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Note: This page contains sample records for the topic "ni pd pt" from the National Library of EnergyBeta (NLEBeta).
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1

Middle distillate hydrotreatment zeolite catalysts containing Pt/Pd or Ni  

E-Print Network (OSTI)

A study on middle distillate hydrotreatment zeolite catalysts containing Pt/Pd and/or Ni was performed. The effect of the addition of the corresponding CoMo, CoMoPd, CoMoPtPd and CoMoNi in PdNiPt-zeolite, Pt-zeolite, Ni-zeolite, and Pd...

Marin-Rosas, Celia

2009-05-15T23:59:59.000Z

2

Geometric structures of thin film: Pt on Pd(110) and NiO on Ni(100)  

SciTech Connect

This thesis is divided into 3 papers: dynamical low-energy electron- diffraction investigation of lateral displacements in topmost layer of Pd(110); determination of (1{times}1) and (1{times}2) structures of Pt thin films on Pd(110) by dynamical low-energy electron-diffraction analysis; and structural determination of a NiO(111) film on Ni(100) by dynamical low-energy electron-diffraction analysis.

Warren, O.L.

1993-07-01T23:59:59.000Z

3

Measurement of Benzenethiol Adsorption to Nanostructured Pt, Pd, and PtPd Films Using Raman Spectroelectrochemistry  

Science Journals Connector (OSTI)

The combination of these techniques affords a powerful and convenient method for guiding the development of sulfur-tolerant PEMFC catalysts. ... Since the motivating factor in this study was to develop methods to evaluate candidates for sulfur-tolerant catalysts for PEMFC anodes, it is appropriate to consider what the above results say about the relative sulfur tolerance of Pt, Pd, and PtPd. ... The potential use of C-supported PtPdy, where y = 1-6, electrocatalysts as CO-tolerant anodes for proton exchange membrane fuel cell (PEMFC) applications was studied. ...

Michael B. Pomfret; Jeremy J. Pietron; Jeffrey C. Owrutsky

2010-02-05T23:59:59.000Z

4

Decomposition of the relativistic hyperfine interaction operator: Application to the ferromagnetic alloy systems fcc FexNi1-x, fcc FexPd1-x, and fcc CoxPt1-x  

Science Journals Connector (OSTI)

A scheme developed by Pyper to decompose within relativistic Hartree-Fock theory the hyperfine interaction operator into the conventional Fermi contact, spin dipolar and orbital contributions is modified to split the hyperfine field of magnetic solids calculated in a fully relativistic way on the basis of spin-density-functional theory in an analogous way. The resulting expressions are used to examine the hyperfine fields for the disordered alloy systems fcc FexNi1-x, fcc FexPd1-x, and fcc CoxPt1-x making use of the spin-polarized relativistic Korringa-Kohn-Rostoker coherent-potential approximation method of band-structure calculation. In particular the contribution of non-s electrons to the hyperfine fields are discussed in detail. Special emphasize is laid on their relationship to the corresponding contributions to the spin and spin-orbit-induced orbital magnetic moments.

M. Battocletti and H. Ebert

2001-08-08T23:59:59.000Z

5

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

Science Journals Connector (OSTI)

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

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

2014-06-01T23:59:59.000Z

6

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

7

Growth of Epitaxial Thin Pd(111) Films on Pt(111) and Oxygen...  

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

Growth of Epitaxial Thin Pd(111) Films on Pt(111) and Oxygen-Terminated FeO(111) Surfaces . Growth of Epitaxial Thin Pd(111) Films on Pt(111) and Oxygen-Terminated FeO(111)...

8

A photoemission study of Pd ultrathin films on Pt(111)  

SciTech Connect

The origin of surface core-level shift (SCLS) of Pd thin films on Pt(111) substrate is investigated. At sub-monolayer coverage of Pd thin films, the splitting of Pd 3d core level peaks indicate the contribution of both initial and final-state of photo-ionization processes while there is almost no change on valence band (VB) spectra. When the coverage of Pd reaches to single monolayer, the final-state relaxation effect on the Pd 3d vanishes and only the initial-state effect, a negative SCLS, is present. Also, the VB spectrum at Pd monolayer films shows a clear band narrowing, that is the origin of the negative SCLS at monolayer coverage. As the Pd coverage is increased to more than monolayer thickness, the Pd 3d peaks start to show the surface layer contribution from second and third layers, positive SCLS, and the VB spectrum shows even narrower band width, possibly due to the formation of surface states and strained effect of Pd adlayers on top of the first pseudomorphic layer.

Mun, Bongjin Simon; Lee, Choongman; Stamenkovic, Vojislav; Markovic, Nenad M.; Ross Jr., Philip N.

2005-05-11T23:59:59.000Z

9

PT AND PT/NI "NEEDLE" ELETROCATALYSTS ON CARBON NANOTUBES WITH HIGH ACTIVITY FOR THE ORR  

SciTech Connect

Platinum and platinum/nickel alloy electrocatalysts supported on graphitized (gCNT) or nitrogen doped carbon nanotubes (nCNT) are prepared and characterized. Pt deposition onto carbon nanotubes results in Pt 'needle' formations that are 3.5 nm in diameter and {approx}100 nm in length. Subsequent Ni deposition and heat treatment results in PtNi 'needles' with an increased diameter. All Pt and Pt/Ni materials were tested as electrocatalysts for the oxygen reduction reaction (ORR). The Pt and Pt/Ni catalysts showed excellent performance for the ORR, with the heat treated PtNi/gCNT (1.06 mA/cm{sup 2}) and PtNi/nCNT (0.664 mA/cm{sup 2}) showing the highest activity.

Colon-Mercado, H.

2011-11-10T23:59:59.000Z

10

Reaction-Driven Restructuring of Rh-Pd and Pt-Pd Core-Shell Nanoparticles  

E-Print Network (OSTI)

measured at 25 o C in UHV as a function of photoelectronPt 0.5 Pd 0.5 measured in UHV at 25 o C as a function of thelocated in a separate UHV chamber, indicating that the

Tao, Feng

2009-01-01T23:59:59.000Z

11

The influence of Pt redistribution on Ni{sub 1-x}Pt{sub x}Si growth properties  

SciTech Connect

We have studied the influence of Pt on the growth of Ni silicide thin films by examining the Pt redistribution during silicide growth. Three different initial Pt configurations were investigated, i.e., a Pt alloy (Ni+Pt/), a Pt capping layer (Pt/Ni/) and a Pt interlayer (Ni/Pt/), all containing 7 at. % Pt relative to the Ni content. The Pt redistribution was probed using in situ real-time Rutherford backscattering spectrometry (RBS) whereas the phase sequence was monitored during the solid phase reaction (SPR) using in situ real-time x-ray diffraction. We found that the capping layer and alloy exhibit a SPR comparable to the pure Ni/ system, whereas Pt added as an interlayer has a much more drastic influence on the Ni silicide phase sequence. Nevertheless, for all initial sample configurations, Pt redistributes in an erratic way. This phenomenon can be assigned to the low solubility of Pt in Ni{sub 2}Si compared to NiSi and the high mobility of Pt in Ni{sub 2}Si compared to pure Ni. Real-time RBS further revealed that the crucial issue determining the growth properties of each silicide phase is the Pt concentration at the Si interface during the initial stages of phase formation. The formation of areas rich in Pt reduce the Ni silicide growth kinetics which influences the phase sequence and properties of the silicides.

Demeulemeester, J.; Smeets, D.; Temst, K.; Vantomme, A. [Instituut voor Kern-en Stralingsfysica and INPAC, K.U.Leuven, Celestijnenlaan 200D, B-3001 Leuven (Belgium); Comrie, C. M. [Department of Physics, University of Cape Town, Rondebosch 7700 (South Africa); Van Bockstael, C.; Knaepen, W.; Detavernier, C. [Department of Solid State Sciences, Ghent University, B-9000 Gent (Belgium)

2010-08-15T23:59:59.000Z

12

Ni-Pt Silicide Formation Through Ti Mediating Layers  

SciTech Connect

With Ni1-xPtxSi, the variation in queue time between the final surface cleaning and Ni-Pt deposition represents a significant manufacturability issue. A short queue time is often difficult to maintain, leading to the formation of an oxide layer on the Si substrate prior to Ni-Pt deposition that can affect the formation of Ni1-xPtxSi and its texture. In this manuscript, it will be shown that an extended queue time prior to Ni-Pt deposition leads to morphological changes in the Ni1-xPtxSi formation sequence. A layer of Ti deposited between Ni-Pt and Si reduces the native oxide and may facilitate Ni1-xPtxSi formation. With increasing Ti thickness, the presence of metal-rich phases is gradually reduced and the formation temperature of Ni1-xPtxSi increases, suggesting a direct formation of Ni1-xPtxSi from Ni-Pt. In the presence of an interfacial oxide, an increase in formation temperature is also observed with increasing Ti interlayer thickness. When the Ti layer is sufficiently thick, the phase formation sequence becomes relatively insensitive to the presence of an interfacial oxide or extended queue time.

Besser,P.; Lavoie, C.; Ozcan, A.; Murray, C.; Strane, J.; Wong, K.; Gribelyuk, M.; Wang, Y.; Parks, C.; Jordan-Sweet, J.

2007-01-01T23:59:59.000Z

13

Investigating magnetic proximity effects in NiO/Pd with polarized neutron reflectometry  

Science Journals Connector (OSTI)

With polarized neutron reflectometry we investigated NiO/Pd heterostructures for the presence of a magnetic proximity effect, which is expected to produce an induced ferromagnetic moment in Pd. Using a specific isotope mixture of Ni in the preparation of NiO, the chemical contrast across the Pd/NiO interface was greatly suppressed, thus enhancing sensitivity to magnetic contrast at the reflecting interface. Despite enhanced sensitivity, no evidence for a proximity effect was observed. If present, the magnetic moment per Pd atom could not be more than 0.01?B, regardless of Pd layer thickness, crystalline interface orientation, and number of NiO/Pd bilayers.

A. Hoffmann; M. R. Fitzsimmons; J. A. Dura; C. F. Majkrzak

2001-12-19T23:59:59.000Z

14

The role of doped Fe on the activity of alumina-supported Pt and Pd diesel exhaust catalysts  

Science Journals Connector (OSTI)

Supported Pt and Pd are most commonly used for oxidation catalysts. They have similar and different characteristics for deactivation factors. The catalytic activity of Pt and Pd catalysts supported on ?-Al2O3 was...

Yeon-Su Kim; Sun Ju Lim; Young Hun Kim; Jin Ha Lee…

2012-03-01T23:59:59.000Z

15

High Performance Plasma Sputtered PdPt Fuel Cell Electrodes with Ultra Low Loading  

E-Print Network (OSTI)

% Pt) catalyst is used to replace platinum at the cathode of a PEMFC MEA whereas pure palladium is used suitable conditions of a working PEMFC (80°C and 3 bar absolute pressure), very high catalysts utilizationPt (10:1 weight ratio) cathode and a pure Pd anode. Keywords: Catalyst thin film, Low Pt content

Paris-Sud XI, Université de

16

Durability study of Pt–Pd/C as PEMFC cathode catalyst  

Science Journals Connector (OSTI)

In this paper, Pt–Pd/C and Pt/C catalysts were evaluated and compared. The catalysts were evaluated as oxygen reduction reaction (ORR) catalysts in half cell test under potential cycling, and cathode catalysts in single cell test under dynamic loading simulating the vehicle operation. Physical and electrochemical techniques were applied to investigate the structure, performance and durability of those catalysts. The electrochemical active surface area (ECA) loss, particle size distribution, polarization behavior and electrochemistry impedance spectroscopy (EIS) suggested that the Pt–Pd/C showed a better durability than Pt/C.

Zhi-Min Zhou; Zhi-Gang Shao; Xiao-Ping Qin; Xu-Guang Chen; Zi-Dong Wei; Bao-Lian Yi

2010-01-01T23:59:59.000Z

17

Effects of heat dissipation on unipolar resistance switching in Pt/NiO/Pt capacitors  

E-Print Network (OSTI)

Effects of heat dissipation on unipolar resistance switching in Pt/NiO/Pt capacitors S. H. Chang,1 151-747, Republic of Korea 3 School of Materials Science and Engineering, Seoul National University tBE and investigated their resistance switching behaviors. The capacitors with tBE 50 nm exhibited

Kahng, Byungnam

18

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

19

Pt/Pd electrocatalyst electrons for fuel cells  

DOE Patents (OSTI)

This invention relates to improved electrochemical cells and to novel electrodes for use therein. In particular, the present invention comprises a fuel cell used primarily for the consumption of impure hydrogen fuels containing carbon monoxide or carbonaceous fuels where the electrode in contact with the fuel is not substantially poisoned by carbon monoxide. The anode of the fuel cell comprises a Pd/Pt alloy supported on a graphitized or partially graphitized carbon material. Fuel cells which comprise as essential elements a fuel electrode, an oxidizing electrode, and an electrolyte between said electrodes are devices for the direct production of electricity through the electrochemical combustion of a fuel and oxidant. These devices are recognized for their high efficiency as energy conversion units, since unlike conventional combustion engines, they are not subject to the limitations of the Carnot heat cycle. It is the primary object of the present invention to provide an electrode having high electrochemical activity for an electrochemical cell. It is another object of the present invention to provide an electrode having an electro-catalyst which is highly resistant to the corrosive environment of an electrochemical cell.

Stonehart, P.

1981-11-03T23:59:59.000Z

20

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

Note: This page contains sample records for the topic "ni pd pt" 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

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

Science Journals Connector (OSTI)

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

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

2011-02-24T23:59:59.000Z

22

Dissociative Adsorption of Methane on Surface Oxide Structures of Pd-Pt Alloys Arezoo Dianat,*,,  

E-Print Network (OSTI)

/C ratio of methane, the heat of combustion per mole of generated CO2 is higher than for other fuels the combustion of methane on these materials. For Pd-Pt alloys, models of surface oxide structures are built. Introduction The catalytic oxidation of hydrocarbons in general, and of methane in particular, is considered

Cuniberti, Gianaurelio

23

Effect of Pd on the Ni{sub 2}Si stress relaxation during the Ni-silicide formation at low temperature  

SciTech Connect

The thermally induced solid-state reaction between a 50-nm-thick Ni(6%Pd) layer and a Si(100) substrate was investigated using in situ and simultaneous x-ray diffraction and sheet resistance. The reaction begins with the growth of the stressed {delta}-Ni{sub 2}Si phase, and the transient {theta}-Ni{sub 2}Si. At the end of the {theta}-Ni{sub 2}Si consumption, a NiSi seed is formed. Then, the {delta}-Ni{sub 2}Si relaxation occurs simultaneously with its subsequent growth and the Pd out diffusion from the unreacted Ni(Pd) layer. It is suggested that the driving force for the Pd diffusion out of the metal layer is linked to both the higher solubility of Pd in NiSi compared to Ni{sub 2}Si and to the Ni{sub 2}Si relaxation.

Putero, M.; Mangelinck, D. [Aix-Marseille Univ., IM2NP, Faculte des Sciences de Jerome, F-13397 Marseille (France); CNRS, IM2NP-UMR 7334, Faculte des Sciences de Jerome, F-13397 Marseille (France)

2012-09-10T23:59:59.000Z

24

Surface segregation effects in electrocatalysis: Kinetics ofoxygen reduction reaction on polycrystalline Pt3Ni alloy surfaces  

SciTech Connect

Effects of surface segregation on the oxygen reduction reaction (ORR) have been studied on a polycrystalline Pt3Ni alloy in acid electrolyte using ultra high vacuum (UHV) surface sensitive probes and the rotating ring disk electrode (RRDE) method. Preparation, modification and characterization of alloy surfaces were done in ultra high vacuum (UHV). Depending on the preparation method, two different surface compositions of the Pt3Ni alloy are produced: a sputtered surface with 75 % Pt and an annealed surface (950 K ) with 100 % Pt. The latter surface is designated as the 'Pt-skin' structure, and is a consequence of surface segregation, i.e., replacement of Ni with Pt atoms in the first few atomic layers. Definitive surface compositions were established by low energy ion scattering spectroscopy (LEISS). The cyclic voltammetry of the 'Pt-skin' surface as well as the pseudocapacitance in the hydrogen adsorption/desorption potential region is similar to a polycrystalline Pt electrode. Activities of ORR on Pt3Ni alloy surfaces were compared to polycrystalline Pt in 0.1M HClO4 electrolyte for the observed temperature range of 293 < T < 333 K. The order of activities at 333 K was: 'Pt-skin' > Pt3Ni (75% Pt) > Pt with the maximum catalytic enhancement obtained for the 'Pt-skin' being 4 times that for pure Pt. Catalytic improvement of the ORR on Pt3Ni and 'Pt-skin' surfaces was assigned to the inhibition of Pt-OHad formation (on Pt sites) versus polycrystalline Pt. Production of H2O2 on both surfaces were similar compared to the pure Pt. Kinetic analyses of RRDE data confirmed that kinetic parameters for the ORR on the Pt3Ni and 'Pt-skin' surfaces are the same as on pure Pt: reaction order, m=1, two identical Tafel slopes, activation energy, {approx} 21-25 kJ/mol. Therefore the reaction mechanism on both Pt3Ni and 'Pt-skin' surfaces is the same as one proposed for pure Pt i.e. 4e{sup -} reduction pathway.

Stamenkovic, V.; Schmidt, T.J.; Ross, P.N.; Markovic, N.M.

2002-11-01T23:59:59.000Z

25

Synthesis of Pt?Pd Core?Shell Nanostructures by Atomic Layer Deposition: Application in Propane Oxidative Dehydrogenation to Propylene  

SciTech Connect

Atomic layer deposition (ALD) was employed to synthesize supported Pt?Pd bimetallic particles in the 1 to 2 nm range. The metal loading and composition of the supported Pt?Pd nanoparticles were controlled by varying the deposition temperature and by applying ALD metal oxide coatings to modify the support surface chemistry. Highresolution scanning transmission electron microscopy images showed monodispersed Pt?Pd nanoparticles on ALD Al2O3 - and TiO2 -modi?ed SiO2 gel. X-ray absorption spectroscopy revealed that the bimetallic nanoparticles have a stable Pt-core, Pd-shell nanostructure. Density functional theory calculations revealed that the most stable surface con?guration for the Pt? Pd alloys in an H2 environment has a Pt-core, Pd-shell nanostructure. In comparison to their monometallic counterparts, the small Pt?Pd bimetallic core?shell nanoparticles exhibited higher activity in propane oxidative dehydrogenation as compared to their physical mixture.

Lei, Y.; Liu, Bin; Lu, Junling; Lobo-Lapidus, Rodrigo J.; Wu, Tianpin; Feng, Hao; Xia, Xiaoxing; Mane, Anil U.; Libera, Joseph A.; Greeley, Jeffrey P.; Miller, Jeffrey T.; Elam, J. W.

2012-08-20T23:59:59.000Z

26

Mechanism for Oxygen Reduction Reaction on Pt3Ni Alloy Fuel Cell Boris V. Merinov,*,  

E-Print Network (OSTI)

, at the cathode of a polymer electrolyte membrane fuel cell (PEMFC) is a critical issue for commercial applicationMechanism for Oxygen Reduction Reaction on Pt3Ni Alloy Fuel Cell Cathode Yao Sha, Ted H. Yu, Boris of this type of fuel cells.1-4 The best current catalysts are Pt and Pt-based binary alloys, such as Pt3Ni.5

Goddard III, William A.

27

Thermomechanical Cyclic Response of TiNiPd High-Temperature Shape Memory Alloys  

E-Print Network (OSTI)

TiNiPd high-temperature shape memory alloys (HTSMAs) have attracted considerable attention as potential solid-state actuators capable of operating at temperatures up to 500 °C, exhibiting excellent corrosion resistance, adequate ductility levels...

Atli, Kadri

2012-10-19T23:59:59.000Z

28

Hydrogen storage of multiwalled carbon nanotubes coated with Pd-Ni nanoparticles under moderate conditions  

Science Journals Connector (OSTI)

A type of novel material with a high hydrogen storage capacity was prepared by supporting PdNi18 alloy nanoparticles, which were synthesized by using a new colloid method, on the surface of pretreated multiwalled...

Jianwei Ren; Shijun Liao; Junmin Liu

2006-12-01T23:59:59.000Z

29

The wetting behavior of NiAl and NiPtAl on polycrystalline alumina  

SciTech Connect

In order to understand the beneficial effect of Pt on the adherence of thermally grown alumina scales, sessile drop experiments were performed to study the wetting of poly-crystalline alumina by nickel-aluminum alloys with or without platinum addition where the amount of Pt ranged from 2.4 to 10 at.%. Subsequent interfacial structure was evaluated using atomic force microscopy. Platinum addition enhances the wettability of NiAl alloys on alumina, reduces the oxide/alloy interface energy and increases the interfacial mass transport rates.

Saiz, Eduardo; Gauffier, Antoine; Saiz, Eduardo; Tomsia, Antoni P.; Hou, Peggy Y.

2007-07-01T23:59:59.000Z

30

Influence of the magnetic phase transition on secondary ion emission from disordered Ni-Pd compounds of various compositions  

Science Journals Connector (OSTI)

Variations in secondary ion emission (SIE) from polycrystals of ferromagnetic disordered Ni-Pd compounds irradiated by argon ions with energy of 10 keV are studied experimentally. A considerable reduction in Ni+ ...

K. F. Minnebaev; K. A. Tolpin…

2012-05-01T23:59:59.000Z

31

Effect of Pt addition on Ni silicide formation at low temperature: Growth, redistribution, and solubility  

SciTech Connect

The formation of Ni silicide during the reaction between Ni(5% Pt) and a Si(100) substrate has been analyzed by differential scanning calorimetry (DSC), in situ x-ray diffraction (XRD), cross-sectional transmission electron microscopy (TEM), and {sup 4}He{sup +} Rutherford backscattering. The DSC measurements show evidence of the Ni{sub 2}Si nucleation followed by lateral growth formation. In situ XRD and TEM have been used to investigate the sequence of formation of the silicides. These experiments show that the formations of Ni{sub 2}Si and NiSi occur simultaneously in the presence of the Pt alloy. The redistribution of platinum at different stages of the Ni silicide growth has been determined. We have estimated the solubility limit of platinum (1 at. % at 573 K) in the Ni{sub 2}Si phase by extrapolation from a measured value at 1073 K. This redistribution is explained in terms of the solubility limits and the diffusion of Pt in the Ni{sub 2}Si and NiSi phases. Pt is more likely to reside at the silicide grain boundaries and the interfaces where it can slow down the silicide growth kinetics.

Hoummada, K.; Perrin-Pellegrino, C.; Mangelinck, D. [Aix-Marseille Universite, IM2NP, Campus de Saint-Jerome, Avenue Escadrille Normandie Niemen-Case 142, F-13397 Marseille Cedex (France); CNRS, IM2NP (UMR 6242), Case 142, Faculte de Saint-Jerome, F-13397 Marseille Cedex (France)

2009-09-15T23:59:59.000Z

32

Improved Oxygen Reduction Activity on Pt3Ni(111) via Increased Surface Site Availability  

Science Journals Connector (OSTI)

...state-of-the-art Pt/C catalysts for PEMFC. The Pt3Ni(111...membrane fuel cell (PEMFC) is used in a demanding...platinum-loading) in current PEMFC stacks is needed...surface area in the cathode must be greatly...if stable cathode catalysts, with an order...

Vojislav R. Stamenkovic; Ben Fowler; Bongjin Simon Mun; Guofeng Wang; Philip N. Ross; Christopher A. Lucas; Nenad M. Markovi?

2007-01-26T23:59:59.000Z

33

Effect of electronic structures on catalytic properties of CuNi alloy and Pd in MeOH-related reactions  

SciTech Connect

We investigated the catalytic properties of a CuNi solid solution and Pd for methanol-related reactions and associated valence electronic structures. Calculations and X-ray photoelectron spectroscopy measurements revealed that the CuNi alloy has a similar valence electronic structure to Pd and hence they exhibited similar CO selectivities in steam reforming of methanol and decomposition of methanol. Samples prepared by various processes were found to have similar CO selectivities. We conjecture that alloying of Cu and Ni dramatically alters the valence electronic structures, making it similar to that of Pd so that the alloy exhibits similar catalytic properties to Pd. First-principles slab calculations of surface electronic structures support this conjecture.

Tsai, An-Pang [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577 (Japan); National Institute for Materials Science, Tsukuba 305-0047 (Japan); Kimura, Tomofumi; Suzuki, Yukinori; Kameoka, Satoshi [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577 (Japan); Shimoda, Masahiko [National Institute for Materials Science, Tsukuba 305-0047 (Japan); Ishii, Yasushi [Department of Physics, Chuo University, Kasuga, Tokyo 112-8551 (Japan)

2013-04-14T23:59:59.000Z

34

Study of Nd3+, Pd2+, Pt4+, and Fe3+ dopant effect on photoreactivity of TiO2 nanoparticles  

Science Journals Connector (OSTI)

...For the purpose of doping, neodymium (III) acetylacetonate, palladium (II) acetylacetonate, platinum (IV) acetylacetonate, and iron (III) acetylacetonate in powder forms were used for Nd 3+ , Pd 2+ , Pt 4+ , and Fe 3+ ion doping...

S. I. Shah; W. Li; C.-P. Huang; O. Jung; C. Ni

2002-01-01T23:59:59.000Z

35

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

SciTech Connect

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

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

2013-01-01T23:59:59.000Z

36

Kondo Effect in an Amorphous Ni41Pd41B18 Alloy Containing Cr  

Science Journals Connector (OSTI)

The results of electrical-resistivity-vs-temperature measurements on an amorphous Ni41 Pd41 B18 alloy containing up to 4-at.% Cr exhibits the characteristics of a Kondo system. The experimental data are used to make a comparison between the Kondo theory and the Hamann theory. It is found that both theories agree very well on the slope of logarithmic temperature dependence of the s-d resistivity. In terms of a universal resistivity curve, the Hamann theory comes to closer agreement with the experimental data in a wider temperature range than does the Kondo theory.

V. K. C. Liang and C. C. Tsuei

1973-04-01T23:59:59.000Z

37

Berkeley, Argonne team report promising Pt/Ni nanocatalysts  

Science Journals Connector (OSTI)

A collaborative effort between researchers at the US Department of Energy's Lawrence Berkeley National Laboratory and Argonne National Laboratory has discovered a new class of bimetallic nanocatalysts that are an order of magnitude higher in activity than the DOE target for 2017. The new catalysts, comprising hollow polyhedral nanoframes of platinum and nickel, feature a 3D catalytic surface activity that makes them significantly more efficient and far less expensive than the best Pt catalysts used in current fuel cells and alkaline electrolysers.

2014-01-01T23:59:59.000Z

38

Effective work function of Pt, Pd, and Re on atomic layer deposited HfO{sub 2}  

SciTech Connect

Platinum and Pd show a significant difference in work function on SiO{sub 2} and high-K materials (HfO{sub 2}). The effective metal work functions for Pd, Pt, and Re on atomic layer deposited HfO{sub 2}, which are different from the vacuum work function and important for device threshold voltage control, are measured by the C-V method. The difference is attributed to the dipoles at the metal/HfO{sub 2} interface, which is a result of charge transfer across the interface. Moreover, the extracted charge neutrality level and screening parameter are correlated with the phase development, film stoichiometry, and density of interface states at the metal/high-K interface.

Gu Diefeng; Dey, Sandwip K.; Majhi, Prashant [Department of Chemical and Materials Engineering, Arizona State University, Tempe, Arizona 85287-6006 (United States) and Department of Electrical Engineering, Arizona State University, Tempe, Arizona 85287-5706 (United States); Planar CMOS Scaling, SEMATECH, Austin, Texas 78741 (United States)

2006-08-21T23:59:59.000Z

39

Phase formation and morphological stability of ultrathin Ni-Co-Pt silicide films formed on Si(100)  

SciTech Connect

Ultrathin Ni, Co, and Pt films, each no more than 4?nm in thickness, as well as their various combinations are employed to investigate the competing growth of epitaxial Co{sub 1-y}Ni{sub y}Si{sub 2} films against polycrystalline Pt{sub 1-z}Ni{sub z}Si. The phase formation critically affects the morphological stability of the resulting silicide films, with the epitaxial films being superior to the polycrystalline ones. Any combination of those metals improves the morphological stability with reference to their parent individual metal silicide films. When Ni, Co, and Pt are all included, the precise initial location of Pt does little to affect the final phase formation in the silicide films and the epitaxial growth of Co{sub 1-x}Ni{sub x}Si{sub 2} films is always perturbed, in accordance to thermodynamics that shows a preferential formation of Pt{sub 1-z}Ni{sub z}Si over that of Co{sub 1-y}Ni{sub y}Si{sub 2}.

Xu, Peng; Wu, Dongping, E-mail: dongpingwu@fudan.edu.cn [State Key Laboratory of ASIC and System, Fudan University, Shanghai 200433 (China); Kubart, Tomas; Gao, Xindong [Solid-State Electronics, The Ångström Laboratory, Uppsala University, P.O. Box 534, 75121 Uppsala (Sweden); Zhang, Shi-Li, E-mail: shili.zhang@angstrom.uu.se [State Key Laboratory of ASIC and System, Fudan University, Shanghai 200433, China and Solid-State Electronics, The Ångström Laboratory, Uppsala University, P.O. Box 534, 75121 Uppsala (Sweden)

2014-05-15T23:59:59.000Z

40

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

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


41

High performance of a carbon supported ternary PdIrNi catalyst for ethanol electro-oxidation in anion-exchange membrane direct ethanol fuel cells  

E-Print Network (OSTI)

, including methanol, ethanol, glycerol, ethylene glycol, and so on, ethanol is the best choice, as it has abundant than Pt and has a much lower price, and thus the cost of fuel cell technology can be greatly. Secondly, Pd is more abundant than Pt and has a much lower price, and thus the cost of fuel cell technology

Zhao, Tianshou

42

Digital Deposition of Ultrathin Pd Films on Well-Defined Pt(111) Electrodes via Surface-Limited Redox Replacement Reaction: An Electron Spectroscopy-Electrochemistry Study  

E-Print Network (OSTI)

In this study, ultrathin (submonolayer to eight-monolayer) Pd films were deposited one layer at a time on well-defined Pt(111) surfaces via a process known as surface-limited redox replacement reaction (SLR^3). In this digital-deposition method, one...

Hossain, Mohammad

2010-12-04T23:59:59.000Z

43

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

44

High Temperature Oxidation Behavior of gamma-Ni+gamma'-Ni3Al Alloys and Coatings Modified with Pt and Reactive Elements  

SciTech Connect

Materials for high-pressure turbine blades must be able to operate in the high-temperature gases (above 1000 C) emerging from the combustion chamber. Accordingly, the development of nickel-based superalloys has been constantly motivated by the need to have improved engine efficiency, reliability and service lifetime under the harsh conditions imposed by the turbine environment. However, the melting point of nickel (1455 C) provides a natural ceiling for the temperature capability of nickel-based superalloys. Thus, surface-engineered turbine components with modified diffusion coatings and overlay coatings are used. Theses coatings are capable of forming a compact and adherent oxide scale, which greatly impedes the further transport of reactants between the high-temperature gases and the underlying metal and thus reducing attack by the atmosphere. Typically, these coatings contain {beta}-NiAl as a principal constituent phase in order to have sufficient aluminum content to form an Al{sub 2}O{sub 3} scale at elevated temperatures. The drawbacks to the currently-used {beta}-based coatings, such as phase instabilities, associated stresses induced by such phase instabilities, and extensive coating/substrate interdiffusion, are major motivations in this study to seek next-generation coatings. The high-temperature oxidation resistance of novel Pt + Hf-modified {gamma}-Ni + {gamma}-Ni{sub 3}Al-based alloys and coatings were investigated in this study. Both early-stage and 4-days isothermal oxidation behavior of single-phase {gamma}-Ni and {gamma}{prime}-Ni{sub 3}Al alloys were assessed by examining the weight changes, oxide-scale structures, and elemental concentration profiles through the scales and subsurface alloy regions. It was found that Pt promotes Al{sub 2}O{sub 3} formation by suppressing the NiO growth on both {gamma}-Ni and {gamma}{prime}Ni{sub 3}Al single-phase alloys. This effect increases with increasing Pt content. Moreover, Pt exhibits this effect even at lower temperatures ({approx}970 C) in the very early stage of oxidation. It was also inferred that Pt enhances the diffusive flux of aluminum from the substrate to the scale/alloy interface. Relatively low levels of hafnium addition to Pt-free {gamma}{prime}-Ni{sub 3}Al increased the extent of external NiO formation due to non-protective HfO{sub 2} formation. Accordingly, this effect intensified with increasing Hf content from 0.2 to 0.5 at.%.

Nan Mu

2007-12-01T23:59:59.000Z

45

Shape memory behavior of ultrafine grained NiTi and TiNiPd shape memory alloys  

E-Print Network (OSTI)

The cyclic instability in shape memory characteristics of NiTi-based shape memory alloys (SMAs), such as transformation temperatures, transformation and irrecoverable strains and transformation hysteresis upon thermal and mechanical cycling limits...

Kockar, Benat

2009-05-15T23:59:59.000Z

46

Solid-State Chemistry-Enabled Scalable Production of Octahedral Pt–Ni Alloy Electrocatalyst for Oxygen Reduction Reaction  

Science Journals Connector (OSTI)

Solid-State Chemistry-Enabled Scalable Production of Octahedral Pt–Ni Alloy Electrocatalyst for Oxygen Reduction Reaction ... The commercial viability of the polymer electrolyte membrane fuel cell (PEMFC) technology, despite its great promise in both energy efficiency and environmental control, has been hindered by the development of oxygen reduction reaction (ORR) catalysts. ... (5) Intensive research activities have been conducted in search of active Pt structures in the past years to reach the targets, which led to the development of many types of alloy,(6-12) skin-layer,(13-16) core–shell, and thin-film electrocatalysts. ...

Changlin Zhang; Sang Youp Hwang; Alexis Trout; Zhenmeng Peng

2014-05-14T23:59:59.000Z

47

Promoting Effect of Pt on Self-activation over NiO–MgO Solid Solution in Oxidative Steam Reforming of Methane  

Science Journals Connector (OSTI)

The addition of Pt on NiO–MgO solid solution enhanced the performance of oxidative steam reforming of methane, especially, the catalyst can be activated during the oxidative reforming of methane at low reaction t...

Mohammad Nurunnabi; Baitao Li; Kimio Kunimori; Kimihito Suzuki…

2005-10-01T23:59:59.000Z

48

A High-Throughput Study of PtNiZr Catalysts for Application in PEM Fuel Cells  

SciTech Connect

The effects of adding Zr to PtNi oxygen reduction reaction (ORR) electrocatalyst alloys were examined in a study aimed at probing the possibility of creating catalysts with enhanced resistance to corrosion in a PEM fuel cell environment. Samples consisting of pure Pt or PtNiZr alloys with a range of compositions (not exceeding 11 at.% Zr) were fabricated using co-sputter deposition. A high-throughput fabrication approach was used wherein 18 distinct thin film catalyst alloy samples with varying compositions were deposited onto a large-area substrate with individual Au current collector structures. A multi-channel pseudo-potentiostat allowed for the simultaneous quantitative study of catalytic activity for all 18 electrodes in a single test bath, a first for the study of ORR electrocatalysts. A properly stirred oxygenated 1 M H{sub 2}SO{sub 4} electrolyte solution was used to provide each electrode with a steady-state flow of reactants during electrochemical evaluation. The onset potentials, absolute current density values, and Tafel analysis data obtained using this technique were compared with literature reports. The analyses showed that most PtNiZr alloys tested offered improvements over pure Pt, however those surfaces with a high mole fraction (>4 at.%) of Zr exhibited reduced activity that was roughly inversely correlated to the amount of Zr present. Film composition, morphology, and crystallographic properties were examined using X-ray energy dispersive spectroscopy (XEDS), X-ray photoelectron spectroscopy (XPS), SEM, and synchrotron X-ray diffraction. These data were then correlated with electrochemical data to elucidate the relationships between composition, structure, and relative performance for this ternary system.

Whitacre, J.F.; Valdez, T.I.; Narayanan, S.R.

2009-05-26T23:59:59.000Z

49

Effects of temperature dependent pre-amorphization implantation on NiPt silicide formation and thermal stability on Si(100)  

SciTech Connect

Using temperature controlled Si and C ion implantation, we studied the effects of pre-amorphization implantation on NiPt alloy silicide phase formation. In situ synchrotron x-ray diffraction and resistance measurements were used to monitor phase and morphology evolution in silicide films. Results show that substrate amorphization strongly modulate the nucleation of silicide phases, regardless of implant species. However, morphological stability of the thin films is mainly enhanced by C addition, independently of the amorphization depth.

Ozcan, Ahmet S.; Wall, Donald [IBM Semiconductor Research and Development Center, 2070 Route 52, Hopewell Junction, New York 12533 (United States)] [IBM Semiconductor Research and Development Center, 2070 Route 52, Hopewell Junction, New York 12533 (United States); Jordan-Sweet, Jean; Lavoie, Christian [IBM T. J. Watson Research Center, 1101 Kitchawan Road, Yorktown Heights, New York 10598 (United States)] [IBM T. J. Watson Research Center, 1101 Kitchawan Road, Yorktown Heights, New York 10598 (United States)

2013-04-29T23:59:59.000Z

50

Evidence of spin phonon coupling in magnetoelectric NiFe{sub 2}O{sub 4}/PMN-PT composite  

SciTech Connect

The coupling of phonon with spin in strain coupled magnetoelectric NiFe{sub 2}O{sub 4} (NFO)/0.65Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3}–0.35PbTiO{sub 3} (PMN-PT) composite was investigated by temperature-dependent Raman spectroscopy and magnetic measurements in the range 30–350?°C. Pure NFO shows usual ferromagnetic behaviour in this temperature range while NFO/PMN-PT composite show dramatic change in magnetic moment across ferroelectric transition temperature (T{sub c}???180?°C) of PMN-PT. The temperature evolution of the Raman spectra for the composite shows significant phonon anomalies in T-site (Fe-O) and O-site (Ni/Fe-O) phonon modes at ferroelectric transition temperature is attributed to spin phonon coupling in NFO/PMN-PT composite. The strain mediated magnetoelectric coupling mechanism in this composite is apparent from the observed spin phonon interaction.

Ahlawat, Anju; Satapathy, S., E-mail: srinu73@rrcat.gov.in, E-mail: srinusatapathy@gmail.com; Gupta, P. K. [Nano Functional Materials Laboratory, Laser Materials Development and Devices Division, Raja Ramanna Centre for Advanced Technology, Indore 452013 (India)] [Nano Functional Materials Laboratory, Laser Materials Development and Devices Division, Raja Ramanna Centre for Advanced Technology, Indore 452013 (India); Sathe, V. G.; Choudhary, R. J. [UGC-DAE Consortium for Scientific Research, Indore 452017 (India)] [UGC-DAE Consortium for Scientific Research, Indore 452017 (India)

2013-12-16T23:59:59.000Z

51

Exploitation of a Self-limiting Process for Reproducible Formation of Ultrathin Ni(1-x)Pt(x) Silicide Films  

SciTech Connect

This letter reports on a process scheme to obtain highly reproducible Ni{sub 1-x}Pt{sub x} silicide films of 3-6 nm thickness formed on a Si(100) substrate. Such ultrathin silicide films are readily attained by sputter deposition of metal films, metal stripping in wet chemicals, and final silicidation by rapid thermal processing. This process sequence warrants an invariant amount of metal intermixed with Si in the substrate surface region independent of the initial metal thickness, thereby leading to a self-limiting formation of ultrathin silicide films. The crystallographic structure, thickness, uniformity, and morphological stability of the final silicide films depend sensitively on the initial Pt fraction.

Z Zhang; B Yang; Y Zhu; S Gaudet; S Rossnagel; A Kellock; A Ozcan; C Murray; P Desjardins; et al.

2011-12-31T23:59:59.000Z

52

Mechanisms Associated with Rumpling of Pt-Modified Beta-NiAl Coatings  

SciTech Connect

The formation of surface undulations (i.e. rumpling) at the bond coat/thermally grown oxide (TGO) interface has been shown to cause failure by spallation of the ceramic top coat in aero-turbine systems. Many mechanisms have been proposed concerning the cause of these surface distortions; however, there is little agreement on what may be the dominating cause of the rumpling behavior. Of there mechanisms, the reversible phase transformation from a cubic {beta}-NiAl structure to a face centered tetragonal (FCT) martensitic phase was of particular interest because of its ability to form surface rumpling in Pt-modified {beta} bulk alloys. However, the bulk alloys used in obtaining that result were simple ternary systems and not relevant to actual coating compositions as other alloying elements enter the coating due to coating/substrate interdiffusion at high temperature. In the current study, the depletion behavior of a commercial coating was studied. Compositions from the depletion path were determined and bulk alloys representing these coating compositions were prepared. The martensitic phase transformation was then characterized using DSC and XRD. The martensitic start temperature on cooling, Ms, was consistently found to be significantly lower than previously reported values (e.g. 530 C vs 100 C). Because of the low Ms temperature, the formation of the martensitic phase was concluded to be unnecessary for the occurrence of rumpling. However, cyclic exposure treatments at low temperature ({approx} 400 C) of bulk alloys and commercial coatings did show the detrimental effects of the phase transformation in the form of crack formation and propagation leading to eventual failure of the alloys. The current work also infers that the differences in coefficient of thermal expansion (CTE) mismatch between the coating and substrate are the dominating factor leading to rumpling. Dilatometry measurements were made on bulk alloys representing depleted coatings and the superalloy substrate to determine CTE as a function of temperature. Finally, simulations were completed to help determine the role of CTE mismatch. It was found that these results compared closely to those collected during experimental cyclic exposure treatments; although, modification to the current model were found to be needed in order to truly simulate rumpling.

