancing its rate by homogeneous catalysts. 9 refs.

Harradine, D.M.; Lyman, J.L.; Oldenborg, R.C.; Pack, R.T.; Schott, G.L.

1989-01-01T23:59:59.000Z

352

Extracellular Palladium Nanoparticle Production using Geobacter sulfurreducens  

E-Print Network (OSTI)

Extracellular Palladium Nanoparticle Production using Geobacter sulfurreducens Matthew D. Yates catalytic nanoparticles. Palladium nanoparticles can be produced via microbial reduction of soluble Pd(II) to Pd(0), but in previous tests using dissimilatory metal reducing bacteria (DMRB), the nanoparticles

353

Nanoparticle Emissions from Internal Combustion Engines | Department...  

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

Nanoparticle Emissions from Internal Combustion Engines Nanoparticle Emissions from Internal Combustion Engines 2004 Diesel Engine Emissions Reduction (DEER) Conference...

354

Apoferritin Templated Synthesis of Metal Phosphate Nanoparticle...  

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

Apoferritin Templated Synthesis of Metal Phosphate Nanoparticle Labels for Electrochemical Immunoassay. Apoferritin Templated Synthesis of Metal Phosphate Nanoparticle Labels for...

355

Supercritical Fluid Attachment of Palladium Nanoparticles on...  

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

Attachment of Palladium Nanoparticles on Aligned Carbon Nanotubes. Supercritical Fluid Attachment of Palladium Nanoparticles on Aligned Carbon Nanotubes. Abstract: Nanocomposite...

356

Apoferritin-Templated Yttrium Phosphate Nanoparticle Conjugates...  

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

Apoferritin-Templated Yttrium Phosphate Nanoparticle Conjugates for Radioimmunotherapy of Cancers. Apoferritin-Templated Yttrium Phosphate Nanoparticle Conjugates for...

357

A nanoparticle label/immunochromatographic electrochemical biosensor...  

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

nanoparticle labelimmunochromatographic electrochemical biosensor for rapid and sensitive detection of prostate-specific A nanoparticle labelimmunochromatographic electrochemical...

358

Stabilization of Platinum Nanoparticle Electrocatalysts for Oxygen...  

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

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

359

Ion irradiation synthesis of Ag–Au bimetallic nanospheroids in SiO{sub 2} glass substrate with tunable surface plasmon resonance frequency  

SciTech Connect

Ag–Au bimetallic nanospheroids with tunable localized surface plasmon resonance (LSPR) were synthesized by 100 keV Ar–ion irradiation of 30 nm Ag–Au bimetallic films deposited on SiO{sub 2} glass substrates. A shift of the LSPR peaks toward shorter wavelengths was observed up to an irradiation fluence of 1.0 × 10{sup 17} cm{sup ?2}, and then shifted toward the longer wavelength because of the increase of fragment volume under ion irradiation. Further control of LSPR frequency over a wider range was realized by modifying the chemical components. The resulting LSPR frequencies lie between that of the pure components, and an approximate linear shift of the LSPR toward the longer wavelength with the Au concentration was achieved, which is in good agreement with the theoretical calculations based on Gans theory. In addition, the surface morphology and compositions were examined with a scanning electron microscope equipped with an energy dispersive spectrometer, and microstructural characterizations were performed using a transmission electron microscope. The formation of isolated photosensitive Ag–Au nanospheroids with a FCC structure partially embedded in the SiO{sub 2} substrate was confirmed, which has a potential application in solid-state devices.

Meng, Xuan; Yu, Ruixuan; Takayanagi, Shinya [Graduate School of Engineering, Hokkaido University, Sapporo, Hokkaido 060–8628 (Japan)] [Graduate School of Engineering, Hokkaido University, Sapporo, Hokkaido 060–8628 (Japan); Shibayama, Tamaki; Watanabe, Seiichi [Center for Advanced Research of Energy and Materials, Faculty of Engineering, Hokkaido University, Sapporo, Hokkaido 060–8628 (Japan)] [Center for Advanced Research of Energy and Materials, Faculty of Engineering, Hokkaido University, Sapporo, Hokkaido 060–8628 (Japan)

2013-08-07T23:59:59.000Z

360

Method for producing catalysts from coal  

DOE Patents (OSTI)

A method for producing catalysts from coal is provided comprising mixing an aqueous alkali solution with the coal, heating the aqueous mixture to treat the coal, drying the now-heated aqueous mixture, reheating the mixture to form carbonized material, cooling the mixture, removing excess alkali from the carbonized material, and recovering the carbonized material, wherein the entire process is carried out in controlled atmospheres, and the carbonized material is a hydrocracking or hydrodehalogenation catalyst for liquid phase reactions. The invention also provides for a one-step method for producing catalysts from coal comprising mixing an aqueous alkali solution with the coal to create a mixture, heating the aqueous mixture from an ambient temperature to a predetermined temperature at a predetermined rate, cooling the mixture, and washing the mixture to remove excess alkali from the treated and carbonized material, wherein the entire process is carried out in a controlled atmosphere. 1 fig.

Farcasiu, M.; Derbyshire, F.; Kaufman, P.B.; Jagtoyen, M.

1998-02-24T23:59:59.000Z

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

Computational Design of Lignin Depolymerization Catalysts  

SciTech Connect

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

362

Jumping-Catalyst Dynamics in Nanowire Growth  

Science Journals Connector (OSTI)

Nanowire growth is generally considered a steady-state process, but oscillatory phenomena are known to often play a fundamental role. Here we identify a natural sequence of distinct growth modes, in two of which the catalyst droplet jumps periodically on and off a crystal facet. The oscillatory modes result from a mismatch between catalyst size and wire diameter; they enable growth of straight smooth-sided wires even when the droplet is too small to span the wire tip. Jumping-catalyst growth modes are seen both in computer simulations of vapor-liquid-solid growth, and in movies of Si nanowire growth obtained by in situ microscopy. Our simulations also provide new insight into nanowire kinking.

K.?W. Schwarz; J. Tersoff; S. Kodambaka; F.?M. Ross

2014-07-30T23:59:59.000Z

363

Catalyst for steam reforming of hydrocarbons  

SciTech Connect

A catalyst's resistance to deactivation by polymer formation is vital to the successful gasification of heavy feedstocks such as kerosene and gas oil. The improved polymer-resistance performance of this steam-reforming catalyst is directly relate to the distribution of the pore sizes in its calcined (but unreduced) precursor form and to a certain pore-size ratio: 1) At least 55% of the pore volume of pores having a radius of between 12 and 120 A(2000A) is in the range of 12-30 A(2000A) and 2) the ratio of the pore volume contained in pores of 10-50 A(2000A) to the volume contained in pores of 50-300 A(2000A) is at least 5:1. The catalyst-preparation method involves coprecipitation with a minimum of heat treatment (at temperatures not greater than 140/sup 0/F or 60/sup 0/C).

Banks, R.G.S.; Williams, A.

1980-08-05T23:59:59.000Z

364

Catalytic studies of supported Pd-Au catalysts  

E-Print Network (OSTI)

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...

Boopalachandran, Praveenkumar

2006-08-16T23:59:59.000Z

365

Volatility of Vanadia from Vanadia-Based SCR Catalysts under...  