Joseph Peter Henderkott

2007-12-01T23:59:59.000Z

53

A theoretical study of the electronic structure of Invar Fe*3Pt and related materials  

SciTech Connect

The Full Potential Linear Augmented Plane Wave (FPLAPW or FLAPW) method is used for a spin-polarized band calculation for ordered Fe{sub 3}Pt. As major purpose, the momentum distributions of the spin-polarized electrons are calculated and compared with results from a magnetic Compton scattering measurement. To get related information, the electronic behavior is also analyzed by examining the partial densities of states and the spatial electron distributions; the role of alloying effects is then explored by studying the electrons in some related alloys: Fe{sub 3}Ni, Fe{sub 3}Pd, Ni{sub 3}Pt and Co{sub 3}Pt.

Zuo, Zhiqi

1997-01-10T23:59:59.000Z

54

PdNi Hollow Nanoparticles for Improved Electrocatalytic Oxygen Reduction in Alkaline Environments  

Science Journals Connector (OSTI)

The electrocatalyst is finally examined in a H2/O2 alkaline anion exchange membrane fuel cell; the results show that such electrocatalysts could work in a real fuel cell application as a more efficient catalyst than state-of-the-art commercially available Pt/C. ... (3-5) It has been well documented that the overpotential for the ORR will be significantly reduced in a high pH (alkaline) environment, thus offering the possibilities of lower usage and wider selection of electrocatalysts other than platinum to be available for this catalytic reaction,(6, 7) while recent advances in the development of alkaline anion exchange membranes (AAEMs) have also seen the performance of the anion exchange membrane fuel cell (AEMFC) approach that of the analogous, conventional acidic Nafion proton exchange membrane fuel cell (PEMFC). ... (8-10) This adds further incentive to the need to develop novel nanostructured electrocatalysts for the ORR in the alkaline medium. ...

Meng Wang; Weimin Zhang; Jiazhao Wang; David Wexler; Simon D. Poynton; Robert C.T. Slade; Huakun Liu; Bjorn Winther-Jensen; Robert Kerr; Dongqi Shi; Jun Chen

2013-11-07T23:59:59.000Z

55

A new class of amorphous cathode active material LixMyPOz (M = Ni, Cu, Co, Mn, Au, Ag, Pd)  

Science Journals Connector (OSTI)

Abstract A new class of amorphous cathode active material LixMyPOz (LiMPO) is proposed. The materials are sputter deposited to thin film form by Li3PO4 together with metal or metal oxide targets. Among several materials tested as thin-film battery, working material found are M = Ni, Cu, Co, Mn, Au, Ag, Pd. The property is intensively studied for LixCuyPOz (LiCuPO) and LixNiyPOz (LiNiPO). Those materials shows wide composition margin such as composition y between 1 and 3, and high capacity for LiNiPO with maximum value of 330 mAh g?1. The capability to charge and discharge at high rate is shown up to 30 C. This preliminary report reveals its high potentiality for further optimization.

Yuichi Sabi; Susumu Sato; Saori Hayashi; Tatsuya Furuya; Susumu Kusanagi

2014-01-01T23:59:59.000Z

56

Mechanism for Oxygen Reduction Reaction on Pt3Ni Alloy Fuel Cell Cathode  

Science Journals Connector (OSTI)

The efficiency of the oxygen reduction reaction (ORR), 4H+ + 4e– + O2 ? 2H2O, at the cathode of a polymer electrolyte membrane fuel cell (PEMFC) is a critical issue for commercial application of this type of fuel cells. ... This agrees with the volcano-like trend for ORR catalysts,(7, 31, 32) when the activity first increases and then decreases as the catalyst d-band center shifts downward. ... Improved Non-Pt Alloys for the Oxygen Reduction Reaction at Fuel Cell Cathodes Predicted from Quantum Mechanics ...

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

2012-09-04T23:59:59.000Z

57

Surface tension-driven shape-recovery of micro/nanometer-scale surface features in a Pt(57.5)Ni(5.3)Cu(14.7)P(22.5) metallic glass in the supercooled liquid region: A numerical modeling capability  

E-Print Network (OSTI)

Recent experiments in the literature show that micro/nano-scale features imprinted in a Pt-based metallic glass, Pt57.5Ni5.3Cu14.7P22.5 [Pt subscript 57.5 Ni subscript 5.3 Cu subscript 14.7 P subscript 22.5], using ...

Henann, David Lee

58

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

SciTech Connect

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

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

1995-12-31T23:59:59.000Z

59

Exploitation of a self-limiting process for reproducible formation of ultrathin Ni{sub 1-x}Pt{sub x} silicide films  

SciTech Connect

This letter reports on a process scheme to obtain highly reproducible Ni{sub 1-x}Pt{sub x} silicide films of 3-6 nm thickness formed on a Si(100) substrate. Such ultrathin silicide films are readily attained by sputter deposition of metal films, metal stripping in wet chemicals, and final silicidation by rapid thermal processing. This process sequence warrants an invariant amount of metal intermixed with Si in the substrate surface region independent of the initial metal thickness, thereby leading to a self-limiting formation of ultrathin silicide films. The crystallographic structure, thickness, uniformity, and morphological stability of the final silicide films depend sensitively on the initial Pt fraction.

Zhang Zhen; Zhu Yu; Rossnagel, Steve; Murray, Conal; Jordan-Sweet, Jean [IBM T.J. Watson Research Center, Yorktown Heights, New York 10598 (United States); Yang, Bin [GlobalFoundries, Inc., T.J. Watson Research Center, Yorktown Heights, New York 10598 (United States); Gaudet, Simon; Desjardins, Patrick [Ecole Polytechnique de Montreal, Montreal, Quebec H3C 3A7 (Canada); Kellock, Andrew J. [IBM Almaden Research Center, San Jose, California 95120 (United States); Ozcan, Ahmet [IBM Microelectronics, Hopewell Junction, New York 12533 (United States); Zhang Shili [Solid-State Electronics, The Angstroem Laboratory, Uppsala University, Box 534, SE-751 21 Uppsala (Sweden); Lavoie, Christian [IBM T.J. Watson Research Center, Yorktown Heights, New York 10598 (United States); Ecole Polytechnique de Montreal, Montreal, Quebec H3C 3A7 (Canada)

2010-12-20T23:59:59.000Z

60

Element-specific structure of materials with intrinsic disorder by high-energy resonant x-ray diffraction and differential atomic pair-distribution functions: A study of PtPd nanosized catalysts  

Science Journals Connector (OSTI)

We demonstrate how high-energy resonant x-ray diffraction (XRD) and differential atomic-pair-distribution function (PDF) analysis can be used to characterize the atomic ordering in materials of limited structural coherence with both excellent spatial resolution and element specificity. First we prove that this experimental approach is feasible by probing the K-absorption edge of Au(?81?keV) atoms in chemically ordered and disordered bulk Cu3Au alloys. The resulting Au-differential PDFs show very clearly the different ways Au atoms are known to occupy the sites of otherwise identical cubic lattices of those materials. Next we apply it to a more complex material: PtPd alloy and core-shell nanosized (?2–4?nm) particles by probing the K-absorption edge of Pt(?78?keV). The resulting Pt-differential atomic PDFs reveal how exactly the atomic ordering of catalytically active Pt atoms is affected by the nanoparticles’ design, thus providing a firm structural basis for understanding their properties. The work is a step forward in expanding the limits of applicability of nontraditional XRD to the rapidly growing field of materials of unusual structural complexity.

V. Petkov and S. D. Shastri

2010-04-21T23:59:59.000Z

Note: This page contains sample records for the topic "ni pd pt" 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

Electrical properties of thin-film structures formed by pulsed laser deposition of Au, Ag, Cu, Pd, Pt, W, Zr metals on n-6H-SiC crystal  

SciTech Connect

Diode structures with ideality factors of 1.28-2.14 and potential barriers from 0.58 to 0.62 eV on the semiconductor side were formed by pulsed laser deposition of Au, Ag, Cu, Pd, Pt, W, and Zr metal films on n-6H-SiC crystal without epitaxial layer preparation. A high density of surface acceptor and donor states was formed at the metal-semiconductor interface during deposition of the laser-induced atomic flux, which violated the correlation between the potential barrier height and metal work function. The barrier heights determined from characteristic currents and capacitance measurements were in quite good agreement. For the used low-resistance semiconductor and contact elements, the sizes of majority carrier (electron) depletion regions were determined as 26-60 nm.

Romanov, R. I.; Zuev, V. V.; Fominskii, V. Yu., E-mail: vyfominskij@mephi.ru; Demin, M. V.; Grigoriev, V. V. [MEPhI National Research Nuclear University (Russian Federation)

2010-09-15T23:59:59.000Z

62

Oxidation of Methanol on 2nd and 3rd Row Group VIII Transition Metals (Pt, Ir, Os, Pd, Rh, and Ru): Application to Direct Methanol  

E-Print Network (OSTI)

to electric energy in a hydrogen/oxygen fuel cell was demon- strated. Although hydrogen/oxygen fuel cells): Application to Direct Methanol Fuel Cells Jeremy Kua and William A. Goddard III* Contribution from and designing new catalysts. We find that methanol dehydrogenation is most facile on Pt, with the hydrogens

Goddard III, William A.

63

Quantum Critical Behavior in the Heavy Fermion Single Crystal Ce(Ni0.935Pd0.065)2Ge2  

SciTech Connect

We have performed magnetic susceptibility, specific heat, resistivity, and inelastic neutron scattering measurements on a single crystal of the heavy Fermion compound Ce(Ni{sub 0.935}Pd{sup 0.065}){sub 2}Ge{sub 2}, which is believed to be close to a quantum critical point (QCP) at T = 0. At lowest temperature (1.8--3.5 K), the magnetic susceptibility behaves as {chi}(T)-{chi} (0) {proportional_to} T{sup -1/6} with {chi} (0) = 0.032 x 10{sup -6} m{sup 3}/mole (0.0025 emu/mole). For T < 1 K, the specific heat can be fit to the formula {Delta} C/T = {gamma}{sub 0} - T{sup 1/2} with {gamma}{sub 0} of order 700 mJ/mole-K{sup 2}. The resistivity behaves as {rho} = {rho}{sub 0} + AT{sup 3/2} for temperatures below 2 K. This low temperature behavior for {gamma} (T) and {rho} (T) is in accord with the SCR theory of Moriya and Takimoto. The inelastic neutron scattering spectra show a broad peak near 1.5 meV that appears to be independent of Q; we interpret this as Kondo scattering with T{sub K} = 17 K. In addition, the scattering is enhanced near Q=(1/2, 1/2, 0) with maximum scattering at {Delta} E = 0.45 meV{sup -}; we interpret this as scattering from antiferromagnetic fluctuations near the antiferromagnetic QCP.

Wang, Cuihuan [ORNL; Lawrence, J M [University of California, Irvine; Christianson, Andrew D [ORNL; Chang, S [NIST Center for Neutron Research (NCRN), Gaithersburg, MD; Bauer, E D [Los Alamos National Laboratory (LANL); Gofryk, K [Los Alamos National Laboratory (LANL); Ronning, F [Los Alamos National Laboratory (LANL); Thompson, J D [Los Alamos National Laboratory (LANL); McClellan, K J [Los Alamos National Laboratory (LANL); Rodriguez-Rivera, J A [NCNR and University of Maryland; Lynn, J W [NIST Center for Neutron Research (NCRN), Gaithersburg, MD

2011-01-01T23:59:59.000Z

64

Durable pd-based alloy and hydrogen generation membrane thereof  

DOE Patents (OSTI)

A durable Pd-based alloy is used for a H.sub.2-selective membrane in a hydrogen generator, as in the fuel processor of a fuel cell plant. The Pd-based alloy includes Cu as a binary element, and further includes "X", where "X" comprises at least one metal from group "M" that is BCC and acts to stabilize the .beta. BCC phase for stability during operating temperatures. The metal from group "M" is selected from the group consisting of Fe, Cr, Nb, Ta, V, Mo, and W, with Nb and Ta being most preferred. "X" may further comprise at least one metal from a group "N" that is non-BCC, preferably FCC, that enhances other properties of the membrane, such as ductility. The metal from group "N" is selected from the group consisting of Ag, Au, Re, Ru, Rh, Y, Ce, Ni, Ir, Pt, Co, La and In. The at. % of Pd in the binary Pd--Cu alloy ranges from about 35 at. % to about 55 at. %, and the at. % of "X" in the higher order alloy, based on said binary alloy, is in the range of about 1 at. % to about 15 at. %. The metals are selected according to a novel process.

Benn, Raymond C. (Madison, CT); Opalka, Susanne M. (Glastonbury, CT); Vanderspurt, Thomas Henry (Glastonbury, CT)

2010-02-02T23:59:59.000Z

65

Regional distribution and sources of Au, Pd and Pt in moss and O-,B- and C-horizon podzol samples in the European Arctic  

Science Journals Connector (OSTI)

...the traditional fire assay methods (classical Pb or NiS fire assay) are prone...ICP-MS) can be used. Fire assay methods are...have been used to release the PGEs from the...of the till fine fraction (mm) in northern...short-term anthropogenic airborne deposition of heavy...

H. Niskavaara; E. Kontas; C. Reimann

66

Regional distribution and sources of Au, Pd and Pt in moss and O-,B- and C-horizon podzol samples in the European Arctic  

Science Journals Connector (OSTI)

...P.O. Box 77, FIN-96101...traditional fire assay methods...Pb or NiS fire assay) are...be used. Fire assay methods...been used to release the PGEs from...till fine fraction (mm) in...anthropogenic airborne deposition...talcum-free rubber gloves) through...definition (box from 25th...

H. Niskavaara; E. Kontas; C. Reimann

67

Search for protons from the H2(d,p)3H reaction in an electrolytic cell with Pd-Pt electrodes  

Science Journals Connector (OSTI)

The production of protons from the H2(d,p)3H reaction was investigated using an electrolytic cell and a proportional counter. The cathode, consisting of a 30.5-mg/cm2-thick Pd foil, separated the gas in the counter from the electrolyte (0.1M LiOD in D2O). The efficiency for proton detection was 28%. The electrolytic cell was operated with current densities up to 650 mA/cm2. Several runs with the current switched on and off and with different Pd foils have been performed with the longest run lasting more than 10 days. No difference in the count rate was observed when the electrolytic cell was on or off. From the high-energy part of the particle spectrum we obtain an upper limit for the proton production from the fusion reaction H2(d,p)3H of 4×10-23 fusion/(dd pair/sec).

K. E. Rehm; W. Kutschera; G. J. Perlow

1990-01-01T23:59:59.000Z

68

An analysis of the pull strength behaviors of fine-pitch, flip chip solder interconnections using a Au-Pt-Pd thick film conductor on Low-Temperature, Co-fired Ceramic (LTCC) substrates.  

SciTech Connect

The assembly of the BDYE detector requires the attachment of sixteen silicon (Si) processor dice (eight on the top side; eight on the bottom side) onto a low-temperature, co-fired ceramic (LTCC) substrate using 63Sn-37Pb (wt.%, Sn-Pb) in a double-reflow soldering process (nitrogen). There are 132 solder joints per die. The bond pads were gold-platinum-palladium (71Au-26Pt-3Pd, wt.%) thick film layers fired onto the LTCC in a post-process sequence. The pull strength and failure modes provided the quality metrics for the Sn-Pb solder joints. Pull strengths were measured in both the as-fabricated condition and after exposure to thermal cycling (-55/125 C; 15 min hold times; 20 cycles). Extremely low pull strengths--referred to as the low pull strength phenomenon--were observed intermittently throughout the product build, resulting in added program costs, schedule delays, and a long-term reliability concern for the detector. There was no statistically significant correlation between the low pull strength phenomenon and (1) the LTCC 'sub-floor' lot; (2) grit blasting the LTCC surfaces prior to the post-process steps; (3) the post-process parameters; (4) the conductor pad height (thickness); (5) the dice soldering assembly sequence; or (5) the dice pull test sequence. Formation of an intermetallic compound (IMC)/LTCC interface caused by thick film consumption during either the soldering process or by solid-state IMC formation was not directly responsible for the low-strength phenomenon. Metallographic cross sections of solder joints from dice that exhibited the low pull strength behavior, revealed the presence of a reaction layer resulting from an interaction between Sn from the molten Sn-Pb and the glassy phase at the TKN/LTCC interface. The thick film porosity did not contribute, explicitly, to the occurrence of reaction layer. Rather, the process of printing the very thin conductor pads was too sensitive to minor thixotropic changes to ink, which resulted in inconsistent proportions of metal and glassy phase particles present during the subsequent firing process. The consequences were subtle, intermittent changes to the thick film microstructure that gave rise to the reaction layer and, thus, the low pull strength phenomenon. A mitigation strategy would be the use of physical vapor deposition (PVD) techniques to create thin film bond pads; this is multi-chip module, deposited (MCM-D) technology.

Uribe, Fernando R.; Kilgo, Alice C.; Grazier, John Mark; Vianco, Paul Thomas; Zender, Gary L.; Hlava, Paul Frank; Rejent, Jerome Andrew

2008-09-01T23:59:59.000Z

69

Fabrication and local laser heating of freestanding Ni{sub 80}Fe{sub 20} bridges with Pt contacts displaying anisotropic magnetoresistance and anomalous Nernst effect  

SciTech Connect

In spin caloritronics, ferromagnetic samples subject to relatively large in-plane temperature gradients ?T have turned out to be extremely interesting. We report on a preparation technique that allows us to create freely suspended permalloy/Pt hybrid structures where a scanning laser induces ?T on the order of a few K/?m. We observe both the anisotropic magnetoresistance at room temperature and the magnetic field dependent anomalous Nernst effect under laser heating. The technique is promising for the realization of device concepts considered in spin caloritronics based on suspended ferromagnetic nanostructures with electrical contacts.

Brandl, F.; Grundler, D., E-mail: grundler@ph.tum.de [Lehrstuhl für Physik funktionaler Schichtsysteme, Physik-Department E10, Technische Universität München, James-Franck-Str. 1, D-85748 Garching b. München (Germany)

2014-04-28T23:59:59.000Z

70

Effect of Spin-Crossover-Induced Pore Contraction on CO{sub 2}-Host Interactions in the Porous Coordination Polymers [Fe(pyrazine)M(CN){sub 4}] (M = Ni, Pt)  

SciTech Connect

Variable-temperature in situ ATR-FTIR spectra are presented for the porous spin-crossover compounds [Fe(pyrazine)- Ni(CN){sub 4}] and [Fe(pyrazine)Pt(CN){sub 4}] under CO{sub 2} pressures of up to 8 bar. Significant shifts in the ?{sub 3} and ?{sub 2} IR absorption bands of adsorbed CO{sub 2} are observed as the host materials undergo transition between low- and high-spin states. Computational models used to determine the packing arrangement of CO{sub 2} within the pore structures show a preferred orientation of one of the adsorbed CO{sub 2} molecules with close O=C=O···H contacts with the pyrazine pillar ligands. The interaction is a consequence of the commensurate distance of the inter-pyrazine separations and the length of the CO{sub 2} molecule, which allows the adsorbed CO{sub 2} to effectively bridge the pyrazine pillars in the structure. The models were used to assign the distinct shifts in the IR absorption bands of the adsorbed CO{sub 2} that arise from changes in the O=C=O···H contacts that strengthen and weaken in correlation with changes in the Fe–N bond lengths as the spin state of Fe changes. The results indicate that spin-crossover compounds can function as a unique type of flexible sorbent in which the pore contractions associated with spin transition can affect the strength of CO{sub 2}–host interactions.

Culp, Jeffrey T.; Chen, De-Li; Liu, Jinchen; Chirdon, Danielle; Kauffman, Kristi; Goodman, Angela; Johnson, J. Karl

2013-02-01T23:59:59.000Z

71

E-Print Network 3.0 - ag-pt alloy nanoparticles Sample Search...  

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

13 JANUARY 2010 | DOI: 10.1038NMAT2490 A general phase-transfer protocol for metal ions Summary: by BSPP treatment of Ag@Pt nanoparticles. (16) Ag-Pd alloy synthesized by the...

72

LEED crystallography studies of the structure of clean and adsorbate-covered Ir, Pt and Rh crystal surfaces  

SciTech Connect

There have only been a few Low Energy Electron Diffraction (LEED) intensity analyses carried out to determine the structure of molecules adsorbed on metal surfaces; most surface crystallography studies concentrated on the structure of clean unreconstructed or atomic adsorbate-covered transition metal faces. The few molecular adsorption systems already investigated by dynamical LEED are CO on Ni(100), Cu(100) and Pd(100) as well as C/sub 2/H/sub 2/ and C/sub 2/H/sub 4/ adsorbed on Pt(111). The emphasis of this thesis research has been to extend the applicability of LEED crystallography to the more complicated unit cells found in molecular overlayers on transition metals or in there constructed surfaces of clean transition metals.

Koestner, R.J.

1982-08-01T23:59:59.000Z

73

Investigation of the electrocatalysis for oxygen reduction reaction by Pt and binary Pt alloys: an XRD, XAS and electrochemical study  

SciTech Connect

Electrocatalysis for the oxygen reduction reaction (ORR) on five binary Pt alloy electrocatalysts (PtCr/C, PtMn/C, PtFe/C, PtCo/C and PtNi/C) supported on carbon have been investigated. The electrochemical characteristics for ORR in a proton conducting fuel cell environment has been correlated with the electronic and structural parameters determined under in situ conditions using XANES and EXAFS technique respectively. Results indicate that all the alloys possess higher Pt 5d band vacancies as compared to Pt/C. There is also evidence of lattice contraction in the alloys (supported by XRD results). Further, the Pt/C shows increase in Pt 5 d band vacancies during potential transitions from 0.54 to 0.84 V vs. RHE, which has been ration@ on the basis of OH type adsorption. In contrast to this, the alloys do not exhibit such an enhancement. Detailed EXAFS analysis supports the presence of OH species on Pt/C and its relative absence in the alloys. Correlation of the electrochemical results with bond distances and d-band vacancies show a volcano type behavior with the PtCr/C on top of the curve.

Mukerjee, S.; McBreen, J. [Brookhaven National Lab., Upton, NY (United States); Srinivasan, S. [Texas A and M Univ., College Station, TX (United States). Texas Engineering Experiment Station

1995-12-31T23:59:59.000Z

74

Kinetic studies of methane steam reforming on ceria-supported Pd  

Science Journals Connector (OSTI)

Steady-state, steam-reforming rates for methane were measured on model and high-surface-...5...and were higher even than rates reported in the literature for Ni catalysts. Model catalysts prepared with Pt or Rh o...

R. Craciun; B. Shereck; R.J. Gorte

75

Novel Mg-rich materials for hydrogen storage: bulk and nanoconfined Mg6Pd1-xTMx  

E-Print Network (OSTI)

Novel Mg-rich materials for hydrogen storage: bulk and nanoconfined Mg6Pd1-xTMx (TM = Ni, Ag, Cu for hydrogen storage: bulk and nanoconfined Mg6Pd1-xTMx (TM = Ni, Ag, Cu) compounds and MgH2-TiH2 on Hydrogen Storage) and in Warsaw (E-MRS Fall Meeting). I would like to share this PhD thesis with all

Paris-Sud XI, Université de

76

Synthesis and characterization of Pd(0), PdS, and Pd-PdO core-shell nanoparticles by solventless thermolysis of a Pd-thiolate cluster  

SciTech Connect

Colloids of palladium nanoparticles have been prepared by the solvated metal atom dispersion (SMAD) method. The as-prepared Pd colloid consists of particles with an average diameter of 2.8{+-}0.1 nm. Digestive ripening of the as-prepared Pd colloid, a process involving refluxing the as-prepared colloid at or near the boiling point of the solvent in the presence of a passivating agent, dodecanethiol resulted in a previously reported Pd-thiolate cluster, [Pd(SC{sub 12}H{sub 25}){sub 2}]{sub 6} but did not render the expected narrowing down of the particle size distribution. Solventless thermolysis of the Pd-thiolate complex resulted in various Pd systems such as Pd(0), PdS, and Pd-PdO core-shell nanoparticles thus demonstrating its versatility. These Pd nanostructures have been characterized using high-resolution electron microscopy and powder X-ray diffraction methods. - Graphical abstract: Solventless thermolysis of a single palladium-thiolate cluster affords various Pd systems such as Pd(0), Pd-PdO core-shell, and PdS nanoparticles demonstrating the versatility of the precursor and the methodology.

Jose, Deepa [Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore 560 012 (India); Jagirdar, Balaji R., E-mail: jagirdar@ipc.iisc.ernet.i [Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore 560 012 (India)

2010-09-15T23:59:59.000Z

77

JUNE 13-PD.xlsx  

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

Object Name 17-PD 040997 D1 REMEDIAL DESIGN FOR WAGS 1 AND 7 RECORD OF DECISION DOE-PAD KDEP, USEPA-4 No I-00515-0006 17-PD 050997 COMMENTS ON THE REMEDIAL DESIGN FOR...

78

IEEE TRANSACTIONS ON MAGNETICS, VOL. 38, NO. 4, JULY 2002 1803 New Ni5Al3 Underlayer for Longitudinal  

E-Print Network (OSTI)

IEEE TRANSACTIONS ON MAGNETICS, VOL. 38, NO. 4, JULY 2002 1803 New Ni5Al3 Underlayer--We describe a new Ni5Al3 underlayer for high-den- sity longitudinal magnetic recording. The Ni5Al3 underlayer has the FCC derivative Ga3Pt5 structure. The Ni5Al3 (221) plane has good lattice match with the Co

Laughlin, David E.

79

Oxygen Reduction Activity of PtxNi1-x Alloy Nanoparticles on Multiwall Carbon Nanotubes  

E-Print Network (OSTI)

PtxNi1 - x nanoparticles (Pt:Ni; 1:0, 4:1, 3:1 and 0.7:1) of ~5 nm, were synthesized on carboxylic acid-functionalized multiwall carbon nanotubes (PtxNi1 - x NPs/MWNT). The oxygen reduction reaction (ORR) activity measurements ...

Kim, Junhyung

80

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

Note: This page contains sample records for the topic "ni pd pt" 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

Highly durable graphene nanoplatelets supported Pt nanocatalysts...  

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

durable graphene nanoplatelets supported Pt nanocatalysts for oxygen reduction . Highly durable graphene nanoplatelets supported Pt nanocatalysts for oxygen reduction . Abstract:...

82

Effect of palladium addition on catalytic activity in steam methane reforming over Ni-YSZ porous membrane  

Science Journals Connector (OSTI)

Abstract This study investigated the additive effects of palladium, and the deposition method of palladium on Ni-YSZ porous membrane in steam methane reforming. Pd–Ni-YSZ porous membrane prepared by the wet impregnation method showed superior catalytic activity, where the methane conversion reached 94.6% at 650 °C, with H2 yield above 3.9. The palladium particles were well dispersed, and the Pd–Ni-YSZ porous membrane exhibited high adsorption capacity for water. The addition of palladium and the deposition method of palladium are very important for the steam methane reforming reaction.

Sang Moon Lee; Sung Chang Hong

2014-01-01T23:59:59.000Z

83

Infrared study on the adsorption of CO and NO on silica-supported Pd and Pt-Pd  

SciTech Connect

The IR spectra of NO adsorbed on silica-supported palladium had bands at 1735 and 1645/cm, which were assigned to linearly bound NO and to NO linearly bound to low-coordinated palladium, respectively. Bands at 1980 and 2070/cm in the spectrum of CO adsorbed on palladium were assigned multiply coordinated and linear CO, respectively. Carbon monoxide was completely displaced from palladium by nitric oxide, preadsorbed nitric oxide was partly displaced from palladium by carbon monoxide, and carbon dioxide and nitrous oxide were formed in both processes. A band at 2180/cm provided evidence for adsorbed isocyanate species. All bands shifted to higher frequencies by approx. 10/cm for 1:1 palladium/platinum bimetallic clusters; the carbon monoxide was readily removed by evacuating at room temperature, a fact that my be used in catalyst surface area determinations.

Grill, C.M.; Gonzalez, R.D.

1980-04-17T23:59:59.000Z

84

Pd oxidation under UHV in a model Pd/ceria–zirconia catalyst  

Science Journals Connector (OSTI)

A model planar catalyst was prepared by depositing Pd onto a thick (few ?m) film of ceria–zirconia in ultrahigh vacuum (UHV), and the oxidation state of Pd ... -ray photoelectron spectroscopy, following thermal t...

M.Yu. Smirnov; G.W. Graham

2001-03-01T23:59:59.000Z

85

Hydrogen Dissociation on Pd4S Surfaces  

SciTech Connect

Exposure of Pd-based hydrogen purification membranes to H,S. a common contaminant in coal gasification streams, can cause membrane performance to deteriorate, either by deactivating surface sites required for dissociative H, adsorption or by forming a low-permeability sulfide scale. In this work. the composition, structure, and catalytic activity of Pd4S, a surface scale commonly observed in Pd-membrane separation of hydrogen from sulfur-containing gas streams, were examined using a combination of experimental characterization and density functional theory (DFT) calculations. A Pd,S sample was prepared by exposing a 100 f1m Pd foil to H2S at 908 K. Both X-ray photoemission depth profiling and low energy ion scattering spectroscopic (LEISS) analysis reveal slight sulfur-enrichment of the top surface of the sample. This view is consistent with the predictions of DFT atomistic thermodynamic calculations. which identified S-terminated Pd,S surfaces as energetically favored over corresponding Pd-terminated surfaces. Activation barriers for H2 dissociation on the Pd,S surfaces were calculated. Although barriers are higher than on Pd(lll). transition state theory analysis identified reaction pathways on the S-terminated surfaces for which hydrogen dissociation rates are high enough to sustain the separation process at conditions relevant to gasification applications.

Miller, J.B.; Alfonso, D.R.; Howard, B.H.; O'Brien, C.P.; Morreale, B.D.

2009-01-01T23:59:59.000Z

86

Antimagnetic rotation in 104Pd  

Science Journals Connector (OSTI)

The electric quadrupole transition rates for the high-spin yrast states of 104Pd have been measured by using the Doppler-shift attenuation method. These values decrease with the increase of angular momentum, which can be associated with the phenomenon of antimagnetic rotation. In the present work, a numerical calculation based on the semiclassical particle plus rotor model for antimagnetic rotation has been employed, giving a good description of the experimental Routhian and the transition rates and providing conclusive evidence of antimagnetic rotation in a nucleus other than cadmium.

N. Rather; S. Roy; P. Datta; S. Chattopadhyay; A. Goswami; S. Nag; R. Palit; S. Pal; S. Saha; J. Sethi; T. Trivedi; H. C. Jain

2014-06-10T23:59:59.000Z

87

UCSF PD Emergency Management Division UCSF PD Website: http://police.ucsf.edu/  

E-Print Network (OSTI)

UCSF PD Emergency Management Division UCSF PD Website: http://police.ucsf.edu/ Emergency Kit 2014.doc Version Date: 02 2014 Emergency Preparedness Kit Suggestions You can purchase premade emergency kits and supplies. UCSF PD has contracted with Your Safety Place to offer specially priced disaster

Derisi, Joseph

88

Phase equilibria, formation, crystal and electronic structure of ternary compounds in Ti-Ni-Sn and Ti-Ni-Sb ternary systems  

SciTech Connect

The phase equilibria of the Ti-Ni-Sn and Ti-Ni-Sb ternary systems have been studied in the whole concentration range by means of X-ray and EPM analyses at 1073 K and 873 K, respectively. Four ternary intermetallic compounds TiNiSn (MgAgAs-type), TiNi{sub 2-x}Sn (MnCu{sub 2}Al-type), Ti{sub 2}Ni{sub 2}Sn (U{sub 2}Pt{sub 2}Sn-type), and Ti{sub 5}NiSn{sub 3} (Hf{sub 5}CuSn{sub 3}-type) are formed in Ti-Ni-Sn system at 1073 K. The TiNi{sub 2}Sn stannide is characterized by homogeneity in the range of 50-47 at% of Ni. The Ti-Ni-Sb ternary system at 873 K is characterized by formation of three ternary intermetallic compounds, Ti{sub 0.8}NiSb (MgAgAs-type), Ti{sub 5}Ni{sub 0.45}Sb{sub 2.55} (W{sub 5}Si{sub 3}-type), and Ti{sub 5}NiSb{sub 3} (Hf{sub 5}CuSn{sub 3}-type). The solubility of Ni in Ti{sub 0.8}NiSb decreases number of vacancies in Ti site up to Ti{sub 0.91}Ni{sub 1.1}Sb composition. - Graphical abstract: Isothermal section of the Ti-Ni-Sn phase diagram and DOS distribution in hypothetical TiNi{sub 1+x}Sn solid solution. Highlights: Black-Right-Pointing-Pointer Ti-Ni-Sn phase diagram was constructed at 1073 K. Black-Right-Pointing-Pointer Four ternary compounds are formed: TiNiSn, TiNi{sub 2-x}Sn, Ti{sub 2}Ni{sub 2}Sn, and Ti{sub 5}NiSn{sub 3}. Black-Right-Pointing-Pointer Three ternary compounds exist in Ti-Ni-Sb system at 873 K. Black-Right-Pointing-Pointer The TiNi{sub 2}Sb compound is absent.

Romaka, V.V., E-mail: romakav@yahoo.com [Department of Materials Engineering and Applied Physics, Lviv Polytechnic National University, Ustyyanovycha Str. 5, 79013 Lviv (Ukraine); Rogl, P. [Institut fur Physikalische Chemie der Universitat Wien, Wahringerstrabe 42, A-1090 Wien (Austria); Romaka, L.; Stadnyk, Yu. [Department of Inorganic Chemistry, Ivan Franko National University of Lviv, Kyryla and Mefodiya Str. 6, 79005 Lviv (Ukraine); Melnychenko, N.; Grytsiv, A.; Falmbigl, M. [Institut fur Physikalische Chemie der Universitat Wien, Wahringerstrabe 42, A-1090 Wien (Austria); Skryabina, N. [Perm State University, Bukireva Str. 15, 614990 Perm (Russian Federation)

2013-01-15T23:59:59.000Z

89

Interaction of CO with Surface PdZn Alloys. | EMSL  

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

Pd(111) surface resulting in the formation of an ordered surface PdZn alloy. Carbon monoxide was found to bond more weakly to the ZnPd(111) alloy surfaces compared to clean...

90

Development and characterization of PdCr temperature-compensaated wire resistance strain gage  

SciTech Connect

A temperature-compensated resistance static strain gage with potential to be used to 600 C was recently developed. Gages were fabricated from specially developed palladium-13 w/o chromium (Pd-13Cr) wire and platinum (Pt) compensator. When bonded to high temperature Hastelloy X, the apparent strain from room temperature to 600 C was within 400 microstrain for gages with no preheat treatment and within 3500 microstrain for gages with 16 hours prestabilization at 640 C. The apparent strain versus temperature relationship of stabilized PdCr gages were repeatable with the reproducibility within 100 microstrain during three thermal cycles to 600 C and an 11 hours soak at 600 C. The gage fabrication, construction and installation is described. Also, the coating system used for this compensated resistance strain gage is explained. The electrical properties of the strain sensing element and main characteristics of the compensated gage including apparent strain, drift and reproducibility are discussed.

Lei, J.F.

1989-10-01T23:59:59.000Z

91

Morphological Stability and Specific Resistivity of sub-10 nm Silicide Films of Ni1 xPtx on Si Substrate  

SciTech Connect

This letter studies the morphological stability and specific resistivity of sub-10 nm silicide films of Ni, Ni{sub 0.95}Pt{sub 0.05}, and Ni{sub 0.9}Pt{sub 0.1} formed on Si(100) substrate. When the deposited metal films are below 1 to 4 nm in thickness depending on the Pt content, the resultant silicide films tend to become epitaxially aligned to the Si substrate and hence exhibit an extraordinary morphological stability up to 800 C. The presence of Pt in the silicides increases the film resistivity through alloy scattering, but alleviates, owing to a reduced electron mean free path, the frequently encountered sharp increase in resistivity in the sub-10 nm regime.

Zhang, Z.; Zhang, S; Yang, B; Zhu, Y; Rossnagel, S; Gaudet, S; Kellock, A; Jordan-Sweet, J; Lavoie, C

2010-01-01T23:59:59.000Z

92

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

Science Journals Connector (OSTI)

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

Partho Sarothi Roy; No-Kuk Park; Kiseok Kim

2014-01-01T23:59:59.000Z

93

Pt Reyes 2005: MASRAD, MASE  

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

Q. Min, C. Berkowitz, J. Wang, E. Andrews, C. Chiu, M. Jensen, N. Riemer , J. Ching, L. Berg, A. S. Frisch, M. Bartholomew, B. Kim, M. Dunn, P. Kollias, B. Albrecht, ... Pt....

94

Invisibility and PT-symmetry  

E-Print Network (OSTI)

For a general complex scattering potential defined on a real line, we show that the equations governing invisibility of the potential are invariant under the combined action of parity and time-reversal (PT) transformation. We determine the PT-symmetric an well as non-PT-symmetric invisible configurations of an easily realizable exactly solvable model that consists of a two-layer planar slab consisting of optically active material. Our analysis shows that although PT-symmetry is neither necessary nor sufficient for the invisibility of a scattering potential, it plays an important role in the characterization of the invisible configurations. A byproduct of our investigation is the discovery of certain configurations of our model that are effectively reflectionless in a spectral range as wide as several hundred nanometers.

Ali Mostafazadeh

2012-06-01T23:59:59.000Z

95

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

96

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

Science Journals Connector (OSTI)

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

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

2014-10-16T23:59:59.000Z

97

Supporting Information Localized Pd Overgrowth on Cubic Pt Nanocrystals for Enhanced  

E-Print Network (OSTI)

. For CO stripping experiments, CO gas (Praxair, 99.99%) was bubbled at an open circuit through 0.5 M H2SO4

Yang, Peidong

98

Pd-Pt Bimetallic Nanodendrites with High Activity for Oxygen Reduction  

Science Journals Connector (OSTI)

...kinetically limited at the cathode (5–8), and the...decade, a number of strategies have been proposed...the performance of an electrocatalyst for the ORR that involved...promising route to the development of next-generation...

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

99

Multimetallic Aerogels by Template-Free Self-Assembly of Au, Ag, Pt, and Pd Nanoparticles  

Science Journals Connector (OSTI)

aerogel; hydrogel; multimetallic; noble metal nanoparticles; alloying; porous metals; template-free; self-assembly ... Their potential areas of application lay in the field of heterogeneous and electro-catalysis, conductive coatings, optical absorbing layers, surface enhanced Raman spectroscopy, and hydrogen storage. ... We report on systematic studies of size-dependent alloy formation of silver-coated gold nanoparticles (NPs) in aq. ...

Anne-Kristin Herrmann; Petr Formanek; Lars Borchardt; Markus Klose; Lars Giebeler; Jürgen Eckert; Stefan Kaskel; Nikolai Gaponik; Alexander Eychmüller

2013-12-09T23:59:59.000Z

100

Author's personal copy Highly active surfaces for CO oxidation on Rh, Pd, and Pt  

E-Print Network (OSTI)

to that found at ultrahigh vacuum (UHV) condi- tions [4]. In contrast, for Ru the reaction mechanism is dra- matically different for CO oxidation at UHV conditions and at atmospheric conditions [14,25]. In UHV, Ru that measured in UHV. The signif- icantly higher activity near one atmosphere at stoichiome- tric reaction

Goodman, Wayne

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101

The formation of PdCx over Pd-based catalysts in vapor-phase vinyl acetate synthesis: does a PdAu alloy catalyst resist carbide formation?  

E-Print Network (OSTI)

­Au alloy catalyst resist carbide formation? Y.-F. Han, D. Kumar, C. Sivadinarayana, A. Clearfield, and D October 2003; accepted 24 February 2004 The formation of Pd carbide (PdCx) during the synthesis of vinyl­Au/SiO2; XRD. 1. Introduction The formation of carbides over supported Pd catalysts was first reported

Goodman, Wayne

102

CP Violation and PT Invariance  

Science Journals Connector (OSTI)

......Physics May 1965 research-article Articles CP Violation and PT Invariance Kichiro Hiida...interaction is presented such that small CP violating weak interactions are invariant...677-679 The Sixth Interaction: Origins of the CP Violation Masami Nakagawa Progress of Theoretical......

Kichiro Hiida

1965-05-01T23:59:59.000Z

103

Interfacial characterization of nickel–yttria-stabilized zirconia cermet anode/interconnect joints with Ag–Pd–Ga active filler for use in solid-oxide fuel cells  

Science Journals Connector (OSTI)

Abstract Nickel–yttria-stabilized zirconia cermet anode (Ni–YSZ)/interconnect joints with silver–palladium–gallium (Ag–9Pd–9Ga) active fillers are prepared by vacuum brazing. The joint structure and microstructure are analyzed by X-ray diffraction (XRD) and scanning electron microscopy coupled with energy dispersive spectroscopy (SEM/EDS), and by using an electron probe microanalyzer (EPMA). SEM observations of the joint show no cracks near the interface, confirming the compatibility of the Ag–9Pd–9Ga filler with a different anode and interconnect. The XRD pattern of the joint specimens oxidized at 800 °C for 250 h shows Cr2O3 and (Mn,Cr)3O4 surface layers. EPMA analysis of the cell/Ag–9Pd–9Ga/alloys joint at the cross section shows Cr, O, Fe, Zr, Ni, Ag, Pd, Ga, Y, and Mn. Overall, the results indicate that the bonding between metal and cermet is well established and the interface is smooth. By correlating the XRD and EPMA analysis results, we also analyzed the possible stages during joint oxidation. The joint strength was evaluated at 25 and 800 °C under shear and tensile loading conditions, respectively, and the brazed Ag–9Pd–9Ga sealant compared favorably with the commercially available glass-ceramic GC-9 counterpart.

Chih-Long Chao; Chun-Lin Chu; Yiin-Kuen Fuh; Ray-Quen Hsu; Shyong Lee; Yung-Neng Cheng

2014-01-01T23:59:59.000Z

104

Rhombohedral AlPt films formed by self-propagating, high temperature synthesis.  

SciTech Connect

High-purity AlPt thin films prepared by self-propagating, high temperature combustion synthesis show evidence for a new rhombohedral phase. Sputter deposited Al/Pt multilayers of various designs are reacted at different rates in air and in vacuum, and each form a new trigonal/hexagonal aluminide phase with unit cell parameters a = 15.571(8) {angstrom}, c = 5.304(1) {angstrom}, space group R-3 (148), and Z, the number of formula units within a unit cell, = 39. The lattice is isostructural to that of the AlPd R-3 lattice as reported by Matkovic and Schubert (Matkovic, 1977). Reacted films have a random in-plane crystallographic texture, a modest out-of-plane (001) texture, and equiaxed grains with dimensions on the order of film thickness.

Adams, David Price; Rodriguez, Mark Andrew; Kotula, Paul Gabriel

2005-11-01T23:59:59.000Z

105

Ferromagnetic behavior of the Kondo lattice compound Np2PtGa3  

Science Journals Connector (OSTI)

Here we report on a study of the ternary Np2PtGa3 compound. The x-ray-powder diffraction analysis reveals that the compound crystallizes in the orthorhombic CeCu2-type crystal structure (space group Imma) with lattice parameters a=0.4409(2) nm, b=0.7077(3) nm, and c=0.7683(3) nm at room temperature. The measurements of dc magnetization, specific heat, and electron transport properties in the temperature range 1.7–300 K and in magnetic fields up to 9 T imply that this intermetallic compound belongs to a class of ferromagnetic Kondo systems. The Curie temperature of TC? 26 K is determined from the magnetization and specific-heat data. An enhanced coefficient of the electronic specific heat ? = 180 mJ/(mol at. Np K2) and a ?lnT dependence of the electrical resistivity indicate the presence of a Kondo effect, which can be described in terms of the S=1 underscreened Kondo-lattice model. The estimated Kondo temperature TK?24 K, Hall mobility of ?16.8 cm2/V s, and effective mass of ?83me are consistent with an assumption that the heavy-fermion state develops in Np2PtGa3 at low temperatures. We compare the observed properties of Np2PtGa3 to that found in Np2PdGa3 and discuss their difference in regard to change in the exchange interaction between the conduction and localized 5f electrons. We have used the Fermi wave vector kF to evaluate the Rudermann-Kittel-Kasuya-Yosida (RKKY) exchange. Based on experimental data of the (U, Np)2(Pd, Pt)Ga3 compounds we suggest that the evolution of the magnetic ground states in these actinide compounds can be explained within the RKKY formalism.

V. H. Tran; J.-C. Griveau; R. Eloirdi; E. Colineau

2014-02-21T23:59:59.000Z

106

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

107

PT-Symmetric Phonon Laser  

E-Print Network (OSTI)

By exploiting recent developments associated with coupled microcavities, we introduce the concept of PT-symmetric phonon laser with balanced gain and loss. This is accomplished by introducing gain to one of the microcavities such that it balances the passive loss of the other. In the vicinity of the gain-loss balance, a strong nonlinear relation emerges between the intracavity photon intensity and the input power. This then leads to a giant enhancement of both optical pressure and mechanical gain, resulting in a highly efficient phonon-lasing action. These results provide a promising approach for manipulating optomechanical systems through PT-symmetric concepts. Potential applications range from enhancing mechanical cooling to designing phonon-laser amplifiers.

H. Jing; Sahin K. Ozdemir; Xin-You Lv; Jing Zhang; Lan Yang; Franco Nori

2014-03-04T23:59:59.000Z

108

Pd modified Au on carbon as an effective and durable catalyst for the direct oxidation of HMF to FDCA  

SciTech Connect

We show that the modification of a gold/carbon catalyst with Pt or Pd produces stable and recyclable catalysts for the selective oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA). This finding is a significant advance over current conversion technology because of the technological importance of FDCA. Indeed, FDCA has been identified as one of twelve potential building blocks for the production of value added chemicals derived from biosources.1 FDCA is a potential replacement source of terephthalic acid, the monomer presently used for the production of polyethylene terephthalate (PET) and derived from hydrocarbon sources.2

Villa, Alberto [Universita di Milano, Italy; Schiavoni, Marco [University of Milan and INFN, Milano, Italy; Campisi, Sebastiano [University of Milan and INFN, Milano, Italy; Veith, Gabriel M [ORNL; Prati, Laura [Universita di Milano, Italy

2013-01-01T23:59:59.000Z

109

Magnetism of Fe/Pd superlattices  

Science Journals Connector (OSTI)

A series of Fe/Pd superlattices of varying numbers of atoms per layer were fabricated. Structural properties were characterized by x-ray diffraction. Magnetic properties were studied by Mössbauer spectroscopy and transport properties by electrical-conductivity measurements. All properties studied could be explained by structural characteristics, such as grain size and interdiffusion, without the need of invoking superlattice effects.

Ahmed Boufelfel; Roy M. Emrick; Charles M. Falco

1991-06-01T23:59:59.000Z

110

Design of FePd spring actuators Taishi Wada*  

E-Print Network (OSTI)

. The coil spring made by a FSMA is activated by the attractive magnetic force produced by electromagnets on the above principle by using polycrystalline FePd alloy. Since the stiffness of the FePd coil spring become actuation. Keywords: actuator, coil spring, FePd, wire, ferromagnetic shape memory alloy, superelasticity

Taya, Minoru

111

Fabrication of Pd/Pd-Alloy Films by Surfactant Induced Electroless Plating for Hydrogen Separation from Advanced Coal Gasification Processes  

SciTech Connect

Dense Pd, Pd-Cu and Pd-Ag composite membranes on microporous stainless steel substrate (MPSS) were fabricated by a novel electroless plating (EP) process. In the conventional Pd-EP process, the oxidation-reduction reactions between Pd-complex and hydrazine result in an evolution of NH{sub 3} and N{sub 2} gas bubbles. When adhered to the substrate surface and in the pores, these gas bubbles hinder uniform Pd-film deposition which results in dendrite growth leading to poor film formation. This problem was addressed by introducing cationic surfactant in the electroless plating process known as surfactant induced electroless plating (SIEP). The unique features of this innovation provide control of Pd-deposition rate, and Pd-grain size distribution. The surfactant molecules play an important role in the EP process by tailoring grain size and the process of agglomeration by removing tiny gas bubbles through adsorption at the gas-liquid interface. As a result surfactant can tailor a nanocrystalline Pd, Cu and Ag deposition in the film resulting in reduced membrane film thickness. Also, it produces a uniform, agglomerated film structure. The Pd-Cu and Pd-Ag membranes on MPSS support were fabricated by sequential deposition using SIEP method. The pre- and post-annealing characterizations of these membranes (Pd, Pd-Cu and Pd-Ag on MPSS substrate) were carried out by SEM, EDX, XRD, and AFM studies. The SEM images show significant improvement of the membrane surface morphology, in terms of metal grain structures and grain agglomeration compared to the membranes fabricated by conventional EP process. The SEM images and helium gas-tightness studies indicate that dense and thinner films of Pd, Pd-Cu and Pd-Ag membranes can be produced with shorter deposition time using surfactant. H{sub 2} Flux through the membranes fabricated by SIEP shows large improvement compared to those by CEP with comparable permselectivity. Pd-MPSS composite membrane was subjected to test for long term performance and thermal cycling (573 - 723 - 573 K) at 15 psi pressure drop for 1200 hours. Pd membranes showed excellent hydrogen permeability and thermal stability during the operational period. Under thermal cycling (573 K - 873 K - 573 K), Pd-Cu-MPSS membrane was stable and retained hydrogen permeation characteristics for over three months of operation. From this limited study, we conclude that SIEP is viable method for fabrication of defect-free, robust Pd-alloy membranes for high-temperature H{sub 2}-separation applications.

Ilias, Shamsuddin; Kumar, Dhananjay

2012-07-31T23:59:59.000Z

112

Kinetics of monolayer graphene growth by segregation on Pd(111)  

SciTech Connect

Using in situ low-energy electron microscopy and density functional theory calculations, we follow the growth of monolayer graphene on Pd(111) via surface segregation of bulk-dissolved carbon. Upon lowering the substrate temperature, nucleation of graphene begins on graphene-free Pd surface and continues to occur during graphene growth. Measurements of graphene growth rates and Pd surface work functions establish that this continued nucleation is due to increasing C adatom concentration on the Pd surface with time. We attribute this anomalous phenomenon to a large barrier for attachment of C adatoms to graphene coupled with a strong binding of the non-graphitic C to the Pd surface.

Mok, H. S.; Murata, Y.; Kodambaka, S., E-mail: kodambaka@ucla.edu [Department of Materials Science and Engineering, University of California Los Angeles, Los Angeles, California 90095 (United States); Ebnonnasir, A.; Ciobanu, C. V. [Department of Mechanical Engineering and Materials Science Program, Colorado School of Mines, Golden, Colorado 80401 (United States); Nie, S.; McCarty, K. F. [Sandia National Laboratories, Livermore, California 94550 (United States)

2014-03-10T23:59:59.000Z

113

Activities of Pt/Sibunit-1562 catalysts in the ORR in PEMFC: Effect of Pt content and Pt load at cathode  

Science Journals Connector (OSTI)

In this paper, a systematic investigation was carried out of activities at 80 °C of Pt supported on Sibunit-1562 graphitized carbon in the electroreduction of oxygen in the polymer electrolyte fuel cell. Pt content in the Pt/Sibunit-1562 catalysts was 20, 40, and 60 wt.% and Pt load at the cathode was varied in the 200–6.25 ?gPt cm?2 interval. The results were compared with the activity of commercial 20 wt.% Pt/Vulcan XC-72 catalyst. To optimize the transport properties of the cathode layer and maintain its thickness upon using Pt/Sibunit ?1562 catalysts with varied Pt content and Pt loads a definite amount of Vulcan-XC-72 carbon support was added to the cathode catalytic inks. Higher activity of Pt/Sibunit-1562 catalysts was found as compared to that of commercial 20 wt.% Pt/Vulcan XC-72 with similar particle size of the active component.

Evgeniy N. Gribov; Anastasiya Yu. Zinovieva; Ivan N. Voropaev; Pavel A. Simonov; Anatoliy V. Romanenko; Aleksey G. Okunev

2012-01-01T23:59:59.000Z

114

Prescission neutron emission from Pd104  

Science Journals Connector (OSTI)

Neutron spectra in coincidence with fission fragments have been measured for the 190 MeV Si28+76Ge populating Pd104 compound nucleus at Ex?133 MeV excitation energy. The extracted prescission multiplicity for symmetric splitting is ?pre=1.1±0.2. The average fission time ?F=6-2+3×10-20 s is determined, in good agreement with the systematics of Hinde et al. for heavier systems (A?125 compound nuclei).

L. Fiore; G. Viesti; P. F. Bortignon; P. Blasi; G. D’Erasmo; D. Fabris; E. M. Fiore; F. Gramegna; F. Lucarelli; G. Nebbia; A. Pantaleo; V. Paticchio; G. Prete; J. A. Ruiz

1993-05-01T23:59:59.000Z

115

AcqGuide39pt1.doc | Department of Energy  

Energy Savers (EERE)

9pt1.doc&0; AcqGuide39pt1.doc&0; AcqGuide39pt1.doc&0; More Documents & Publications Chapter 39 - Acquisition of Information Technology Policy Flash 2012-6 Policy Flash 2012-49...

116

Carbon nanotubes decorated with Pt nanoparticles via electrostatic...  

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

nanotubes decorated with Pt nanoparticles via electrostatic self-assembly: a highly active oxygen reduction Carbon nanotubes decorated with Pt nanoparticles via electrostatic...

117

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...

118

Oxygen Coverage Dependence of NO Oxidation on Pt(111). | EMSL  

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

Dependence of NO Oxidation on Pt(111). Abstract: The interaction of NO with adsorbed atomic oxygen on Pt(111) was studied with temperature programmed desorption (TPD),...

119

PT1_US.xls  

Gasoline and Diesel Fuel Update (EIA)

PT1. Energy Production Estimates in Physical Units, United States, 1960 - 2011 PT1. Energy Production Estimates in Physical Units, United States, 1960 - 2011 1960 436,425 12,771,038 2,574,933 NA 1961 422,535 13,254,025 2,621,758 NA 1962 441,072 13,876,622 2,676,189 NA 1963 479,356 14,746,663 2,752,723 NA 1964 506,453 15,546,592 2,786,822 NA 1965 529,355 16,039,753 2,848,514 NA 1966 549,065 17,206,628 3,027,763 NA 1967 567,031 18,171,325 3,215,742 NA 1968 558,995 19,322,400 3,329,042 NA 1969 573,226 20,698,240 3,371,751 NA 1970 614,969 21,920,642 3,517,450 NA 1971 563,122 22,493,012 3,453,914 NA 1972 602,491 22,531,698 3,455,368 NA 1973 598,569 22,647,549 3,360,903 NA 1974 610,021 21,600,522 3,202,585 NA 1975 654,641 20,108,661 3,056,779 NA 1976 684,914 19,952,438 2,976,180 NA 1977 697,205 20,025,463 3,009,265 NA 1978 670,164 19,974,033 3,178,216 NA 1979 781,135 20,471,260 3,121,310 NA 1980 829,747 20,179,724 3,146,365 NA

120

ternay-pd-alloys-pall | netl.doe.gov  

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

Program Goals & Targets Systems Analysis Regulatory Drivers Program Plan Capture Handbook Designing and Validating Ternay Pd Alloys for Optimum SulfurCarbon Resistance...

Note: This page contains sample records for the topic "ni pd pt" 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

Direct (?+,pd) cross sections for light nuclei  

Science Journals Connector (OSTI)

The angular distributions of the inclusive (?+,pd) cross section were measured for Li6, Li7, and C at T?=70, 130, and 165 MeV over a wide angular range. They were found very similar to that of the ?+3H(3He)?N+d reaction at the low-momentum-transfer region, especially for Li isotopes. However, at the higher-momentum-transfer region, slight peaks which were not expected in the ?+3H(3He)?N+d were observed.

H. Yokota; S. Igarashi; K. Hama; T. Mori; T. Katsumi; K. Nakayama; K. Ichimaru; R. Chiba; K. Nakai; J. Chiba

1989-05-01T23:59:59.000Z

122

Two-neutron transfer in Pt nuclei and the structure of Pt200  

Science Journals Connector (OSTI)

The Pt194,196,198(t,p) reactions have been measured with 17 MeV tritons on enriched and natural Pt targets. The level structure of Pt200 is probed for the first time, and several new excited O+ states have been identified in Pt196,198,200. Systematics in level structure of Pt192-200 are fairly constant, although there is evidence that Pt198,200 are becoming more vibrational in structure, with the ?-unstable shape of the lighter Pt nuclides becoming more oblate-like. Systematics of L=4 strengths are considered and can be qualitatively understood. The (t,p) strengths measured in the present study are combined with earlier Pt(p,t) and Os(t,p) measurements and compared with the systematics of two-neutron transfer strengths predicted by the interacting boson approximation, schematic, boson expansion, and pairing vibration models.NUCLEAR REACTIONS Pt194,196,198(t,p), E=17 MeV; enriched targets; measured energy levels, ?(?) in Pt196,198,200; DWBA.NUCLEAR STRUCTURE L=4 transitions, interacting boson approximation model, schematic model, boson expansion technique, pairing vibration model.

J. A. Cizewski; E. R. Flynn; Ronald E. Brown; D. L. Hanson; S. D. Orbesen; J. W. Sunier

1981-04-01T23:59:59.000Z

123

Scanning tuneeling microscopy studies of fivefold surfaces of icosahedral Al-Pd-Mn quasicrystals and of thin silver films on those surfaces  

SciTech Connect

The present work in this dissertation mainly focuses on the clean fivefold surfaces of i-Al-Pd-Mn quasicrystals as well as the nucleation and growth of Ag films on these surfaces. In addition, Ag film growth on NiAl(110) has been explored in the frame of this dissertation. First, we have investigated the equilibration of a fivefold surface of icosahedral Al-Pd-Mn quasicrystal at 900-915 K and 925-950 K, using Omicron variable temperature scanning tunneling microscope (STM). Annealing at low temperatures resulted in many voids on some terraces while the others were almost void-free. After annealing at 925-950K, void-rich terraces became much rarer. Our STM images suggest that through growth and coalescence of the voids, a different termination becomes exposed on host terraces. All of these observations in our study indicate that even after the quasicrystalline terrace-step structure appears, it evolves with time and temperature. More specifically, based on the STM observations, we conclude that during the annealing a wide range of energetically similar layers nucleate as surface terminations, however, with increasing temperature (and time) this distribution gets narrower via elimination of the metastable void-rich terraces. Next, we have examined the bulk structural models of icosahedral Al-Pd-Mn quasicrystal in terms of the densities, compositions and interplanar spacings for the fivefold planes that might represent physical surface terminations. In our analyses, we mainly have focused on four deterministic models which have no partial or mixed occupancy but we have made some comparisons with an undeterministic model. We have compared the models with each other and also with the available experimental data including STM, LEED-IV, XPD and LEIS. In all deterministic models, there are two different families of layers (a pair of planes), and the nondeterministic model contains similar group of planes. These two families differ in terms of the chemical decoration of their top planes. Hence, we name them as Pd+(with Pd) and Pd-(without Pd). Based on their planer structure and the step height, it can be said that these two families can be viable surface terminations. However, besides the Pd content, these two sets differ in terms of relative densities of their top planes as well as the gap separating the layer from the nearest atomic plane. The experimental data and other arguments lead to the conclusion that the Pd- family is favored over the Pd+. This has an important implication on the interpretation of local motifs seen in the high resolution STM images. In other words, the dark stars are not formed by cut-Bergmans rather they are formed by cut-Mackays.

Unal, Baris

2008-12-01T23:59:59.000Z

124

Vibrational Character of Pd104 and a Spectroscopic Study of Pd104 by Pickup Reactions  

Science Journals Connector (OSTI)

The Pd105(d, t)Pd104 and Ag107(p, ?)Pd104 pickup reactions were studied at bombarding energies of 17 and 12 MeV, respectively. Tritons were detected by nuclear emulsions in an Enge split-pole spectrograph with 5-7-keV resolution, and 43 (d, t) angular distributions were measured for transitions to low-lying levels in Pd104. Comparison of the (d, t) data with distorted-wave Born-approximation (DWBA) calculations predominantly led to l=0, 2, and 4 assignments and yielded spectroscopic factors and quantitative estimates for single-neutron state occupancies. A previously postulated doublet at 1.33 MeV was resolved as a nearly degenerate triplet, in agreement with the two-phonon description for collective vibrations. Further evidence for the vibrational structure of the low-lying levels of Pd104 might be furnished by the well-isolated multiplet near 1.80 MeV, which may contain some or all of the members of the three-phonon quintet. In the (p, ?) experiment, cross sections were found to be very small (<20 ?b/sr), and thick targets had to be used which limited the resolution to 40 keV for Si detector data and ?30 keV for magnetic spectrograph analysis. (p, ?) angular distributions are given for the four strongest groups below 2 MeV. Very good agreement between the experimental results and j-dependent DWBA calculations based on a triton-cluster transfer mechanism supports the interpretation that direct pickup is the dominant (p, ?) reaction process in this mass and energy region.

D. L. Dittmer and W. W. Daehnick

1969-11-20T23:59:59.000Z

125

Thermomechanical Characterization of a TiPdNi High Temperature SMA under Tension  

E-Print Network (OSTI)

Electrode Discharge Machining (EDM). A high temperature experimental setup was developed on a load frame

126

PT2_US.xls  

Gasoline and Diesel Fuel Update (EIA)

PT2. Energy Production Estimates in Trillion Btu, United States, 1960 - 2011 PT2. Energy Production Estimates in Trillion Btu, United States, 1960 - 2011 1960 10,590 14,119 14,935 6 NA 2,928 2,928 42,578 1961 10,239 14,642 15,206 20 NA 2,952 2,952 43,060 1962 10,671 15,322 15,522 26 NA 3,117 3,117 44,658 1963 11,605 16,270 15,966 38 NA 3,096 3,096 46,976 1964 12,274 17,152 16,164 40 NA 3,225 3,225 48,854 1965 12,832 17,691 16,521 43 NA 3,396 3,396 50,483 1966 13,281 18,967 17,561 64 NA 3,432 3,432 53,305 1967 13,697 20,019 18,651 88 NA 3,690 3,690 56,146 1968 13,487 21,276 19,308 142 NA 3,773 3,773 57,986 1969 13,833 22,764 19,556 154 NA 4,095 4,095 60,402 1970 14,877 24,098 20,401 239 NA 4,070 4,070 63,686 1971 13,518 24,747 20,033 413 NA 4,262 4,262 62,972 1972 14,392 24,819 20,041 584 NA 4,382 4,382 64,218 1973 14,006 24,873 19,493 910 NA 4,411 4,411 63,694 1974 14,025 23,723 18,575 1,272 NA 4,742 4,742 62,336 1975 14,982 22,098 17,729 1,900 NA 4,687 4,687

127

PT-Symmetric Optomechanically-Induced Transparency  

E-Print Network (OSTI)

Optomechanically-induced transparency (OMIT) and the associated slow-light propagation provide the basis for storing photons in nanofabricated phononic devices. Here we study OMIT in parity-time (PT)-symmetric microresonators with a tunable gain-to-loss ratio. This system features a reversed, non-amplifying transparency: inverted-OMIT. When the gain-to-loss ratio is steered, the system exhibits a transition from the PT-symmetric phase to the broken-PT-symmetric phase. We show that by tuning the pump power at fixed gain-to-loss ratio or the gain-to-loss ratio at fixed pump power, one can switch from slow to fast light and vice versa. Moreover, the presence of PT-phase transition results in the reversal of the pump and gain dependence of transmission rates. These features provide new tools for controlling light propagation using optomechanical devices.

H. Jing; S. K. Özdemir; Z. Geng; J. Zhang; X. -Y. Lü; B. Peng; L. Yang; F. Nori

2014-12-09T23:59:59.000Z

128

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

129

Optical, structural, and electrical properties of Mg{sub 2}NiH{sub 4} thin films in situ grown by activated reactive evaporation  

SciTech Connect

Mg{sub 2}NiH{sub 4} thin films have been prepared by activated reactive evaporation in a molecular beam epitaxy system equipped with an atomic hydrogen source. The optical reflection spectra and the resistivity of the films are measured in situ during deposition. In situ grown Mg{sub 2}NiH{sub 4} appears to be stable in vacuum due to the fact that the dehydrogenation of the Mg{sub 2}NiH{sub 4} phase is kinetically blocked. Hydrogen desorption only takes place when a Pd cap layer is added. The optical band gap of the in situ deposited Mg{sub 2}NiH{sub 4} hydride, 1.75 eV, is in good agreement with that of Mg{sub 2}NiH{sub 4} which has been formed ex situ by hydrogenation of metallic Pd capped Mg{sub 2}Ni films. The microstructure of these in situ grown films is characterized by a homogeneous layer with very small grain sizes. This microstructure suppresses the preferred hydride nucleation at the film/substrate interface which was found in as-grown Mg{sub 2}Ni thin films that are hydrogenated after deposition.

Westerwaal, R. J.; Slaman, M.; Broedersz, C. P.; Borsa, D. M.; Dam, B.; Griessen, R.; Borgschulte, A.; Lohstroh, W.; Kooi, B.; Brink, G. ten; Tschersich, K. G.; Fleischhauer, H. P. [Faculty of Sciences, Department of Physics and Astronomy, Condensed Matter Physics, Vrije Universiteit, De Boelelaan 1081, 1081 HV Amsterdam (Netherlands); GKSS-Research Center Geesthacht GmbH, WTP, Building 59 Max-Planck-Strasse 1, 21502 Geesthacht (Germany); Institut fuer Nanotechnologie, Forschungszentrum Karlsruhe GmbH, Postfach 36 40 76021 Karlsruhe (Germany); Department of Applied Physics, University of Groningen, Nijenborgh 4, 9747 AG Groningen (Netherlands); Institut fuer Schichten und Grenzflaechen, Forschungszentrum Juelich GmbH, 52425 Juelich (Germany)

2006-09-15T23:59:59.000Z

130

Vortex properties in superconducting Nb/Pd multilayers  

Science Journals Connector (OSTI)

We have investigated the upper critical magnetic field Hc2, the critical current density Jc, and the pinning force Fp in sputtered Nb/Pd multilayers, varying the temperatures T, the Pd thicknesses dPd and the magnetic field H orientation (parallel and perpendicular to the plane of the sample). In perpendicular fields, the vortex dynamics was strongly influenced by grain-boundary pinning. In parallel fields, a peak was observed in the Jc(H) curves for samples with Pd thicknesses dPd>100 Å. After comparing the experimental results with the existing theories, we have related the presence of this peak effect to the matching of vortex kinks with the layered artificial structure.

C. Coccorese; C. Attanasio; L. V. Mercaldo; M. Salvato; L. Maritato; J. M. Slaughter; C. M. Falco; S. L. Prischepa; B. I. Ivlev

1998-04-01T23:59:59.000Z

131

C. Gerber -Fermilab W and Z PT DistributionsW and Z PT Distributions  

E-Print Network (OSTI)

C. Gerber - Fermilab 1 W and Z PT DistributionsW and Z PT Distributions Cecilia Gerber (gerber@fnal.gov) (Fermilab) for the CDF and D-Zero Collaborations QCD and Weak Boson Physics at Run2 Photon and Weak Bosons Working Group Fermilab March 6, 1999 #12;C. Gerber - Fermilab 2 OutlineOutline Motivation Introduction

Gerber, Cecilia E.

132

Decarboxylative-Coupling of Allyl Acetate Catalyzed by Group 10 Organometallics, [(phen)M(CH3)]+  

Science Journals Connector (OSTI)

In step 2a, allylic alkylation occurs to give 1-butene and reform metal acetate, [(phen)M(O2CCH3)]+, with Ni (36%) > Pd (28%) > Pt (2%). ...

Matthew Woolley; Alireza Ariafard; George N. Khairallah; Kim Hong-Yin Kwan; Paul S. Donnelly; Jonathan M. White; Allan J. Canty; Brian F. Yates; Richard A. J. O’Hair

2014-10-20T23:59:59.000Z

133

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

134

CX-009904: Categorical Exclusion Determination | Department of...  

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

using high surface area nitrogen doped titania nanotube arrays, sensitized with nano-dimensional islands of co-catalysts copper and Ni, Pd or Pt. CX-009904.pdf More...

135

Published: February 24, 2011 r 2011 American Chemical Society 572 dx.doi.org/10.1021/jz101753e |J. Phys. Chem. Lett. 2011, 2, 572576  

E-Print Network (OSTI)

reduction reaction (ORR).1-4 Currently the best cathode catalysts are Pt or alloys of Pt with Co or Ni,5 Reduction Reaction at Pt and Pd Fuel Cell Catalysts Yao Sha, Ted H. Yu, Boris V. Merinov, Pezhman Shirvanian to the performance of polymer electrolyte membrane fuel cells (PEMFCs) is the efficiency of the reaction in which

Goddard III, William A.

136

Journal of Power Sources 196 (2011) 45154523 Contents lists available at ScienceDirect  

E-Print Network (OSTI)

as cathode electro- catalysts in PEMFCs [13­25]. Pt-rich Pt­Co catalysts [11,26] have shown significant 2011 Keywords: Fuel cell Electrocatalyst Core­shell structure Catalyst durability a b s t r a c t Pd­Pt­Ni nanoalloy catalysts have been synthesized by a polyol reduction method and characterized for the oxygen

Ferreira, Paulo J.

137

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

138

Electrical current suppression in Pd-doped vanadium pentoxide nanowires caused by reduction in PdO due to hydrogen exposure  

SciTech Connect

Pd nanoparticle-doped vanadium pentoxide nanowires (Pd-VONs) were synthesized. Electrical current suppression was observed when the Pd-VON was exposed to hydrogen gas, which cannot be explained by the work function changes mentioned in previous report such as Pd-doped carbon nanotubes and SnO{sub 2} nanowires. Using the x-ray photoelectron spectroscopy, we found that the reduction in PdO due to hydrogen exposure plays an important role in the current suppression of the Pd-VON.

Kim, Byung Hoon; Oh, Soon-Young; Yu, Han Young; Yun, Yong Ju; Kim, Yark Yeon; Hong, Won G. [Electronics and Telecommunications Research Institute (ETRI), Daejeon 305-700 (Korea, Republic of); Jeong, Hu Young; Lee, Jeong Yong [Department of Materials Science and Engineering, KAIST, Daejeon 305-701 (Korea, Republic of); Kim, Hae Jin [Korea Basic Science Institute, Daejeon 305-333 (Korea, Republic of)

2010-04-19T23:59:59.000Z

139

Methane Combustion over Pd/ZrO2/SiC, Pd/CeO2/SiC, Pd/Zr0.5Ce0.5O2/SiC Catalysts  

E-Print Network (OSTI)

1 Methane Combustion over Pd/ZrO2/SiC, Pd/CeO2/SiC, Pd/Zr0.5Ce0.5O2/SiC Catalysts Xiaoning Guo a Laboratory of Coal Conversion, Institute of Coal Chemistry, Taiyuan 030001, PR China b GREMI UMR6606 CNRS0.5O2 solid solution) modified Pd/SiC catalysts for methane combustion are studied. XRD and XPS

Paris-Sud XI, Université de

140

Thermal diffusion in Au?WTi?Pd metallization on silicon  

Science Journals Connector (OSTI)

This paper presents the results of investigation of thermal diffusion in Au?Wti?Pd metallization on (111) n-Si. Thin films were deposited by dc sputtering to the thickness of 50 (Pd), 100–200 (WTi) and 70–200 nm (Au). After deposition the samples were subjected to thermal treatments vacuum 1 × 10?5 mbar, at temperatures up to 600°C. Characterization included RBS, AES, XRD and SEM structural analysis and sheet resistivity measurements. During annealing up to 450°C diffusion occurs only at the Pd?Si interface, at 500°C other components interdiffuse at isolated areas of the samples and at 600°C there is total interdiffusion on components. Thermal degradation oftthe \\{WTi\\} diffusion barrier is enhanced by the growth of Pd2Si phase, during which silicon is released from the substrate and mechanical stress is introduced. Better diffusion barrier properties were obtained when \\{WTi\\} films were deposited in nitrogen or oxygen atmosphere.

M Milosavljevi?; N Bibi?; M Stojanovi?; J Turkovi?; I.H Wilson

1990-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "ni pd pt" 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

Aerosol synthesis and Rietveld analysis of tetragonal () PdZn...  

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

method. Detailed structural analysis shows that this material contains little or no vacancies and minimal PdZn disorder. Citation: Peterson EJ, B Halevi, B Kiefer, MN Spilde, AK...

142

The PD-1/PD-L1 complex resembles the antigen-binding Fv domains of antibodies and T cell receptors  

SciTech Connect

Signaling through the programmed death 1 (PD-1) inhibitory receptor upon binding its ligand, PD-L1, suppresses immune responses against autoantigens and tumors and plays an important role in the maintenance of peripheral immune tolerance. Release from PD-1 inhibitory signaling revives 'exhausted' virus-specific T cells in chronic viral infections. Here we present the crystal structure of murine PD-1 in complex with human PD-L1. PD-1 and PD-L1 interact through the conserved front and side of their Ig variable (IgV) domains, as do the IgV domains of antibodies and T cell receptors. This places the loops at the ends of the IgV domains on the same side of the PD-1/PD-L1 complex, forming a surface that is similar to the antigen-binding surface of antibodies and T cell receptors. Mapping conserved residues allowed the identification of residues that are important in forming the PD-1/PD-L1 interface. Based on the structure, we show that some reported loss-of-binding mutations involve the PD-1/PD-L1 interaction but that others compromise protein folding. The PD-1/PD-L1 interaction described here may be blocked by antibodies or by designed small-molecule drugs to lower inhibitory signaling that results in a stronger immune response. The immune receptor-like loops offer a new surface for further study and potentially the design of molecules that would affect PD-1/PD-L1 complex formation and thereby modulate the immune response.

Lin, David Yin-wei; Tanaka, Yoshimasa; Iwasaki, Masashi; Gittis, Apostolos G.; Su, Hua-Poo; Mikami, Bunzo; Okazaki, Taku; Honjo, Tasuku; Minato, Nagahiro; Garboczi, David N. (NIH); (Kyoto)

2008-07-29T23:59:59.000Z

143

Reversibility of Pt-Skin and Pt-Skeleton Nanostructures in Acidic Media  

Science Journals Connector (OSTI)

In acidic and oxidizing conditions, Pt is the only metal that can efficiently catalyze the oxygen reduction reaction (ORR), the reaction that limits the PEMFC performance. ... In this paper, atomically resolved pictures of the different nanostructures that can be derived from a benchmark Pt3Co/C catalyst in a model PEMFC environment were obtained. ... The electrocatalytic trends established for extended surfaces are used to explain the activity pattern of Pt3M nanocatalysts as well as to provide a fundamental basis for the catalytic enhancement of cathode catalysts. ...

Julien Durst; Miguel Lopez-Haro; Laetitia Dubau; Marian Chatenet; Yvonne Soldo-Olivier; Laure Guétaz; Pascale Bayle-Guillemaud; Frédéric Maillard

2014-01-14T23:59:59.000Z

144

Studies of Various Hydrocarbon Conversion Reactions on Pt Catalysts  

E-Print Network (OSTI)

for helping me learn how to use UHV chamber; Dr. AashaniPt(111) surface at 80 K under UHV as a function of initialcrystal Pt(111) surface under UHV leads to an enhancement in

Kaneko, Shinji

2011-01-01T23:59:59.000Z

145

UHV-EC Characterization of Ultrathin Films Electrodeposited on Well-Defined Noble Metals. I: Pd on Pt(111)  

Science Journals Connector (OSTI)

Tandem ultrahigh vacuum-electrochemistry (UHV-EC) experiments were performed using a stainless ... displacement of the single-crystal electrode inside the UHV-EC assembly. A custom-built electrochemical cell...

Jack H. Baricuatro; Mohammad A. Hossain; Yeon-Su Park…

2010-05-01T23:59:59.000Z

146

Interfacial Reactivity of Au, Pd, and Pt on BiI3 (001): Implications for Electrode Selection  

Science Journals Connector (OSTI)

Sensitivity factors for quantitative analysis were taken from the PHI XPS Handbook and assumed a 90 degree relationship between the incident X-rays and the electron analyzer. ... This research is supported in part by DOD, Defense Threat Reduction Agency (Contract HDTRA 10710013) and DOE/NNSA Grant no. ...

Wei Qiu; Gregory J. Dudder; Xueying Zhao; Scott S. Perry; Juan C. Nino

2011-05-06T23:59:59.000Z

147

Free Tetra-and hexa-coordinated Platinum-Cyanide Dianions, PT...  

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

Dianions, PT(CN)4 2- and PT(CN)6 2-: A Combined Photodetachment Photoelectron Free Tetra-and hexa-coordinated Platinum-Cyanide Dianions, PT(CN)4 2- and PT(CN)6 2-: A...

148

Electron-Transport Properties of Amorphous (Zr0.64ni0.36)1-Xalx Alloys  

E-Print Network (OSTI)

-4242 (Received 28 November 1988; revised manuscript received 16 March 1989) Measurements of the electrical resistivity p(T), thermopower S(T), and Hall coe%cient RH for a series of rapidly quenched Zr-Ni-Al alloys are reported for concentrations from x =0 to 0...-metal or ?metalloid amorphous alloys, the sign of RH can change from positive to negative as the concentration of the early transition metal is decreased. This is particular- ly well illustrated by measurements on amorphous Zr- based alloys, Zr-Cu, ' ' Zr-Ni, ' Zr...

BHATNAGAR, AK; PAN, R.; Naugle, Donald G.

1989-01-01T23:59:59.000Z

149

Two-neutron transfer study on /sup 195/Pt  

SciTech Connect

The /sup 195/Pt(t,p)/sup 197/Pt reaction was investigated. Three states below 1 MeV are populated with a large fraction of the L = 0 strength, which is seen in the even-to-even cases. This is in contrast to other (p,t) and (t,p) studies on Pt targets, where the L = 0 strength is concentrated in the ground state. 1 figure, 1 table.

Cizewski, J.A.; Flynn, E.R.; Brown, R.E.; Sunier, J.W.

1980-01-01T23:59:59.000Z

150

In situ neutron-reflectometry measurements of hydrogen and deuterium absorption in a Pd/Nb/Pd layered film  

Science Journals Connector (OSTI)

We present in situ neutron-reflectivity measurements of the hydrogen and deuterium absorption from the gas phase in a Pd/Nb/Pd thin film multilayer. Hydrogen and deuterium were both preferentially absorbed into the Nb layer at room temperature and at a pressure of 10 Torr. Genetic algorithm fits to the specular data indicate concentrations of approximately 0.71 [H]/[Nb] and 0.51 [D]/[Nb], placing the Nb well into the ? phase (or an ??-like phase).

Alan E. Munter; Brent J. Heuser; M. W. Ruckman

1997-06-01T23:59:59.000Z

151

Molecular Dynamics Simulations of Supported Pt Nanoclusters  

E-Print Network (OSTI)

¤Introduction and Background ¤Constructing a Physical Model ¤Details of the Simulation ¤Results and Conclusions · Petroleum reformation · Gasification of biomass for biofuels #12;Previous Investigation of NanoclustersMolecular Dynamics Simulations of Supported Pt Nanoclusters Jeffrey Moore #12;A Brief Outline

Washington at Seattle, University of - Department of Physics, Electroweak Interaction Research Group

152

Location of platinum clusters in PtCaY and PtNaY zeolites  

E-Print Network (OSTI)

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

Treybig, Duane Steven

2012-06-07T23:59:59.000Z

153

Stretching dependence of the vibration modes of a single-molecule Pt-H2-Pt bridge D. Djukic,1  

E-Print Network (OSTI)

Stretching dependence of the vibration modes of a single-molecule Pt-H2-Pt bridge D. Djukic,1 K. S of the experiment in terms of a Pt-H2-Pt bridge is verified by density- functional theory calculations. Thygesen,2 C. Untiedt,1, * R. H. M. Smit,1, K. W. Jacobsen,2 and J. M. van Ruitenbeek1, 1Kamerlingh Onnes

Thygesen, Kristian

154

Complex SrRuO3?Pt and LaRuO3?Pt Catalysts for Direct Alcohol Fuel Cells  

Science Journals Connector (OSTI)

Complex SrRuO3?Pt and LaRuO3?Pt Catalysts for Direct Alcohol Fuel Cells ... While currently LaRuO3/Pt composition possesses the highest activity, optimization of perovskite structure (by doping from A and B sites) may lead even to more advanced catalysts. ...

Aidong Lan; Alexander S. Mukasyan

2008-07-02T23:59:59.000Z

155

PdZnAl Catalysts for the Reactions of Water-Gas-Shift, Methanol Steam Reforming, and Reverse-Water-Gas-Shift  

SciTech Connect

Pd/ZnO/Al2O3 catalysts were studied for water-gas-shift (WGS), methanol steam reforming, and reverse-water-gas-shift (RWGS) reactions. WGS activity was found to be dependent on the Pd:Zn ratio with a maximum activity obtained at approximately 0.50, which was comparable to that of a commercial Pt-based catalyst. The catalyst stability was demonstrated for 100 hours time-on-stream at a temperature of 3600C without evidence of metal sintering. WGS reaction rates were approximately 1st order with respect to CO concentration, and kinetic parameters were determined to be Ea = 58.3 kJ mol-1 and k0 = 6.1x107 min-1. During methanol steam reforming, the CO selectivities were observed to be lower than the calculated equilibrium values over a range of temperatures and steam/carbon ratios studied while the reaction rate constants were approximately of the same magnitude for both WGS and methanol steam reforming. These results indicate that although Pd/ZnO/Al2O3 are active WGS catalysts, WGS is not involved in methanol steam reforming. RWGS rate constants are on the order of about 20 times lower than that of methanol steam reforming, suggesting that RWGS reaction could be one of the sources for small amount of CO formation in methanol steam reforming.