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

Vanadia from Vanadia-Based SCR Catalysts under Accelerated Aging Conditions Volatility of Vanadia from Vanadia-Based SCR Catalysts under Accelerated Aging Conditions TiO2-supported...

366

Steam Gasification of Biomass Surrogates: Catalyst Development and Kinetic Modelling.  

E-Print Network (OSTI)

??This study reports a new fluidizable La2O3 promoted Ni/?-Al2O3 catalyst. Prepared catalysts are characterized using BET specific surface area, XRD, TPR, TPO, H2-pulse chemisorptions, Pyridine… (more)

Mazumder, A S M Jahirul Islam

2014-01-01T23:59:59.000Z

367

Harvard Catalyst Pilot Grants Projects Funded for Year Three  

E-Print Network (OSTI)

Harvard Catalyst Pilot Grants Projects Funded for Year Three Experimental Approach to Genotype the Harvard Catalyst Program we aim to:1) Review, select and culturally adapt evidence-based modules from

Paulsson, Johan

368

Reaction of adsorption substitution of oxygen on a cracking catalyst  

SciTech Connect

In an investigation of catalysts for methanol synthesis and carbon monoxide conversion, the authors have observed, for the first time, the reaction of adsorption substitution of strongly bound oxygen on catalysts containing zeolites and compounds of lanthanum and cerium.

Vishnetskaya, M.V.; Takhtarova, G.N.; Topchieva, K.V.

1986-04-01T23:59:59.000Z

369

Catalysts for Selective Hydrocarbon Combustion in the Presence of CO  

Science Journals Connector (OSTI)

As fast screen for catalyst performance, relative heat of reaction was selected. A high-throughput...35–37]. In brief, the library filled with catalysts was placed in a tight gas phase reactor covered by an IR-tr...

P. Rajagopalan; K. Stöwe; W. F. Maier

2010-02-01T23:59:59.000Z

370

Breakout Session: Open Innovation: SunShot Catalyst & Next Generation...  

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

Open Innovation: SunShot Catalyst & Next Generation Government Prizes Breakout Session: Open Innovation: SunShot Catalyst & Next Generation Government Prizes May 21, 2014 2:45PM to...

371

Long term experiences with HDD SCR Catalysts | Department of...  

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

term experiences with HDD SCR Catalysts Long term experiences with HDD SCR Catalysts Test bench results and on-road experiences of more than 1 million km offer comparisons of...

372

Applications of hydrogenation and dehydrogenation on noble metal catalysts  

E-Print Network (OSTI)

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

Wang, Bo

2009-05-15T23:59:59.000Z

373

Perovskite-Based Catalysts for Direct Methanol Fuel Cells  

Science Journals Connector (OSTI)

Perovskite-Based Catalysts for Direct Methanol Fuel Cells ... The addition of Ru substantially improves the CO tolerance of the catalyst, and there has been a great deal of research on the optimization of the alloy composition and structure. ...

Aidong Lan; Alexander S. Mukasyan

2007-06-14T23:59:59.000Z

374

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...

375

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

Energy Savers (EERE)

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

376

Evolution of the Surface Science of Catalysis from Single Crystals to Metal Nanoparticles under Pressure  

SciTech Connect

Vacuum studies of metal single crystal surfaces using electron and molecular beam scattering revealed that the surface atoms relocate when the surface is clean (reconstruction) and when it is covered by adsorbates (adsorbate induced restructuring). It was also discovered that atomic steps and other low coordination surface sites are active for breaking chemical bonds (H-H, O=O, C-H, C=O and C-C) with high reaction probability. Investigations at high reactant pressures using sum frequency generation (SFG)--vibrational spectroscopy and high pressure scanning tunneling microscopy (HPSTM) revealed bond breaking at low reaction probability sites on the adsorbate-covered metal surface, and the need for adsorbate mobility for continued turnover. Since most catalysts (heterogeneous, enzyme and homogeneous) are nanoparticles, colloid synthesis methods were developed to produce monodispersed metal nanoparticles in the 1-10 nm range and controlled shapes to use them as new model catalyst systems in two-dimensional thin film form or deposited in mesoporous three-dimensional oxides. Studies of reaction selectivity in multipath reactions (hydrogenation of benzene, cyclohexene and crotonaldehyde) showed that reaction selectivity depends on both nanoparticle size and shape. The oxide-metal nanoparticle interface was found to be an important catalytic site because of the hot electron flow induced by exothermic reactions like carbon monoxide oxidation.

Somorjai, Gabor A.; Park, Jeong Y.

2008-03-06T23:59:59.000Z

377

Deactivation and poisoning of fuel cell catalysts  

SciTech Connect

The deactivation and poisoning phenomena reviewed are: the poisoning of anode (fuel electrode) catalyst by carbon monoxide and hydrogen sulfide; the deactivation of the cathode (air electrode) catalyst by sintering; and the deactivation of the cathode by corrosion of the support. The anode catalyst is Pt supported on a conductive, high area carbon black, usually at a loading of 10 w/o. This catalyst is tolerant to some level of carbon monoxide or hydrogen sulfide or both in combination, the level depending on temperature and pressure. Carbon monoxide poisoning has been studied extensively, including detailed adsorption studies at various temperatures and pressures. Predictive models have been developed that effectively predict anode tolerance to carbon monoxide. Much less is known about hydrogen sulfide poisoning. Typical tolerance levels are 2% CO, and 10 ppM H/sub 2/S. The cathode catalyst is typically Pt supported on a graphitic carbon black, usually a furnace black heat-treated to 2700/sup 0/C. The Pt loading is typically 10 w/o, and the dispersion (or percent exposed) as-prepared is typically 30%. The loss of dispersion in use depends on the operational parameters, most especially the cathode potential history, i.e. higher potentials cause more rapid decrease in dispersion. The mechanism of loss of dispersion is not well known. The graphitic carbon support corrodes at a finite rate that is also potential dependent. Support corrosion causes thickening of the eletrolyte film between the gas pores and the catalyst particles, which in turn causes increased diffusional resistance and performance loss. In addition, support corrosion may also cause loss of Pt into the separator. Support corrosion appears to be the life limiting factor for phosphoric acid fuel cells.

Ross, P.N. Jr.

1985-06-01T23:59:59.000Z

378

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

379

Adhesion of Nanoparticles  

Science Journals Connector (OSTI)

Nanoparticles are ubiquitous: in the vacuum of space where they are visible through their spectral signatures,1 and also on earth where they are present in the atmosphere as aerosols, in fresh waters where the...

Professor Kevin Kendall; Dr Michaela Kendall…

2011-01-01T23:59:59.000Z

380

Photo-Targeted Nanoparticles  

Science Journals Connector (OSTI)

Photo-Targeted Nanoparticles ... The photo-dependent inhibition could be eliminated by prior addn. of glutathione or bisulfite to the irradiated soln. ... Photo-mediated gene activation using caged RNA/DNA in zebrafish embryos ...

Tal Dvir; Matthew R. Banghart; Brian P. Timko; Robert Langer; Daniel S. Kohane

2009-11-11T23:59:59.000Z

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

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

382

90 Seconds of Discovery: Biofuel Catalyst Life and Plugs  

SciTech Connect

Scientist at PNNL are working to extend the life of the catalysts used in the production of biomass fuels.