Dagle, Robert A.; Platon, Alexandru; Datye, Abhaya K.; Vohs, John M.; Wang, Yong; Palo, Daniel R.

2008-03-07T23:59:59.000Z

156

Giant Quadrupole-Resonance in Ni Isotopes  

E-Print Network (OSTI)

Inelastic scattering of 129 MeV alpha particles has been used to excite the giant quadrupole resonance in Ni-58, Ni-60, Ni-62, Ni-64. The resonance was found to exhaust 58 +/- 12%, 76 +/- 14%, 78 +/- 14%, and 90 +/-16% of the E2 energy-weighted sum...

Youngblood, David H.; Lui, YW; Garg, U.; Peterson, R. J.

1992-01-01T23:59:59.000Z

157

Synthesis And Characterization of Pt Clusters in Aqueous Solutions  

SciTech Connect

Extended X-ray absorption fine structure (EXAFS) and UV-visible (UV-vis) spectroscopies were used to monitor the various steps involved in the synthesis of unprotected and poly(vinyl alcohol) (PVA)-protected aqueous colloidal Pt suspensions. The results indicate that on hydrolysis of the H{sub 2}PtCl{sub 6} precursor, the Cl{sup -} ligands were partially replaced by aquo ligands in the first coordination shell of Pt to form [PtCl{sub 2}(H{sub 2}O){sub 4}]{sup 2+}. Treatment of these species with NaBH{sub 4} under controlled pH conditions led to the formation of nearly uniform Pt{sub 4} and Pt{sub 6} clusters in the absence and presence of PVA, respectively. These highly dispersed colloidal Pt suspensions were stable for several months. The addition of 2-propanol (IPA) to both types of Pt suspensions led to some sintering of the Pt clusters, although both suspensions retained their colloidal nature. Less sintering was evident in the PVA-protected Pt suspension. Both the unprotected and the PVA-protected colloidal Pt suspensions were catalytically active for the liquid-phase selective oxidation of 2-propanol to acetone, with the unprotected suspension exhibiting the highest activity.

Siani, A.; Wigal, K.R.; Alexeev, O.S.; Amiridis, M.D.

2009-05-26T23:59:59.000Z

158

Exponentially Fragile PT Symmetry in Lattices with Localized Eigenmodes  

SciTech Connect

We study the effect of localized modes in lattices of size N with parity-time (PT) symmetry. Such modes are arranged in pairs of quasidegenerate levels with splitting deltaapproxexp{sup -N/x}i where xi is their localization length. The level 'evolution' with respect to the PT breaking parameter gamma shows a cascade of bifurcations during which a pair of real levels becomes complex. The spontaneous PT symmetry breaking occurs at gamma{sub PT}approxmin(delta), thus resulting in an exponentially narrow exact PT phase. As N/xi decreases, it becomes more robust with gamma{sub PT}approx1/N{sup 2} and the distribution P(gamma{sub PT}) changes from log-normal to semi-Gaussian. Our theory can be tested in the frame of optical lattices.

Bendix, Oliver; Fleischmann, Ragnar [MPI for Dynamics and Self-Organization, Bunsenstrasse 10, Goettingen (Germany); Kottos, Tsampikos [Wesleyan University, Middletown, Connecticut, 06459 (United States); Shapiro, Boris [Technion - Israel Institute of Technology, Technion City, Haifa 32000 (Israel)

2009-07-17T23:59:59.000Z

159

Linear polarization measurements on gamma rays from Pb104 and Pd106  

Science Journals Connector (OSTI)

The linear polarizations of ? rays from the deexcitation of Pd104 and Pd106 following (heavy ion, x n) reactions were measured using a Compton polarimeter. Multipolarities for these ? rays are tabulated and level schemes are given. Polarization measurements clearly show negative parity for two major quasirotational sidebands in both Pd104 and Pd106.NUCLEAR REACTIONS Zr94(C13,3 n), E=47 MeV; Zr96(C13,3 n), E=42 MeV. Linear polarization of Pd104 and Pd106 ? rays measured.

D. C. Stromswold; D. O. Elliott; Y. K. Lee; J. A. Grau; L. E. Samuelson; F. A. Rickey; P. C. Simms

1976-04-01T23:59:59.000Z

160

PT Symmetric Aubry-Andre Model  

E-Print Network (OSTI)

PT symmetric Aubry-Andre model describes an array of N coupled optical waveguides with position dependent gain and loss. We show that the reality of the spectrum depends sensitively on the degree of disorder for small number of lattice sites. We obtain the Hofstadter Butterfly spectrum and discuss the existence of the phase transition from extended to localized states. We show that rapidly changing periodical gain/loss materials almost conserves the total intensity.

C. Yuce

2014-02-12T23:59:59.000Z

Note: This page contains sample records for the topic "ni pd pt" 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

Bulk Migration of Ni/NiO in Ni-YSZ during Reducing Conditions...  

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

random grain orientation. The surface analysis and mapping were carried out using ToF-SIMS and AES whereas EDS maps on FIB sliced areas on Ni-YSZ were utilized for the bulk...

162

Synthesis, Characterization, and Application of PVP-Pd NP in the Aerobic Oxidation of 5-Hydroxymethylfurfural (HMF)  

Science Journals Connector (OSTI)

PVP stabilized Pd nanoparticles (Pd NP) were prepared in ethylene glycol at three different NaOH/Pd ratios and characterized by XRD, transmission electron microscopy (TEM), and small-angle X-ray scattering (SAXS)...

Baraa Siyo; Matthias Schneider; Marga-Martina Pohl; Peter Langer…

2014-03-01T23:59:59.000Z

163

Methanol Synthesis from CO2 Hydrogenation over a Pd4/In2O3 Model...  

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

Methanol Synthesis from CO2 Hydrogenation over a Pd4In2O3 Model Catalyst: A Combined DFT and Kinetic Study. Methanol Synthesis from CO2 Hydrogenation over a Pd4In2O3 Model...

164

Comparative and Functional Genomics of Rhodococcus opacus PD630 for Biofuels Development  

E-Print Network (OSTI)

Comparative and Functional Genomics of Rhodococcus opacus PD630 for Biofuels Development Jason W and Functional Genomics of Rhodococcus opacus PD630 for Biofuels Development. PLoS Genet 7(9): e1002219. doi:10

Sinskey, Anthony J.

165

Development and Applications of Pd Catalysts for C-N Cross-Coupling Reactions  

E-Print Network (OSTI)

Chapter 1 A procedure for forming a highly active Pd(0) catalyst from Pd(OAc) 2, water, and biarylphosphine ligands has been developed. This protocol generates a catalyst system, which exhibits excellent reactivity and ...

Fors, Brett P

2011-01-01T23:59:59.000Z

166

Hydrogen Absorption in Pd-based Nanostructures - Final Report  

SciTech Connect

Pd is known to absorb hydrogen. Molecules are normally chemisorbed at the surface in a process where the molecule breaks into two hydrogen atoms, and the protons are then absorbed into the bulk. This process consists of electron filling holes in the Pd 4d band near the Fermi energy, which due to the high density of states at the Fermi energy, is an energetically favorable process. Our aim with this project was to determine possible changes in magnetic properties with Pd nm-length-scale thick layers intercalated by magnetic materials. Before the start of this work, the literature indicated that there were several possible scenarios by which this could happen: i) the Pd will be magnetized due to a proximity effect with nearby magnetic layers, resulting in changes in the magnetization due to H2 absorption; ii) some H will be absorbed into the magnetic layers, causing a change in the magnetic exchange interactions; or iii) absorption of H2 will cause an expansion of the lattice, resulting in a magnetoelastic effect which changes the magnetic properties.

David Lederman

2012-10-22T23:59:59.000Z

167

Relativistic calculations of electronic states of PdH  

Science Journals Connector (OSTI)

Complete active space MCSCF(CASSCF)/first?order configuration interaction (FOCI) calculations followed by relativistic configuration interaction (RCI) calculations are carried out on 2?+ 2? 2? and 2?+(II) ?–s states and 1/2 3/2 1/2(II) 3/2(II) and 5/2 ?–? states of PdH. Our calculations predict that the ground state is 2?+ 1/2. The spin–orbit splitting and contamination of the excited states (2? and 2?) are quite large. The two 3/2 states are quite mixed [3/2(I): 66% 2?3 / 2 29% 2?3 / 2] in character. The spectroscopic properties (R e T e D e and ? e ) of all the above states are calculated and compared with available experimental results on the ground state of PdD. The Mulliken population analysis of the low?lying states of PdH shows that the 2?+ state is ionic (Pd+H?) but the excited 2? and 2? states are a bit more ionic with the same polarity as the ground state. The 3/2 state exhibits an interesting avoided crossing.

K. Balasubramanian; P. Y. Feng; M. Z. Liao

1987-01-01T23:59:59.000Z

168

Vacancies below the ,,111... surface of Pd Russel P. Kauffman*  

E-Print Network (OSTI)

Vacancies below the ,,111... surface of Pd Russel P. Kauffman* Department of Physics, Muhlenberg is used to investigate vacancies at or below the 111 surface of palladium and in the bulk. An accurate. The interaction of the vacancy, a point defect, with a surface, a planar defect, is investigated. Also studied

Rappe, Andrew M.

169

Data Abstraction Form for population PK, PD publications MODEL BUILDING Data Abstraction Form  

E-Print Network (OSTI)

Data Abstraction Form for population PK, PD publications MODEL BUILDING 1 Data Abstraction Form for population PK/PD publications MODEL BUILDING Brendel K.1* , Dartois C.2* , Comets E.1 , Lemenuel-Diot A.3;Data Abstraction Form for population PK, PD publications MODEL BUILDING 2 Table of contents Purpose

Boyer, Edmond

170

Ethylene combustion on unsupported and supported Pd: a comparative , Y.-F. Hana,b  

E-Print Network (OSTI)

Ethylene combustion on unsupported and supported Pd: a comparative study D. Kumara , Y.-F. Hana Ethylene combustion is studied at elevated pressures on Pd(100) and compared with supported Pd catalysts; the highest reaction rate was achieved for relatively low coverage of surface carbon. KEY WORDS: ethylene

Goodman, Wayne

171

Graphene decorated with PtAu alloy nanoparticles: facile synthesis...  

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

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

172

Approved Module Information for PD2003, 2014/5 Module Title/Name: Engineering Principles 2 Module Code: PD2003  

E-Print Network (OSTI)

to apply further engineering principles of mechanics, solid mechanics, energy systems and thermo-fluids and understanding of the fundamental engineering principles of mechanics, solid mechanics and thermo- fluidsApproved Module Information for PD2003, 2014/5 Module Title/Name: Engineering Principles 2 Module

Neirotti, Juan Pablo

173

The Obviative Suffix -ni- In Algonquian  

E-Print Network (OSTI)

the marker -ni- is used specifically when an argument has been established as obviative earlier in the discourse. By tracing -ni- in the morphology of Fox and Kickapoo and in Bloomfield's comparative Algonquian work (Bloomfield 1946), the present paper...

Gathercole, Geoffrey

1979-01-01T23:59:59.000Z

174

Monopole Strength in Ni-58  

E-Print Network (OSTI)

PHYSICAL REVIEW C VOLUME 44, NUMBER 5 Monopole strength in Ni NOVEMBER 1991 D. H. Youngblood and Y.-W. Lui Cyclotron Institute, Texas AdkM Uni Uersi ty, College Station, Texas 77843 (Received 20 June 1991) Differential cross-section data from... of Ener- gy under Grant No. DE-FG05-86ER40256. MONOPOLE STRENGTH IN "Ni 1881 [1]D. H. Youngblood, P. Bogucki, J. D. Bronson, U. Garg, Y.-W. Lui, and C. M. Rozsa, Phys. Rev. C 23, 1997 (1981). [2] M. Buenerd, J. Phys. C 4, 115 (1984). [3] S...

Youngblood, David H.; Lui, YW.

1991-01-01T23:59:59.000Z

175

Sulfur Tolerant Pd/Cu and Pd/Au Alloy Membranes for H2 Separation with High Pressure CO2 for Sequestration  

SciTech Connect

The effect of H{sub 2}S poisoning on Pd, Pd/Cu, and Pd/Au alloy composite membranes prepared by the electroless deposition method on porous Inconel supports was investigated to provide a fundamental understanding of the durability and preparation of sulfur tolerant membranes. X-ray photoelectron spectroscopy (XPS) studies showed that the exposure of pure Pd to 50 ppm H{sub 2}S/H{sub 2} mixtures caused bulk sulfide formation at lower temperatures and surface sulfide formation at higher temperatures. Lower temperatures, longer exposure times, and higher H{sub 2}S concentrations resulted in a higher degree of sulfidation. In a Pd membrane, the bulk sulfide formation caused a drastic irrecoverable H{sub 2} permeance decline and an irreparable loss in selectivity. Pd/Cu and Pd/Au alloy membranes exhibited permeance declines due to surface sulfide formation upon exposure to 50 ppm H{sub 2}S/H{sub 2} gas mixtures. However in contrast to the pure Pd membrane, the permeances of the Pd/Cu and Pd/Au alloy membranes were mostly recovered in pure H{sub 2} and the selectivity of the Pd alloy layers remained essentially intact throughout the characterization in H{sub 2}, He and H{sub 2}S/H{sub 2} mixtures which lasted several thousand hours. The amount of irreversible sulfur poisoning decreased with increasing temperature due to the exothermicity of H{sub 2}S adsorption. Longer exposure times increased the amount of irreversible poisoning of the Pd/Cu membrane but not the Pd/Au membrane. Pd/Au coupon studies of the galvanic displacement method showed that higher Au{sup 3+} concentrations, lower pH values, higher bath temperatures and stirring the bath at a rate of 200 rpm yielded faster displacement rates, more uniform depositions, and a higher Au content within the layers. While 400 C was found to be sufficient to form a Pd/Au alloy on the surface, high temperature X-ray diffraction (HTXRD) studies showed that even after annealing between 500-600 C, the Pd/Cu alloys could have part or all of the surface in the less sulfur resistant {beta} phase.

Yi Hua Ma; Natalie Pomerantz; Chao-Huang Chen

2008-09-30T23:59:59.000Z

176

Magnetism in CePtPb  

Science Journals Connector (OSTI)

We report the behavior of the hexagonal compound CePtPb, which has an antiferromagnetic transition at TN=0.9 K. The magnetic susceptibility is highly anisotropic, with the ratio ?ab?ac extrapolating to the value 65 at TN. The low-temperature magnetization is also anisotropic with Mab saturating to 0.92?BCe atom at B=5 T, where Mc is five times smaller. The anisotropy is due both to low-symmetry crystal fields and to exchange anisotropy, which causes basal plane ferromagnetic fluctuations to develop below T?15 K. Three facts suggest that the magnetic order might coexist with heavy-fermion behavior: heat-capacity data show a linear-in-temperature contribution ??300 mJ/mol K2 in the antiferromagnetic state; the resistivity is quadratic in temperature below TN; and the magnetic entropy is generated very slowly with temperature reaching a value of only 0.7R ln2 at T=2TN. On the other hand, the long high-temperature tail of the heat-capacity data correlates with the ferromagnetic fluctuations above TN; and ac susceptibility measurements under hydrostatic pressure (to 17 kbar) show that TN increases with pressure at an approximate rate 20 mK/kbar, which suggests that CePtPb sits in the small T limit of the Doniach phase diagram; hence heavy-fermion effects may be negligible.

R. Movshovich; J. M. Lawrence; M. F. Hundley; J. Neumeier; J. D. Thompson; A. Lacerda; Z. Fisk

1996-03-01T23:59:59.000Z

177

Design of graphene sheets-supported Pt catalyst layer in PEM...  

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

graphene sheets-supported Pt catalyst layer in PEM fuel cells. Design of graphene sheets-supported Pt catalyst layer in PEM fuel cells. Abstract: A series of cathodes using Pt...

178

Rh and Pt catalysts activated by UHV treatments  

Science Journals Connector (OSTI)

The H2?D2...exchange activity of Rh powder was enhanced by high-temperature UHV treatment accompanied with an enrichment of the...2PtCl6·6H2O under UHV condition resulted in an extremely active Pt...

S. Nishiyama; K. Yoshioka; S. Matsuura…

1987-01-01T23:59:59.000Z

179

Kinetics of Ni Sorption in Soils: Roles of Soil Organic Matter and Ni Precipitation  

SciTech Connect

The kinetics of Ni sorption to two Delaware agricultural soils were studied to quantitatively assess the relative importance of Ni adsorption on soil organic matter (SOM) and the formation of Ni layered double hydroxide (Ni-LDH) precipitates using both experimental studies and kinetic modeling. Batch sorption kinetic experiments were conducted with both soils at pH 6.0, 7.0, and 7.5 from 24 h up to 1 month. Time-resolved Ni speciation in soils was determined by X-ray absorption spectroscopy (XAS) during the kinetic experiments. A kinetics model was developed to describe Ni kinetic reactions under various reaction conditions and time scales, which integrated Ni adsorption on SOM with Ni-LDH precipitation in soils. The soil Ni speciation (adsorbed phases and Ni-LDH) calculated using the kinetics model was consistent with that obtained through XAS analysis during the sorption processes. Under our experimental conditions, both modeling and XAS results demonstrated that Ni adsorption on SOM was dominant in the short term and the formation of Ni-LDH precipitates accounted for the long-term Ni sequestration in soils, and, more interestingly, that the adsorbed Ni may slowly transfer to Ni-LDH phases with longer reaction times.

Shi, Zhenqing; Peltier, Edward; Sparks, Donald L. (Delaware); (Kansas)

2012-12-10T23:59:59.000Z

180

Direct Determination of the Ionization Energies of PtC, PtO, and PtO2 with VUV Radiation  

E-Print Network (OSTI)

of the third-row transition metal carbides. 48 For PtC, theyIntroduction Transition metal oxides and carbides have beenunsaturated transition metal oxides and carbides. In

Citir, Murat

2008-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "ni pd pt" 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

Decay of Ag104 and Levels in Pd104  

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The radioactive decay of the isomers of Ag104 has been investigated using scintillation spectrometers and a magnetic beta-ray spectrometer. Half-lives of (66±1) and (29.8±0.5) minutes were determined for the spin 5 and spin 2 isomers, respectively. Conversion electrons corresponding to 15 gamma rays assigned to Pd104 were observed. Two allowed positron transitions were detected: one of end-point energy (990±10) kev from the spin 5 isomer of Ag104; and the other of end-point energy (2705±15) kev from the spin 2 isomer. Gamma-gamma and beta-gamma coincidences were observed. The experimental data together with data obtained by other investigators is used to determine the spins and parities of the low-lying excited states of Pd104.

H. Nutley and J. B. Gerhart

1960-12-01T23:59:59.000Z

182

The PD algorithm: a simulation based partitioning algorithm for ATPG  

E-Print Network (OSTI)

to FAN (time measured in sec) II The result compared to SOCRATES (time measured in sec) III The result compared to recursive learning(time in sec) vu1 LIST OF FIGURES FIGURE Page Illustration of Redundanc1es Illustration of the Circle Concept 10... Illustration of the PD ('oncept Illustration of Simulation and Imphcat1on The System Implementation. . . . The SETUP Procedure Flow Chart . The IMPLICATION Procedure Flow Chart The SIMULATION Procedure Flow Chart . The GOAL Procedure Flow Chart The BACIa...

Lin, Shyh-Horng

2012-06-07T23:59:59.000Z

183

Highly Dispersed and Nano-sized Pt-based Electrocatalysts for Low-Temperature Fuel Cells  

Science Journals Connector (OSTI)

The present article reviews the development of highly dispersed and nano-sized Pt- ... the addition of metal oxide to Pt/C electrocatalyst as cathode material.

Dong-Ha Lim; Weon-Doo Lee; Ho-In Lee

2008-12-01T23:59:59.000Z

184

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

E-Print Network (OSTI)

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

Calvo, Sergio Rafael

2009-05-15T23:59:59.000Z

185

Interface structures in FePtFe3Pt hard-soft exchange-coupled magnetic nanocomposites  

E-Print Network (OSTI)

Interface structures in FePtÃ?Fe3Pt hard-soft exchange-coupled magnetic nanocomposites Jing Li with sizes 10 nm. This ensures the effective exchange coupling of magnetically hard and soft phases. High magnetic materials, the performance of conventional bulk permanent magnetic ma- terials is limited by its

Liu, J. Ping

186

Effect of Pt film thickness on PtSi formation and film surface morphology Jinghua Yina,*, Wei Caib  

E-Print Network (OSTI)

Platinum silicide (PtSi) has been one of the most widely used metal silicides in Si based microelectronic film thickness on the formation of platinum silicide (PtSi) phase, distribution of silicides in the literature [9­12]. According to the annealing conditions, the different silicide structures can be observed

Zheng, Yufeng

187

Rh i isoelectronic sequence observed from Er[sup 23+] to Pt[sup 33+  

SciTech Connect

The TEXT tokamak was used to obtain spectra of highly ionized Er, Yb, Hf, W, and Pt. Injection of these elements into the plasma was achieved by laser ablation of thin films of metal deposited on glass slides and mounted at the inner wall of the vessel. The spectra were photographed with a 2.2-m grazing-incidence spectrograph set at a grazing angle of 4[degree]. These spectra occur in a very small wavelength interval, for example, [similar to]2 A at 50 A in W. In this spectral range we previously classified lines of the Ag and Pd isoelectronic sequences. We have now classified lines of the Rh isoelectronic sequence 4[ital d][sup 9--4][ital d][sup 84][ital f], which accounts for the remaining strong lines in this dense but well-resolved group. No lines of this array have previously been identified. They were classified by comparison of observed and calculated transition energies along the isoelectronic sequence.

Sugar, J.; Kaufman, V. (National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States)); Rowan, W.L. (Fusion Research Center, University of Texas, Austin, Texas 78712 (United States))

1993-11-01T23:59:59.000Z

188

Department of Energy Pt. 824, App. A  

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

5 5 Department of Energy Pt. 824, App. A not been paid within sixty calendar days after the assessment has been issued, the DOE shall institute an ac- tion in the appropriate District Court of the United States for an order af- firming the assessment of the civil pen- alty. § 824.15 Collection of civil penalties. If any person fails to pay an assess- ment of a civil penalty after it has be- come a final order or after the appro- priate District Court has entered final judgment for DOE under § 824.14, DOE shall institute an action to recover the amount of such penalty in an appro- priate District Court of the United States. § 824.16 Direction to NNSA contrac- tors. (a) Notwithstanding any other provi- sion of this part, the NNSA Adminis- trator, rather than the Director, signs,

189

Department of Energy Pt. 824, App. A  

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

5 5 Department of Energy Pt. 824, App. A not been paid within sixty calendar days after the assessment has been issued, the DOE shall institute an ac- tion in the appropriate District Court of the United States for an order af- firming the assessment of the civil pen- alty. § 824.15 Collection of civil penalties. If any person fails to pay an assess- ment of a civil penalty after it has be- come a final order or after the appro- priate District Court has entered final judgment for DOE under § 824.14, DOE shall institute an action to recover the amount of such penalty in an appro- priate District Court of the United States. § 824.16 Direction to NNSA contrac- tors. (a) Notwithstanding any other provi- sion of this part, the NNSA Adminis- trator, rather than the Director, signs,

190

Invisibility in PT-symmetric complex crystals  

E-Print Network (OSTI)

Bragg scattering in sinusoidal PT-symmetric complex crystals of finite thickness is theoretically investigated by the derivation of exact analytical expressions for reflection and transmission coefficients in terms of modified Bessel functions of first kind. The analytical results indicate that unidirectional invisibility, recently predicted for such crystals by coupled-mode theory [Z. Lin et al., Phys. Rev. Lett. 106, 213901 (2011)], breaks down for crystals containing a large number of unit cells. In particular, for a given modulation depth in a shallow sinusoidal potential, three regimes are encountered as the crystal thickness is increased. At short lengths the crystal is reflectionless and invisible when probed from one side (unidirectional invisibility), whereas at intermediate lengths the crystal remains reflectionless but not invisible; for longer crystals both unidirectional reflectionless and invisibility properties are broken.

Stefano Longhi

2011-11-15T23:59:59.000Z

191

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

192

Pt/SWNT?Pt/C Nanocomposite Electrocatalysts for Proton-Exchange Membrane Fuel Cells  

Science Journals Connector (OSTI)

The dependence of the fuel cell performance on the dispersion and accessibility of SWNT support and Pt electrocatalysts in the electrocatalyst mixture for the oxygen reduction reaction in PEMFC has been discussed. ... Further, in PEMFC, most of the recent work is being focused on the development of cathode electrocatalyst materials. ... to 500-800°, and reducing PEMFC system complexity be developing 'water-free' membranes which can also be operated at temps. ...

A. Leela Mohana Reddy; S. Ramaprabhu

2007-10-17T23:59:59.000Z

193

Microstructure and Corrosion Behavior of the Cu-Pd-X Ternary Alloys for Hydrogen Separation Membranes  

SciTech Connect

CuPd alloys are among the most promising candidate materials for hydrogen separation membranes and membrane reactor applications due to their high hydrogen permeability and better sulfur resistance. In order to reduce the Pd content and, therefore, the cost of the membrane materials, efforts have been initiated to develop CuPdM ternary alloys having a bcc structure. The advantages of having Pd as a hydrogen separation membrane are: (1) high hydrogen selectivity; and (2) high hydrogen permeability. The disadvantages are: (1) high cost; (2) hydrogen embrittlement ({alpha} {yields} {beta} Pd hydride); and (3) sulfur poisoning. Experiments (XRD, SEM/EDS) verified that Mg, Al, La, Y and Ti are promising alloying elements to expand the B2 phase region in Cu-Pd binary system. HT-XRD showed that the B2 to FCC transition temperatures for Cu-Pd-X (X = Mg, Al, La, Y and Ti) are higher than that of Cu-Pd binary alloys. While the Cu-50Pd alloy had the highest corrosion resistance to the H2S containing syngas, the Cu-Pd-Mg alloy had a comparable resistance.

O.N. Dogan; M.C. Gao; B.H. Howard

2012-02-26T23:59:59.000Z

194

Interaction of carbon monoxide with oxygen in the adsorbed layer on Pd, Ce, Pd-Ce catalysts supported on /gamma/-Al/sub 2/O/sub 3/  

SciTech Connect

The adsorption of CO and the interaction of CO/sub ads/ with O/sub 2/ on Pd, Ce, and Pd-Ce//gamma/-Al/sub 2/O/sub 3/ (0.5 wt. % Pd, 2.0 wt. % Ce) has been studied using the methods of IR spectroscopy and differential scanning calorimetry. The identity of the adsorbed CO complexes, the temperature ranges over which they desorb, and their reactivity with O/sub 2/ have been established. The interaction of bridging and carbonate - carboxylate CO complexes and carbon (disproportionation and dissociation products) with O/sub 2/ on Pd and Pd-Ce catalysts is preceded by the coadsorption of oxygen and the evolution of heat. During the oxidation of CO, autooscillation, heat evolution, and the concentration of oxygen in the flow are observed.

Savel'eva, G.A.; Sass, A.S.; Speranskaya, G.V.; Tenchev, K.K.; Petrov, L.A.; Vozdvizhenskii, V.F.; Galeev, T.K.; Popova, N.M.

1989-01-01T23:59:59.000Z

195

Ni Sorption on Pyrophyllite: Evidence for the Formation of Ni-Al Hydroxide and Its Transformation into Ni-Silicate by Visible,  

E-Print Network (OSTI)

Ni Sorption on Pyrophyllite: Evidence for the Formation of Ni-Al Hydroxide and Its Transformation. Ford, K. S. Scheckel Former EXAFS studies of the sorption of Co and Ni on Al-containing clay minerals

Sparks, Donald L.

196

Improving the phase stability and oxidation resistance of B-NiAl  

SciTech Connect

High temperature alloys are essential to many industries that require a stable material to perform in harsh oxidative environments. Many of these alloys are suited for specific applications such as jet engine turbine blades where most other materials would either melt or oxidize and crumble (1). These alloys must have a high melting temperature, excellent oxidation resistance, good creep resistance, and decent fracture toughness to be successfully used in such environments. The discovery of Ni based superalloys in the 1940s revolutionized the high temperature alloy industry and there has been continued development of these alloys since their advent (2). These materials are capable of operating in oxidative environments in the presence of combustion gases, water vapor and at temperatures around 1050 C. Demands for increased f uel efficiency, however, has highlighted the need for materials that can be used under similar atmospheres and at temperatures in excess of 1200 C. The current Ni based superalloys are restricted to lower temperatures due to the presence of a number of low melting phases that result in softening of the alloys above 1000 C. Therefore, recent research has been aimed at exploring and developing newer alloy systems that can meet the escalating requirements. This thesis comprises a part of such an effort. The motivation of this work is to develop a novel high temperature alloy system that shows improved performance at higher temperatures than the currently employed alloys. The desired alloy should be in accordance with the requirements established in the National Energy Technology Laboratory (NETL) FutureGen program having an operating temperature around 1300 C. Alloys based on NiAl offer significant potential payoffs as structural materials in gas turbine applications due to a unique range of physical and mechanical properties. Alloying additions to NiAl could be used to further improve the pertinent properties that currently limit this system from replacing Ni based superalloys. Modifications to NiAl were explored to increase the phase stability and oxidation resistance which would allow these alloys to be used at even higher temperatures yielding greater efficiencies. The extended Miedema model was an effective tool that screened all of the potential phase space for ternary substitutions to NiAl and found the few potential systems worth further investigation. After production of the alloys it was determined that Ir, Rh, and Pd were the top candidates for substitution on Ni site up to 12 at%. The melting temperature of NiAl could be increased as much as 150 C with 12 at% Ir and 130 C with 12 at% Rh substitution. Pall adium on the other hand decreased the melting temperature by 50 C at the 12 at% substitution level. The grain size was found to have a profound influence on the oxidation resistance. Both Ir and Rh substitutions resulted in finer grain sizes compared to Pd substitutions or base NiAl. The grain size increased drastically during high temperature annealing with the PGM substitutions hindering grain growth only slightly. However, the addition of 0.05 at% Hf limited the grain growth dramatically during high temperature annealing. NiAl inherently has respectable oxidation resistance up to 1100 C. It was found through experimental testing that both Ir and Rh substitutions improve the oxidation resistance of NiAl at ultra-high temperatures with Ir performing the best. Both PGM substitutions decreased the growth rate as well as forming a more adherent oxide scale. Pd substitutions appeared to have a negligible effect to the oxidation resistance of NiAl. Hafnium addition of 0.05 at% was found to decrease the oxidation rate as well as increase the scale adherence. The combination of both Ir substitution (6-9 at%) and Hf addition (0.05 at%) produced the alloy with the best oxidation resistance. Although improvements in phase stability and oxidation resistance have been made to the NiAl system, more development and testing are still needed. Two major issues yet to be resolved are the low fracture toughn

Brammer, Travis

2011-08-15T23:59:59.000Z

197

Extended, Continuous Pt Nanostructures in Thick, Dispersed Electrodes  

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

Bryan Pivovar (PI) Bryan Pivovar (PI) National Renewable Energy Laboratory Sept 30, 2009 Extended, Continuous Pt Nanostructures in Thick, Dispersed Electrodes This presentation does not contain any proprietary, confidential, or otherwise restricted information Objectives To assist the DOE Fuel Cell Technologies (FCT) Program in meeting cost, durability, and performance targets in the areas of Electrocatalysts and MEAs. Approach: Novel Synthesis and Electrode Studies Pt nanotubes (UC-R) Pt coated carbon nanotubes Synthesis of novel catalysts based on extended surfaces due to 3M's demonstrated improvements in specific activity and durability using similar systems. Electrode architecture design, based on novel catalyst structures that allow thick (~10 µm), dispersed electrodes to

198

High Throughput Combinatorial Screening of Biometic Metal-Organic...  

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

O O OH O HO OH O Co V 3+ Cr 3+ Mn 2+ Fe 2+ Co 2+ Ni 2+ Cu 2+ Ni Pd Pt SBU metal ions bare metal Carboxylate linkers Vibrational Spectroscopy of Hydrogen Raman *H 2 in gas...

199

Three dimensional magnetism and coupling to conduction electrons in PdCrO2  

SciTech Connect

We report density functional calculations addressing the electronic structure and magnetic properties of delafossite PdCrO{sub 2}. We find substantial magnetic interactions in the c-axis direction as well as beyond first nearest neighbors in-plane, so that PdCrO{sub 2} is a three-dimensional (3D) frustrated antiferromagnet. We also find substantial coupling between the Cr moments and the Pd derived conduction electrons.

Ong, Khuong P [IHPC, Singapore; Singh, David J [ORNL

2012-01-01T23:59:59.000Z

200

6PA40 6PA41 Sputtering ofW-Pd Bimetallic System under Nitrogen  

E-Print Network (OSTI)

be useful not only for fusion problem, bur for numerous plasma appli- cations (hydrogen power engineering at magnetic field 0.05T in nitrogen at pres sure 2.10V3 Torr. The ion energy value8 were 0.8 keV - 1.6 ke coefficient weakly depends on ion energy for both Pd and W-Pd system and its value (1.3at./ion for Pd and 0

Harilal, S. S.

Note: This page contains sample records for the topic "ni pd pt" 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

Properties of spark-deposited Ni–Cr–NiAl coatings  

Science Journals Connector (OSTI)

The structure and phase composition of sintered Ni–Cr–NiAl alloys and the kinetics of their electrospark deposition onto 45 steel are examined. It is ... shown that the mass transfer coefficient for the deposition

A. V. Paustovskii; R. A. Alfintseva…

2009-07-01T23:59:59.000Z

202

Differentiation of O–H and C–H Bond Scission Mechanisms of Ethylene Glycol on Pt and Ni/Pt Using Theory and Isotopic Labeling Experiments  

Science Journals Connector (OSTI)

Understanding and controlling bond-breaking sequences of oxygenates on transition metal catalysts can greatly impact the utilization of biomass feedstocks for fuels and chemicals. ...

Michael Salciccioli; Weiting Yu; Mark A. Barteau; Jingguang G. Chen; Dionisios G. Vlachos

2011-04-28T23:59:59.000Z

203

Hydrogenation of Acetylene-Ethylene Mixtures over Pd and Pd-Ag Alloys: First-Principles Based Kinetic Monte Carlo Simulations  

SciTech Connect

The kinetics for the selective hydrogenation of acetylene-ethylene mixtures over model Pd(111) and bimetallic Pd-Ag alloy surfaces were examined using first principles based kinetic Monte Carlo (KMC) simulations to elucidate the effects of alloying as well as process conditions (temperature and hydrogen partial pressure). The mechanisms that control the selective and unselective routes which included hydrogenation, dehydrogenation and C-?C bond breaking pathways were analyzed using first-principle density functional theory (DFT) calculations. The results were used to construct an intrinsic kinetic database that was used in a variable time step kinetic Monte Carlo simulation to follow the kinetics and the molecular transformations in the selective hydrogenation of acetylene-ethylene feeds over Pd and Pd-Ag surfaces. The lateral interactions between coadsorbates that occur through-surface and through-space were estimated using DFT-parameterized bond order conservation and van der Waal interaction models respectively. The simulation results show that the rate of acetylene hydrogenation as well as the ethylene selectivity increase with temperature over both the Pd(111) and the Pd-Ag/Pd(111) alloy surfaces. The selective hydrogenation of acetylene to ethylene proceeds via the formation of a vinyl intermediate. The unselective formation of ethane is the result of the over-hydrogenation of ethylene as well as over-hydrogenation of vinyl to form ethylidene. Ethylidene further hydrogenates to form ethane and dehydrogenates to form ethylidyne. While ethylidyne is not reactive, it can block adsorption sites which limit the availability of hydrogen on the surface and thus act to enhance the selectivity. Alloying Ag into the Pd surface decreases the overall rated but increases the ethylene selectivity significantly by promoting the selective hydrogenation of vinyl to ethylene and concomitantly suppressing the unselective path involving the hydrogenation of vinyl to ethylidene and the dehydrogenation ethylidene to ethylidyne. This is consistent with experimental results which suggest only the predominant hydrogenation path involving the sequential addition of hydrogen to form vinyl and ethylene exists over the Pd-Ag alloys. Ag enhances the desorption of ethylene and hydrogen from the surface thus limiting their ability to undergo subsequent reactions. The simulated apparent activation barriers were calculated to be 32-44 kJ/mol on Pd(111) and 26-31 kJ/mol on Pd-Ag/Pd(111) respectively. The reaction was found to be essentially first order in hydrogen over Pd(111) and Pd-Ag/Pd(111) surfaces. The results reveal that increases in the hydrogen partial pressure increase the activity but decrease ethylene selectivity over both Pd and Pd-Ag/Pd(111) surfaces. Pacific Northwest National Laboratory is operated by Battelle for the US Department of Energy.

Mei, Donghai; Neurock, Matthew; Smith, C Michael

2009-10-22T23:59:59.000Z

204

Stretching dependence of the vibration modes of a single-molecule Pt-H2-Pt bridge  

Science Journals Connector (OSTI)

A conducting bridge of a single hydrogen molecule between Pt electrodes is formed in a break junction experiment. It has a conductance near the quantum unit, G0=2e2?h, carried by a single channel. Using point-contact spectroscopy three vibration modes are observed and their variation upon isotope substitution is obtained. The stretching dependence for each of the modes allows uniquely classifying them as longitudinal or transversal modes. The interpretation of the experiment in terms of a Pt-H2-Pt bridge is verified by density-functional theory calculations for the stability, vibrational modes, and conductance of the structure.

D. Djukic; K. S. Thygesen; C. Untiedt; R. H. M. Smit; K. W. Jacobsen; J. M. van Ruitenbeek

2005-04-20T23:59:59.000Z

205

Mechanism of O2 Activation and Methanol Production by (Di(2-pyridyl)methanesulfonate)PtII  

E-Print Network (OSTI)

conversion of methane to methanol at low temper- ature is crucial for transportation of shale gas produced it to methanol and its derivatives. In this system, the kinetics of the oxidation of Pt(II) is important because activation and selective conversion of Pt(II) monomethyl complex (dpms)PtII Me(OH2) to its monomethyl Pt

Goddard III, William A.

206

In-situ synchrotron energy-dispersive x-ray diffraction study of thin Pd foils with Pd:D and Pd:H concentrations up to 1:1  

SciTech Connect

Time resolved, in-situ, energy dispersive x-ray diffraction was performed in an electrolysis cell during electrochemical loading of palladium foil cathodes with hydrogen and deuterium. Concentrations of H:Pd (D:Pd) up to 1:1 in 0.1 M LiOH (LiOD) in H{sub 2}O (D{sub 2}O) electrolyte were obtained, as determined by both the Pd lattice parameter and cathode resistivity. In addition, some indications on the kinetics of loading and deloading of hydrogen from the Pd surface were obtained. The alpha-beta phase transformations were clearly delineated but no new phases at high concentration were determined.

Knies, D. L.; Grabowski, K. S.; Dominguez, D. D.; Qadri, S. B.; Hubler, G. K. [U.S. Naval Research Laboratory, Washington, DC 20375 (United States); Violante, V. [ENEA, Frascati (Italy); Hu, J. Z. [NSLS, Brookhaven National Laboratory, Brookhaven, New York 11973 (United States); He, J. H. [Nova Research, Alexandria, Virginia 22308 (United States)

2012-10-15T23:59:59.000Z

207

Formation of FePt nanoparticles by organometallic synthesis  

SciTech Connect

Our interest in determining the mechanism of FePt nanoparticle formation has led to this study of the evolution of particle size and composition during synthesis. FePt nanoparticles were prepared by the simultaneous reduction of platinum acetylacetonate and thermal decomposition of iron pentacarbonyl. During the course of the reaction, samples were removed and the particle structure, size, and composition were determined using x-ray diffraction, transmission electron microscopy (TEM), and scanning electron microscopy-energy dispersive x-ray spectrometry. Early in the reaction the particles were Pt rich (greater than 95 at. % Pt) and as the reaction proceeded the Fe content increased to the target of 50%. The particle diameter increased from 3.1 to 4.6 nm during the reaction. Energy dispersive x-ray spectrometry measurements of individual particle compositions using a high resolution TEM showed a broad distribution of particle compositions with a standard deviation greater than 15% of the average composition.