Zacher, Alan; Olarte, Mariefel

2014-06-11T23:59:59.000Z

383

Fuel Cell Catalyst Layers: A Polymer Science Perspective  

Science Journals Connector (OSTI)

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

Steven Holdcroft

2013-06-28T23:59:59.000Z

384

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

385

Tethered catalysts for the hydration of carbon dioxide  

DOE Patents (OSTI)

A system is provided that substantially increases the efficiency of CO.sub.2 capture and removal by positioning a catalyst within an optimal distance from the air-liquid interface. The catalyst is positioned within the layer determined to be the highest concentration of carbon dioxide. A hydrophobic tether is attached to the catalyst and the hydrophobic tether modulates the position of the catalyst within the liquid layer containing the highest concentration of carbon dioxide.

Valdez, Carlos A; Satcher, Jr., Joe H; Aines, Roger D; Wong, Sergio E; Baker, Sarah E; Lightstone, Felice C; Stolaroff, Joshuah K

2014-11-04T23:59:59.000Z

386

The Effects of Hydrothermal Agingon a Commercial Cu SCR Catalyst  

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

Examines the effect of hydrothermal aging on the Nox reduction over a commercial Cu-zeolite SCR catalyst.

387

Catalyst and process for steam-reforming of hydrocarbons  

SciTech Connect

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

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

1980-11-11T23:59:59.000Z

388

Materials Needs for Catalysts To Improve our Environment  

Science Journals Connector (OSTI)

Materials Needs for Catalysts To Improve our Environment ... Industrial & Engineering Chemistry Research1997 36 (7), 2533-2536 ...

John N. Armor

1994-06-01T23:59:59.000Z

389

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

390

90 Seconds of Discovery: Biofuel Catalyst Life and Plugs  

ScienceCinema (OSTI)

Scientist at PNNL are working to extend the life of the catalysts used in the production of biomass fuels.

Zacher, Alan; Olarte, Mariefel

2014-06-12T23:59:59.000Z

391

The Challenges for PEMFC Catalysts in Automotive Applications  

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

Presentation by Stephen Campbell for the 2013 DOE Catalysis Working Group Meeting on PEMFC catalysts in automotive applications.

392

Reversible chemisorption on highly dispersed Ru catalysts  

SciTech Connect

Hydrogen and carbon monoxide adsorptions have been studied by static gas volumetric measurement on a range of highly dispersed Y-zeolite-supported ruthenium catalysts prepared by ion exchange. At ambient temperature, the absorption isotherms indicated two distinct types of adsorption - reversible (composed of both physisorption and weak chemisorption) and irreversible (strongly chemisorbed). The catalysts were highly dispersed and had average particle diameters ranging from 0.9 to 1.6 nm. Reversible hydrogen chemisorption was found to be a function of average particle diameter and dispersion. On the other hand, reversible carbon monoxide chemisorption seemed to be mainly due to interaction with the support.

Yang, C.H.; Goodwin, J.G. Jr.

1982-11-01T23:59:59.000Z

393

Deposition of Platinum Nanoparticles on Carbon Nanotubes by Supercritical Fluid Method  

SciTech Connect

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

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

2005-11-05T23:59:59.000Z

394

Decorating multi-walled carbon nanotubes with nickel nanoparticles for selective hydrogenation of citral  

SciTech Connect

The nanocomposites of multi-walled carbon nanotubes (MWNTs) decorated with nickel nanoparticles were conveniently prepared by a chemical reduction of nickel salt in the present of poly(acrylic acid) grafted MWNTs (PAA-g-MWNTs). Due to the strong interaction between Ni{sup 2+} and -COOH, PAA-g-MWNTs became an excellent supporting material for Ni nanoparticles. The morphology and distribution of Ni nanoparticles on the surface of MWNTs were greatly influenced by the reduction temperatures, the experimental results also showed that the distribution of Ni nanoparticles was greatly improved while the MWNTs were modified by poly(acrylic acid) (PAA). The hydrogenation activity and selectivity of MWNTs decorated with Ni nanoparticles (Ni-MWNTs) for alpha, beta-unsaturated aldehyde (citral) were also studied, and the experimental results showed that the citronellal, an important raw material for flavoring and perfumery industries, is the favorable product with a percentage as high as 86.9%, which is 7 times higher than that of catalyst by Ni-supported active carbon (Ni-AC). - Abstract: Nickel nanoparticles decorated multi-walled carbon nanotubes (Ni-MWNTs) nanocomposites were conveniently prepared by a chemical reduction of nickel salt in the present of poly(acrylic acid) grafted MWNTs (PAA-g-MWNTs). These nanocomposites possessed excellent catalytic activity and selectivity for hydrogenation of citral.

Tang Yuechao; Yang Dong [Key Laboratory of Molecular Engineering of Polymers (Ministry of Education), Department of Macromolecular Science and Advanced Materials Laboratory, Fudan University, Shanghai 200433 (China); Qin Feng [Department of Chemistry, Fudan University, Shanghai 200433 (China); Hu Jianhua [Key Laboratory of Molecular Engineering of Polymers (Ministry of Education), Department of Macromolecular Science and Advanced Materials Laboratory, Fudan University, Shanghai 200433 (China); Wang Changchun, E-mail: ccwang@fudan.edu.c [Key Laboratory of Molecular Engineering of Polymers (Ministry of Education), Department of Macromolecular Science and Advanced Materials Laboratory, Fudan University, Shanghai 200433 (China); Xu Hualong [Department of Chemistry, Fudan University, Shanghai 200433 (China)

2009-08-15T23:59:59.000Z

395

Changes in the catalytic properties of a multicomponent molybdenum catalyst under vibro-fluidized catalyst bed conditions  

Science Journals Connector (OSTI)

Activation effect of oxidative dehydrogenation of butene-l on a multicomponent molybdenum catalyst at various temperatures has been studied by ... only reactive but also adsorption properties of the catalyst surf...

A. V. Simakov; S. A. Veniaminov; W. Walkov…

1985-01-01T23:59:59.000Z

396

Supported metal catalysts for alcohol/sugar alcohol steam reforming  

SciTech Connect

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

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

2014-08-21T23:59:59.000Z

397

Reaction Rates and Catalysts in Ethanol Production (1 Activity)  

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

Students will have the opportunity to investigate alternative catalysts for the degradation of hydrogen peroxide, which will be used as a model system for the breaking down of cellulose into sugar. After identifying other potential catalysts, students will develop their own research question about catalysts and conduct an additional experiment of their own design to investigate their question.

398

Catalyst: Seeing Through the Eyes of a Cat Jeremy Long  

E-Print Network (OSTI)

Catalyst: Seeing Through the Eyes of a Cat Jeremy Long University of Victoria jsl present Catalyst, an educational game that uses our simulation to teach players about the differences between human and cat vi- sion. The tasks in Catalyst are based on the principle of situated cognition

Gooch, Amy

399

Dynamic Restructuring Of Solid Catalyst Cluster During Carbon Nanotube CVD  

E-Print Network (OSTI)

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

Dunin-Borkowski, Rafal E.