Bagaria, H. G.; Johnson, D. T.; Srivastava, C.; Thompson, G. B.; Shamsuzzoha, M.; Nikles, D. E. [Department of Chemical and Biological Engineering, The University of Alabama, P.O. Box 870203, Tuscaloosa, Alabama 35487 and Center for Materials for Information Technology, The University of Alabama, P.O. Box 870209, Tuscaloosa, Alabama 35487 (United States); Department of Metallurgical and Materials Engineering, The University of Alabama, P.O. Box 870202, Tuscaloosa, Alabama 35487 and Center for Materials for Information Technology, The University of Alabama, P.O. Box 870209, Tuscaloosa, Alabama 35487 (United States); School of Mines and Energy Development, The University of Alabama, Tuscaloosa, Alabama 35487 (United States); Department of Chemistry, The University of Alabama, P.O. Box 870336, Tuscaloosa, Alabama 35487 and Center for Materials for Information Technology, The University of Alabama, P.O. Box 870209, Tuscaloosa, Alabama 35487 (United States)

2007-05-15T23:59:59.000Z

208

Growth of Ordered Ultrathin Tungsten Oxide Films on Pt(111)....  

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

tungsten oxide ultra-thin films were prepared on a Pt(111) substrate at 700 K via direct sublimation of monodispersed cyclic (WO3)3 trimers. The surface composition, structure and...

209

Pt-free, Perovskite-based Lean NOx Trap Catalysts  

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

Conference Pt-free, Perovskite-based Lean NO x Trap Catalysts Gongshin Qi, Chang H. Kim, and Wei Li GM Global Research & Development 2010 DEER Conference Overview LNT Chemistry...

210

Pt NANOCLUSTERS ON CARBON NANOMATERIALS FOR HYDROGEN FUEL CELLS  

Science Journals Connector (OSTI)

The detailed study of carbon nanomaterials constitution with allowance for of reduction conversions Pt (II, IV) allows to realize directional looking up of methods of preparation of platinum catalysts for redo...

N.S. KUYUNKO; S.D. KUSHCH; V.E. MURADYAN…

2007-01-01T23:59:59.000Z

211

Magnetism in Ni-Cu Alloys  

Science Journals Connector (OSTI)

On the assumption that in Ni-Cu alloys the spin moment on a Ni atom depends on the local atomic environment, it was possible to find moment values for the various atomic configurations so as to give average moments in reasonable quantitative agreement with the values measured in the ferromagnetic composition range. The local environment is specified by the number of Ni nearest neighbors and the number of Ni second-nearest neighbors. This model allows also a consistent qualitative interpretation of the effect on the average moment of low-temperature annealing treatment and of plastic deformation.

C. G. Robbins; Helmut Claus; Paul A. Beck

1969-06-16T23:59:59.000Z

212

Surface localized states and the Fermi contour of Pd(001)  

Science Journals Connector (OSTI)

Angle-resolved photoemission measurements of the surface localized electronic states of the clean Pd(001) surface are presented. Several surface localized levels were observed, in qualitative agreement with an existing surface band-structure calculation. In particular, a state was observed which crosses the Fermi level (EF) near the X¯ point of the surface Brillouin zone. The segment of the Fermi contour derived from this crossing lies largely within a gap in the projected bulk Fermi surface and is parallel to the Brillouin-zone edge. The nesting properties of this segment of the Fermi contour suggest the possibility of a fairly strong electronic coupling to phonon excitations.

G. S. Elliott, K. E. Smith, and S. D. Kevan

1991-02-15T23:59:59.000Z

213

Permeation and Diffusion of Hydrogen Through Pd Membranes  

SciTech Connect

Hydrogen diffusion through Pd membranes has been measured under non-UHV conditions, i.e., the membranes are evacuated under non-UHV conditions. Despite this, the results indicate that bulk diffusion is the slow step and the diffusion constants agree with earlier workers results where UHV conditions obtained. The activation energy for H2 permeation in the dilute phase was determined from an Arrhenius plot over a series of temperatures from 423 to 503 K. The solubilities of H2 were determined over the same temperature range and from these data, the diffusion constants were determined.

Shanahan, K.L.

2003-01-29T23:59:59.000Z

214

Kinetics of Ni Sorption in Soils: Roles of Soil Organic Matter and Ni Precipitation  

E-Print Network (OSTI)

Kinetics of Ni Sorption in Soils: Roles of Soil Organic Matter and Ni Precipitation Zhenqing Shi, Lawrence, Kansas 66045-7609, United States *S Supporting Information ABSTRACT: The kinetics of Ni sorption) precipitates using both experimental studies and kinetic modeling. Batch sorption kinetic experiments were

Sparks, Donald L.

215

Thermal Fluctuations in the Structure of Naturally Chiral Pt Surfaces  

SciTech Connect

The intrinsic chirality of metal surfaces with kinked steps (e.g. Pt(643)) endows them with enantiospecific adsorption properties (D. S. Shell, Langmuir, 14, 1998, 862). To understand these properties quantitatively the impact of thermally-driven step wandering must be assessed. The authors derive a lattice-gas model of step motion on Pt(111) surfaces using diffusion barriers from Density Functional Theory. This model is used to examine thermal fluctuations of straight and kinked steps.

ASTHAGIRI,ARAVIND; FEIBELMAN,PETER J.; SHOLL,DAVID S.

2000-07-20T23:59:59.000Z

216

Unidirectional Invisibility Induced by PT-Symmetric Periodic Structures  

SciTech Connect

Parity-time (PT) symmetric periodic structures, near the spontaneous PT-symmetry breaking point, can act as unidirectional invisible media. In this regime, the reflection from one end is diminished while it is enhanced from the other. Furthermore, the transmission coefficient and phase are indistinguishable from those expected in the absence of a grating. The phenomenon is robust even in the presence of Kerr nonlinearities, and it can also effectively suppress optical bistabilities.

Lin Zin; Ramezani, Hamidreza; Kottos, Tsampikos [Department of Physics, Wesleyan University, Middletown, Connecticut 06459 (United States); Eichelkraut, Toni; Christodoulides, Demetrios N. [College of Optics and Photonics-CREOL, University of Central Florida, Orlando, Florida 32816 (United States); Cao Hui [Department of Applied Physics, Yale University, New Haven, Connecticut 06520 (United States)

2011-05-27T23:59:59.000Z

217

Bond formation at the Ni/ZrO2 interface  

Science Journals Connector (OSTI)

We report on the formation of strong chemical bonds at the Ni(100)/cubic-ZrO2(100) polar interfaces. Ab initio density functional theory calculations demonstrate that both Zr/Ni and O/Ni junctions are energetically stable, and predict that two different interactions determine the interface adhesion. Our results reveal that O-Ni ionic bonds are formed by Ni electron donation, while the Zr-Ni bonds show a mixed character with ionic and electron hybridization contributions.

J. I. Beltrán; S. Gallego; J. Cerdá; J. S. Moya; M. C. Muñoz

2003-08-07T23:59:59.000Z

218

Positron-annihilation measurements of vacancy formation in Ni and Ni(Ge)  

SciTech Connect

Vacancy formation in Ni and in dilute Ni(Ge) alloys was studied under thermal equilibrium conditions using positron-annihilation Doppler broadening. A monovacancy formation enthalpy of 1.8 +- 0.1 eV was determined for pure Ni; combining this result with that from previous tracer self-diffusion measurements, a monovacancy migration enthalpy of 1.1 +- 0.1 eV was also deduced. Analysis of the vacancy formation measurements in Ni(0.3 at.% Ge) and Ni(1 at.% Ge) yielded a value for the vacancy-Ge binding enthalpy of 0.20 +- 0.04 eV.

Smedskjaer, L.C.; Fluss, M.J.; Legnini, D.G.; Chason, M.K.; Siegel, R.W.

1982-03-01T23:59:59.000Z

219

Purification and Characterization of [NiFe]-Hydrogenase of Shewanella...  

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

Purification and Characterization of NiFe-Hydrogenase of Shewanella oneidensis MR-1. Purification and Characterization of NiFe-Hydrogenase of Shewanella oneidensis MR-1....

220

Edinburgh Research Explorer Quantifying the implicit process flow abstraction in SBGN-PD  

E-Print Network (OSTI)

Edinburgh Research Explorer Quantifying the implicit process flow abstraction in SBGN-PD diagrams the implicit process flow abstraction in SBGN-PD diagrams with Bio-PEPA'. in Proceedings of COMPMOD 2009. ETPCS to publication record in Edinburgh Research Explorer Published In: Proceedings of COMPMOD 2009 General rights

Millar, Andrew J.

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


221

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

222

Total Hydrogenation of Furfural and 5-Hydroxymethylfurfural over Supported Pd–Ir Alloy Catalyst  

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Total Hydrogenation of Furfural and 5-Hydroxymethylfurfural over Supported Pd–Ir Alloy Catalyst ... Total hydrogenation of 5-hydroxymethylfurfural was also possible using Pd–Ir/SiO2 catalyst. ... (8-11) Furfural and 5-hydroxymethylfurfural (HMF) are produced from sugars via dehydration and are promising intermediates in biorefinery. ...

Yoshinao Nakagawa; Kana Takada; Masazumi Tamura; Keiichi Tomishige

2014-07-09T23:59:59.000Z

223

Vacancy Jumps in PdIn: Reconciling Nuclear Relaxation and Diffusion Measurements  

E-Print Network (OSTI)

Vacancy Jumps in PdIn: Reconciling Nuclear Relaxation and Diffusion Measurements Gary S. Collins Keywords: point defect, vacancy, diffusion, defect interaction, intermetallic compound, perturbed angular correlation, PAC, nuclear relaxation, diffusion mechanisms Abstract. Vacancy jump frequencies in PdIn were

Collins, Gary S.

224

Direct Determination of the Ionization Energies of PtC, PtO, and PtO2 with VUV Murat Citir and Ricardo B. Metz*  

E-Print Network (OSTI)

and carbides. I. Introduction Transition-metal oxides and carbides have been the subject of numerous transition-metal oxide cations, including PtO+, can directly convert methane to methanol. Schwarz and co energies and bond dissociation energies for catalytically interesting species such as metal oxides

Metz, Ricardo B.

225

A study of Mo-modified Pd/MWCNT catalysts for ethanol oxidation in the alkaline solution  

Science Journals Connector (OSTI)

The effect of the modification of Pd-based electrocatalysts by molybdenum on the catalytic performance toward ethanol oxidation in the alkaline solution is investigated. ... the poison resistance of Pd-based nano...

Weimin Chen; Yu Zhang

2014-02-01T23:59:59.000Z

226

Microscopic return point memory in Co/Pd multilayer films  

SciTech Connect

We report soft x-ray speckle metrology measurements of microscopic return point and complementary point memory in Co/Pd magnetic films having perpendicular anisotropy. We observe that the domains assemble into a common labyrinth phase with a period that varies by nearly a factor of two between initial reversal and fields near saturation. Unlike previous studies of similar systems, the ability of the film to reproduce its domain structure after magnetic cycling through saturation varies from loop to loop, from position to position on the sample, and with the part of the speckle pattern used in the metrology measurements. We report the distribution of memory as a function of field and discuss these results in terms of the reversal process.

Seu, K.A.; Su, R.; Roy, S.; Parks, D.; Shipton, E.; Fullerton, E.E.; Kevan, S.D.

2009-10-01T23:59:59.000Z

227

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

228

Magnetic order of Co{sub 0.1}Pt{sub 0.9} in proximity in CoPt{sub 3}  

SciTech Connect

A polarized neutron reflectometry study of the magnetization density depth profile of a Co{sub 0.1}Pt{sub 0.9}-CoPt{sub 3} bilayer film found evidence for an induced moment in the Co{sub 0.1}Pt{sup 0.9} overlayer in close proximity to the CoPt{sub 3} underlayer. If the moment of Co in these films is that of the bulk, then the {mu}{sub Pt} = 0.09(1){mu}{sub B} in the overlayer, and {mu}{sub Pt} = 0.04(1){mu}{sub B} in the underlayer. In addition, ferromagnetic order of the Co{sub 0.1}Pt{sub 0.9} overlayer was observed 8K above {Tc} for the material in the bulk.

Shapiro, A.L.; Hellman, F. [Univ. of California, San Diego, La Jolla, CA (United States); Fitzsimmons, M.R. [Los Alamos National Lab., NM (United States)

1998-12-01T23:59:59.000Z

229

Why Is Pt So Unique A Chemical Physics Approach  

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

Is Pt So Unique Is Pt So Unique A Chemical Physics Approach Philip N. Ross, Jr. Materials Sciences Division Lawrence Berkeley National Laboratory Berkeley, CA 94708 Outline * A brief history of electrode kinetics * Reaction pathway for oxygen reduction * Effect of pH * Systematic trends across Periodic Table * One electron makes a big difference d 9 s 1 versus d 10 s 1 * Pt at the top of the Volcano Curve Mechanism of the ORR at metal electrodes Addition of first electron needed to break O-O bond Rate limiting step in electrochemical reduction of O 2 is 1 st electron transfer O 2 + - → (O 2 - ) sol Outer Sphere E 0 ' =-0.3 V) O 2 + - → (O 2 - ) ads Inner Sphere (E 0 ' + ∆G ad /F) O 2 - adsorption strength nic properties of the electrode material Establish general trends across Periodic Table using

230

Radiosonde observations at Pt. Reyes and cloud properties retrieved from  

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

Radiosonde observations at Pt. Reyes and cloud properties retrieved from Radiosonde observations at Pt. Reyes and cloud properties retrieved from GOES-WEST Inoue, Toshiro MRI/JMA Category: Field Campaigns Low-level cloud formed off the west coast of continents plays an important role in general circulation and climate. Marine Stratus Radiation Aerosol and Drizzle (MASRAD) was conducted at the ARM mobile site deployed at Pt Reyes, California during April to September. Here, we studied the relationship between meteorological parameters observed by GPS sonde and cloud properties observed from GOES-WEST during the MASRAD intensive operational period. Cloud properties are retrieved from VISST (Visible Infrared Solar-infrared Split window Technique). The vertical profile of stability, relative humidity (RH) and wind speed observed by GPS sonde are

231

Electronic structure of AgxPt1-x alloys  

Science Journals Connector (OSTI)

Fully relativistic Korringa-Kohn-Rostoker coherent-potential approximation calculations are performed for AgxPt1-x, x=0.06, 0.15, 0.30, 0.40, 0.50, 0.70, and 0.90. The electronic structure of the AgxPt1-x alloys is discussed in terms of densities of states, d3/2-like and d5/2-like partial local densities of states for the components Ag and Pt, and in terms of Bloch spectral functions. For all alloys ‘‘Fermi-surface cuts’’ in the ?XK, ?XU, and ?KU planes are shown. The variation of the unenhanced density of states at the Fermi energy with the concentration x agrees rather well with the variation of the experimental molar susceptibilities. From the Bloch spectral functions, but also, from the densities of states, it is found that the electronic structure undergoes strong changes when the molar fraction varies.

H. Ebert, P. Weinberger, and J. Voitländer

1985-06-15T23:59:59.000Z

232

Optimizing CO2 reduction conditions to increase carbon atom conversion using a Pt-RGO||Pt-TNT photoelectrochemical cell  

Science Journals Connector (OSTI)

Abstract This study aimed to determine the optimum conditions required to increase the carbon atom conversion rate in a Pt-RGO||Pt-TNT photoelectrochemical cell. The effects of Pt-RGO reduction time on CO2 conversion, voltage applied through the cell, catholyte pH, and pore size of nickel foam as a catalyst support were investigated. The conversion rate of C atoms initially increased and then decreased with increasing Pt-RGO reduction time, increasing electrolyte pH, and decreasing nickel foam pore size. Although carbon atom conversion showed sustainable growth as the applied voltage increased, the current efficiency of CO2 reduction products decreased because of enhanced proton interference when the voltage applied through the cell exceeds 2 V. A maximum carbon atom conversion rate of 1500 nmol/(cm2 h) was obtained by Pt-RGO reduction for 24 h when a 2 V voltage was applied through the cell, the catholyte pH was 8.8, and nickel foam with an average pore size of 160 ?m was used as a support. Under optimum conditions, the liquid product selectivity of CO2 reduction reached 99%. The results of the study indicate that RGO-based catalysts have potential use as blueprints for CO2 reduction.

Jun Cheng; Meng Zhang; Gai Wu; Xin Wang; Junhu Zhou; Kefa Cen

2015-01-01T23:59:59.000Z

233

Ni{sub 3}Al aluminide alloys  

SciTech Connect

This paper provides a brief review of the recent progress in research and development of Ni{sub 3}Al and its alloys. Emphasis has been placed on understanding low ductility and brittle fracture of Ni{sub 3}Al alloys at ambient and elevated temperatures. Recent studies have resulted in identifying both intrinsic and extrinsic factors governing the fracture behavior of Ni{sub 3}Al alloys. Parallel efforts on alloy design using physical metallurgy principles have led to properties for structural use. Industrial interest in these alloys is high, and examples of industrial involvement in processing and utilization of these alloys are briefly mentioned.

Liu, C.T.

1993-10-01T23:59:59.000Z

234

WChPT analysis of twisted mass lattice data  

E-Print Network (OSTI)

We perform a Wilson Chiral Perturbation Theory (WChPT) analysis of quenched twisted mass lattice data. The data were generated by two independent groups with three different choices for the critical mass. For one choice, the so-called pion mass definition, one observes a strong curvature for small quark masses in various mesonic observables (''bending phenomenon''). Performing a combined fit to the next-to-leading (NLO) expressions, we find that WChPT describes the data very well and the fits provide very reasonable values for the low-energy parameters.

Sinya Aoki; Oliver Bar

2006-10-13T23:59:59.000Z

235

Electroslag surfacing of steel shafting with Ni alloy 625 and 70Cu-30Ni strip  

SciTech Connect

A comprehensive study of electroslag surfacing (ESS) of steel with Ni Alloy 625 and 70Cu-30Ni strip electrodes was conducted to establish the feasibility of replacing forged bearing sleeves on propulsion shafting with integral weld surfacing. The base material was MIL-S-23284, Class 1 steel in the form of 41--66 cm (16--26 in.) diameter shafting and 76 mm (3 in.) thick flat plate. All ESS was carried out at a heat input level of approximately 5.9kJ/mm (150 kJ/in.) using 30 x 0.5 mm (1.2 x 0.02 in.) strip electrodes. Assessments of mechanical properties and microstructure of Ni Alloy 625 surfacing and 70Cu-30Ni surfacing were conducted to establish the structure-property relationships in these complex alloy systems. In addition, a solidification cracking test was developed to determine the relative cracking susceptibilities of these strip surfacing alloys. Although the Ni Alloy 625 surfacing contained small islands of interdendritic MC type carbides and Laves phase, the mechanical properties of this surfacing were satisfactory. The 70Cu-30Ni surfacing required a buttering layer of 30Cu-70Ni or pure Ni to prevent solidification cracking. The inherent ductility-dip sensitivity of 70Cu-30Ni surfacing was overcome by the development of a suitable ESS procedure.

Devletian, J.H.; Gao, Y.P.; Wood, W.E. [Oregon Graduate Inst. of Science and Technology, Portland, OR (United States)

1996-12-31T23:59:59.000Z

236

PdAgAu alloy with high resistance to corrosion by H{sub 2}S  

SciTech Connect

PdAgAu alloy films were prepared on porous stainless steel supports by sequential electroless deposition. Two specific compositions, Pd{sub 83}Ag{sub 2}Au{sub 15} and Pd{sub 74}Ag{sub 14}Au{sub 12}, were studied for their sulfur tolerance. The alloys and a reference Pd foil were exposed to 1000 H{sub 2}S/H{sub 2} at 623 K for periods of 3 and 30 hours. The microstructure, morphology and bulk composition of both nonexposed and H{sub 2}S-exposed samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). XRD and SEM analysis revealed time-dependent growth of a bulk Pd{sub 4}S phase on the Pd foil during H{sub 2}S exposure. In contrast, the PdAgAu ternary alloys displayed the same FCC structure before and after H{sub 2}S exposure. In agreement with the XRD and SEM results, sulfur was not detected in the bulk of either ternary alloy samples by EDS, even after 30 hours of H{sub 2}S exposure. X-ray photoelectron spectroscopy (XPS) depth profiles were acquired for both PdAgAu alloys after 3 and 30 hours of exposure to characterize sulfur contamination near their surfaces. Very low S 2p and S 2s XPS signals were observed at the top-surfaces of the PdAgAu alloys, and those signals disappeared before the etch depth reached ~ 10 nm, even for samples exposed to H{sub 2}S for 30 hours. The depth profile analyses also revealed silver and gold segregation to the surface of the alloys; preferential location of Au on the alloys surface may be related to their resistance to bulk sulfide formation. In preliminary tests, a PdAgAu alloy membrane displayed higher initial H{sub 2} permeability than a similarly prepared pure Pd sample and, consistent with resistance to bulk sulfide formation, lower permeability loss in H{sub 2}S than pure Pd.

Braun, Fernando; Miller, James B.; Gellman, Andrew J.; Tarditi, Ana M.; Fleutot, Benoit; Petro, Kondratyuk, Cornaglia, Laura M

2012-12-01T23:59:59.000Z

237

New Ni Amidinate Source for ALD/CVD of NiNx, NiO and NiSi , Thiloma Perera1  

E-Print Network (OSTI)

to be particularly important in memory as well as logic applications. Nickel silicide (NiSi) is emerging with a metal-insulator-metal (MIM) structure, offer potential applications for the next generation nonvolatile

238

Facile synthesis of PtAu alloy nanoparticles with high activity...  

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

synthesis of PtAu alloy nanoparticles with high activity for formic acid oxidation. Facile synthesis of PtAu alloy nanoparticles with high activity for formic acid oxidation....

239

The durability dependence of Pt/CNT electrocatalysts on the nanostruct...  

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

The durability dependence of PtCNT electrocatalysts on the nanostructures of carbon nanotubes: hollow- and bamboo-CNTs. The durability dependence of PtCNT electrocatalysts on the...

240

Pt–Sn/C as a Possible Methanol-Tolerant Cathode Catalyst for DMFC  

Science Journals Connector (OSTI)

An effective method was developed for preparing highly dispersed nano-sized Pt–Sn/C electrocatalyst synthesised by a modified polyol reduction method. From XRD patterns, the Pt–Sn/C peaks shifted slightly to l...

Lynwill G. Martin; Ivan Green; X. Wang; Sivakumar Pasupathi…

2013-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "ni pd pt" 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

Electrostatic Self-Assembly of Pt-around-Au Nanocomposite with...  

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

Self-Assembly of Pt-around-Au Nanocomposite with High Activity towards Formic Acid Oxidation. Electrostatic Self-Assembly of Pt-around-Au Nanocomposite with High Activity towards...

242

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

243

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

244

Preparation and characterization of PAA/PVDF membrane-immobilized Pd/Fe nanoparticles for dechlorination of trichloroacetic acid  

Science Journals Connector (OSTI)

Poly(vinylidene fluoride) (PVDF) microfiltration (MF) membrane was successfully hydrophilized by coating with a novel hydrophilic layer, which was mainly composed of polyvinyl alcohol (PVA), glutaraldehyde, and polyethylene glycol (PEG). Pd/Fe nanoparticles (NPs) were prepared and immobilized in hydrophilized polyacrylic acid (PAA)/PVDF MF membrane. The unmodified and modified PVDF MF membranes were characterized by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR). The membrane-supported Pd/Fe \\{NPs\\} exhibited high reactivity in the dechlorination of trichloroacetic acid (TCAA). The effects of several important parameters, including Pd content, Pd/Fe NP loading, the preservation time of Pd/Fe NP membrane system on the dechlorination of TCAA were investigated. The stability of Pd/Fe NP membrane system was tested, and the kinetics and product distribution of dechlorination of TCAA by Pd/Fe NP membrane system were discussed.

Xiangyu Wang; Chao Chen; Huiling Liu; Jun Ma

2008-01-01T23:59:59.000Z

245

FTIR study of hydrogen and carbon monoxide adsorption on Pt/TiO{sub 2}, Pt/ZrO{sub 2}, and Pt/Al{sub 2}O{sub 3}  

SciTech Connect

The Pt/TiO{sub 2}, Pt/ZrO{sub 2}, and Pt/Al{sub 2}O{sub 3} catalysts submitted to low-temperature reduction (LTR,200 C) and high-temperature reduction (HTR, 500 C) and exposed to hydrogen and carbon monoxide at room temperature were studied by infrared spectroscopy. There is a strong loss of transmission in the entire infrared spectra on Pt/TiO{sub 2} after its exposure to hydrogen, which is related to the reducibility of the support. A typical SMSI behavior (strong metal-support interaction), such as the decrease in carbon monoxide adsorption capacity, was detected on Pt/TiO{sub 2} and Pt/ZrO{sub 2} after exposure to hydrogen, even for the catalysts submitted to LTR treatment. Also a carbonyl band shift to lower wavenumber was observed on LTR-treated Pt/TiO{sub 2}, Pt/ZrO{sub 2}, and Pt/Al{sub 2}O{sub 3} after exposure to hydrogen. The authors interpreted this SMSI behavior as an electronic rather than morphological effect, which was induced by the presence of hydrogen spillover.

Benvenutti, E.V.; Franken, L.; Moro, C.C.; Davanzo, C.U.

1999-11-09T23:59:59.000Z

246

Bridge-bonded atomic oxygen on Pt(110)  

Science Journals Connector (OSTI)

We use hybrid density-functional theory (DFT) and scanning tunneling microscopy (STM) to study oxygen adsorption on the Pt(110) surface. In the STM images oxygen appear as bright protrusions on the ridges of the “missing row” reconstructed surface. DFT calculations of binding energies for atomic oxygen on a bridge site shows a clear preference over hollow sites.

E. Janin; H. von Schenck; M. Göthelid; U. O. Karlsson; M. Svensson

2000-05-15T23:59:59.000Z

247

Ultrafine FePt Nanoparticles Prepared by the Chemical Reduction Method  

E-Print Network (OSTI)

of about 2 nm have been prepared by 1,2-hexadecanediol reduction of iron acetylacetonate and platinum acetylacetonate in dioctyl ether. The as-synthesized particles have a chemically disordered fcc structure and canPt nanoparticles via the simultaneous reduction of FeCl2 and Pt(acac)2 as well as Fe and Pt acetylacetonate has

Wang, Zhong L.

248

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

Science Journals Connector (OSTI)

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

Fei Wen; Ulrich Simon

2007-06-16T23:59:59.000Z

249

Enhanced activity and stability of Pt catalysts on functionalized graphene sheets for electrocatalytic oxygen reduction  

E-Print Network (OSTI)

to be improved [2]. Currently, the leading cathode electrocatalysts are Pt and Pt-based alloys supported online 28 February 2009 Keywords: Functionalized graphene sheets Fuel cell Pt Cathode durability a b and stationary power supplies [1]. Although considerable progress has been made in developing better PEMFCs

Aksay, Ilhan A.

250

Growth of Pt nanoparticle for proton-exchange-membrane fuel cells by  

E-Print Network (OSTI)

at anode side of a polymer electrolyte membrane (PEM) fuel cell. With a Pt loading of 25 g-Pt/cm2 , current, PEM fuel cell, Mass specific power density, Electrochemical active surface area, Oxygen reduction PEMFC Growth of Pt nanoparticle for proton-exchange-membrane fuel cells

251

Electron Source in Photoinduced Hydrogen Production on Pt-Supported TiO2 Particles  

Science Journals Connector (OSTI)

Electron Source in Photoinduced Hydrogen Production on Pt-Supported TiO2 Particles ... Comment on “Electron Source in Photoinduced Hydrogen Production on Pt-Supported TiO2 Particles” ... Comment on “Electron Source in Photoinduced Hydrogen Production on Pt-Supported TiO2 Particles” ...

Toshiyuki Abe; Eiji Suzuki; Kentaro Nagoshi; Kohichi Miyashita; Masao Kaneko:

2000-03-24T23:59:59.000Z

252

Regional distribution and sources of Au, Pd and Pt in moss and O-,B- and C-horizon podzol samples in the European Arctic  

Science Journals Connector (OSTI)

...of stannous chloride as a reducing agent and collected to a mercury precipitate (Kontas et al. 1990; Niskavaara Kontas 1990,a ). During...needed to get complete datasets (no samples returning values a DLa a see explanation below). The fact that the mean concentration...

H. Niskavaara; E. Kontas; C. Reimann

253

ARPA-e's "PD Roadshow" | Department of Energy  

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

ARPA-e's "PD Roadshow" ARPA-e's "PD Roadshow" ARPA-e's "PD Roadshow" November 4, 2010 - 3:36pm Addthis Andy Oare Andy Oare Former New Media Strategist, Office of Public Affairs At the end of October, the Advanced Research Projects Agency's (ARPA-E) Program Directors (PDs) launched the "PD Roadshow" - a series of day-long campus visits to top science and engineering schools. Meeting with university students and faculty, we will use this as an opportunity to exchange ideas with the next generation of energy innovators, and introduce ARPA-E's role in advancing innovation. ARPA-E kicked off the tour with a visit to Cornell University on October 21. On each visit, PDs and an ARPA-E Fellow will share meals with students and staff, meet with university researchers and present a seminar on ARPA-E's

254

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

255

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.

256

Activation of Pd-Ag Catalyst for Selective Hydrogenation of Acetylene via Nitrous Oxide Addition  

Science Journals Connector (OSTI)

Hydrogenation of acetylene in the presence of a large excess of ethylene has been investigated on the Pd-Ag catalyst under 60°C and a space velocity...?1.... It was found that an enhancement in the performance of...

Piyasan Praserthdam; Suphot Phatanasri…

2000-05-01T23:59:59.000Z

257

Adsorbate-Induced Segregation in a PdAg Membrane Model System...  

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

composition on adsorption and vice versa. Therefore, the interaction between hydrogen, carbon monoxide or oxygen with the surface of a PdAg model alloy was studied using periodic...

258

The role of Pd in the transport of Ag in SiC  

Science Journals Connector (OSTI)

This paper presents results in support of a newly proposed transport mechanism to account for the release of Ag from intact TRISO particles during HTR reactor operation. The study reveals that the migration of Ag in polycrystalline SiC can occur in association with Pd, a relatively high yield metallic fission product. The migration takes place primarily along grain boundary routes, seen in the form of distinct Pd, Ag and Si containing nodules. Pd is known to rapidly migrate to the SiC and iPyC interface within TRISO particles during operation. It has been shown to chemically corrode the SiC to form palladium silicides. These palladium silicides are found present along SiC grain boundaries in nodule like form. It is suggested that Ag penetrates these nodules together with the palladium silicide, to form a Pd, Ag and Si solution capable of migrating along SiC grain boundaries over time.

E.J. Olivier; J.H. Neethling

2013-01-01T23:59:59.000Z

259

Synthesis of 5,5-Disubstituted Butenolides Based on a Pd-Catalyzed ?-Arylation Strategy  

E-Print Network (OSTI)

Methods for the construction of quaternary carbon centers are of great interest to synthetic chemists due to their presence in natural products. Development of the Pd-catalyzed arylation of butenolides with high selectivity ...

Hyde, Alan M.

260

Enhanced Electrooxidation of Ethanol Using Pd/C + TiO2 Electrocatalysts in Alkaline Media  

Science Journals Connector (OSTI)

This work describes the use of Pd nanoparticles synthetized by the borohydride process and supported on physical mixtures of C + TiO2 toward the ethanol electrooxidation reaction in alkaline media. In this...2 ra...

J. C. M. Silva; G. S. Buzzo; R. F. B. De Souza; E. V. Spinacé…

2014-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "ni pd pt" 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

ARPA-e's "PD Roadshow" | Department of Energy  

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

e's "PD Roadshow" e's "PD Roadshow" ARPA-e's "PD Roadshow" November 4, 2010 - 3:36pm Addthis Andy Oare Andy Oare Former New Media Strategist, Office of Public Affairs At the end of October, the Advanced Research Projects Agency's (ARPA-E) Program Directors (PDs) launched the "PD Roadshow" - a series of day-long campus visits to top science and engineering schools. Meeting with university students and faculty, we will use this as an opportunity to exchange ideas with the next generation of energy innovators, and introduce ARPA-E's role in advancing innovation. ARPA-E kicked off the tour with a visit to Cornell University on October 21. On each visit, PDs and an ARPA-E Fellow will share meals with students and staff, meet with university researchers and present a seminar on ARPA-E's

262

Control of Self-Assembling Processes of Polyamidoamine Dendrimers and Pd Nanoparticles  

Science Journals Connector (OSTI)

Control of Self-Assembling Processes of Polyamidoamine Dendrimers and Pd Nanoparticles ... Note that GN and Z are interrelated under the fixed conditions of r and [Pd(OAc)2] as described above. ... However, we must note that such a superstructure may be formed during the solvent evaporation process of the specimens for TEM observations, because the process causes a change in template concentration and an aggregation of the templates driven by surface tension. ...

Hirokazu Tanaka; Takeji Hashimoto; Satoshi Koizumi; Hideaki Itoh; Kensuke Naka; Yoshiki Chujo

2008-02-12T23:59:59.000Z

263

Photosensitivity of the Ni-A state of [NiFe] hydrogenase from Desulfovibrio vulgaris Miyazaki F with visible light  

SciTech Connect

Highlights: Black-Right-Pointing-Pointer Ni-A state of [NiFe] hydrogenase showed light sensitivity. Black-Right-Pointing-Pointer New FT-IR bands were observed with light irradiation of the Ni-A state. Black-Right-Pointing-Pointer EPR g-values of the Ni-A state shifted upon light irradiation. Black-Right-Pointing-Pointer The light-induced state converted back to the Ni-A state under the dark condition. -- Abstract: [NiFe] hydrogenase catalyzes reversible oxidation of molecular hydrogen. Its active site is constructed of a hetero dinuclear Ni-Fe complex, and the oxidation state of the Ni ion changes according to the redox state of the enzyme. We found that the Ni-A state (an inactive unready, oxidized state) of [NiFe] hydrogenase from Desulfovibrio vulgaris Miyazaki F (DvMF) is light sensitive and forms a new state (Ni-AL) with irradiation of visible light. The Fourier transform infrared (FT-IR) bands at 1956, 2084 and 2094 cm{sup -1} of the Ni-A state shifted to 1971, 2086 and 2098 cm{sup -1} in the Ni-AL state. The g-values of g{sub x} = 2.30, g{sub y} = 2.23 and g{sub z} = 2.01 for the signals in the electron paramagnetic resonance (EPR) spectrum of the Ni-A state at room temperature varied for -0.009, +0.012 and +0.010, respectively, upon light irradiation. The light-induced Ni-AL state converted back immediately to the Ni-A state under dark condition at room temperature. These results show that the coordination structure of the Fe site of the Ni-A state of [NiFe] hydrogenase is perturbed significantly by light irradiation with relatively small coordination change at the Ni site.

Osuka, Hisao [Graduate School of Life Science, University of Hyogo, 3-2-1, Koto, Kamigori-cho, Ako-gun, Hyogo 678-1297 (Japan) [Graduate School of Life Science, University of Hyogo, 3-2-1, Koto, Kamigori-cho, Ako-gun, Hyogo 678-1297 (Japan); Graduate School of Materials Science, Nara Institute of Science and Technology, 8916-5, Takayama-cho, Ikoma-shi, Nara 630-0192 (Japan); Shomura, Yasuhito; Komori, Hirofumi; Shibata, Naoki [Graduate School of Life Science, University of Hyogo, 3-2-1, Koto, Kamigori-cho, Ako-gun, Hyogo 678-1297 (Japan)] [Graduate School of Life Science, University of Hyogo, 3-2-1, Koto, Kamigori-cho, Ako-gun, Hyogo 678-1297 (Japan); Nagao, Satoshi [Graduate School of Materials Science, Nara Institute of Science and Technology, 8916-5, Takayama-cho, Ikoma-shi, Nara 630-0192 (Japan)] [Graduate School of Materials Science, Nara Institute of Science and Technology, 8916-5, Takayama-cho, Ikoma-shi, Nara 630-0192 (Japan); Higuchi, Yoshiki, E-mail: hig@sci.u-hyogo.ac.jp [Graduate School of Life Science, University of Hyogo, 3-2-1, Koto, Kamigori-cho, Ako-gun, Hyogo 678-1297 (Japan) [Graduate School of Life Science, University of Hyogo, 3-2-1, Koto, Kamigori-cho, Ako-gun, Hyogo 678-1297 (Japan); CREST, JST, Gobancho, Chiyoda-ku, Tokyo 102-0076 (Japan); Hirota, Shun, E-mail: hirota@ms.naist.jp [Graduate School of Materials Science, Nara Institute of Science and Technology, 8916-5, Takayama-cho, Ikoma-shi, Nara 630-0192 (Japan) [Graduate School of Materials Science, Nara Institute of Science and Technology, 8916-5, Takayama-cho, Ikoma-shi, Nara 630-0192 (Japan); CREST, JST, Gobancho, Chiyoda-ku, Tokyo 102-0076 (Japan)

2013-01-04T23:59:59.000Z

264

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

265

Size effects in Ni/Ni(OH)2 nanomaterials for electrochemical capacitors.  

SciTech Connect

Electrochemical capacitors based on redox-active metal oxides show great promise for many energy-storage applications. These materials store charge through both electric double-layer charging and faradaic reactions in the oxide. The dimensions of the oxide nanomaterials have a strong influence on the performance of such capacitors. Not just due to surface area effects, which influence the double-layer capacitance, but also through bulk electrical and ionic conductivities. Ni(OH)2 is a prime candidate for such applications, due to low cost and high theoretical capacity. We have examined the relationship between diameter and capacity for Ni/Ni(OH)2 nanorods. Specific capacitances of up to 511 F/g of Ni were recorded in 47 nm diameter Ni(OH)2 nanorods.

Bunker, Bruce Conrad; Limmer, Steven J.; Yelton, William Graham

2010-04-01T23:59:59.000Z

266

Influence of surface segregation on magnetic properties of FePt nanoparticles  

SciTech Connect

Surface segregation leads to chemical disordering in magnetic alloy nanostructures and thus could have profound impact upon the magnetic properties of these nanostructures. In this study, we used the first-principles density functional theory calculation method to determine how Pt surface segregation (exchanging interior Pt with surface Fe atoms) would affect the magnetic properties of L1{sub 0} ordered FePt nanoparticles. For both cuboid and cuboctahedral FePt nanoparticles, we predicted that the Pt surface segregation process could cause a decrease in total magnetic moments, a change in (easy and/or hard) magnetization axes, and a reduction in magnetic anisotropy.

Lv, Hongyan [Department of Mechanical Engineering and Materials Science, University of Pittsburgh, Pittsburgh, Pennsylvania 15261 (United States) [Department of Mechanical Engineering and Materials Science, University of Pittsburgh, Pittsburgh, Pennsylvania 15261 (United States); Key Laboratory of Artificial Micro- and Nano-Structures of Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan 430072 (China); Lei, Yinkai; Datta, Aditi; Wang, Guofeng [Department of Mechanical Engineering and Materials Science, University of Pittsburgh, Pittsburgh, Pennsylvania 15261 (United States)] [Department of Mechanical Engineering and Materials Science, University of Pittsburgh, Pittsburgh, Pennsylvania 15261 (United States)

2013-09-23T23:59:59.000Z

267

Ethanol electro-oxidation on partially alloyed Pt-Sn-Rh/C catalysts  

Science Journals Connector (OSTI)

Abstract Ternary Pt-Sn-Rh/C catalysts of Pt:Sn:Rh = 1:0.8:0.2 and 1:1:0.33 atomic ratios were synthesized using the formic acid method and their electrochemical activities were compared for ethanol oxidation with that of binary Pt-Sn/C (1:1) and Pt-Rh/C (1:0.11) catalysts. XRD analysis indicated the presence of Sn in both alloyed and oxide form and suggested the formation of a ternary Pt-Sn-Rh alloy in both catalysts. The particle size by TEM was around 3.5 nm for all catalysts. The efficiency for Pt utilization increased with Rh content. Pt-Sn-Rh/C catalysts exhibited higher catalytic activity for ethanol oxidation than Pt-Rh/C, but lower than Pt-Sn/C. Among ternary catalysts, Pt-Sn-Rh/C (1:0.8:0.2) was the most active. In situ IRRAS showed Rh plays a dual counteracting role during ethanol electro-oxidation on Pt-Sn-Rh/C catalysts, once it promotes C-C bond breaking, thus favouring CO2 formation, but hinders adsorption of ethanol, decreasing the production of acetic acid.