400

Shape-selective sieving layers on an oxide catalyst surface  

E-Print Network (OSTI)

Shape-selective sieving layers on an oxide catalyst surface Christian P. Canlas1 , Junling Lu2 of molecules or can modify the product selectivity (regioselectivity or enantioselectivity) of catalyst sites, and not all catalyst classes can be readily synthesized with pores of the correct dimensions. Here, we present

Mohseni, Hooman

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

Technology Offer Heterogeneous Leaching Free Pd-Catalyst  

E-Print Network (OSTI)

Technology Offer Heterogeneous Leaching Free Pd-Catalyst For further information please contact) of the carrier particles and the catalyst Potential Fields of Application Production of substituted biphenyls-coupling reactions Overview The present invention relates to non-leaching Pd-catalysts for C-C, C-O or C-N couplings

402

Separation of catalyst from Fischer-Tropsch slurry  

SciTech Connect

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

403

Nanoparticles synthesis of tungsten disulfide via AOT-based microemulsions  

SciTech Connect

Graphical abstract: A controlled synthesis of WS2 nanoparticles (most probably inorganic fullerene (IF)) via microemulsion was applied for the first time to prepare WS2 (7–12 nm) by acidification of the water cores of the AOT reverse microemulsion. Highlights: ? An innovative reverse microemulsion technique was developed for WS{sub 2} synthesis. ? WS{sub 2} nanoparticles were obtained with narrow size distribution in range of 7–12 nm. ? Operating cost of microemulsion was lower in contrast to quartz reactor method. ? WS{sub 2} morphology could be controlled to obtain highly active and selective catalysts. ? Lower size of WS{sub 2} in this study overcomes the shortcoming of quartz reactor method. -- Abstract: The tungsten disulfide (WS{sub 2}) nanoparticles (most probably inorganic fullerene (IF)) with a narrow size distribution were synthesized by a reverse micelle technique for the first time. The particle size was controlled by varying water-to-surfactant molar ratio (W{sub 0}), aging time and reagent concentration. The synthesized WS{sub 2} nanoparticles were characterized by zetasizer, UV–visible spectrophotometers and transmission electron microscopy (TEM). The WS{sub 2} nanoparticles with particle diameter size of 7–12 nm were obtained via 24 h aging time. The particle size was controlled by changing the aging time and molar ratio of water/surfactant. Doubling W{sub 0} increased the amount and particle size of WS{sub 2} by 22 and 26%, respectively. The effect of aging time in the range of 6–24 h was investigated and the complete disappearance of yellowish color at 24 h resulted in an optically clear solution, which was the indication of WS{sub 2} formation with 100% conversion of reactant ((NH{sub 4}){sub 2}WS{sub 4}) in the batch reactor.

Ghoreishi, S.M., E-mail: ghoreshi@cc.iut.ac.ir [Department of Chemical Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Nanotechnology and Advanced Materials Institute, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Meshkat, S.S. [Department of Chemical Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of) [Department of Chemical Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Department of Chemical Engineering, Urmia University of Technology, Urmia 57155-419 (Iran, Islamic Republic of); Ghiaci, M. [Department of Chemistry, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of)] [Department of Chemistry, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Dadkhah, A.A. [Department of Chemical Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of)] [Department of Chemical Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of)

2012-06-15T23:59:59.000Z

404

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

Science Journals Connector (OSTI)

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

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

2006-01-01T23:59:59.000Z

405

Kinetics of catalyst regeneration by coke combustion. II. Influence of temperature rise in the catalyst particles  

Science Journals Connector (OSTI)

A grain-pellet model has been used to study the effect of high reaction rates upon the temperature profiles developed during regeneration of coked catalyst particles. The possibility of falsification of kinetic.....

D. Lafarga; C. Royo; A. Monzón; M. Menéndez…

1991-08-01T23:59:59.000Z

406

Catalyst for splitting water &Catalyst for splitting water & Synthetic Modeling of InorganicSynthetic Modeling of Inorganic  

E-Print Network (OSTI)

Importance Hydrogen technology in fuel cellsHydrogen technology in fuel cells As a combustion fuel, it producesCatalyst for splitting water &Catalyst for splitting water & Synthetic Modeling of Inorganic of evolution ·Optimized catalyst for water splitting in all oxygenic phototrophs S0 S4 S1 S2 S3 O2 2 H O2 e- e

Petta, Jason

407

Direct hierarchical assembly of nanoparticles  

DOE Patents (OSTI)

The present invention provides hierarchical assemblies of a block copolymer, a bifunctional linking compound and a nanoparticle. The block copolymers form one micro-domain and the nanoparticles another micro-domain.

Xu, Ting; Zhao, Yue; Thorkelsson, Kari

2014-07-22T23:59:59.000Z

408

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

409

Probing Solid Catalysts Under Operating Conditions  

Science Journals Connector (OSTI)

...J.W., TRACING THE CONVERSION OF AURICHALCITE TO A COPPER CATALYST BY COMBINED X-RAY...synthetic variants of the mineral phase aurichalcite [Cu5, Zn,(OH)6(CO3)21...stages of the thermal treatment of the aurichalcite, no significant changes occur in the...

John Meurig Thomas; G. Neville Greaves

1994-09-16T23:59:59.000Z

410

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

411

Nanotube/Nanowire Based ORR Catalyst  

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

Presentation about nanotube or nanowire-based oxygen reduction reaction (ORR) catalysts, presented by Yushan Yan, University of Delaware, at the kick-off meeting of the U.S. Department of Energy Fuel Cell Technologies Program's Catalysis Working Group, held May 14, 2012, in Arlington, Virginia.

412

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

413

Fluidizable Catalysts for Hydrogen Production from Biomass  

E-Print Network (OSTI)

Fluidizable Catalysts for Hydrogen Production from Biomass Pyrolysis/Steam Reforming K. Magrini/Objective Develop and demonstrate technology to produce hydrogen from biomass at $2.90/kg plant gate price based Bio-oil aqueous fraction CO H2 CO2 H2O Trap grease Waste plastics textiles Co-processing Pyrolysis

414

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

415

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

416

Nanoparticle assay detects prostate cancer  

Science Journals Connector (OSTI)

MedWire News: US researchers have developed a nanoparticle assay that distinguishes cancerous prostate tissue from...

2012-05-01T23:59:59.000Z

417

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

418

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

419

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

420

A Comprehensive Search for Stable Pt-Pd Nanoalloy Configurations and Their Use as Tunable Catalysts  

SciTech Connect

Using density-functional theory, we predict stable alloy configurations (ground states) for a 1 nm Pt–Pd cuboctahedral nanoparticle across the entire composition range and demonstrate their use as tunable alloy catalysts via hydrogen-adsorption studies. Unlike previous works, we use simulated annealing with a cluster expansion Hamiltonian to perform a rapid and comprehensive search that encompasses both high and low-symmetry configurations. The ground states show Pt(core)–Pd(shell) type configurations across all compositions but with specific Pd patterns. For catalysis studies at room temperatures, the ground states are more realistic structural models than the commonly assumed random alloy configurations. Using the ground states, we reveal that the hydrogen adsorption energy increases (decreases) monotonically with at. % Pt for the {111} hollow ({100} bridge) adsorption site. Such trends are useful for designing tunable Pd–Pt nanocatalysts for the hydrogen evolution reaction.