Elson A. de Souza; M.Janete Giz; Giuseppe A. Camara; Ermete Antolini; Raimundo R. Passos

2014-01-01T23:59:59.000Z

268

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

Science Journals Connector (OSTI)

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

Xingwen Yu; Siyu Ye

2007-01-01T23:59:59.000Z

269

Consistent Data Assimilation of Isotopes: 242Pu and 105Pd  

SciTech Connect

In this annual report we illustrate the methodology of the consistent data assimilation that allows to use the information coming from integral experiments for improving the basic nuclear parameters used in cross section evaluation. A series of integral experiments are analyzed using the EMPIRE evaluated files for 242Pu and 105Pd. In particular irradiation experiments (PROFIL-1 and -2, TRAPU-1, -2 and -3) provide information about capture cross sections, and a critical configuration, COSMO, where fission spectral indexes were measured, provides information about fission cross section. The observed discrepancies between calculated and experimental results are used in conjunction with the computed sensitivity coefficients and covariance matrix for nuclear parameters in a consistent data assimilation. The results obtained by the consistent data assimilation indicate that not so large modifications on some key identified nuclear parameters allow to obtain reasonable C/E. However, for some parameters such variations are outside the range of 1 s of their initial standard deviation. This can indicate a possible conflict between differential measurements (used to calculate the initial standard deviations) and the integral measurements used in the statistical data adjustment. Moreover, an inconsistency between the C/E of two sets of irradiation experiments (PROFIL and TRAPU) is observed for 242Pu. This is the end of this project funded by the Nuclear Physics Program of the DOE Office of Science. We can indicate that a proof of principle has been demonstrated for a few isotopes for this innovative methodology. However, we are still far from having explored all the possibilities and made this methodology to be considered proved and robust. In particular many issues are worth further investigation: • Non-linear effects • Flexibility of nuclear parameters in describing cross sections • Multi-isotope consistent assimilation • Consistency between differential and integral experiments

G. Palmiotti; H. Hiruta; M. Salvatores

2012-09-01T23:59:59.000Z

270

Structure Analysis of a Precipitate Phase in an Ni-Rich High...  

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

Analysis of a Precipitate Phase in an Ni-Rich High Temperature NiTiHf Shape Memory Alloy. Structure Analysis of a Precipitate Phase in an Ni-Rich High Temperature NiTiHf Shape...

271

Airtricity Developments NI Ltd | Open Energy Information  

Open Energy Info (EERE)

NI Ltd NI Ltd Jump to: navigation, search Name Airtricity Developments NI Ltd Place Belfast, Northern Ireland, United Kingdom Zip BT2 7AF Sector Wind energy Product Focused on construction of wind farms in Northern Ireland. Coordinates 54.595295°, -5.934524° 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":54.595295,"lon":-5.934524,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

272

Magnetic quantum diesel engine in Ni2  

Science Journals Connector (OSTI)

Quantum Diesel cycles are numerically realized using the electronic states of a Ni2 dimer. The quantum nature and the complexity of the electronic structure of the Ni2 dimer result in new features in the evolution of the pressure as well as in the heat-work transformation. The multitude of internal degrees of freedom in the isobaric process in molecules can result in crossing of the two adiabatic processes in the P-V diagram. The interplay of heat and work, originating from thermal nonequilibrium effects, can lead to a thermal efficiency of up to 100%. The spin moment of the Ni2 can be decreased by the isobaric process. To link the molecular heat capacity to easily accessible experimental quantities, we also calculate the Kerr effect and the magnetic susceptibility at different temperatures and magnetic fields.

C. D. Dong; G. Lefkidis; W. Hübner

2013-12-20T23:59:59.000Z

273

Shape coexistence and band crossings in Pt174  

Science Journals Connector (OSTI)

High-spin states in Pt174 were populated via the Mo92(Sr84,2p) and Mo92(Sr84,2p2n) reactions. The ground-state band has been extended from I=14 to 24 (tentatively 26) and a new side band is observed up to a spin of 21 (tentatively 23). A low-frequency crossing is observed in the latter band at a rotational frequency that is similar to that seen in the ground-state band. The first and second i13?2 neutron alignments are also observed in Pt174. Surprisingly, these crossings occur at approximately the same frequency. Total Routhian surface and cranked shell model calculations are used in an attempt to understand this behavior.

J. TM. Goon; D. J. Hartley; L. L. Riedinger; M. P. Carpenter; F. G. Kondev; R. V. F. Janssens; K. H. Abu Saleem; I. Ahmad; H. Amro; J. A. Cizewski; C. N. Davids; M. Danchev; T. L. Khoo; A. Heinz; T. Lauritsen; W. C. Ma; G. L. Poli; J. Ressler; W. Reviol; D. Seweryniak; M. B. Smith; I. Wiedenhöver; Jing-ye Zhang

2004-07-15T23:59:59.000Z

274

Structure of Chemisorbed Sulfur on a Pt(111) Electrode  

Science Journals Connector (OSTI)

Contribution from the Department of Chemistry, University of Illinois and Frederick Seitz Materials Research Laboratory, 600 S. Mathews Ave., Urbana, Illinois 61801, and Département de Chimie, Université de Sherbrooke, Sherbrooke, Québec, J1K 2R1, Canada ... Sulfur was deposited from aqueous sulfide and bisulfide media on Pt(111), and the interrogations were conducted by low electron energy diffraction (LEED), Auger electron spectroscopy (AES), and core-level electron energy loss spectroscopy (CEELS). ...

Y.-E. Sung; W. Chrzanowski; A. Zolfaghari; G. Jerkiewicz; A. Wieckowski

1997-01-08T23:59:59.000Z

275

Increase of entanglement by local PT -symmetric operations  

E-Print Network (OSTI)

Entanglement plays a central role in the field of quantum information science. It is well known that the degree of entanglement cannot be increased under local operations. Here, we show that the concurrence of a bipartite entangled state can be increased under the local PT -symmetric operation. This violates the property of entanglement monotonicity. We also use the Bell-CHSH and steering inequalities to explore this phenomenon.

Shin-Liang Chen; Guang-Yin Chen; Yueh-Nan Chen

2014-10-17T23:59:59.000Z

276

Energy absorption in Ni-Mn-Ga/ polymer composites  

E-Print Network (OSTI)

In recent years Ni-Mn-Ga has attracted considerable attention as a new kind of actuator material. Off-stoichiometric single crystals of Ni2MnGa can regularly exhibit 6% strain in tetragonal martensites and orthorhombic ...

Feuchtwanger, Jorge

2006-01-01T23:59:59.000Z

277

Carbon Nanotube Growth Using Ni Catalyst in Different Layouts  

E-Print Network (OSTI)

Vertically aligned carbon nanotubes have been grown using Ni as catalyst by plasma enhanced chemical vapor deposition system (PECVD) in various pre-patterned substrates. Ni was thermally evaporated on silicon substrates ...

Nguyen, H. Q.

278

Oxygen-related dielectric relaxation and leakage characteristics of Pt,,Ba,Sr...TiO3 Pt thin-film capacitors  

E-Print Network (OSTI)

Oxygen-related dielectric relaxation and leakage characteristics of Pt�,,Ba,Sr...TiO3 �Pt thin to the postannealing temperature in oxygen and nitrogen atmosphere. High leakage currents and low-frequency dielectric and subsequently annealed in oxygen at 350 °C. Such results are related to the mobile oxygen ions and oxygen

Cao, Wenwu

279

Good and bad features of Ni-Cd cell designs  

SciTech Connect

Processes for spacecraft Ni-Cd cells are reviewed. Mechanical impregnation is compared against chemical and thermochemical impregnation.

Gross, S.

1996-02-01T23:59:59.000Z

280

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

Note: This page contains sample records for the topic "ni pd pt" 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

Dampfdruckmessungen und Protonenresonanzuntersuchung an Hydriden der intermetallischen Phasen Ti2(Ni, Co) und Ti2(Ni, Fe)  

Science Journals Connector (OSTI)

NMR and hydrogen equilibrium pressure measurements were performed on hydrides of the intermetallic compounds Ti2(Ni, Co) and Ti2(Ni, Fe). The following values of enthalpy ?H and entropy ?S for the formation of th...

Engelbert Tuscher; Kurt Hiebl; Helmut Bittner

1981-02-01T23:59:59.000Z

282

CoNiGa High Temperature Shape Memory Alloys  

E-Print Network (OSTI)

commercially successful SMAs such as NiTi and Cu-based alloys. In recent years, the CoNiGa system has emerged as a new ferromagnetic shape memory alloy with some compositions exhibiting high martensitic transformation temperatures which makes CoNiGa a potential...

Dogan, Ebubekir

2011-10-21T23:59:59.000Z

283

High Temperature coatings based on {beta}-NiAI  

SciTech Connect

High temperature alloys are reviewed, focusing on current superalloys and their coatings. The synthesis, characerization, and oxidation performance of a NiAl–TiB{sub 2} composite are explained. A novel coating process for Mo–Ni–Al alloys for improved oxidation performance is examined. The cyclic oxidation performance of coated and uncoated Mo–Ni–Al alloys is discussed.

Severs, Kevin

2012-07-10T23:59:59.000Z

284

Pd menbrane having improved H.sub.2-permeance, and method of making  

DOE Patents (OSTI)

An H.sub.2-permeable membrane system (117) comprises an electroless-deposited plating (115) of Pd or Pd alloy on a porous support (110, 110'). The Pd plating comprises face-centered cubic crystals cumulatively having a morphology of hexagonal platelets. The permeability to H.sub.2 of the membrane plating (115) on the porous support is significantly enhanced, being at least greater than about 1.3.times.10.sup.-8 molm.sup.-1s.sup.-Pa.sup.-0.5 at 350.degree. C., and even greater than about 3.4.times.10.sup.-8 molm.sup.-1s.sup.-1Pa.sup.-0.5. The porous support (110, 110') may be stainless steel (1100 and include a thin ceramic interlayer (110') on which the Pd is plated. The method of providing the electroless-deposited plating includes preheating a Pd electroless plating solution to near a plating temperature substantially greater than room temperature, e.g. 60.degree. C., prior to plating.

Vanderspurt, Thomas Henry (Glastonbury, CT); She, Ying (Worcester, MA); Dardas, Zissis (Worcester, MA); Walker, Craig (South Glastonbury, CT); MacLeod, James D. (Vernon, CT)

2011-12-06T23:59:59.000Z

285

Grain boundary compositon in NiAl  

SciTech Connect

The high temperature strength and oxidation resistance of many transition metal aluminides makes these intermetallic materials attractive for high temperature applications. However, these aluminides are generally brittle at low temperatures and this restricts their technological applications. However, these aluminides are generally brittle at low temperatures and this restricts their technological applications. It has been demonstrated that the addition of more than 200 ppm of boron to the L1{sub 2}-ordered Ni{sub 3}Al changes the fracture behavior from intergranular to transgranular and increases the ductility. The B2-ordered NiAl nickel aluminide is particularly attractive because of its low density and high melting temperature. This aluminide also fractures intergranularly at room temperature. However, no improvement in ductility is observed with similar boron additions even though the intergranular fracture is suppressed and there is a significant increase in the yield strength. In this paper, the results of an atom probe field ion microscopy investigation of the compositions of the grain boundaries in undoped and boron-doped NiAl are presented. The suitability of the atom probe field ion microscopy technique for the characterization of boundaries has clearly been demonstrated in many previous investigations including the characterization of boron segregation to grain boundaries and other planar features in Ni{sub 3}Al.

Miller, M.K.; Jayaram, R.; Camus, P.P. (Metals and Ceramics Div., Oak Ridge National Lab., Oak Ridge, TN (US))

1992-02-15T23:59:59.000Z

286

Cu-Pd Hydrogen Separation Membranes with Reduced Palladium Content and Improved Performance  

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

Cu-Pd Hydrogen Separation Membranes with Reduced Cu-Pd Hydrogen Separation Membranes with Reduced Palladium Content and Improved Performance Opportunity This patent-pending technology, "Cu-Pd Hydrogen Separation Membranes with Reduced Palladium Content and Improved Performance," consists of copper-palladium alloy compositions for hydrogen separation membranes that use less palladium and have a potential increase in hydrogen permeability and resistance to sulfur degradation compared to currently available copper-palladium membranes. This technology is available for licensing and/or further collaborative research with the U.S. Department of Energy's National Energy Technology Laboratory. Overview NETL is working to help produce and deliver hydrogen from fossil fuels including coal in commercially applicable and environmentally

287

The revised BS PD 6493 assessment procedure -- Application to offshore structures  

SciTech Connect

The BS PD 6493 procedure for the assessment of defects in welded components, which was originally published in 1980 and subsequently revised in 1991, has been used with some success by industry and is now applied extensively to offshore structures. Particular applications are the fitness-for-purpose assessment of fabrication and in-service defects, inspection scheduling and the determination of whether post-weld heat treatment is required. However, the current BS PD 6493 procedure is based on general principles and the extensive application of the procedure to a wide range of complex practical problems over the years has highlighted some of its limitations. These have been addressed in the latest review by the British Standards Institution`s WEE/37 Committee and this has resulted in a major revision of the PD 6493 procedure. A particularly important development is the incorporation of specific guidance on the assessment of offshore structures. This paper describes the new recommendations for offshore structures.

Stacey, A. [Health and Safety Executive, London (United Kingdom). Offshore Safety Div.; Burdekin, F.M. [UMIST, Manchester (United Kingdom). Dept. of Civil and Structural Engineering; Maddox, S.J. [Welding Inst., Cambridge (United Kingdom). Structural Integrity Dept.

1996-12-01T23:59:59.000Z

288

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

SciTech Connect

Carbon supported Pt and Pt-Co electrocatalysts for the oxygen reduction reaction in low temperature fuel cells were prepared by the reduction of the metal salts with sodium borohydride and sodium formate. The effect of surface treatment with nitric acid on the carbon surface and Co on the surface of carbon prior to the deposition of Pt was studied. The catalysts where Pt was deposited on treated carbon the ORR reaction preceded more through the two electron pathway and favored peroxide production, while the fresh carbon catalysts proceeded more through the four electron pathway to complete the oxygen reduction reaction. NaCOOH reduced Pt/C catalysts showed higher activity that NaBH{sub 4} reduced Pt/C catalysts. It was determined that the Co addition has a higher impact on catalyst activity and active surface area when used with NaBH{sub 4} as reducing agent as compared to NaCOOH.

Fox, E.; Colon-Mercado, H.

2010-01-19T23:59:59.000Z

289

Photocatalytic Hydrogen Production from Noncovalent Biohybrid Photosystem I/Pt Nanoparticle Complexes  

Science Journals Connector (OSTI)

Photocatalytic Hydrogen Production from Noncovalent Biohybrid Photosystem I/Pt Nanoparticle Complexes ... (11) The PSI/Pt nanoparticle system described here, with a soluble donor, reproducibly produces H2 at the same order of magnitude as the fully optimized PSI/molecular wire/Pt nanoparticle system and potentially could produce even higher rates of H2 with a cross-linked donor. ... Experimental methods for sample preparation, H2 production studies, EPR measurements, and video of H2 production. ...

Lisa M. Utschig; Nada M. Dimitrijevic; Oleg G. Poluektov; Sergey D. Chemerisov; Karen L. Mulfort; David M. Tiede

2011-01-19T23:59:59.000Z

290

Comparison of Three Ni-Hard I Alloys  

Office of Scientific and Technical Information (OSTI)

Comparison of Three Ni-Hard I Alloys Comparison of Three Ni-Hard I Alloys Ö. N. Do-an 1 , J.A. Hawk 1 , and J.Rice 2 1 U.S. Department of Energy, Albany Research Center, Albany, Oregon 2 Texaloy Foundry Co., Inc., Floresville, Texas Keywords: Ni-Hard white irons, Bainite, Martensite, Austenite, Abrasion resistant iron Abstract This report documents the results of an investigation which was undertaken to reveal the similarities and differences in the mechanical properties and microstructural characteristics of three Ni-Hard I alloys. One alloy (B1) is ASTM A532 class IA Ni-Hard containing 4.2 wt. pct. Ni. The second alloy (B2) is similar to B1 but higher in Cr, Si, and Mo. The third alloy (T1) also falls in the same ASTM specification, but it contains 3.3 wt. pct. Ni. The alloys were evaluated in both as-cast and

291

Angular correlations and internal conversion coefficients of ?-ray transitions in 104Pd  

Science Journals Connector (OSTI)

The nucleus 104Pd, populated in the electron capture and ?+ decay of 104Ag, has been investigated by means of ?-? coincidence, ?-? angular correlation, and K internal conversion coefficient measurements. The results have led to an improved knowledge of the decay scheme, to spin-parity assignment to several levels, and to the determination of E2/M1 mixing ratios for the most intense transitions. Information on E0 transitions between 0+ states and between states of same J?0 has also been deduced. The new spectroscopic data have been used to give an updated version of the decay scheme of 104Pd.

M. E. Bellizzi; A. Giannatiempo; A. Nannini; A. Perego; P. Sona

2001-05-18T23:59:59.000Z

292

Local atomic order in low Pt-content nanocatalysts investigated in situ by XAS  

Science Journals Connector (OSTI)

The unique features of X-ray absorption spectroscopy allow investigations of nanosized catalysts for fuel cells under working conditions. We present the results of an experiment carried out on a low Pt content electrocatalyst supported by a mesoporous heteropolyacid salt and used at the cathode of a proton exchange membrane fuel cell (PEMFC). The analysis of the EXAFS signal at the Pt L3-edge indicates that upon operating the fuel cell a substantial oxygen desorption from the Pt catalytic surface occurs followed by a tangible structural change on the Pt local order.

Emiliano Principi; Agnieszka Witkowska; Andrea Di Cicco

2009-01-01T23:59:59.000Z

293

E-Print Network 3.0 - acute abdomen pt Sample Search Results  

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

PHYSICIAN'S PERSONAL COPY TO: STREET CITY ZIP Summary: % BILIRUBIN mg% RBC HOSPITAL TUBE STATION 31 Platelet Count: INR: PT: PTT: 12;GASTRO INTESTINAL ANGIOGRAPHIC... CONTRAST)...

294

Degradation phenomena and design principles for stable and active Pt/C fuel cell catalysts.  

E-Print Network (OSTI)

??Stabile und aktive Elektrodenmaterialien sind entscheidend für moderne elektrochemische Energiewandler wie Brennstoffzellen. Diese Arbeit untersucht die Aktivität und insbesondere Stabilität von Pt/ C Brennstoffzellenkatalysatoren. In… (more)

Meier, Josef Christian

2013-01-01T23:59:59.000Z

295

Effect of substrate temperature on the magnetic properties of epitaxial sputter-grown Co/Pt  

SciTech Connect

Epitaxial Co/Pt films have been deposited by dc-magnetron sputtering onto heated C-plane sapphire substrates. X-ray diffraction, the residual resistivity, and transmission electron microscopy indicate that the Co/Pt films are highly ordered on the atomic scale. The coercive field and the perpendicular magnetic anisotropy increase as the substrate temperature is increased from 100–250?°C during deposition of the Co/Pt. Measurement of the domain wall creep velocity as a function of applied magnetic field yields the domain wall pinning energy, which scales with the coercive field. Evidence for an enhanced creep velocity in highly ordered epitaxial Co/Pt is found.

Mihai, A. P.; Whiteside, A. L.; Canwell, E. J.; Marrows, C. H.; Moore, T. A., E-mail: t.a.moore@leeds.ac.uk [School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT (United Kingdom); Benitez, M. J.; McGrouther, D.; McVitie, S.; McFadzean, S. [School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ (United Kingdom)] [School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ (United Kingdom)

2013-12-23T23:59:59.000Z

296

Basic Reaction Model of Automobile Exhaust Gas Treatment over Pt?Rh Catalyst  

Science Journals Connector (OSTI)

Basic Reaction Model of Automobile Exhaust Gas Treatment over Pt?Rh Catalyst ... The reactor is heated by a three-section electric furnace. ...

Motoaki Kawase; Hiroyasu Fujitsuka; Hitoshi Nakanishi; Tatsuya Yoshikawa; Kouichi Miura

2010-09-02T23:59:59.000Z

297

Nox reduction with CO over supported Pd catalysts under simulated post Euro-IV diesel exhaust conditions  

Science Journals Connector (OSTI)

The catalytic reduction of NOx with CO over Pd/Al2O3 and Pd/TiO2/Al2O3 under simulated post Euro-IV diesel exhaust conditions was studied. The catalytic activities obtained...2 loadings and total amounts of reduc...

Yinghua Li; Dae-Won Lee; Young-Chul Ko…

2008-12-01T23:59:59.000Z

298

PHYSICAL REVIEW B 85, 205443 (2012) Growth structure and work function of bilayer graphene on Pd(111)  

E-Print Network (OSTI)

PHYSICAL REVIEW B 85, 205443 (2012) Growth structure and work function of bilayer graphene on Pd of bilayer graphene on Pd(111). Low-energy electron diffraction analysis established that the two graphene layer. We propose that the faceted shapes are due to the zigzag-terminated edges bounding graphene

Ciobanu, Cristian

299

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

300

Photo- and Thermodesorption of Helium on Pt(111)  

Science Journals Connector (OSTI)

In a detailed study of thermal desorption of monolayers of both H4e and H3e adsorbed on Pt(111) (binding energy about 9 meV), we have observed photodesorption induced by the blackbody radiation from a room temperature environment. This process proceeds independently of the thermal desorption. Theoretical treatments of both thermal and photodesorption are given and agree very well with the data in all important aspects. We conclude that the photodesorption is due to direct coupling of photons to the adsorbate.

T. Niedermayer; H. Schlichting; D. Menzel; S. H. Payne; H. J. Kreuzer

2002-08-30T23:59:59.000Z

Note: This page contains sample records for the topic "ni pd pt" 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

SF 6432-NI (04-95)  

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

6/14/11 6/14/11 Page 1 of 14 Printed copies of this document are uncontrolled. Retrieve latest version electronically. SF 6432-NI (06/14/11) SECTION II STANDARD TERMS AND CONDITIONS FOR FIXED PRICE CONTRACTS WITH THE NEWLY INDEPENDENT STATES OF THE FORMER SOVIET UNION INDEX OF CLAUSES. THE FOLLOWING CLAUSES APPLY TO REQUESTS FOR QUOTATION AND CONTRACTS AS INDICATED UNLESS SPECIFICALLY DELETED, OR EXCEPT TO THE EXTENT THEY ARE SPECIFICALLY SUPPLEMENTED OR AMENDED IN WRITING IN THE SIGNATURE PAGE OR SECTION I. NI01 - ACCEPTANCE OF TERMS AND CONDITIONS Contractor, by signing this Agreement, beginning performance, and/or delivering Items or services ordered under this Agreement, agrees to comply with all the terms and conditions and all specifications and other documents that this Contract incorporated by

302

Microsoft Word - NiR.doc  

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

Side-on Cu-Nitrosyl Coordination by Nitrite Reductase Side-on Cu-Nitrosyl Coordination by Nitrite Reductase Elitza I. Tocheva and Michael E. P. Murphy Department of Microbiology & Immunology, The University of British Columbia, Vancouver, BC, Canada V6T 1Z3. Nitric oxide (NO) is one of the smallest and simplest biologically active molecules. In mammals, NO is produced from arginine by isoforms of nitric oxide synthase, and it func- tions in signal transduction and as a cytoprotective or cytotoxic agent. In bacteria, NO is produced by nitrite reductase (NiR), a copper-containing enzyme, which is responsible for the reduction of nitrite to nitric oxide (NO) in the process of dissimilatory denitrification. Cu- containing NiRs are homotrimers with two distinct Cu sites per monomeric unit (1). The type

303

Magnetic and electronic properties of the ferromagnetic Kondo-lattice system Np2PdGa3  

Science Journals Connector (OSTI)

Intermetallic compounds Lu2PdGa3 and Np2PdGa3 have been found to crystallize in an orthorhombic CeCu2-type structure with the Imma space group. The lattice parameters at room temperature are: a=0.4382(2), b=0.6870(3), and c=0.7593(3)?nm for Lu2PdGa3 and a=0.4445(2), b=0.7089(3), and c=0.7691(3)?nm for Np2PdGa3. The electronic ground-state properties of these compounds were established by magnetic, calorimetric, electrical resistivity, magnetoresistance, and Hall coefficient measurements. The experimental data reveal a metallic behavior for Pauli paramagnetic Lu2PdGa3, characterized by Sommerfeld ratio ?=2.5?mJ/K2?mol?Lu and temperature-independent susceptibility ?0?1×10?4?emu/mol. In contrast to the nonmagnetic Lu2PdGa3 reference, Np2PdGa3 behaves as a local-moment ferromagnet with the Curie temperature TC=62.5(2)?K. Low-temperature properties of Np2PdGa3 are characterized by a large Sommerfeld ratio ?=120(2)?mJ/K2?mol?Np and a small Fermi momentum kF=0.44?Å?1. The observed features in Np2PdGa3 are well interpreted by assuming competition of three different interactions: Rudermann-Kittel-Kasuya-Yosida (RKKY), crystal electric field (CEF) and Kondo effect, which are represented by respective energies kBTRKKY, ?CEF, and kBTK. We argue that Np2PdGa3 is the Np-based ferromagnetic Kondo-lattice system with TK

V. H. Tran; J.-C. Griveau; R. Eloirdi; W. Miiller; E. Colineau

2010-09-03T23:59:59.000Z

304

Surface morphology of atomic nitrogen on Pt(111)  

SciTech Connect

The surface morphology of chemisorbed N on the Pt(111) surface has been studied at the atomic level with low temperature scanning tunneling microscopy (STM). When N is coadsorbed with O on the surface, they form a mixed (2 × 2)-N+O structure. When the surface is covered with N atoms only, isolated atoms and incomplete (2 × 2) patches are observed at low coverages. In a dense N layer, two phases, (?3 × ?3)R30°-N and p(2 × 2)-N, are found to coexist at temperatures between 360 and 400 K. The (?3 × ?3)R30° phase converts to the (2 × 2) phase as temperature increases. For both phases, nitrogen occupies fcc-hollow sites. At temperatures above 420 K, nitrogen starts to desorb. The p(2 × 2)-N phase shows a honeycomb structure in STM images with three nitrogen and three platinum atoms forming a six-membered ring, which can be attributed to the strong nitrogen binding to the underlying Pt surface.

Liang, Zhu; Trenary, Michael, E-mail: mtrenary@uic.edu [Department of Chemistry, University of Illinois at Chicago, 845 West Taylor Street, Chicago, Illinois 60607 (United States)] [Department of Chemistry, University of Illinois at Chicago, 845 West Taylor Street, Chicago, Illinois 60607 (United States); Jin Yang, Hyun [Surface and Interface Science Laboratory, RIKEN, 2-1 Hirosawa, Wako-shi, Saitama 351-0198 (Japan) [Surface and Interface Science Laboratory, RIKEN, 2-1 Hirosawa, Wako-shi, Saitama 351-0198 (Japan); Department of Advanced Materials Science, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8561 (Japan); Kim, Yousoo, E-mail: ykim@riken.jp [Surface and Interface Science Laboratory, RIKEN, 2-1 Hirosawa, Wako-shi, Saitama 351-0198 (Japan)] [Surface and Interface Science Laboratory, RIKEN, 2-1 Hirosawa, Wako-shi, Saitama 351-0198 (Japan)

2014-03-21T23:59:59.000Z

305

The Effect of Pitch Composition on the Adsorption Behavior of Pd-Doped ACF  

SciTech Connect

Recent studies indicate that metal-containing activated carbon fibers (ACF) are promising adsorbents for hydrogen storage applications. In these studies, Pd compounds were added to a petroleum precursor and formed into ACFs. Results showed that the molecular composition of the pitch had a significant affect on critical characteristics of the ACFs, such as pore size and Pd particle size. In an ongoing Department of Energy project, we are testing pitch precursors with carefully controlled chemical compositions in order to develop an optimum precursor for hydrogen storage applications. A low softening point pitch made by Marathon Oil is being separated into narrow molecular weight fractions using a dense gas extraction (DGE) process. In the current series of tests the heavier portion of the extracted pitch was used to prepare both undoped and Pd-doped carbon fibers. These fibers were activated over a range of temperatures to determine the effect of temperature and pitch composition on ACF properties. Lower activation temperatures resulted in increased microporosity (desirable for hydrogen adsorption) for all Pd-doped pitch precursors. Comparing ACFs produced from various DGE-extracted pitches showed that even small quantities of mesophase-forming components inhibited activation and significantly reduced microporosity. Additional DGE pitch fractions are now being tested to further refine the optimum composition for hydrogen storage applications.

Tekinalp, Halil [Clemson University; Cervo, Eduardo [Clemson University; Thies, Mark C [ORNL; Contescu, Cristian I [ORNL; Gallego, Nidia C [ORNL; Edie, Dan [Clemson University

2007-01-01T23:59:59.000Z

306

Micro Catalytic Combustor with Pd/Nano-porous Alumina for High-Temperature Application  

E-Print Network (OSTI)

, the mixture temperature at the combustor inlet is set to 630 o C. Thermal conductivity of the ceramic wall Keywords: Catalytic combustion, Pd/nano-porous alumina, Ceramic tape casting, Thermophotovoltaic Abstract: A micro-scale catalytic combustor using high-precision ceramic tape-casting technology has been developed

Kasagi, Nobuhide

307

Tables for Trials and Failures with PD for Designated Confidence Level  

SciTech Connect

Two attachments are provided for performance testing of sensors and other Physical Protection System (PPS) components.#2; The first attachment is a table of Trials and Failures, giving Probability of Detection (PD) for a designated confidence level and sorted by trials.#2; The second attachment contains the same data, sorted by failures.

Leach, Janice

2014-02-01T23:59:59.000Z

308

Single Pd atoms in activated carbon fibers and their contribution to hydrogen storage 5  

E-Print Network (OSTI)

Single Pd atoms in activated carbon fibers and their contribution to hydrogen storage 5 Cristian I surface area carbon materials for hydrogen storage continues to attract interest because predicted high potential for hydrogen storage on metal-decorated carbon supports, the experimental

Pennycook, Steve

309

PT-/non-PT-Symmetric and non-Hermitian Hellmann Potential: Approximate Bound and Scattering States with Any $\\ell$-Values  

E-Print Network (OSTI)

We investigate the approximate bound state solutions of the Schr\\"odinger equation for the PT-/non-PT-symmetric and non Hermitian Hellmann potential. Exact energy eigenvalues and corresponding normalized wave functions are obtained. Numerical values of energy eigenvalues for the bound states are compared with the ones obtained before. Scattering state solutions are also studied. Phase shifts of the potential are written in terms of the angular momentum quantum number $\\ell$.

Altug Arda; Ramazan Sever

2014-08-29T23:59:59.000Z

310

Reduction of Sintering during Annealing of FePt Nanoparticles Coated with Iron Oxide  

E-Print Network (OSTI)

are first obtained by reduction of iron(III) acetylacetonate and platinum(II) acetylacetonateReduction of Sintering during Annealing of FePt Nanoparticles Coated with Iron Oxide Chao LiuVised Manuscript ReceiVed October 12, 2004 FePt/iron oxide core/shell nanoparticles are synthesized by a two step

Laughlin, David E.

311

Real-Time Imaging of Pt3Fe Nanorod Growth in Solution  

Science Journals Connector (OSTI)

...real time. A growth solution of Pt(acetylacetonate) 2 (20 mg/mL) and Fe(acetylacetonate) 2 (20 mg/mL) dissolved in a solvent...real time. A growth solution of Pt(acetylacetonate)2 (20 mg/mL) and Fe(acetylacetonate...

Hong-Gang Liao; Likun Cui; Stephen Whitelam; Haimei Zheng

2012-05-25T23:59:59.000Z

312

Pt IB Paper 8 Photo Editing Course 1 Part IB Paper 8  

E-Print Network (OSTI)

Pt IB Paper 8 Photo Editing Course 1 Part IB Paper 8 Information Engineering Option A ­ Photo. Lecture 6: Examples Class Contents 1 Program Framework for the Photo Editor 5 1.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 #12;2 Pt IB Paper 8 Photo Editing Course 4 Rotating the image: ph rotate 25 4.1 The script ph

Kingsbury, Nick

313

How Does a Single Pt Nanocatalyst Behave in Two Different Reactions? A Single-Molecule Study  

E-Print Network (OSTI)

How Does a Single Pt Nanocatalyst Behave in Two Different Reactions? A Single-Molecule Study Kyu ABSTRACT: Using single-molecule microscopy of fluoro- genic reactions we studied Pt nanoparticle catalysis. KEYWORDS: Single-particle catalysis, platinum nanoparticles, single-molecule imaging, deacetylation

Chen, Peng

314

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

315

Determination of the Pt spin diffusion length by spin-pumping and spin Hall effect  

SciTech Connect

The spin diffusion length of Pt at room temperature and at 8 K is experimentally determined via spin pumping and spin Hall effect in permalloy/Pt bilayers. Voltages generated during excitation of ferromagnetic resonance from the inverse spin Hall effect and anisotropic magnetoresistance effect were investigated with a broadband approach. Varying the Pt layer thickness gives rise to an evolution of the voltage line shape due to the superposition of the above two effects. By studying the ratio of the two voltage components with the Pt layer thickness, the spin diffusion length of Pt can be directly extracted. We obtain a spin diffusion length of ?1.2 nm at room temperature and ?1.6 nm at 8 K.

Zhang, Wei; Pearson, John E.; Hoffmann, Axel [Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States)] [Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Vlaminck, Vincent [Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States) [Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Colegio de Ciencias e Ingenería, Universidad San Fransciso de Quito, Quito (Ecuador); Divan, Ralu [Center for Nanoscale Materials, Argonne National Laboratory, Illinois 60439 (United States)] [Center for Nanoscale Materials, Argonne National Laboratory, Illinois 60439 (United States); Bader, Samuel D. [Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States) [Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Center for Nanoscale Materials, Argonne National Laboratory, Illinois 60439 (United States)

2013-12-09T23:59:59.000Z

316

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

Science Journals Connector (OSTI)

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

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

2001-01-01T23:59:59.000Z

317

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

318

Self-Assembled Free-Standing Polypyrrole Nanotube Membrane as an Efficient FTO- and Pt-Free Counter Electrode for Dye-Sensitized Solar Cells  

Science Journals Connector (OSTI)

Photovolatic Performance Data of DSSCs Employing FTO/Pt and PPy Membrane CEs and EIS Data of the Symmetrical Cells Based on Pt/FTO and PPy CEs ...

Tao Peng; Weiwei Sun; Chengliang Huang; Wenjing Yu; Bobby Sebo; Zhigao Dai; Shishang Guo; Xing-Zhong Zhao

2013-12-17T23:59:59.000Z

319

Fusion of radioactive $^{132}$Sn with $^{64}$Ni  

E-Print Network (OSTI)

Evaporation residue and fission cross sections of radioactive $^{132}$Sn on $^{64}$Ni were measured near the Coulomb barrier. A large sub-barrier fusion enhancement was observed. Coupled-channel calculations including inelastic excitation of the projectile and target, and neutron transfer are in good agreement with the measured fusion excitation function. When the change in nuclear size and shift in barrier height are accounted for, there is no extra fusion enhancement in $^{132}$Sn+$^{64}$Ni with respect to stable Sn+$^{64}$Ni. A systematic comparison of evaporation residue cross sections for the fusion of even $^{112-124}$Sn and $^{132}$Sn with $^{64}$Ni is presented.

J. F. Liang; D. Shapira; J. R. Beene; C. J. Gross; R. L. Varner; A. Galindo-Uribarri; J. Gomez del Campo; P. A. Hausladen; P. E. Mueller; D. W. Stracener; H. Amro; J. J. Kolata; J. D. Bierman; A. L. Caraley; K. L. Jones; Y. Larochelle; W. Loveland; D. Peterson

2007-04-05T23:59:59.000Z

320

Computing Free Energy Landscapes: Application to Ni-based Electrocatal...  

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

Computing Free Energy Landscapes: Application to Ni-based Electrocatalysts with Pendant Amines for H2 Production and Oxidation. Computing Free Energy Landscapes: Application to...

Note: This page contains sample records for the topic "ni pd pt" 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

Characterization of Pt/Al/sub 2/O/sub 3/ catalysts by extended X-ray absorption fine structure  

SciTech Connect

Three different Pt/Al/sub 2/O/sub 3/ catalysts with average crystallite sizes of 95, 26, and 8 A., as assessed by hydrogen chemisorption measurements, and reference samples of platimum foil and PtO/sub 2/ were examined by transmission X-ray absorption measurements near the Pt L/sub I//sub I//sub I/ X-ray absorption edge. The fine structure for the reduced catalysts showed that the first Pt-Pt interatomic separation distance in the crystallites did not change with crystallite size. The 95 and 26 A. catalysts had Pt crystallites with fcc crystal structure, the same as in bulk platimum. Adsorption of carbon monoxide on the 26 A. catalyst at room temperature did not disturb crystallite structure, but oxygen chemisorption on that catalyst significantly reduced the magnitude of the first Pt-Pt peak, implying a reduction in the average number of first-nearest-neighbor Pt atoms. The Fourier transform indicated coordination of Pt atoms with oxygen. All Pt-Pt bands vanished when the 8 A. catalyst was exposed to oxygen. Platimum atom electron deficiency decreased significantly after carbon monoxide or oxygen adsorption on the catalysts.

Lornston, J.M.

1980-01-01T23:59:59.000Z

322

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

323

XAFS Characterization of Pt–Fe/zeolite Catalysts for Preferential Oxidation of CO in Hydrogen Fuel Gases  

Science Journals Connector (OSTI)

We have developed a new Pt–Fe/mordenite (Pt–Fe/M) catalyst which shows remarkably high activity and selectivity for the oxidation of CO in H2-rich gas compared with Pt/M. In the present work, to understand the ro...

Masashi Kotobuki; Takafumi Shido; Mizuki Tada; Hiroyuki Uchida…

2005-10-01T23:59:59.000Z

324

Enhanced photocatalytic efficiency in zirconia buffered n-NiO/p-NiO single crystalline heterostructures by nanosecond laser treatment  

SciTech Connect

We report the formation of NiO based single crystalline p-n junctions with enhanced photocatalytic activity induced by pulsed laser irradiation. The NiO epilayers were grown on Si(001) substrates buffered with cubic yttria-stabilized zirconia (c-YSZ) by using pulsed laser deposition. The NiO/c-YSZ/Si heterostructures were subsequently laser treated by 5 pulses of KrF excimer laser (pulse duration = 25 Multiplication-Sign 10{sup -9} s) at lower energies. Microstructural studies, conducted by X-ray diffraction ({theta}-2{theta} and {phi} techniques) and high resolution transmission electron microscope, showed a cube-on-cube epitaxial relationship at the c-YSZ/Si interface; the epitaxial relationship across the NiO/c-YSZ interface was established as NiO<111 > Double-Vertical-Line Double-Vertical-Line c-YSZ<001> and in-plane NiO<110> Double-Vertical-Line Double-Vertical-Line c-YSZ<100>. Electron microscopy studies showed that the interface between the laser annealed and the pristine region as well as the NiO/c-YSZ interface was atomically sharp and crystallographically continuous. The formation of point defects, namely oxygen vacancies and NiO, due to the coupling of the laser photons with the NiO epilayers was confirmed by XPS. The p-type electrical characteristics of the pristine NiO epilayers turned to an n-type behavior and the electrical conductivity was increased by one order of magnitude after laser treatment. Photocatalytic activity of the pristine (p-NiO/c-YSZ/Si) and the laser-annealed (n-NiO/p-NiO/c-YSZ/Si) heterostructures were assessed by measuring the decomposition rate of 4-chlorophenol under UV light. The photocatalytic reaction rate constants were determined to be 0.0059 and 0.0092 min{sup -1} for the as-deposited and the laser-treated samples, respectively. The enhanced photocatalytic efficiency was attributed to the suppressed charge carrier recombination in the NiO based p-n junctions and higher electrical conductivity. Besides, the oxygen vacancies ease the adsorption of 4-chlorophenol, hydroxyl, and water molecules to the surface. Thus, n-NiO/p-NiO single crystalline catalysts can be introduced as a potent candidate to remediate the environmental pollution.

Molaei, R.; Bayati, M. R.; Alipour, H. M.; Nori, S.; Narayan, J. [Department of Materials Science and Engineering, NC State University, EB-1, Raleigh, North Carolina 27695-7907 (United States)] [Department of Materials Science and Engineering, NC State University, EB-1, Raleigh, North Carolina 27695-7907 (United States)

2013-06-21T23:59:59.000Z

325

Formation of a Novel Ordered Ni3Al Surface Structure by Codeposition on NiAl(110)  

SciTech Connect

The formation of a new type of ordered 2D Ni3Al overlayer by low-temperature codeposition on NiAl(110) is demonstrated by kinetic Monte Carlo simulation of a multisite atomistic lattice-gas model with a precise treatment of surface diffusion kinetics. Simultaneous codeposition with 3?1 Ni?Al yields poor ordering at 300 K but well-ordered structures by ?500??K. Sequential codeposition of Ni then Al yields unmixed core-ring nanostructures at 300 K but strong intermixing and ordering by ?500??K.

Han, Yong; Unal, Baris; Evans, James W.

2012-05-23T23:59:59.000Z

326

Paramagnetic neutron scattering from Ni (invited)  

Science Journals Connector (OSTI)

New polarized beammeasurements have been carried out in the paramagnetic phase of 6 0Ni in order to enlarge the (q ?) range previously studied by Steinsvoll e t a l. Magnetic scattering has been detected up to halfway to the zone boundary. The results can be successfully interpreted in terms of a diffusive?type scattering function over an unexpected wide (q ?) range qneutron data are also compared with the predictions of the very recent band model by Callaway. Finally we point out important similarities and differences in the paramagnetic scattering from localized systems such as EuO and itinerant systems and discuss the universality of the paramagnetic scattering function.