Tan, Teck L.; Wang, Lin-Lin; Johnson, Duane D.; Bai, Kewu

2012-08-15T23:59:59.000Z

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

Glycerol electrooxidation on highly active Pd supported carbide/C aerogel composites catalysts  

Science Journals Connector (OSTI)

The nanosized carbide supported on carbon aerogel composites have been synthesized by polycondensation of resorcinol and formaldehyde (RF) method in the presence of sodium tungstate and sodium molybdate. The materials are characterized by X-ray diffraction, transmission electron microscopy, energy dispersive X-ray spectroscopy (EDS), and cyclic voltammetry. The Pd nanoparticles supported on binary-carbide and carbon aerogel composites (Pd@WC-Mo2C/C) for glycerol oxidation are investigated for the first time. The Pd@WC-Mo2C/C as electrocatalyst shows a superior activity toward the glycerol oxidation in terms of the peak current density, which is almost two times higher than that of Pd/C and show better poison-resistant ability. The binary transition-metal carbide will be the potential catalyst support for the direct alcohol fuel cells.

Xiaofei Zhang; Pei Kang Shen

2013-01-01T23:59:59.000Z

422

Colloidally Synthesized Monodisperse Rh Nanoparticles Supported on SBA-15 for Size- and Pretreatment-Dependent Studies of CO Oxidation  

SciTech Connect

A particle size dependence for CO oxidation over rhodium nanoparticles of 1.9-11.3 nm has been investigated and determined to be modified by the existence of the capping agent poly(vinylpyrrolidone) (PVP). The particles were prepared using a polyol reduction procedure with PVP as the capping agent. The Rh nanoparticles were subsequently supported on SBA-15 during hydrothermal synthesis to produce Rh/SBA-15 supported catalysts for size-dependent catalytic studies. CO oxidation by O{sub 2} at 40 Torr CO and 100 Torr O{sub 2} was investigated over two series of Rh/SBA-15 catalysts: as-synthesized Rh/SBA-15 covering the full range of Rh sizes and the same set of catalysts after high temperature calcination and reduction. The turnover frequency at 443 K increases from 0.4 to 1.7 s{sup -1} as the particle size decreases from 11.3 to 1.9 nm for the as-synthesized catalysts. After calcination and reduction, the turnover frequency is between 0.1 and 0.4 s{sup -1} with no particle size dependence. The apparent activation energy for all catalysts is {approx}30 kcal mol{sup -1} and is independent of particle size and thermal treatment. Infrared spectroscopy of CO on the Rh nanoparticles indicates that the heat treatments used influence the mode of CO adsorption. As a result, the particle size dependence for CO oxidation is altered after calcination and reduction of the catalysts. CO adsorbs at two distinct bridge sites on as-synthesized Rh/SBA-15, attributable to metallic Rh(0) and oxidized Rh(I) bridge sites. After calcination and reduction, however, CO adsorbs only at Rh(0) atop sites. The change in adsorption geometry and oxidation activity may be attributable to the interaction between PVP and the Rh surface. This capping agent affect may open new possibilities for the tailoring of metal catalysts using solution nanoparticle synthesis methods.

Grass, Michael E.; Joo, Sang Hoon; Somorjai, Gabor A.

2009-02-12T23:59:59.000Z

423

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

SciTech Connect

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

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

1995-05-01T23:59:59.000Z

424

Novel Attrition-Resistant Fischer Tropsch Catalyst  

SciTech Connect

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

425

Lactose oxidation kinetics with oxygen in catalyst-solution-gas three-phase system with simultaneous electrical potential measurement of supported gold catalyst  

Science Journals Connector (OSTI)

Lactose oxidation kinetics was studied on an supported gold catalyst with simultaneous control of catalyst potential. The experimental data were described well...

D. Yu. Murzin; E. V. Murzina; A. V. Tokarev…

2009-09-01T23:59:59.000Z

426

Nanoparticle shuttle memory  

DOE Patents (OSTI)

A device for storing data using nanoparticle shuttle memory having a nanotube. The nanotube has a first end and a second end. A first electrode is electrically connected to the first end of the nanotube. A second electrode is electrically connected to the second end of the nanotube. The nanotube has an enclosed nanoparticle shuttle. A switched voltage source is electrically connected to the first electrode and the second electrode, whereby a voltage may be controllably applied across the nanotube. A resistance meter is also connected to the first electrode and the second electrode, whereby the electrical resistance across the nanotube can be determined.

Zettl, Alex Karlwalter (Kensington, CA)

2012-03-06T23:59:59.000Z

427

Novel Au-TiC Catalysts for CO Oxidation and Desulfurization Processes  

SciTech Connect

Recent articles dealing with the physical and chemical properties of novel Au-TiC catalysts are reviewed. High-resolution photoemission, scanning tunneling microscopy and first-principles periodic density-functional calculations were used to study the deposition of gold on a TiC(0 0 1) surface. Gold grows forming two-dimensional (very low coverage) and three-dimensional (medium and large coverage) islands on the carbide substrate. A positive shift in the binding energy of the C 1s core level is observed after the deposition of Au on TiC(0 0 1). The results of the density-functional calculations corroborate the formation of Au-C bonds. In general, the bond between Au and the TiC(0 0 1) surface exhibits very little ionic character, but there is a substantial polarization of electrons around Au that facilitates bonding of the adatoms with electron-acceptor molecules (CO, O{sub 2}, C{sub 2}H{sub 4}, SO{sub 2}, thiophene, etc.). Experimental measurements indicate that Au/TiC(0 0 1) is a very good catalysts for the oxidation of CO, the destruction of SO{sub 2} and the hydrodesulfurization of thiophene. At temperatures below 200 K, Au/TiC(0 0 1) is able to perform the 2CO + O{sub 2} {yields} 2CO{sub 2} reaction and the full decomposition of SO{sub 2}. Furthermore, in spite of the very poor hydrodesulfurization performance of TiC(0 0 1) or Au(1 1 1), a Au/TiC(0 0 1) surface displays a hydrodesulfurization activity higher than that of conventional Ni/MoS{sub x} catalysts. Metal carbides are excellent supports for enhancing the chemical reactivity of gold. The Au/TiC system is more chemically active than systems generated by depositing Au nanoparticles on oxide surfaces.

J Rodriguez; P Liu; Y Takahashi; F Vines; L Feria; E Florez; K Nakamura

2011-12-31T23:59:59.000Z

428

Electrocodeposition of nanoparticle composite films using an impinging jet electrode  

E-Print Network (OSTI)

Electrocodeposition of Nanoparticle Composite Films Using anElectrocodeposition of Nanoparticle Composite Films Using an

Osborne, Steven J.

2006-01-01T23:59:59.000Z

429

Effect of steam on supported metal catalysts  

SciTech Connect

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

Ruckenstein, E.; Hu, X.D.

1986-07-01T23:59:59.000Z

430

Selective Monoterpene-like Cyclization Reactions Achieved by Water Exclusion from Reactive Intermediates in a Supramolecular Catalyst  

E-Print Network (OSTI)

in a Supramolecular Catalyst William M.  Hart?Cooper, confinement of the catalyst’s interior, Prins cyclizations acidic solution  Entry  Catalyst  pH  Conv.  (%)  1 a  

Hart-Cooper, William

2014-01-01T23:59:59.000Z

431

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

432

HIGHLY DISPERSED ALLOY CATHODE CATALYST FOR DURABILITY  

E-Print Network (OSTI)

Understanding high performance materials Pt/C cathode B.S.E. Pt PtCo/C cathode IrB.S.E. Pt Co PtIrCo/C cathodeHIGHLY DISPERSED ALLOY CATHODE CATALYST FOR DURABILITY T. D. Jarvi UTC Power Corporation Electrochemical Area Loss Activity at 900 mVRHE (IR-Free) 0.44 A/mg Pt Specific Activity at 900 m

433

Oxidation of propylene over copper oxide catalysts  

E-Print Network (OSTI)

to the study of propylene oxidation. Dunlop (17) reported that small quantities of iron compounds substantially enhanced the catalytic activity of chromia-alumina catalysts with respect to propylene oxidation, Woodharn (72) has suggested that under... between 360 C and 430oC the rate of propane oxidation decreases as the teznperature is increased, and the rate of conversion to olefins, especially propylene, becomes progressively greater. Above 430 C the proportion of propane converted to ethylene in...

Billingsley, David Stuart

2012-06-07T23:59:59.000Z

434

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

435

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,

436

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

437

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

438

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

439

Transition metal-promoted oxygen ion conductors as oxidation catalyst  

SciTech Connect

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

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

1994-12-31T23:59:59.000Z

440

Effect of Graphitic Content on Carbon Supported Catalyst Performance  

SciTech Connect

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

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

2011-07-01T23:59:59.000Z

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

Effect of Graphitic Content on Carbon Supported Catalyst Performance  

SciTech Connect

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

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

2011-07-01T23:59:59.000Z

442

Electron Dynamics in Metallic Nanoparticles M. Aeschlimann  

E-Print Network (OSTI)

nanoparticles are discussed in the light of the results of line width measurements and femtosecond pump...............................................................................................................3 II. ADSORPTION OF LIGHT IN METALLIC NANOPARTICLES...................................4 A. General...............................................18 C. Heat transfer between the nanoparticles and the support

Bauer, Michael

443

Spectroscopy of gallium selenide nanoparticle nuclei  

E-Print Network (OSTI)

by the presence of GaSe nanoparticle nuclei which are non-Superradiance in GaSe Nanoparticle Aggregates”, Journal ofStrongly-Coupled GaSe Nanoparticle Aggregates”, Journal of

Lair, Deborah L.

2011-01-01T23:59:59.000Z

444

Superparamagnetic Nanoparticle Capture of Prions for Amplification  

Science Journals Connector (OSTI)

...ANTIVIRAL AGENTS Superparamagnetic Nanoparticle Capture of Prions for Amplification...findings suggest that coupling magnetic nanoparticle capture with PMCA could accelerate...not detected by immunoblot, we used nanoparticle-treated supernatants to seed PMCA...

Michael B. Miller; Surachai Supattapone

2011-01-12T23:59:59.000Z

445

Toward multifunctional nanoparticle-based therapeutics  

E-Print Network (OSTI)

D. A. ; Langer, R. , Nanoparticle-aptamer bioconjugates: aof DNA-linked gold nanoparticle assemblies? J Am Chem Socalpha(nu)beta3- targeted nanoparticle and 1.5 tesla magnetic

Derfus, Austin Matthew

2006-01-01T23:59:59.000Z

446

Issue --04 Catalyst.Management School --Autumn 2012  

E-Print Network (OSTI)

Issue -- 04 Catalyst.Management School -- Autumn 2012 SChooL newS page 09 Move to new world class InTernATIonAL BuSIneSS GrowTh CATALYST -- Become a business growth leader In The CITY -- The City in touch 03 04 05 08 12 14 16 17 18 20 22 23 24 26 28 30 32 34 ThIS ISSue In this issue of Catalyst we take

Stevenson, Mark

447

Comparative studies of hydrodenitrogenation by mixed metal sulfide catalysts  

E-Print Network (OSTI)

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

Luchsinger, Mary Margaret

1990-01-01T23:59:59.000Z

448

Enhanced catalyst stability for cyclic co methanation operations  

DOE Patents (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

449

Thiophene Hydrogenation to Tetrahydrothiophene over Tungsten Sulfide Catalysts  

Science Journals Connector (OSTI)

Independent reactions of thiophene reduction to tetrahydrothiophene and thiophene hydrogenolysis to form hydrogen sulfide...4...hydrocarbons are shown to occur over supported tungsten sulfide catalysts and unsupp...

A. V. Mashkina

2003-03-01T23:59:59.000Z

450

Catalyst for Improving the Combustion Efficiency of Petroleum...  

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

for Improving the Combustion Efficiency of Petroleum Fuels in Diesel Engines Catalyst for Improving the Combustion Efficiency of Petroleum Fuels in Diesel Engines 2005 Diesel...

451

Development of Optimal Catalyst Designs and Operating Strategies...  

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

Coupled LNTSCR Development of Optimal Catalyst Designs and Operating Strategies for Coupled LNTSCR We introduce a new bench-scale engine generator testing system for different...

452

Impact of Fuel-Borne Catalysts on Diesel Aftertreatment | Department...  

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

Fuel-Borne Catalyst Assisted DPF regeneration on a Renault truck MD9 Engine Outfitted with SCR Fuel Additivies for Improved Performance of Diesel Aftertreatment Systems...

453

Development of Optimal Catalyst Designs and Operating Strategies...  

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

of Optimal Catalyst Designs & Operating Strategies for Lean NOx Reduction in Coupled LNT-SCR Systems Mike Harold, Vemuri Balakotaiah, Dan Luss U. Houston Mark Crocker, U. Kentucky...

454

Development of Optimal Catalyst Designs and Operating Strategies...  

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

Development of Optimal Catalyst Designs and Operating Strategies for Coupled LNTSCR Mike Harold, Vemuri Balakotaiah, and Dan Luss University of Houston Mark Crocker University of...

455

Effectiveness of a Diesel Oxidation Catalyst (DOC) to control...  

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

Effectiveness of a Diesel Oxidation Catalyst (DOC) to control CO and hydrocarbon emissions from Reactivity Controlled Compression Ignition (RCCI) combustion Effectiveness of a...

456

Impact of Fuel Metal Impurities on Diesel Exhaust Catalysts  

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

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

457

Catalyst-Assisted Production of Olefins from Natural Gas Liquids...  

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

Catalyst-Assisted Production of Olefins from Natural Gas Liquids: Prototype Development and Full-Scale Testing New Process Produces Ethylene More Efficiently and Reduces Coke...

458

LSU EFRC - Center for Atomic Level Catalyst Design - About Us  

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

Catalysis and Atomic-Level Synthesis" The mission of LSU's Center for Atomic Level Catalyst Design is to advance: the ability of computational methods to accurately model...

459

Road Blocks Yield Key Information about a Catalyst | The Ames...  

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

Road Blocks Yield Key Information about a Catalyst Researchers systematically blocked key chemical reaction pathways to get unambiguous information about how carbon-nitrogen bonds...

460

LSU EFRC - Center for Atomic Level Catalyst Design - Project  

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

new computational tools that will guide the formulation of novel heterogeneous catalyst materials. An important class of reactions involving CO hydrogenation and oxidation...