P. Böni; G. Shirane

1985-01-01T23:59:59.000Z

327

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

328

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

329

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

330

Local atomic structure in equilibrium and supercooled liquid Zr[subscript 75.5]Pd[subscript 24.5  

SciTech Connect

Atomic structures were obtained in equilibrium and supercooled eutectic Zr{sub 75.5}Pd{sub 24.5} liquids by in situ high-energy synchrotron diffraction measurements using the beamline electrostatic levitation (BESL) technique, which provides a high-vacuum, containerless, environment. Reverse Monte Carlo fits to the x-ray static structure factors, constrained using partial pair correlation functions obtained from ab initio molecular dynamics simulations, indicate the presence of medium-range order (MRO) in the form of a strong tendency for Pd-Pd (solute-solute) avoidance. This order persists over the entire temperature range studied, from 170 C above the equilibrium liquidus temperature to 263 C below it. Further, a quantitative analysis of the atomic structures obtained indicates a modest degree of icosahedral-like local order around Pd atoms, with the clusters showing an increased tendency for face-sharing to form more extended structures with decreasing temperature.

Mauro, N.A.; Fu, W.; Bendert, J.C.; Cheng, Y.Q.; Ma, E.; Kelton, K.F. (WU); (ORNL); (JHU)

2012-09-06T23:59:59.000Z

331

UHV-EC Characterization of Ultrathin Films Electrodeposited on Well-Defined Noble Metals. II: Co on Pd(111)  

Science Journals Connector (OSTI)

Tailoring the magnetic properties of Co–Pd superlattices requires a clear understanding of the growth mechanism for this bimetallic system. Early studies utilizing low-energy ion scattering spectroscopy and X-...

Jack H. Baricuatro; Manuel P. Soriaga

2010-05-01T23:59:59.000Z

332

Synthesis of AuPd alloyed nanoparticles via room-temperature electron reduction with argon glow discharge as electron source  

Science Journals Connector (OSTI)

Argon glow discharge has been employed as a cheap, environmentally friendly, and convenient electron source for simultaneous reduction of HAuCl4 and PdCl2...on the anodic aluminum oxide (AAO) substrate. The therm...

Manman Yang; Zongyuan Wang; Wei Wang; Chang-jun Liu

2014-08-01T23:59:59.000Z

333

E-Print Network 3.0 - al-ni-co decagonal quasicrystal Sample...  

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

Summary: of decagonal Al-Ni-Co K. Pussi Department of Electrical Engineering, Lappeenranta University of Technology, P... . EARLIER WORK ON d-Al-Ni-Co STRUCTURES Decagonal...

334

''Bare'' single-particle energies in Ni-56  

E-Print Network (OSTI)

The structure of the low-lying levels in the mirror nuclei Ni-57 and Cu-57 is described within the extended unified model. The problem of single-particle energies in Ni-56 is treated in detail. ''Bare'' single-particle energies are extracted from...

Trache, L.; Kolomiets, A.; Shlomo, S.; Heyde, K.; Dejbakhsh, H.; Gagliardi, Carl A.; Tribble, Robert E.; Zhou, XG; Jacob, VE; Oros, AM.

1996-01-01T23:59:59.000Z

335

Lanthanide Al-Ni base Ericsson cycle magnetic refrigerants  

DOE Patents (OSTI)

A magnetic refrigerant for a magnetic refrigerator using the Ericsson thermodynamic cycle comprises DyAlNi and (Gd{sub 0.54}Er{sub 0.46})AlNi alloys having a relatively constant {Delta}Tmc over a wide temperature range. 16 figs.

Gschneidner, K.A. Jr.; Takeya, Hiroyuki

1995-10-31T23:59:59.000Z

336

Lanthanide Al-Ni base Ericsson cycle magnetic refrigerants  

DOE Patents (OSTI)

A magnetic refrigerant for a magnetic refrigerator using the Ericsson thermodynamic cycle comprises DyAlNi and (Gd.sub.0.54 Er.sub.0.46)AlNi alloys having a relatively constant .DELTA.Tmc over a wide temperature range.

Gschneidner, Jr., Karl A. (Ames, IA); Takeya, Hiroyuki (Ibaraki, JP)

1995-10-31T23:59:59.000Z

337

Phase relations in the system Ni-As  

Science Journals Connector (OSTI)

...n' ' , / / I , 852(N_i,As)+VN',Asz+L+V ima+L+v/IpnncC;rVrlrl+V(NiAs)+NisAsz+V-, , I I// INIs.xAs +mama+ncll Ni,_xAS,+V/i +V +VJ[ Inc+prm+V , , , , , , , .i,, .! , . I0 20 30 40 50 60 70 Weight per...

R. A. Yund

338

Low temperature epitaxial growth of Ge on cube- textured Ni  

SciTech Connect

Quasi- single crystal Ge films were grown on [001]<010> textured Ni substrate at a temperature of 350 oC using an insulating buffer layer of CaF2. A direct deposition of Ge on Ni at 350 oC was shown to alloy with Ni. From x- ray pole figure analysis, it was shown that Ge grew epitaxially with the same orientation as CaF2 and the dispersions in the out- of- plane and in- plane directions were found to be 1.7 0.1o and 6 1o, respectively. In the out- of- plane direction, Ge[111]||CaF2[111]||Ni[001]. In addition, the Ge consisted of four equivalent in- plane oriented domains such that two mutually orthogonal directions: Ge 211 and Ge 011 are parallel to mutually orthogonal directions: Ni 110 and Ni 110 , respectively of the Ni(001) surface. This was shown to be originated from the four equivalent in- plane oriented domains of CaF2 created to minimize the mismatch strain between CaF2 and Ni in those directions.

GIARE, C [Rensselaer Polytechnic Institute (RPI); Palazzo, J [Rensselaer Polytechnic Institute (RPI); Goyal, Amit [ORNL; WANG, G [Rensselaer Polytechnic Institute (RPI); LU, T [Rensselaer Polytechnic Institute (RPI)

2012-01-01T23:59:59.000Z

339

Autocatalytic decomposition of water on Ni(110)  

SciTech Connect

The interaction of water with clean Ni(110) at temperatures between 425 and 770 K has been studied by work function ([Delta][phi]), desorption mass analysis, and low-energy electron diffraction (LEED). Water is observed to dissociate on clean Ni(110), forming adsorbed oxygen and H[sub 2](g) in a process which is itself catalyzed (and hence termed autocatalytic) by the adsorbed oxygen product. Initial dissociation of water is believed to originate on defects where adsorbed oxygen then promotes growth of O (2 [times] 1) islands in a process which becomes self-poisoning in the limit of saturation of the (2 [times] 1) phase (0.5 ML (ML = monolayer)). The growth kinetics indicate the autocatalysis process is most active when the oxygen coverage is 0.1 ML. A statistical theory supported by computer simulation is developed which models the autocatalytic growth kinetics in terms of nucleation of islands along step edges. The temperature dependence of autocatalysis exhibits a maximum at approx. 600 K. This complex temperature dependence is explained in terms of transition-state theory. 25 refs., 10 figs.

Callen, B.W.; Griffiths, K.; Norton, P.R. (Univ. of Western Ontario, London (Canada)); Harrington, D.A. (Univ. of Victoria, British Columbia (Canada))

1992-12-24T23:59:59.000Z

340

COMMENTS ON ANOMALOUS EFFECTS IN CHARGING OF PD POWDERS WITH HIGH DENSITY HYDROGEN ISOTOPES  

SciTech Connect

In Kitamura, et al, Pd-containing materials are exposed to isotopes of hydrogen and anomalous results obtained. These are claimed to be a replication of another experiment conducted by Arata and Zhang. Erroneous basic assumptions are pointed out herein that alter the derived conclusions significantly. The final conclusion is that the reported results are likely normal chemistry combined with noise. Thus the claim to have proven that cold fusion is occurring in these systems is both premature and unlikely.

Shanahan, K.

2009-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "ni pd pt" 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

Synthesis of Methanol and Dimethyl Ether from Syngas over Pd/ZnO/Al2O3 Catalysts  

SciTech Connect

A Pd/ZnO/Al2O3 catalyst was developed for the synthesis of methanol and dimethyl ether (DME) from syngas. Studied were temperatures of operation ranging from 250°C to 380°C. High temperatures (e.g. 380°C) are necessary when combining methanol and DME synthesis with a methanol to gasoline (MTG) process in a single reactor bed. A commercial Cu/ZnO/Al2O3 catalyst, utilized industrially for the synthesis of methanol at 220-280°C, suffers from a rapid deactivation when the reaction is conducted at high temperature (>320°C). On the contrary, a Pd/ZnO/Al2O3 catalyst was found to be highly stable for methanol and DME synthesis at 380°C. The Pd/ZnO/Al2O3 catalyst was thus further investigated for methanol and DME synthesis at P=34-69 bars, T= 250-380°C, GHSV= 5 000-18 000 h-1, and molar feeds H2/CO= 1, 2, and 3. Selectivity to DME increased with decreasing operating temperature, and increasing operating pressure. Increased GHSV’s and H2/CO syngas feed ratios also enhanced DME selectivity. Undesirable CH4 formation was observed, however, can be minimized through choice of process conditions and by catalyst design. By studying the effect of the Pd loading and the Pd:Zn molar ratio the formulation of the Pd/ZnO/Al2O3 catalyst was optimized. A catalyst with 5% Pd and a Pd:Zn molar ratio of 0.25:1 has been identified as the preferred catalyst. Results indicate that PdZn particles are more active than Pdº particles for the synthesis of methanol and less active for CH4 formation. A correlation between DME selectivity and the concentration of acid sites of the catalysts has been established. Hence, two types of sites are required for the direct conversion of syngas to DME: 1) PdZn particles are active for the synthesis of methanol from syngas, and 2) acid sites which are active for the conversion of methanol to DME. Additionally, CO2 formation was problematic as PdZn was found to be active for the water-gas-shift (WGS) reaction, under all the conditions evaluated.

Lebarbier, Vanessa MC; Dagle, Robert A.; Kovarik, Libor; Lizarazo Adarme, Jair A.; King, David L.; Palo, Daniel R.

2012-10-01T23:59:59.000Z

342

Electron Source in Photoinduced Hydrogen Production on Pt-supported TiO2 Particles  

Science Journals Connector (OSTI)

Electron Source in Photoinduced Hydrogen Production on Pt-supported TiO2 Particles ... After recovering the TiO2/Pt particles used in the long-term reaction, they were reused in a photocatalytic H+ reduction by adding methanol as an electron donor, but no H2 production was observed showing that the TiO2/Pt particles have lost their photocatalytic activity after the long-term reaction. ... A 100 W high-pressure Hg lamp was used as a light source. ...

Toshiyuki Abe; Eiji Suzuki; Kentaro Nagoshi; Kohichi Miyashita; Masao Kaneko

1999-02-04T23:59:59.000Z

343

Granular L1{sub 0} FePt-B and FePt-B-Ag (001) thin films for heat assisted magnetic recording  

SciTech Connect

A comparison was made of FePt-B and FePt-B-Ag thin films having different volume contents of boron, which were RF sputtered with in-situ heating at 425-575 deg. C onto Si substrates with 20 nm thick (002) MgO. By introducing boron into FePt and varying the sputtering conditions, films with grain sizes ranging from 2.5 to 10 nm were produced. The boron promoted columnar growth, but made ordering more difficult. However, by adding Ag into FePt-B, ordering improved while coercivity increased from 7 to 11 kOe with no significant impact on the microstructure. We obtained films with grain sizes down to 2.5 nm with center-to-center spacing of 3.1 nm. The reduced grain size, columnar microstructure and increase in ordering and coercivity by adding Ag into the FePt-B thin films are favorable for application in heat assisted magnetic recording.

Granz, Steven D.; Barmak, Katayun; Kryder, Mark H. [Data Storage System Center, Carnegie Mellon University, 5000 Forbes Ave., Pittsburgh, Pennsylvania 15213 (United States)

2012-04-01T23:59:59.000Z

344

Metal-and hydrogen-bonding competition during water absorption on Pd(111) and Ru(0001)  

SciTech Connect

The initial stages of water adsorption on the Pd(111) and Ru(0001) surfaces have been investigated experimentally by Scanning Tunneling Microscopy in the temperature range between 40 K and 130 K, and theoretically with Density Functional Theory (DFT) total energy calculations and STM image simulations. Below 125 K water dissociation does not occur at any appreciable rate and only molecular films are formed. Film growth starts by the formation of flat hexamer clusters where the molecules bind to the metal substrate through the O-lone pair while making H-bonds with neighboring molecules. As coverage increases, larger networks of linked hexagons are formed with a honeycomb structure, which requires a fraction of the water molecules to have their molecular plane perpendicular to the metal surface with reduced water-metal interaction. Energy minimization favors the growth of networks with limited width. As additional water molecules adsorb on the surface they attach to the periphery of existing islands, where they interact only weakly with the metal substrate. These molecules hop along the periphery of the clusters at intermediate temperatures. At higher temperatures they bind to the metal to continue the honeycomb growth. The water-Ru interaction is significantly stronger than the water-Pd interaction, which is consistent with the greater degree of hydrogen-bonded network formation and reduced water-metal bonding observed on Pd relative to Ru.

Tatarkhanov, Mouslim; Ogletree, D. Frank; Rose, Franck; Mitsui, Toshiyuki; Fomin, Evgeny; Rose, Mark; Cerda, Jorge I.; Salmeron, Miquel

2009-09-03T23:59:59.000Z

345

Neutron spectroscopy of H impurities in PdD: Covibrations of the H and D atoms  

Science Journals Connector (OSTI)

Three powder samples of solid isotopic solutions PdD1?xHx with x=0.050, 0.072, and 0.091 are prepared under high pressure, and the spectra of their optical vibrations are studied by inelastic neutron scattering at ambient pressure and 5 K using the high-luminosity IN1-BeF spectrometer at ILL, Grenoble. These spectra are shown to be well represented by a linear combination of a contribution from the undisturbed matrix of stoichiometric PdD and a contribution due to the H impurity. The optical spectrum of PdD consists of a strong peak at 37 meV with a shoulder extending to 65 meV. The spectrum due to the H impurity is composed of a broad peak of defect H modes centered at 68 meV and superimposed on a broad N-shaped feature with a range of negative intensity near 36 meV and a shallow maximum at 45 meV. Simulations using the Born-von Kármán model show that this unusual feature is a result of the formation of a band of optical vibrations of the D and H atoms with equal frequencies (covibrations) caused by H-D interactions.

V. E. Antonov; A. I. Davydov; V. K. Fedotov; A. S. Ivanov; A. I. Kolesnikov; M. A. Kuzovnikov

2009-10-15T23:59:59.000Z

346

Kinetics of CO adsorption on epitaxial (111)Cu on (111)Pd thin films  

SciTech Connect

CO adsorption has been studied on (111)Cu/Pd thin-film surfaces grown epitaxially on mica in UHV of base pressure 5 x 10/sup -11/ Torr. Auger electron spectroscopy investigations of the growth of Cu on (111)Pd films showed that layer growth occurred. The Kelvin probe, work function method was used to monitor the CO adsorption at 298 K as a function of Cu overlayer thickness. It was found that very thin Cu overlayers had a drastic effect on saturation CO coverage: one monolayer of copper reduced the saturation CO coverage by /similar to/95%. For the pure (111)Pd thin-film surface, the data showed that the rate of CO adsorption changes when the CO fractional coverage approaches /similar to/0.4. This result is most likely due to the previously reported change in CO superlattice structure that occurs with increasing coverage. The kinetic adsorption data for various bilayers were interpreted in terms of a first-order Kisliuk mobile precursor model.

Oral, B.; Kothari, R.; Vook, R.W.

1989-05-01T23:59:59.000Z

347

Corrosion resistance of artificial passivation films of Fe[sub 2]O[sub 3]-Cr[sub 2]O[sub 3]-NiO formed by metalorganic chemical vapor deposition  

SciTech Connect

A series of thin Fe[sub 2]O[sub 3]-Cr[sub 2]O[sub 3]-NiO films were formed on Pt by an MOCVD technique using Fe(III), Cr(III), and Ni(II) acetylacetonate. The corrosion resistance of the films was examined in H[sub 2]SO[sub 4] and HCl by measuring the film thickness using ellipsometry and the chemical analysis of test solutions with ICPS. The dissolution rate of Fe[sub 2]O[sub 3]-Cr[sub 2]O[sub 3] composite films decreases exponentially with an increase in the cationic mass fraction of Cr[sup 3+] ions, X[sub Cr], of the films, and at the values of X[sub Cr] larger than 0.7 it becomes two orders of magnitude lower than that of Fe[sub 2]O[sub 3] films. The same type of changes in the dissolution rate with X[sub Cr] was observed for the NiO-Cr[sub 2]O[sub 3] composite films. Therefore, the addition of Cr[sub 2]O[sub 3] to Fe[sub 2]O[sub 3] and NiO films effectively improves the corrosion resistance. The addition of NiO to Fe[sub 2]O[sub 3]-Cr[sub 2]O[sub 3] composite films containing an adequate amount of Cr[sub 2]O[sub 3] does not bring an effective improvement in corrosion resistance. Therefore, the corrosion resistance of Fe[sub 2]O[sub 3]-Cr[sub 2]O[sub 3]-NiO composite films is determined primarily by the Cr[sub 2]O[sub 3] content of the films.

Sugimoto, Katsuhisa; Seto, Masahiro; Tanaka, Shigeaki; Hara, Nobuyoshi (Tohoku Univ., Sendai (Japan). Dept. of Metallurgy)

1993-06-01T23:59:59.000Z

348

Density Functional Theory and Reaction Kinetics Studies of the Water–Gas Shift Reaction on Pt–Re Catalysts  

SciTech Connect

Periodic, self-consistent density functional theory calculations (DFT-GGA-PW91) on Pt(111) and Pt3Re(111) surfaces, reaction kinetics measurements, and microkinetic modeling are employed to study the mechanism of the water–gas shift (WGS) reaction over Pt and Pt–Re catalysts. The values of the reaction rates and reaction orders predicted by the model are in agreement with the ones experimentally determined; the calculated apparent activation energies are matched to within 6% of the experimental values. The primary reaction pathway is predicted to take place through adsorbed carboxyl (COOH) species, whereas formate (HCOO) is predicted to be a spectator species. We conclude that the clean Pt(111) is a good representation of the active site for the WGS reaction on Pt catalysts, whereas the active sites on the Pt–Re alloy catalyst likely contain partially oxidized metal ensembles.

Carrasquillo-Flores, Ronald; Gallo, Jean Marcel R.; Hahn, Konstanze; Dumesic, James A.; Mavrikakis, Manos

2013-12-01T23:59:59.000Z

349

Formation of a Novel Ordered Ni3Al Surface Structure by Codeposition on NiAl(110)  

E-Print Network (OSTI)

The formation of a new type of ordered 2D Ni3Al overlayer by low-temperature codeposition on NiAl(110) is demonstrated by kinetic Monte Carlo simulation of a multisite atomistic lattice-gas model with a precise treatment ...

Han, Yong

350

A trinuclear palladium(II) complex containing N,S-coordinating 2-(benzyl­sulfanyl)anilinide and 1,3-benzo­thia­zole-2-thiol­ate ligands with a central square-planar PdN4 motif  

Science Journals Connector (OSTI)

A linear trinuclear Pd3 complex containing N,S-coordinating 2-(benzyl­sulfanyl)anilinide and 1,3-benzo­thia­zole-2-thiol­ate ligands has symmetry and a PdPd separation of 3.2012 (4) ?. All three PdII atoms have a square-planar geometry, while the central PdII core shows an all N-coordination. 1,3-Benzothiazole-2-thiolate was formed in situ from 2-(benzyl­sulfanyl)aniline.

Cross, E.D.

2013-12-14T23:59:59.000Z

351

Evaluation of electron capture reaction rates in Ni isotopes in stellar environments  

SciTech Connect

Electron capture rates in Ni isotopes are studied in stellar environments, that is, at high densities and high temperatures during the core-collapse and postbounce explosive nucleosynthesis in supernovae. Reaction rates in {sup 58}Ni and {sup 60}Ni, as well as in {sup 56}Ni, {sup 62}Ni, and {sup 64}Ni, are evaluated by shell-model calculations with the use of a new shell-model Hamiltonian in the fp shell, GXPF1J. While the previous shell-model calculations failed to reproduce the measured peaks of Gamow-Teller strength in {sup 58}Ni and {sup 60}Ni, the present new Hamiltonian is found to reproduce them very well, as well as the capture rates obtained from the observed strengths. Strengths and energies of the Gamow-Teller transitions in {sup 56}Ni, {sup 62}Ni, and {sup 64}Ni are also found to be consistent with the observations.

Suzuki, Toshio [Department of Physics and Graduate School of Integrated Basic Sciences, College of Humanities and Sciences, Nihon University Sakurajosui 3-25-40, Setagaya-ku, Tokyo 156-8550 (Japan); Center for Nuclear Study, University of Tokyo, Hirosawa, Wako-shi, Saitama 351-0198 (Japan); National Astronomical Observatory of Japan, Mitaka, Tokyo 181-8588 (Japan); Honma, Michio [Center for Mathematical Sciences, University of Aizu, Aizu-Wakamatsu, Fukushima 965-8580 (Japan); Mao, Helene [ENSPS, Pole API-Parc d'Innovation, Boulevard Sebastien Brant, BP 10413, F-67412 Illkirch Cedex (France); Otsuka, Takaharu [Department of Physics and Center for Nuclear Study, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824 (United States); Kajino, Toshitaka [National Astronomical Observatory of Japan, Mitaka, Tokyo 181-8588 (Japan); Deaprtment of Astronomy, Graduate School of Science, University of Tokyo, Bunkyo-ku, Tokyo 113-0033 (Japan)

2011-04-15T23:59:59.000Z

352

Synthesis, crystal structure and physico-chemical properties of the new quaternary oxide Sr{sub 5}BiNi{sub 2}O{sub 9.6}  

SciTech Connect

A new black quaternary oxide Sr{sub 5}BiNi{sub 2}O{sub 9.6} was synthesized by solid state reaction at 1200 Degree-Sign C. Its structure was solved by electron crystallography and X-ray powder refinement, yielding a tetragonal structure with space group I4/mmm, a=5.3637 (2) A, c=17.5541(5) A, Z=4. The structure can be described as a stacking of (Bi,Sr)-O rocksalt slabs and SrNiO{sub 3-{delta}} perovskite slabs. The initial nickel valence is close to +3.1. Thermogravimetry and high-temperature oxygen coulometry showed that this compound has variable oxygen content as a function of temperature and oxygen pressure, and ultimately decomposes when heated in low oxygen pressure above 800 Degree-Sign C. It is a metallic conductor with n-type conduction. Its thermoelectric power was determined and found to be -20 and -38 {mu}V/K at 300 and 650 Degree-Sign C, respectively. Magnetic measurements confirm the nickel valence close to +3 and show evidence of magnetic ordering at 20 K. - Graphical Abstract: View of the structure of new Sr{sub 5}BiNi{sub 2}O{sub 9.6} oxide. Highlights: Black-Right-Pointing-Pointer Discovery of a new, unreported phase in the Sr-Bi-Ni-O system. Black-Right-Pointing-Pointer Full crystal structure determination by electron and X-ray diffraction. Black-Right-Pointing-Pointer Oxygen stoichiometry variation determination vs. P,T. Black-Right-Pointing-Pointer Determination of electrical and magnetic properties.

Novitskaya, Mariya; Makhnach, Leonid [Department of Chemistry, Belarus State University, 14 Leningradskaya Str., 220030 Minsk (Belarus); Ivashkevich, Ludmila [Institute of Physicochemical Problems, Belarus State University, 14 Leningradskaya Str., 220030 Minsk (Belarus); Pankov, Vladimir [Department of Chemistry, Belarus State University, 14 Leningradskaya Str., 220030 Minsk (Belarus); Klein, Holger; Rageau, Amelie; David, Jeremy [Institut Neel CNRS and Universite J. Fourier, BP 166, 38042 Grenoble Cedex (France); Gemmi, Mauro [Institut Neel CNRS and Universite J. Fourier, BP 166, 38042 Grenoble Cedex (France); Center for Nanotechnology Innovation, NEST Istituto Italiano di Tecnologia, Piazza S.SIlvestro 12, 56127 Pisa (Italy); Hadermann, Joke [Electron Microscopy for Materials Research (EMAT), University of Antwerp, Groenenborgerlaan 171, B-2020, Antwerp (Belgium); Strobel, Pierre, E-mail: pierre.strobel@grenoble.cnrs.fr [Institut Neel CNRS and Universite J. Fourier, BP 166, 38042 Grenoble Cedex (France)

2011-12-15T23:59:59.000Z

353

Improvement of magnetic properties of FePt nanoparticles by adding Mn  

SciTech Connect

FePtMn nanoparticles were synthesized by the simultaneous reduction of iron acetylacetonate, platinum acetylacetonate, and manganese acetylacetonate with 1,2-hexadecanediol as the reducing reagent in the polyol process. The coercivity of annealed nanoparticles strongly depends on the amount of Mn addition. A maximum coercivity of 19 kOe at room temperature was obtained for (Fe{sub 32}Pt{sub 68}){sub 87}Mn{sub 13} nanoparticles annealed at 700 deg. C for 1 h. The presence of Mn in the FePt L1{sub 0} lattice may induce local strain so the ordering is accelerated. In addition, the high coercivity can presumably be partially related to the local bonding of Pt-Mn (or Fe-Mn) in the L1{sub 0} structure.

Lai, C.-H.; Ho, C.-H. [Department of Materials Science and Engineering, National Tsing Hua University, 300, Hsinchu, Taiwan (China)

2005-05-15T23:59:59.000Z

354

Preparation and characterization of Pt/C catalysts for PEMFC cathode: effect of different reduction methods  

Science Journals Connector (OSTI)

Three Pt/C catalysts for PEMFC cathode were prepared by impregnation-reduction method using...4, and N2H4...as reductant, respectively, and characterized by BET, CV and XRD. The effect of reduction methods on the...

Jianlu Zhang; Xiaoli Wang; Chuan Wu…

355

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

356

Adsorption-induced surface core-level shifts of Pt(110)  

SciTech Connect

A detailed investigation of surface- and adsorbate-induced binding-energy shifts of the Pt 4f core level has been carried out using photoemission with synchrotron radiation. Spectra recorded from the clean Pt(110)-(1 x 2) surface show a single surface peak shifted by -0.46 eV relative to the bulk peak. This result is discussed in light of recent structural studies of the reconstructed Pt(110) surface. Adsorption of H, atomic and molecular oxygen, and CO reveal two surface-atom contributions, whose origins are discussed. In some cases the second peak is believed to arise from former bulk atoms that are influenced by the adsorbate. The main adsorption-induced shifts correlate with thermodynamic data in the framework of a Born-Haber cycle. The shifts cannot be directly rationalized in terms of a charge transfer between the adsorbate and the Pt surface atoms.

Dueckers, K.; Prince, K.C.; Bonzel, H.P.; Chab, V.; Horn, K.

1987-10-15T23:59:59.000Z

357

Degradation of proton exchange membrane by Pt dissolved/deposited in fuel cells  

Science Journals Connector (OSTI)

An accelerated single cell test and single electrode cell test were carried out to investigate membrane degradation by Pt dissolved/deposited on the membrane. For a cell operating under accelerated conditions ...

Taehee Kim; Ho Lee; Woojong Sim; Jonghyun Lee…

2009-09-01T23:59:59.000Z

358

Unconventional behavior of the Ce3Pt23Si11 ferromagnet C. Opagiste,1,  

E-Print Network (OSTI)

) model. More surprisingly, the inelastic neutron scattering shows two CEF peaks while neutron diffraction counter part La3Pt23Si11 together with studies at the microscopic scale using neutrons scattering in order

Boyer, Edmond

359

Enhanced activity of Pt foil model catalysts thermally treated under UHV conditions  

Science Journals Connector (OSTI)

The thermal treatment of Pt foil model catalysts under UHV conditions leads to an enhanced activity for...2-D2 exchange. For the enhanced activity, the UHV atmosphere, a temperature of 1073 K and ... surface roug...

Satoru Nishiyama; Masahiro Akemoto…

1996-09-01T23:59:59.000Z

360

Optimization of in-vacuo template-stripped Pt surfaces via UHV STM  

Science Journals Connector (OSTI)

A recently demonstrated [1] in-vacuo template-stripping process is applied to the study of platinum films stripped from ultra-flat silicon-oxide surfaces. Template-stripped (TS) Pt surfaces, prepared with a range...

D. Ohlberg; J.J. Blackstock; R. Ragan; S. Kim; R. Stanley Williams

2005-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "ni pd pt" 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

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

362

Biohydrogen production from CO-rich syngas via a locally isolated Rhodopseudomonas palustris PT  

Science Journals Connector (OSTI)

Biohydrogen production through water–gas shift (WGS) reaction...Rhodopseudomonas palustris...PT was able to utilize carbon monoxide and simultaneously produce hydrogen. Light exposure was provided as an indispen...

Fatemeh Pakpour; Ghasem Najafpour…

2014-05-01T23:59:59.000Z

363

Size Influence on the Oxygen Reduction Reaction Activity and Instability of Supported Pt Nanoparticles  

E-Print Network (OSTI)

Size-dependent oxygen reduction reaction activity (ORR) and instability of Pt nanoparticles is of great importance in proton exchange membrane fuel cell applications. In this study, the size-dependence of ORR activity on ...

Sheng, Wenchao

364

Break-up of Pt catalyst surfaces by high CO coverage  

E-Print Network (OSTI)

a) in ultra-high vacuum UHV with a background pressure of 1×images of the Pt(557) under UHV conditions (base pressure 1×in a pressure range from UHV to atmospheric and even higher

Tao, Feng

2010-01-01T23:59:59.000Z

365

Graphitic Electrical Contacts to Metallic Single Walled Carbon Nanotubes Using Pt Electrodes  

E-Print Network (OSTI)

in an ultrahigh vacuum (UHV) apparatus described previously.?G f (%) of in situ in UHV. Figure 3 . CVs of Pt films in 1at 550, 920, and 1050 K in UHV in the region of interest

Collins, Philip G

2009-01-01T23:59:59.000Z

366

First principles Tafel kinetics of methanol oxidation on Pt(111)  

Science Journals Connector (OSTI)

Abstract Electrocatalytic methanol oxidation is of fundamental importance in electrochemistry and also a key reaction in direct methanol fuel cell. To resolve the kinetics at the atomic level, this work investigates the potential-dependent reaction kinetics of methanol oxidation on Pt(111) using the first principles periodic continuum solvation model based on modified-Poisson–Boltzmann equation (CM-MPB), focusing on the initial dehydrogenation elementary steps. A theoretical model to predict Tafel kinetics (current vs potential) is established by considering that the rate-determining step of methanol oxidation (to CO) is the first CH bond breaking (CH3OH(aq) ? CH2OH* + H*) according to the computed free energy profile. The first CH bond breaking reaction needs to overcome a large entropy loss during methanol approaching to the surface and replacing the adsorbed water molecules. While no apparent charge transfer is involved in this elementary step, the charge transfer coefficient of the reaction is calculated to be 0.36, an unconventional value for charge transfer reactions, and the Tafel slope is deduced to be 166 mV. The results show that the metal/adsorbate interaction and the solvation environment play important roles on influencing the Tafel kinetics. The knowledge learned from the potential-dependent kinetics of methanol oxidation can be applied in general for understanding the electrocatalytic reactions of organic molecules at the solid–liquid interface.

Ya-Hui Fang; Zhi-Pan Liu

2014-01-01T23:59:59.000Z

367

Mild Hydrocracking of Synthetic Crude Gas Oil over Pt Supported on Pillared and Delaminated Clays  

Science Journals Connector (OSTI)

The modified acidity in PILC materials is conducive to catalyzing mild hydrocracking reactions. ... The differences in catalyst performance were attributed to the more open pore structure of the PILC material and possible aggregation of clay lamellas, which are both expected to enhance diffusion of multi-ring gas oil components. ... Pt-supported pillared clay (Pt/PILC) catalyst was prepared according to published procedures using Accofloc 350, a naturally occurring montmorillonite supplied by the American Colloid Company. ...

Hong Yang; Michael Wilson; Craig Fairbridge; Zbigniew Ring; Josephine M. Hill

2002-06-18T23:59:59.000Z

368

Geometric and Electronic Structures of the Ni(I) and Methyl-Ni(III)  

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

9 9 Geometric and Electronic Structures of the Ni(I) and Methyl-Ni(III) Intermediates of Methyl-Coenzyme M Reductase Methyl-coenzyme M reductase (MCR) from methanogenic archaea catalyzes the terminal step in biological methane synthesis. Using coenzyme B (CoBSH) as the two-electron donor, MCR reduces methyl-coenzyme M (methyl-SCoM) to form methane and the heterodisulfide product, CoBS-SCoM. MCR contains an essential redox active nickel tetrapyrrolic cofactor called coenzyme F430 at its active site, which is active in the reduced Ni(I) state (MCRred1). All of the biologically generated methane, amounting to 1 billion tons per annum globally, is formed by MCR. Furthermore, recent evidence indicates that anaerobic methane oxidation is also catalyzed by MCR and occurs by a reversal of the methane synthesis reaction. Methane is a potent greenhouse gas, trapping 20 times more heat than CO2. In addition, methane is also an important and clean fuel as it produced the least amount of CO2 per unit of heat released. Thus, it is critically important to understand the mechanism of formation of the smallest hydrocarbon in nature.

369

Enhanced Electrocatalytic Oxygen Reduction through Electrostatic Assembly of Pt Nanoparticles onto Porous Carbon Supports from SnCl2-Stabilized Suspensions  

Science Journals Connector (OSTI)

This is a serious drawback to PEMFC development, since ORR on Pt is known to be structure-sensitive on the basis of single crystal bulk electrode investigations. ... Current Pt electrocatalyst synthesis methods for PEMFC application involve precipitation of Pt metal into porous carbon supports using wet chemical methods. ... This schematic does not illustrate Pt nanoparticle deposition within the Vulcan carbon pores, which is evident in HAADF-STEM images of Pt–C electrocatalysts. ...

Samuel St. John; Indrajit Dutta; Anastasios P. Angelopoulos

2011-04-15T23:59:59.000Z

370

Pt nanoparticles modified by rare earth oxides: Electronic effect and influence to catalytic hydrogenation of 3-phenoxybenzaldehyde  

SciTech Connect

Graphical abstract: - Highlights: • The rare earths modified Pt/Al{sub 2}O{sub 3} were prepared by colloidal deposition method. • Modification of Pt by the rare earth enhanced catalytic hydrogenation activity. • The activity improvement is due to electron interaction between Pt and rare earth. • The hydrogenation mechanism of rare earth modified Pt catalyst was proposed. - Abstract: The rare earth elements (La, Ce, Nd, Sm, Pr, and Gd) modified Pt/Al{sub 2}O{sub 3} catalysts were prepared by the colloidal deposition and chemical reduction methods, respectively. Pt nanoparticles with average size 3 ± 0.5 nm were uniformly dispersed on the surface of Al{sub 2}O{sub 3} for the samples prepared by the colloidal deposition method, which exhibited higher activities in the hydrogenation of 3-phenoxybenzadehyde than the corresponding samples prepared by chemical reduction method. Moreover, except Gd, the catalysts modified by rare earth elements showed better catalytic performance than unmodified Pt/Al{sub 2}O{sub 3}. For Pt–Ce/Al{sub 2}O{sub 3} catalyst, when the weight percent of Pt and Ce was 0.5 and 0.25, respectively, the hydrogenation conversion of 3-phenoxybenzaldehyde was 97.3% after 6 h reaction. This activity improvement is due to the electronic interaction between Pt and rare earth elements, which was investigated by X-ray photoelectron spectroscopy.

Mou, Zhigang; Han, Ming; Li, Gang; Du, Yukou [College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123 (China); Yang, Ping, E-mail: pyang@suda.edu.cn [College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123 (China); Zhang, Hailu [Suzhou Institute of Nano-tech and Nano-bionics, Chinese Academy of Sciences, Suzhou 215123 (China); Deng, Zongwu, E-mail: zwdeng2007@sinano.ac.cn [Suzhou Institute of Nano-tech and Nano-bionics, Chinese Academy of Sciences, Suzhou 215123 (China)

2013-11-15T23:59:59.000Z

371

Graphene Monolayer Rotation on Ni(111) Facilities Bilayer Graphene Growth  

SciTech Connect

Synthesis of bilayer graphene by chemical vapor deposition is of importance for graphene-based field effect devices. Here, we demonstrate that bilayer graphene preferentially grows by carbon-segregation under graphene sheets that are rotated relative to a Ni(111) substrate. Rotated graphene monolayer films can be synthesized at growth temperatures above 650 C on a Ni(111) thin-film. The segregated second graphene layer is in registry with the Ni(111) substrate and this suppresses further C-segregation, effectively self-limiting graphene formation to two layers.

Batzill M.; Sutter P.; Dahal, A.; Addou, R.

2012-06-11T23:59:59.000Z

372

On the road to doubly-magic {sup 48}Ni  

SciTech Connect

A relativistic primary beam of {sup 58}Ni from the SIS synchrotron at GSI was used to produce proton-rich isotopes in the titanium-to-nickel region by projectile fragmention at the FRS. We report here on the first observation of the T{sub z}=-7/2 nuclei {sup 45}Fe and {sup 49}Ni. In addition, the new isotope {sup 42}Cr (T{sub z}=-3) was identified. This opens the route to the yet unobserved doubly-magic nucleus {sup 48}Ni.

Blank, B.; Czajkowski, S.; Davi, F.; Del Moral, R.; Dufour, J. P.; Fleury, A.; Marchand, C.; Pravikoff, M. S. [Centre d'Etudes Nucleaires de Bordeaux-Gradignan, F-33175 Gradignan Cedex (France); Benlliure, J.; Boue, F.; Collatz, R.; Heinz, A.; Hellstroem, M.; Hu, Z.; Roeckl, E.; Shibata, M.; Suemmerer, K. [Gesellschaft fuer Schwerionenforschung, Planckstr. 1, D-64291 Darmstadt (Germany); Lewitowicz, M. [Grand Accelerateur National des Ions Lourds, B.P. 5027, F-14021 Caen Cedex (France); Janas, Z.; Karny, M. [Institute of Experimental Physics, University of Warsaw, PL-00-681 Warsaw, Hoza 69 (Poland)] (and others)

1998-12-21T23:59:59.000Z

373

Surface Patterns of Tetragonal Phase FePt Thin Films from Pt{at}Fe2O3 Core-Shell Nanoparticles Using Combined Langmuir-Blodgett and Soft Lithographic Techniques  

SciTech Connect

OAK B204 We present the fabrication of micron-sized patterns of FePt thin films from Pt{at}Fe2O3 core-shell nanoparticles. In a typical procedure, Pt@Fe2O3 core-shell nanoparticles were spread and formed a Langmuir film using water as the subphase. This film was lifted onto polydimethylsiloxane (PDMS) stamps with micron-sized patterns of lines, dots and wells, and transferred onto silicon wafers using microcontact printing (u-CP). The patterns of Pt@Fe2O3 core-shell nanoparticles were converted into face-centered tetragonal phase FePt alloy at enhanced temperatures in the presence of 5% hydrogen. Scanning electron microscopy (SEM), atomic force microscopy (AFM), powder X-ray diffraction (PXRD) and superconducting quantum interference device (SQUID) magnetometer were used to characterize the patterns and the properties of the final FePt alloy films.

Guo, Q.; Teng, X.; Yang, H.

2003-09-30T23:59:59.000Z

374

Hydrogen production from methanol decomposition over Pt/Al2O3 and ceria promoted Pt/Al2O3 catalysts  

E-Print Network (OSTI)

rights reserved. Keywords: Methanol decomposition; Pt/alumina; Ceria; Hydrogen; PEM fuel cell 1 exchange mem- brane (PEM) fuel cell system. PEM fuel cells convert hydrogen gas into useful electric power is seen as an attractive means of providing the necessary hydrogen to the fuel cell. With the exception

Gulari, Erdogan

375

Ni(NiO)/single-walled carbon nanotubes composite: Synthesis of electro-deposition, gas sensing property for NO gas and density functional theory calculation  

SciTech Connect

Graphical abstract: The Ni(NiO)/semiconducting single-walled carbon nanotubes composite collected from the cathode after electro-deposition shows a high sensitivity to low-concentration NO gas at room temperature (18 °C). Display Omitted Highlights: ? Ni(NiO) nanoparticles were deposited on semiconducting SWCNTs by electro-deposition. ? Ni(NiO)/semiconducting SWCNTs film shows a high sensitivity to NO gas at 18 °C. ?Theoretical calculation reveals electron transfer from SWCNTs to NO via Ni. -- Abstract: Single-walled carbon nanotubes which contains metallic SWCNTs (m-SWCNTs) and semiconducting SWCNTs (s-SWCNTs) have been obtained under electric arc discharge. Their separation can be effectively achieved by the electro-deposition method. The Ni(NiO)/s-SWCNTs composite was found on cathode where Ni was partially oxidized to NiO at ambient condition with Ni(NiO) nanoparticles deposited uniformly on the bundles of SWCNTs. These results were confirmed by Raman spectra, transmission electron microscopy (TEM), scanning electron microscopy (SEM), UV–vis–NIR and TG characterizations. Furthermore, investigation of the gas sensing property of Ni(NiO)/s-SWCNTs composite film to NO gas at 18 °C demonstrated the sensitivity was approximately 5% at the concentration of 97 ppb. Moreover, density functional theory (DFT) calculations were performed to explore the sensing mechanism which suggested the adsorption of NO molecules onto the composite through N–Ni interaction as well as the proposition of electron transfer mechanisms from SWCNTs to NO via the Ni medium.