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.


461

LSU EFRC - Center for Atomic Level Catalyst Design - Project  

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

to provide guidance to the computational description of the fundamental steps on the catalyst surface. It is centered at Utrecht University (assembly of 3D model systems,...

462

LSU EFRC - Center for Atomic Level Catalyst Design  

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

Catalysis and Atomic-Level Synthesis" The mission of LSU's Center for Atomic Level Catalyst Design is to advance: the ability of computational methods to accurately model...

463

Cooperative Catalyst leads to Transformative Results | The Ames...  

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

Cooperative Catalyst leads to Transformative Results Capitalizing on the concept that everything proceeds faster with a little cooperation, researchers showed how designing...

464

LSU EFRC - Center for Atomic Level Catalyst Design - Contact...  

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

Contact Us >> space control Center for Atomic-Level Catalyst Design (CALCD) 110 Chemical Engineering South Stadium Road Baton Rouge, LA 70803 Telephone: 225.578.1426 Fax:...

465

Catalyst Structure-Performance Relationship Identified by High...  

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

Identified by High-Throughput Operando Method: New Insight for Silica-Supported Catalyst Structure-Performance Relationship Identified by High-Throughput Operando Method: New...

466

LSU EFRC - Center for Atomic Level Catalyst Design - Contact...  

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

Control of Structures on Complex Catalyst Supports space control Ulrike Diebold Wayne Goodman Richard Kurtz Ward Plummer David Sholl Phil Sprunger Ye Xu space control PI names &...

467

Catalyst Activity Comparison of Alcohols over Zeolites. | EMSL  

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

Activity Comparison of Alcohols over Zeolites. Catalyst Activity Comparison of Alcohols over Zeolites. Abstract: Alcohol transformation to transportation fuel range hydrocarbon on...

468

Biomass-derived Hydrogen-evolution catalyst and electrode - Energy...  

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

Hydrogen and Fuel Cell Hydrogen and Fuel Cell Find More Like This Return to Search Biomass-derived Hydrogen-evolution catalyst and electrode Brookhaven National Laboratory Contact...

469

SunShot Catalyst Program | Department of Energy  

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

vast array of tools, capabilities, data assets and additional resources developed by Energy Department and the national laboratories. Catalyst's open, fast-paced innovation cycle...

470

DOE's Fuel Cell Catalyst R&D Activities  

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

Test and Polarization Curve Protocols (http:www.uscar.orgcommandsfilesdownload.php?filesid267), Catalyst Support Cycle and Metrics (Table 2). Activity loss is based on...

471

Pt Nanophase supported catalysts and electrode systems for water electrolysis .  

E-Print Network (OSTI)

??In this study novel composite electrodes were developed, in which the catalytic components were deposited in nanoparticulate form. The efficiency of the nanophase catalysts and… (more)

Petrik, Leslie Felicia

2008-01-01T23:59:59.000Z

472

Catalysts and process for liquid hydrocarbon fuel production  

DOE Patents (OSTI)

The present invention provides a novel process and system in which a mixture of carbon monoxide and hydrogen synthesis gas, or syngas, is converted into hydrocarbon mixtures composed of high quality gasoline components, aromatic compounds, and lower molecular weight gaseous olefins in one reactor or step. The invention utilizes a novel molybdenum-zeolite catalyst in high pressure hydrogen for conversion, as well as a novel rhenium-zeolite catalyst in place of the molybdenum-zeolite catalyst, and provides for use of the novel catalysts in the process and system of the invention.

White, Mark G; Liu, Shetian

2014-12-09T23:59:59.000Z

473

What Makes a Good Catalyst for the Deacon Process?  

Science Journals Connector (OSTI)

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

Herbert Over; Reinhard Schomäcker

2013-04-04T23:59:59.000Z

474

Development of Optimal Catalyst Designs and Operating Strategies...  

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

SCR is promising non-urea solution PARTNERS U. Houston (lead) Center for Applied Energy Research (U. Kentucky) Ford Motor Company BASF Catalysts LLC Oak Ridge...

475

Searching for novel catalysts for water oxidation | Center for...  

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

Center News Research Highlights Center Research News Media about Center Center Video Library Bisfuel Picture Gallery Searching for novel catalysts for water oxidation 30 Oct 2012...

476

Small Catalyst Finding Could Lead to Big Breakthrough for Fuel...  

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

hold the promise of helping us dramatically reduce our dependence on oil while reducing air pollution. Yet, the high costs of fuel cell catalysts, which rely on expensive...

477

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

478

Characterization of uraninite nanoparticles produced by Shewanella...  

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

uraninite nanoparticles produced by Shewanella oneidensis MR-1 . Characterization of uraninite nanoparticles produced by Shewanella oneidensis MR-1 . Abstract: The reduction of...

479

Stabilization of Electrocatalytic Metal Nanoparticles at Metal...  

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

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

480

Enzyme Nanoparticles-Based Electronic Biosensor. | EMSL  

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

method for fabricating electronic biosensors based on coupling enzyme nanoparticles and self assembly technology is illustrated. Redox horseradish peroxidase nanoparticles were...

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.


481

Toward multifunctional nanoparticle-based therapeutics.  

E-Print Network (OSTI)

??The diagnosis and treatment of solid tumors may be improved by tailoring nanoparticles for drug delivery and medical imaging. The core of the nanoparticle can… (more)

Derfus, Austin Matthew

2006-01-01T23:59:59.000Z

482

Direct Observation of Aggregative Nanoparticle Growth: Kinetic...  

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

Aggregative Nanoparticle Growth: Kinetic Modeling of the Size Distribution and Growth Rate. Direct Observation of Aggregative Nanoparticle Growth: Kinetic Modeling of the Size...

483

Patterns and instabilities in colloidal nanoparticle assemblies.  

E-Print Network (OSTI)

??Colloidal nanoparticles exhibit unusual individual and collective behaviour, often associated with interesting electrical, optical or electromagnetic properties. Thiol-passivated colloidal gold nanoparticles possess in addition a… (more)

Pauliac-Vaujour, Emmanuelle

2008-01-01T23:59:59.000Z

484

Sandia National Laboratories: nanoparticle production method  

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

nanoparticle production method Novel Nanoparticle Production Method Could Lead to Better Lights, Lenses, Solar Cells On July 1, 2014, in Capabilities, CINT, Energy, Energy...

485

Silica Supported Ceria Nanoparticles: A Hybrid Nanostructure...  

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

Nanoparticles: A Hybrid Nanostructure To Increase Stability And Surface Reactivity Of Nano-crystalline Silica Supported Ceria Nanoparticles: A Hybrid Nanostructure To Increase...

486

Catalyst performance of novel Pt/Mg(Ga)(Al)O catalysts for alkane dehydrogenation Georges Siddiqi, Pingping Sun, Vladimir Galvita, Alexis T. Bell *  

E-Print Network (OSTI)

Catalyst performance of novel Pt/Mg(Ga)(Al)O catalysts for alkane dehydrogenation Georges Siddiqi dehydrogenation Pt Hydrotalcite a b s t r a c t The dehydrogenation of ethane and propane using a Pt catalyst supported on a novel Mg(Ga)(Al)O mixed oxide support was investigated. Catalyst performance is strongly

Bell, Alexis

487

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.

488

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

489

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

490

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

E-Print Network (OSTI)

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

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

2007-01-01T23:59:59.000Z

491

DOE's Fuel Cell Catalyst R&D Activities | Department of Energy  

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

Fuel Cell Catalyst R&D Activities DOE's Fuel Cell Catalyst R&D Activities Presentation about the U.S. Department of Energy's (DOE) fuel cell catalyst R&D activities, presented by...

492

Understanding the Distributed Intra-Catalyst Impact of Sulfation on Water Gas Shift in a Lean NOx Trap Catalyst  

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

The Lean NOx Trap catalyst is an aftertreatment technology for abatement of nitrogen-oxide emissions from lean-burn vehicle engines.

493

The Use of Soluble Polyolefins as Supports for Transition Metal Catalysts  

E-Print Network (OSTI)

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

Hobbs, Christopher Eugene

2012-10-19T23:59:59.000Z

494

Subnanometer and nanometer catalysts, method for preparing size-selected catalysts  

DOE Patents (OSTI)

Highly uniform cluster based nanocatalysts supported on technologically relevant supports were synthesized for reactions of top industrial relevance. The Pt-cluster based catalysts outperformed the very best reported ODHP catalyst in both activity (by up to two orders of magnitude higher turn-over frequencies) and in selectivity. The results clearly demonstrate that highly dispersed ultra-small Pt clusters precisely localized on high-surface area supports can lead to affordable new catalysts for highly efficient and economic propene production, including considerably simplified separation of the final product. The combined GISAXS-mass spectrometry provides an excellent tool to monitor the evolution of size and shape of nanocatalyst at action under realistic conditions. Also provided are sub-nanometer gold and sub-nanometer to few nm size-selected silver catalysts which possess size dependent tunable catalytic properties in the epoxidation of alkenes. Invented size-selected cluster deposition provides a unique tool to tune material properties by atom-by-atom fashion, which can be stabilized by protective overcoats.

Vajda, Stefan (Lisle, IL), Pellin, Michael J. (Naperville, IL); Elam, Jeffrey W. (Elmhurst, IL); Marshall, Christopher L. (Naperville, IL); Winans, Randall A. (Downers Grove, IL); Meiwes-Broer, Karl-Heinz (Roggentin, GR)

2012-04-03T23:59:59.000Z

495

Subnanometer and nanometer catalysts, method for preparing size-selected catalysts  

DOE Patents (OSTI)

Highly uniform cluster based nanocatalysts supported on technologically relevant supports were synthesized for reactions of top industrial relevance. The Pt-cluster based catalysts outperformed the very best reported ODHP catalyst in both activity (by up to two orders of magnitude higher turn-over frequencies) and in selectivity. The results clearly demonstrate that highly dispersed ultra-small Pt clusters precisely localized on high-surface area supports can lead to affordable new catalysts for highly efficient and economic propene production, including considerably simplified separation of the final product. The combined GISAXS-mass spectrometry provides an excellent tool to monitor the evolution of size and shape of nanocatalyst at action under realistic conditions. Also provided are sub-nanometer gold and sub-nanometer to few nm size-selected silver catalysts which possess size dependent tunable catalytic properties in the epoxidation of alkenes. Invented size-selected cluster deposition provides a unique tool to tune material properties by atom-by-atom fashion, which can be stabilized by protective overcoats.

Vajda, Stefan (Lisle, IL); Pellin, Michael J. (Naperville, IL); Elam, Jeffrey W. (Elmhurst, IL); Marshall, Christopher L. (Naperville, IL); Winans, Randall A. (Downers Grove, IL); Meiwes-Broer, Karl-Heinz (Roggentin, GR)

2012-03-27T23:59:59.000Z

496

The durability of carbon supported Pt nanowire as novel cathode catalyst for a 1.5 kW PEMFC stack  

Science Journals Connector (OSTI)

Abstract Carbon supported platinum nanowires (PtNW/C) synthesized by a simple and inexpensive template-free methodology has been used for the first time as a cathode catalyst in a 15 cell with an active area of 250 cm2, 1.5 kW proton exchange membrane fuel cell (PEMFC) stack. Drive cycle testing along with in-situ and ex-situ accelerated degradation testing (ADT) showed that the PtNW/C catalyst exhibited better durability than commercial Pt/C. After a 420 h dynamic drive cycle durability testing, the PEMFC stacks exhibited a performance degradation rate of 14.4% and 17.9% for PtNW/C and commercial Pt/C based cathodes, respectively. It was found that the majority of performance loss was due to degradation of the commercial Pt/C anode materials, resulting from the rapidly changing load frequencies used in the testing protocol, ultimately leading to harsh fuel/air starvation conditions and subsequent Pt nanoparticle growth and agglomeration. Notably, based on post-testing characterization, the structure, electrochemically active surface area (ECSA) and oxygen reduction activity of the PtNW/C cathode catalyst remained unchanged during the drive cycling, indicating its excellent stability under these practical conditions. Conversely, when using commercial Pt/C as a cathode catalyst, significant Pt nanoparticle growth and agglomeration were observed, resulting in the reduced PEMFC stack durability. Therefore, PtNW/C materials are presented as promising replacements to conventional Pt/C as cathode electrocatalysts for PEMFCs, and particularly demonstrate improved stability under the practical conditions encountered for automotive applications.

Bing Li; Drew C. Higgins; Qiangfeng Xiao; Daijun Yang; Cunman Zhng; Mei Cai; Zhongwei Chen; Jianxin Ma

2015-01-01T23:59:59.000Z

497

Iron(III) Oxide Nanoparticles in the Thermally Induced Oxidative Decomposition of Prussian Blue, Fe4[Fe(CN)6]3  

Science Journals Connector (OSTI)

Iron(III) Oxide Nanoparticles in the Thermally Induced Oxidative Decomposition of Prussian Blue, Fe4[Fe(CN)6]3 ... Iron(III) oxides, particularly in the form of nanoparticles, are being used as catalysts, pigments, gas sensors, contrast agents in the magnetic resonance imaging, magnetic storage media, and furthermore, as basic components in the ferrofluid technologies or in biomagnetic separation processes. ... Structural and magnetic properties, methods of synthesis, and applications of seven Fe(III) oxide polymorphs, including rare beta, epsilon, amorphous, and high-pressure forms, are reviewed. ...

Radek Zboril; Libor Machala; Miroslav Mashlan; Virender Sharma

2004-10-05T23:59:59.000Z

498

Reflection of nanoparticles  

E-Print Network (OSTI)

This work is devoted to molecular dynamics modeling of collision of nanoparticle having a small number of degrees of freedom with a structureless plain. The new regularities are established that determine properties of such particles. Generalized collision law is obtained where particle properties are determined by two coefficient, on of which corresponds to restitution coefficient. The discovered regularity predicts the existence of anomalous mode of particle reflection from a massive plain. In this mode, velocity of nanoparticle after reflection from a plain can exceed the initial one. The criterion of realization of such mode is obtained. Anomalous collision mode was observed during numerical modeling. Physical mechanism are discussed of phenomena that are observed during numerical experiments.

M. A. Ratner; A. V. Tur; V. V. Yanovsky

2013-12-18T23:59:59.000Z

499

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

500

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