Li, Li; Zhang, Guo; Chen, Lei [Key Laboratory of Chemical Engineering Process and Technology for High-efficiency Conversion, College of Heilongjiang Province, Heilongjiang University, Harbin 150080 (China)] [Key Laboratory of Chemical Engineering Process and Technology for High-efficiency Conversion, College of Heilongjiang Province, Heilongjiang University, Harbin 150080 (China); Bi, Hong-Mei [Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education, School of Chemistry and Materials Science, Heilongjiang University, Harbin 150080 (China)] [Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education, School of Chemistry and Materials Science, Heilongjiang University, Harbin 150080 (China); Shi, Ke-Ying, E-mail: shikeying2008@yahoo.cn [Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education, School of Chemistry and Materials Science, Heilongjiang University, Harbin 150080 (China)] [Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education, School of Chemistry and Materials Science, Heilongjiang University, Harbin 150080 (China)

2013-02-15T23:59:59.000Z

376

Enhanced quantum coherence in graphene caused by Pd cluster deposition and its zero-temperature saturation  

E-Print Network (OSTI)

We report on the unexpected increase in the dephasing lengths of a graphene sheet caused by the deposition of Pd nanoclusters, as demonstrated by weak localization measurements. The dephasing lengths reached saturated values at low temperatures, which was essentially related to zero-temperature dephasing. The temperature-dependent dephasing was described by 1/(TlnT) and the saturated dephasing period was found to depend on {\\sigma}le, revealing disorder-induced zero-temperature dephasing in our defect-enriched graphene. Taken together with our theoretical calculations, we suggest that competition between surface scattering and charge transfer leads to the improvement of quantum coherence in cluster-decorated graphene.

Yuyuan Qin; Junhao Han; Guoping Guo; Zhaoguo Li; Yongping Du; You Song; Li Pi; Xuefeng Wang; Xiangang Wan; Wei Ning; Feng Miao; Xinran Wang; Zhe Qu; Jianfeng Zhou; Jianguo Wan; Min Han; Fengqi Song; Baigeng Wang; Guanghou Wang

2014-02-14T23:59:59.000Z

377

1/f resistance noise complements anelasticity measurements of hydrogen motion in amorphous Pd80Si20  

Science Journals Connector (OSTI)

The time-dependent resistance fluctuations due to motion of H in amorphous PdSi metal films exhibit 1/f noise with two thermally activated peaks, one at 80 K and one shifting with H concentration between 160 and 130 K. The higher peak closely matches an internal-friction peak, showing that the same H hops can relax elastic strain and modulate resistance, while the lower peak reflects hops that do not relax strain. Thus resistance fluctuations and mechanical dissipation provide complementary probes of defect motion.

Neil M. Zimmerman and Watt W. Webb

1990-08-20T23:59:59.000Z

378

Evidence for a Cluster-Based Structure of AlPdMn Single Quasicrystals  

Science Journals Connector (OSTI)

For the first time quasicrystal surfaces produced by in situ cleavage in ultrahigh vacuum have been investigated by scanning tunneling microscopy. Twofold and fivefold surfaces of icosahedral AlPdMn single quasicrystals have been studied. The surfaces were found to be rough. Their structure is determined by cluster aggregates formed on the basis of an elementary cluster whose contrast behavior and diameter of about 1 nm point to the Mackay-type cluster. Crack propagation occurs along zones of lower strength between clusters. This supports the cluster approach to quasicrystal structure.

Ph. Ebert, M. Feuerbacher, N. Tamura, M. Wollgarten, and K. Urban

1996-10-28T23:59:59.000Z

379

The stellar (n,gamma) cross section of 62Ni  

E-Print Network (OSTI)

The 62Ni(n,gamma)63Ni(t_1/2=100+-2 yrs) reaction plays an important role in the control of the flow path of the slow neutron-capture (s-) nucleosynthesis process. We have measured for the first time the total cross section of this reaction for a quasi-Maxwellian (kT = 25 keV) neutron flux. The measurement was performed by fast-neutron activation, combined with accelerator mass spectrometry to detect directly the 63Ni product nuclei. The experimental value of 28.4+-2.8 mb, fairly consistent with a recent theoretical estimate, affects the calculated net yield of 62Ni itself and the whole distribution of nuclei with 62

380

Transverse acoustic actuation of Ni-Mn-Ga single crystals  

E-Print Network (OSTI)

Two methods for the transverse acoustic actuation of {110}-cut Ni-Mn-Ga single crystals are discussed. In this actuation mode, crystals are used that have the {110}- type twinning planes parallel to the base of the crystal. ...

Simon, Jesse Matthew

2007-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "ni pd pt" 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

Fr skulares Gleichgewicht gilt: bzw. Ai = iNi  

E-Print Network (OSTI)

Potts 1987 #12;Für säkulares Gleichgewicht gilt: 1N1 = 2N2 A1 = A2 bzw. Ai = iNi z. B. (230Th/238U

Siebel, Wolfgang

382

Thermal behavior simulation of Ni/MH battery  

Science Journals Connector (OSTI)

Thermal behavior of overcharged Ni/MH battery is studied with microcalorimeter. The battery is installed in a special device in ... Quantity of heat and heat capacity of the battery charged at different state of ...

DaHe Li; Kai Yang; Shi Chen; Feng Wu

2009-05-01T23:59:59.000Z

383

Electrodeposition of amorphous matrix Ni-W/Wp̳ composites  

E-Print Network (OSTI)

An amorphous Ni-W alloy matrix was incorporated with W particulate through two types of electrodeposition. The plating bath for the electrodeposition contained nickel sulfate, sodium tungstate, sodium citrate, ammonium ...

Jenket, Donald R. (Donald Robert)

2005-01-01T23:59:59.000Z

384

Effects of Reduction Temperature and Metal-Support Interactions on the Catalytic Activity of Pt/g-Al2O3 and Pt/TiO2 for the Oxidation of CO in the Presence and Absence of H2.  

SciTech Connect

TiO2- and -Al2O3-supported Pt catalysts were characterized by HRTEM, XPS, EXAFS, and in situ FTIR spectroscopy after activation at various conditions, and their catalytic properties were examined for the oxidation of CO in the absence and presence of H2 (PROX). When {gamma}-Al{sub 2}O{sub 3} was used as the support, the catalytic, electronic, and structural properties of the Pt particles formed were not affected substantially by the pretreatment conditions. In contrast, the surface properties and catalytic activity of Pt/TiO2 were strongly influenced by the pretreatment conditions. In this case, an increase in the reduction temperature led to higher electron density on Pt, altering its chemisorptive properties, weakening the Pt-CO bonds, and increasing its activity for the oxidation of CO. The in situ FTIR data suggest that both the terminal and bridging CO species adsorbed on fully reduced Pt are active for this reaction. The high activity of Pt/TiO2 for the oxidation of CO can also be attributed to the ability of TiO2 to provide or stabilize highly reactive oxygen species at the metal-support interface. However, such species appear to be more reactive toward H{sub 2} than CO. Consequently, Pt/TiO{sub 2} shows substantially lower selectivities toward CO oxidation under PROX conditions than Pt/{gamma}-Al{sub 2}O{sub 3}.

Alexeev,O.; Chin, S.; Engelhard, M.; Ortiz-Soto, L.; Amiridis, M.

2005-01-01T23:59:59.000Z

385

Nanostructured Polyaniline-Decorated Pt/C@PANI Core–Shell Catalyst with Enhanced Durability and Activity  

Science Journals Connector (OSTI)

(1) However, the insufficient electrocatalytic activity and durability of Pt cathode catalysts still remains a major obstacle for PEMFC applications. ... Figure 4. Polarization curves of single PEM fuel cells with cathodes fabricated from (a) PANI@Pt/C (30%) and (b) Pt/C catalysts after the indicated numbers of CV cycles. ... Time-effective and reliable methods for studying catalyst durability are indispensable for developing PEMFC catalysts. ...

Siguo Chen; Zidong Wei; XueQiang Qi; Lichun Dong; Yu-Guo Guo; Lijun Wan; Zhigang Shao; Li Li

2012-08-01T23:59:59.000Z

386

Mechanistic Study of the Oxidation of a Methyl Platinum(II) Complex with O2 in Water: PtII  

E-Print Network (OSTI)

scavenger TEMPO do not support a homolytic mechanism. A SN2 mechanism was proposed for the formation. At pH 8, the reaction leads to a C1-symmetric monomethyl PtIV complex (dpms)PtIV Me(OH)2 (5) with high selectivity 97%; the reaction rate is first-order in [PtII Me] and fastest at pH 8.0. This behavior

Goddard III, William A.

387

The Role of Partial Crystallinity on Hydrogen Permeation in Fe–Ni–B–Mo Based Metallic Glass Membranes  

SciTech Connect

A potentially exciting material for membrane separations are metallic glass materials due to their low cost, high elastic toughness and resistance to hydrogen embrittlement as compared to crystalline Pd-based membrane systems. However, at elevated temperatures and extended operation times structural changes including partial crystallinity may appear in these amorphous metallic systems. This study reports on the investigation of time and temperature dependent crystalline phase formation in conjunction with in situ crystallization/hydrogen permeation experiments at elevated temperatures. At temperatures near 400 C a FeNi crystalline phase appears as 22 vol.% inside the host amorphous matrix and the resulting composite structure remains stable over 3 h at temperature. The hydrogen permeation at 400 C of the partially crystalline material is similar to the fully amorphous material near 5 x 10{sup -9} mol H{sub 2}/m s Pa{sup 1/2}, while ambient temperature electrochemical permeation at 25 C revealed an order of magnitude decrease in the permeation of partially crystalline materials due to differences in the amorphous versus crystalline phase activation energy for hydrogen permeation.

Brinkman, K.; Su, D.; Fox, E.; Korinko, P.; Missimer, D.; Adams, T.

2011-08-15T23:59:59.000Z

388

MICROSTRUCTURE OF LONG-TERM AGED IN617 NI-BASE SUPERALLOY  

SciTech Connect

The microstructure of the Ni-base superalloy IN617 that had undergone prolonged aging (approximately 65,000 hours) at a series of temperatures from 482 C to 871 C has been characterized by microhardness measurements, optical microscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Cr23C6, Mo-rich eta-M6C, and Ti(C,N) constitute the major primary coarse precipitates both within the grains and along the grain boundaries. The secondary carbides were mostly fine Cr23C6, which had a cube-on-cube orientation relationship (OR) with the fcc matrix, and at long times were present in cuboidal and plate-shape forms within the grains and as films along the grain boundaries. Fine, eta-M6C carbides were also observed at low to intermediate temperatures with an OR given by [011] carbide//[011] matrix, carbide// matrix. The coarse eta-M6C carbides increased in extent at 871 C, whereas the counterpart fine carbides were absent. The phase was found to be present at all aging temperatures up to 871 C, with a volume fraction ranging from very low to approximately 5 pct at 593 C, where the peak in microhardness occurs. The observations have also suggested that the presence of a very small amount of at temperatures as high as 871 C at long times may be associated with a reaction between the fine eta-carbides and the matrix. Ultrafine precipitates of the intermetallic phase Ni2(Cr,Mo) with the Pt2Mo-type structure was observed in addition to in samples aged for 28,300 hours at the lowest aging temperature of 482 C. These precipitates were absent in samples aged at higher temperatures. The various observations made have suggested that the long-term thermal stability of the IN617 alloy is reasonably good over a wide temperature range of 538 C to 704 C, whereas at higher temperatures (871 C), the substantial decrease in the volume fraction of and coarsening and clustering of the carbides lead to a large drop in the microhardness. A modified time-temperature-transformation (TTT) diagram was constructed based on the results of this study and comparison with previous reports.

Wu, Quanyan [University of Cincinnati; Shingledecker, John P [ORNL; Vasudevan, Vijay [University of Cincinnati; Swindeman, Robert W [ORNL

2008-01-01T23:59:59.000Z

389

High-temperature phase stability and tribological properties of laser clad Mo{sub 2}Ni{sub 3}Si/NiSi metal silicide coatings  

SciTech Connect

Mo{sub 2}Ni{sub 3}Si/NiSi wear-resistant metal silicide composite coatings consisting of Mo{sub 2}Ni{sub 3}Si primary dendrite and interdendritic Mo{sub 2}Ni{sub 3}Si/NiSi eutectic were fabricated on substrate of an austenitic stainless steel AISI321 by laser cladding using Ni-Mo-Si elemental powder blends. The high-temperature structural stability of the coating was evaluated by aging at 800 deg. C for 1-50 h. High-temperature sliding wear resistance of the as-laser clad and aged coatings was evaluated at 600 deg. C. Results indicate that the Mo{sub 2}Ni{sub 3}Si/NiSi metal silicides coating has excellent high temperature phase stability. No phase transformation except the dissolution of the eutectic Mo{sub 2}Ni{sub 3}Si and the corresponding growth of the Mo{sub 2}Ni{sub 3}Si primary dendrite and no elemental diffusion from the coating into the substrate were detected after aging the coating at 800 deg. C for 50 h. Aging of the coating at 800 deg. C leads to gradual dissolution of the interdendritic eutectic Mo{sub 2}Ni{sub 3}Si and subsequent formation of a dual-phase structure with equiaxed Mo{sub 2}Ni{sub 3}Si primary grains distributed in the NiSi single-phase matrix. Because of the strong covalent-dominated atomic bonds and high volume fraction of the ternary metal silicide Mo{sub 2}Ni{sub 3}Si, both the original and the aged Mo{sub 2}Ni{sub 3}Si/NiSi coating has excellent wear resistance under pin-on-disc high-temperature sliding wear test conditions, although hardness of the aged coating is slightly lower than that of the as-clad coating.

Lu, X.D. [Laboratory of Laser Materials Processing and Surface Engineering, School of Materials Science and Engineering, Beihang University (China); Wang, H.M. [Laboratory of Laser Materials Processing and Surface Engineering, School of Materials Science and Engineering, Beihang University (China)]. E-mail: wanghuaming@263.net

2004-10-18T23:59:59.000Z

390

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

391

Evolution of the composition and structure of cleaved and heat-treated icosahedral Al-Pd-Mn quasicrystal surfaces  

Science Journals Connector (OSTI)

We investigated the changes in composition and structure induced by heat treatment of cleaved fivefold icosahedral Al-Pd-Mn quasicrystal surfaces by scanning electron microscopy and calibrated Auger electron spectroscopy. With increasing temperature we observed five different composition ranges of the surface coupled with distinct changes in the surface morphology. The changes in composition can be explained by successive evaporation and diffusion processes occurring with increasing temperatures. First, Mn evaporates from the uppermost surface layer, then Al evaporation starts and induces a further Mn evaporation leading to an enrichment in Pd. The enrichment is reduced by Mn diffusion from the bulk, Al diffusion from the bulk, and probably simultaneously occurring Pd desorption. Finally, a recrystallization of the surface is induced by the full diffusive mobility of all elements and preferential evaporation of Mn and to a lesser degree of Al. We also discuss the signature of the bonding configuration of Al in the Auger spectra of all investigated compositions.

Ph. Ebert, F. Kluge, B. Grushko, and K. Urban

1999-07-01T23:59:59.000Z

392

Electronic structure mechanism of spin-polarized electron transport in a NiC60Ni system  

E-Print Network (OSTI)

between Ni leads. The tunnel current has a much higher magnitude when Ni is bonded to hole sites (H6, H5) than at bridge sites (B66, B56) of the fullerene cage. Furthermore, the magnitude of junction. For example, the B66 site is the bridge site over a C@C double bond, the B56 site is the bridge site over a C

Pandey, Ravi

393

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

394

The effect of metallurgical variables on the electrocatalytic properties of PtCr alloys  

SciTech Connect

In this investigation, the effect of alloying on catalysis, especially with respect to oxygen and the ORR, was examined. A series of PtCr alloys allowed four major aspects of alloying to be investigated: (i) effect of decreasing lattice parameter with increasing Cr content in the Pt terminal solid solution, (ii) effect of an order/disorder transition, (iii) difference between intermetallic and solid solution structures, and (iv) effect of dendritic segregation. Results indicated that contrary to the findings of previous investigators, decreased lattice spacing did not correlate with an increase in ORR activity. Atomic ordering in low Cr content specimens, however, was found to generally increase catalysis. Results also indicated that disordered structures interact more strongly with impurities than the ordered structures. ORR Tafel slopes, however, were unaffected by atomic ordering although additional chromium, up to at least 35 atom percent (a/o), caused a decrease in Tafel slope apparently due to oxide reduction effects. At higher Cr concentrations, catalysis decreased due to the passive nature of chromium oxide. The change in crystal structure which occurs for the 80 a/o Cr sample and the dendritic structure, had little effect on most of the electrochemical parameters studied relative simply to the additional Cr content. The results of this work also indicated that, in general, no alloy in the PtCr system is more catalytic than pure Pt. This result is in contrast to gas diffusion cell studies which have shown significant increases in catalysis due to PtCr alloying.

Glass, J.T.; Cahen, G.L. Jr.; Stoner, G.E.; Taylor, E.J.

1987-01-01T23:59:59.000Z

395

Fatigue, fracture, and plastic collapse of offshore tubular joints using BSI PD 6493:1991  

SciTech Connect

The second version of the BSI Document PD 6493, on the assessment of the significance of weld defects on a fitness for purpose basis, was published in 1991. To extend the application of PD 6493 to offshore structures, a major program of research was carried out at a number of UK universities under the title of ``the Defect Assessment Programme`` sponsored by SERC/MTD Ltd. and a number of industrial companies. The program, carried out in the period 1985--1991, provided a specific methodology for the assessment of defects in tubular joints and detailed guidance on the evaluation of parameters required for fatigue and fracture assessments. The methodology includes a combined equation approach to Stress Intensity Factor (SIF) determination based on detailed knowledge of the local and global stress fields, an approach for estimation of the plastic collapse load of cracked tubular joints based on analytical and experimental studies, guidance on treatments of welding residual stresses, and data for application of the partial safety factor approach intended to enable rational treatments of uncertainties in input parameters for fracture assessment. This paper outlines key aspects of the fatigue and fracture procedures, and presents parametric equations required for application of the methodology relating to weld toe effects, degree of bending, and plastic collapse.

Cheaitani, M.J. [Billington Osborne-Moss Engineering Ltd., Maidenhead (United Kingdom); Thurlbeck, S.D. [EQE International Ltd., Warrington (United Kingdom); Burdekin, F.M. [UMIST, Manchester (United Kingdom). Dept. of Civil and Structural Engineering

1995-12-31T23:59:59.000Z

396

Sol-gel-derived NiO/NiAl{sub 2}O{sub 4} oxygen carriers for chemical-looping combustion by coal char  

SciTech Connect

This paper focuses on the investigation of Ni-based oxygen carriers for CLC by coal char. First, Al(OC{sub 3}H{sub 7}){sub 3} and Ni(NO{sub 3}){sub 2} are selected as the main raw materials to prepare sol-gel-derived NiO/NiAl{sub 2}O{sub 4} oxygen carriers. The oxygen carrier with a mass content of 60% NiO, a sintering temperature of 1300{sup o}C, and a sintering time of 6 h performs comparatively well. Second, the reduction reaction of the NiO/NiAl{sub 2}O{sub 4} oxygen carriers with char and the circular reduction/oxidation reactions of the NiO/NiAl{sub 2}O{sub 4} oxygen carriers with char/air or hydrogen/air are carried out in a thermogravimetric analysis (TGA) instrument to investigate the reactivities and chemical life of the prepared NiO/NiAl{sub 2}O{sub 4} oxygen carriers. The experimental results show that (a) when the TGA temperature is higher than 850{sup o}C, NiO/NiAl{sub 2}O{sub 4} starts to react with coal char rapidly, which indicates that CLC of coal char using NiO/NiAl{sub 2}O{sub 4} as oxygen carriers is a feasible technology of energy utilization in principle; (b) NiO/NiAl{sub 2}O{sub 4}, which maintains its activity over single-cycle reduction/oxidation reactions with char/air or multiple-cycle reduction/oxidation reactions with hydrogen/air, exhibits extremely good recyclablity; (c) the porous beehive structure of the NiO/NiAl{sub 2}O{sub 4} particle is maintained, and the sintering behavior between different particles is not observed during cyclic studies. Those experimental results prove the sol-gel-derived oxygen carrier NiO/NiAl{sub 2}O{sub 4} is capable of being used in chemical-looping combustion fueled by coal char or H{sub 2}. 51 refs., 5 figs., 5 tabs.

Haibo Zhao; Liming Liu; Baowen Wang; Di Xu; Linlin Jiang; Chuguang Zheng [Huazhong University of Science and Technology, Wuhan (China). State Key Laboratory of Coal Combustion

2008-03-15T23:59:59.000Z

397

Hydrogenation of CO on Pd-Fe/. gamma. -Al/sub 2/O/sub 3/ catalysts  

SciTech Connect

A study has been made of CO hydrogenation on 5% Pd-Fe/..gamma..-Al/sub 2/O/sub 3/ catalysts with various contents of iron. It has been shown that the introduction of iron into the composition of the palladium catalyst reduces the quantity of chemisorbed hydrogen and carbon monoxide and lowers the activity in CO hydrogenation. The observed effects are related to the formation of cationic states of the metals and heteronuclear Pd-Fe clusters, which have little activity in processes of adsorption and catalysis.

Zakumbaeva, G.D.; Dagirov, T.S.; Dostiyarov, A.M.; Kuanyshev, A.Sh.; Naidin, V.A.; Vozdvizhenskii, V.F.

1986-09-01T23:59:59.000Z

398

ARM - Field Campaign - MASRAD: Cloud Study from the 2NFOV at Pt. Reyes  

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

govCampaignsMASRAD: Cloud Study from the 2NFOV at Pt. Reyes Field govCampaignsMASRAD: Cloud Study from the 2NFOV at Pt. Reyes Field Campaign Campaign Links AMF Point Reyes Website Related Campaigns MArine Stratus Radiation Aerosol and Drizzle (MASRAD) IOP 2005.03.14, Miller, AMF Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : MASRAD: Cloud Study from the 2NFOV at Pt. Reyes Field Campaign 2005.06.02 - 2005.09.30 Lead Scientist : Warren Wiscombe For data sets, see below. Description Cloud optical depth is one of the most important cloud optical properties, and vital for any cloud-radiation parameterization. Our ARM Science Team project has pioneered an algorithm to retrieve cloud optical depth in a fully three-dimensional cloud situation using zenith radiances from the ARM

399

Easy axis alignment of chemically partially ordered FePt nanoparticles  

SciTech Connect

Partially ordered Fe{sub 53}Pt{sub 47} nanoparticles with size around 8 nm were prepared by the simultaneous decomposition of iron pentacarbonyl and platinum acetylacetonate. The high boiling point chemical, hexadecylamine, was used as a solvent, and 1-adamantanecarboxylic acid was used as a stabilizer. X-ray diffraction measurements reveal that as-made FePt particles were partially transformed into the ordered L1{sub 0} phase with some weak superlattice peaks. The room-temperature hysteresis loop and remanence curve suggest a broad distribution of anisotropies in the partially ordered particles. By coating the partially ordered FePt nanoparticles with a polyvinylchloride polymer binder, the particles could be re-dispersed in cyclohexanone. Furthermore, the easy axis of the particles coated with the polyvinylchloride polymer binder could be aligned under an external field. Easy axis alignment was confirmed from both alternating gradient magnetometer and x-ray diffraction measurements.

Kang, Shishou; Jia Zhiyong; Shi, Shifan; Nikles, David E.; Harrell, J.W. [Center for Materials for Information Technology, University of Alabama, Tuscaloosa, Alabama 35487-0209 (United States)

2005-02-07T23:59:59.000Z

400

Measuring size dependent electrical properties from nanoneedle structures: Pt/ZnO Schottky diodes  

SciTech Connect

This work reports the fabrication and testing of nanoneedle devices with well-defined interfaces that are amenable to a variety of structural and electrical characterization, including transmission electron microscopy. Single Pt/ZnO nanoneedle Schottky diodes were fabricated by a top down method using a combination of electro-polishing, sputtering, and focused ion beam milling. The resulting structures contained nanoscale planar heterojunctions with low ideality factors, the dimensions of which were tuned to study size-dependent electrical properties. The diameter dependence of the Pt/ZnO diode barrier height is explained by a joule heating effect and/or electronic inhomogeneity in the Pt/ZnO contact area.

Mao, Shimin; Anderson, Daniel D. [Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States); Shang, Tao [Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States); Park, Byoungnam [Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States); Department of Materials Science and Engineering, Hongik University, 72-1 Sangsu-dong, Mapo-gu, Seoul 121-791 (Korea, Republic of); Dillon, Shen J., E-mail: sdillon@illinois.edu [Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States); Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States)

2014-04-14T23:59:59.000Z

Note: This page contains sample records for the topic "ni pd pt" 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

A unidirectional invisible PT-symmetric complex crystal with arbitrary thickness  

E-Print Network (OSTI)

We introduce a new class of $\\mathcal{PT}$-symmetric complex crystals which are almost transparent and one-way reflectionless over a broad frequency range around the Bragg frequency, i.e. unidirectionally invisible, regardless of the thickness $L$ of the crystal. The $\\mathcal{PT}$-symmetric complex crystal is synthesized by a supersymmetric transformation of an Hermitian square well potential, and exact analytical expressions of transmission and reflection coefficients are given. As $L$ is increased, the transmittance and reflectance from one side remain close to one and zero, respectively, whereas the reflectance from the other side secularly grows like $ \\sim L^2$ owing to unidirectional Bragg scattering. This is a distinctive feature as compared to the previously studied case of the complex sinusoidal $\\mathcal{PT}$-symmetric potential $V(x)=V_0 \\exp(-2i k_ox)$ at the symmetry breaking point, where transparency breaks down as $L \\rightarrow \\infty$.

Stefano Longhi

2014-10-20T23:59:59.000Z

402

Swift heavy ion irradiation of Pt nanocrystals: II. Structural changes and H desorption  

SciTech Connect

The structural properties and H desorption from embedded Pt nanocrystals (NCs) following irradiation with swift heavy ions were investigated as a function of energy and fluence. From x-ray absorption near-edge spectroscopy analysis, Pt-H bonding was identified in NCs annealed in a forming gas (95% N{sub 2} + 5% H{sub 2}) ambient. The H content decreased upon irradiation and the desorption process was NC-size dependent such that larger NCs required a higher fluence to achieve a H-free state. Pt-H bonding and NC dissolution both perturbed the NC structural parameters (coordination number, bond-length and mean-square relative displacement) as determined with extended x-ray absorption fine structure measurements.

Giulian, R.; Araujo, L.L.; Kluth, P.; Sprouster, D.J.; Schnohr, C.S.; Byrne, A.P.; Ridgway, M.C. (ANU)

2014-09-24T23:59:59.000Z

403

Ensemble effects on ethylene dehydrogenation on PdAu(001) surfaces investigated with first-principles calculations and nudged-elastic-band simulations  

E-Print Network (OSTI)

Ensemble effects on ethylene dehydrogenation on PdAu(001) surfaces investigated with first on adsorption and dehydrogenation of ethylene on PdAu 001 bimetallic surfaces are systematically investigated that ethylene dehydrogenation is inhabited under ambient reaction temperature on the most popular second

Gong, Xingao

404

Conversion of CH4 into H2 at 300 C using Pd/MnO2 catalyst made with an effect of water oxidation  

SciTech Connect

A novel electricity-free deposition of palladium on the surface of manganese dioxide, which has a crystal structure of ramsdellite, was studied. Using the Pd deposition, a nano-particle of Pd/MnO2 was prepared, and it was used for a catalytic performance for reforming methane into hydrogen at 300 C.

Koyanaka, Hideki [Forward Science Laboratory Ltd, Oita, Japan] [Forward Science Laboratory Ltd, Oita, Japan; Takeuchi, K [Tokyo University of Science, Oshamanbe Hokkaido, Japan] [Tokyo University of Science, Oshamanbe Hokkaido, Japan; Kolesnikov, Alexander I [ORNL] [ORNL

2014-01-01T23:59:59.000Z

405

Effect of Na exchange of a HBEA zeolite on the activity and the selectivity of a bifunctional Pt-HBEA catalyst for n-hexadecane hydroisomerization. Comparison with a Pt-HZSM-22 catalyst  

Science Journals Connector (OSTI)

The transformation of n...-hexadecane was carried out in a fixed-bed reactor at 220 °C under 30 bar total pressure on bifunctional Pt-zeolite catalysts. The Pt-HBEA catalyst was very active but yielded much crack...

Razika Merabti; Ludovic Pinard…

2010-06-01T23:59:59.000Z

406

Restructuring of hex-Pt(100) under CO gas environments: formation of 2-D nanoclusters  

SciTech Connect

The atomic-scale restructuring of hex-Pt(100) induced by carbon monoxide with a wide pressure range was studied with a newly designed chamber-in-chamber high-pressure STM and theoretical calculations. Both experimental and DFT calculation results show that CO molecules are bound to Pt nanoclusters through a tilted on-top configuration with a separation of {approx}3.7-4.1 {angstrom}. The phenomenon of restructuring of metal catalyst surfaces induced by adsorption, and in particular the formation of small metallic clusters suggests the importance of studying structures of catalyst surfaces under high pressure conditions for understanding catalytic mechanisms.

Tao, Feng; Dag, Sefa; Wang, Lin-Wang; Liu, Zhi; Butcher, Derek; Salmeron, Miquel; Somorjai, Gabor A.

2009-04-24T23:59:59.000Z

407

Spin-wave excitation and propagation in microstructured waveguides of yttrium iron garnet/Pt bilayers  

SciTech Connect

We present an experimental study of spin-wave excitation and propagation in microstructured waveguides consisting of a 100?nm thick yttrium iron garnet/platinum (Pt) bilayer. The life time of the spin waves is found to be more than an order of magnitude higher than in comparably sized metallic structures, despite the fact that the Pt capping enhances the Gilbert damping. Utilizing microfocus Brillouin light scattering spectroscopy, we reveal the spin-wave mode structure for different excitation frequencies. An exponential spin-wave amplitude decay length of 31??m is observed which is a significant step towards low damping, insulator based micro-magnonics.

Pirro, P.; Chumak, A. V.; Lägel, B.; Leven, B.; Hillebrands, B. [Fachbereich Physik and Landesforschungszentrum OPTIMAS, Technische Universität Kaiserslautern, D-67663 Kaiserslautern (Germany)] [Fachbereich Physik and Landesforschungszentrum OPTIMAS, Technische Universität Kaiserslautern, D-67663 Kaiserslautern (Germany); Brächer, T. [Fachbereich Physik and Landesforschungszentrum OPTIMAS, Technische Universität Kaiserslautern, D-67663 Kaiserslautern (Germany) [Fachbereich Physik and Landesforschungszentrum OPTIMAS, Technische Universität Kaiserslautern, D-67663 Kaiserslautern (Germany); Graduate School Materials Science in Mainz, Gottlieb-Daimler-Strasse 47, D-67663 Kaiserslautern (Germany); Dubs, C.; Surzhenko, O.; Görnert, P. [Innovent e.V., Prüssingstraße 27B, 07745 Jena (Germany)] [Innovent e.V., Prüssingstraße 27B, 07745 Jena (Germany)

2014-01-06T23:59:59.000Z

408

Oxidation of stepped Pt(111) studied by x-ray photoelectron spectroscopy and density functional theory  

SciTech Connect

In this comparative density functional theory and x-ray photoelectron spectroscopy study on the interaction of oxygen with stepped Pt(111) surfaces, we show that both the initial adsorption and oxidation occur at the steps rather than terraces. An equivalent behavior was observed for the oxide formation at higher chemical potentials, where, after the formation of a one-dimensional PtO{sub 2}-type oxide at the steps, similar oxide chains form on the (111) terraces, indicating the initial stages of bulk oxide formation.

Bandlow, Jochen; Kaghazchi, Payam; Jacob, Timo [Institut fuer Elektrochemie, Universitaet Ulm, Albert-Einstein-Allee 47, D-89069 Ulm (Germany); Papp, C.; Traenkenschuh, B.; Streber, R.; Lorenz, M. P. A.; Fuhrmann, T.; Steinrueck, H.-P. [Lehrstuhl fuer Physikalische Chemie II, Universitaet Erlangen-Nuernberg, Egerlandstr. 3, D-91058 Erlangen (Germany); Denecke, R. [Wilhelm-Ostwald-Institut fuer Physikalische und Theoretische Chemie, Universitaet Leipzig, Linnestr. 2, D-04103 Leipzig (Germany)

2011-05-01T23:59:59.000Z

409

Modified Ni-Cu catalysts for ethanol steam reforming  

SciTech Connect

Three Ni-Cu catalysts, having different Cu content, supported on ?-alumina were synthesized by wet co-impregnation method, characterized and tested in the ethanol steam reforming (ESR) reaction. The catalysts were characterized for determination of: total surface area and porosity (N{sub 2} adsorption - desorption using BET and Dollimer Heal methods), Ni surface area (hydrogen chemisorption), crystallinity and Ni crystallites size (X-Ray Diffraction), type of catalytic active centers (Hydrogen Temperature Programmed Reduction). Total surface area and Ni crystallites size are not significantly influenced by the addition of Cu, while Ni surface area is drastically diminished by increasing of Cu concentration. Steam reforming experiments were performed at atmospheric pressure, temperature range 150-350°C, and ethanol - water molar ration of 1 at 30, using Ar as carrier gas. Ethanol conversion and hydrogen production increase by the addition of Cu. At 350°C there is a direct connection between hydrogen production and Cu concentration. Catalysts deactivation in 24h time on stream was studied by Transmission Electron Microscopy (TEM) and temperature-programmed reduction (TPR) on used catalysts. Coke deposition was observed at all studied temperatures; at 150°C amorphous carbon was evidenced, while at 350°C crystalline, filamentous carbon is formed.

Dan, M.; Mihet, M.; Almasan, V.; Borodi, G. [National Institute for Research and Development of Isotopic and Molecular Technologies, 65-103 Donath Street, 400293, Cluj-Napoca (Romania)] [National Institute for Research and Development of Isotopic and Molecular Technologies, 65-103 Donath Street, 400293, Cluj-Napoca (Romania); Katona, G.; Muresan, L. [Univ. Babes Bolyai, Fac. Chem. and Chem. Eng.,11 Arany Janos, 400028, Cluj-Napoca (Romania)] [Univ. Babes Bolyai, Fac. Chem. and Chem. Eng.,11 Arany Janos, 400028, Cluj-Napoca (Romania); Lazar, M. D., E-mail: diana.lazar@itim-cj.ro [65-103 Donath Street (Romania)

2013-11-13T23:59:59.000Z

410

Pt Heater/Sensor Microarray for Distributed Fluidic Cooling Assessment Yong-Kyu Yoon and Mark G. Allen  

E-Print Network (OSTI)

the Pt (i.e., a four-point measurement), each pixel can be heated by making this sense current. Pt (1000Ã?) is deposited and patterned using standard lift-off process. Next, SiO2 (4000Ã? a pad that aids in a more even distribution of heat. This gold is patterned by again using the lift

411

Ternary PtSnRhSnO2 nanoclusters: synthesis and electroactivity for ethanol oxidation fuel cell reaction  

E-Print Network (OSTI)

Ternary PtSnRh­SnO2 nanoclusters: synthesis and electroactivity for ethanol oxidation fuel cell a superior long-term activity and stability towards ethanol oxidation than the commercial Pt catalyst. Our. Ethanol becomes an attractive fuel in the fuel cell reactions compared with methanol and hydrogen, because

Frenkel, Anatoly

412

Oxygen reduction on bare and Pt monolayer-modified Ru(0001), 1/0) and Ru nanostructured surfaces  

E-Print Network (OSTI)

cathodes [1,2]. Recent efforts to develop fuel cells have demonstrated the need for O2 electrocatalysts, but nevertheless still less active than bulk Pt. An electrocatalyst made by the deposition 0.5 monolayers of Pt of its complex kinetics and the need for better electrocatalysts and hence more efficient fuel cell

Brankovic, Stanko R.

413

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

414

Atomistic modeling of the directed-assembly of bimetallic Pt-Ru nanoclusters on Ru(0001)-supported monolayer graphene  

E-Print Network (OSTI)

)-supported monolayer graphene Yong Han,1 Albert K. Engstfeld,2 R. Juergen Behm,2 and James W. Evans1,3,* 1 of Pt-Ru nanoclusters (NC's) by sequential deposition of Pt and Ru on a periodically rumpled graphene. The periodic variation of the adsorption energy across the graphene sheet directs the assembly of NC

Ulm, Universität

415

A CO-Tolerant Hydrogen Fuel Cell System Designed by Combining with an Extremely Active Pt/CNT Catalyst  

Science Journals Connector (OSTI)

Complete oxidation of 2,000 ppm CO in H2 is attained over 10 wt.% Pt/CNT (carbon nano-tube) catalyst (0.019 g) at room temperature by adding 2,000 ppm O2 to hydrogen flowing at 100 mL/min. By insetting 5 wt.% Pt/...

Ken-ichi Tanaka; Masashi Shou; Hong He; Changbin Zhang; Daling Lu

2009-01-01T23:59:59.000Z

416

Oxygen-assisted room-temperature deposition of CoPt3 films with perpendicular magnetic anisotropy  

E-Print Network (OSTI)

Oxygen-assisted room-temperature deposition of CoPt3 films with perpendicular magnetic anisotropy B Jolla, California 92093 Received 23 July 2002; accepted 30 September 2002 Trace amounts of oxygen CoPt3 grown by vapor deposition at or slightly above room temperature. Oxygen is known to act

Hellman, Frances

417

Unoccupied electronic states of icosahedral Al-Pd-Mn quasicrystals: Evidence of image potential resonance and pseudogap  

SciTech Connect

We study the unoccupied region of the electronic structure of the fivefold symmetric surface of an icosahedral (i) Al-Pd-Mn quasicrystal. A feature that exhibits parabolic dispersion with an effective mass of (1.15±0.1)me and tracks the change in the work function is assigned to an image potential resonance because our density functional calculation shows an absence of band gap in the respective energy region. We show that Sn grows pseudomorphically on i?Al?Pd?Mn as predicted by density functional theory calculations, and the energy of the image potential resonance tracks the change in the work function with Sn coverage. The image potential resonance appears much weaker in the spectrum from the related crystalline Al-Pd-Mn surface, demonstrating that its strength is related to the compatibility of the quasiperiodic wave functions in i?Al?Pd?Mn with the free-electron-like image potential states. Our investigation of the energy region immediately above EF provides unambiguous evidence for the presence of a pseudogap, in agreement with our density functional theory calculations.

Maniraj, M [UGC-DAE Confortium for Scientific Research; Rai, Abhishek [UGC-DAE Confortium for Scientific Research; Barman, S R [UGC-DAE Confortium for Scientific Research; Krajci, M [Slovak Academy of Sciences; Schlagel, Deborah L [Ames Laboratory; Lograsso, Thomas A [Ames Laboratory; Horn, K [Fritz-Haber-Institut der Max-Planck-Gesellschaft

2014-09-01T23:59:59.000Z

418

Durable Therapeutic Efficacy Utilizing Combinatorial Blockade against IDO, CTLA-4, and PD-L1 in Mice with Brain Tumors  

Science Journals Connector (OSTI)

...IDO, CTLA-4, and PD-L1 in Mice with Brain Tumors Derek A. Wainwright Alan L. Chang...mlesniak@surgery.bsd.uchicago.edu The Brain Tumor Center, The University of Chicago...Although protected by both the blood-brain and blood-tumor barriers, GBMs are actively...

Derek A. Wainwright; Alan L. Chang; Mahua Dey; Irina V. Balyasnikova; Chung Kwon Kim; Alex Tobias; Yu Cheng; Julius W. Kim; Jian Qiao; Lingjiao Zhang; Yu Han; Maciej S. Lesniak

2014-10-15T23:59:59.000Z

419

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

420

Synthesis and study of ligands for Pd-catalyzed C-O and C-N coupling  

E-Print Network (OSTI)

A new ligand, AdBrettPhos, was synthesized and its use, along with tBuBrettPhos, in C-O coupling reactions at low temperatures was investigated. Using Pd catalysts containing these ligands, electron-neutral aryl bromides ...

Davis, Nicole R

2009-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "ni pd pt" 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

ccsd-00093858,version1-13Sep2006 APS/123-QED Cleaved surface of i-AlPdMn quasicrystals  

E-Print Network (OSTI)

a perfectly brittle behavior to a nanoductile one. PACS numbers: 62.20.Mk, 64.60.Ht, 68.35.Ct, 81.40.Np, 61 by Scanning Tun- neling Microscopy (STM) of cleaved i-AlPdMn samples in ultra high vacuum (UHV) were obtained

Paris-Sud XI, Université de

422

Synthesis of graphene-based Pt nanoparticles by a one-step in situ plasma approach under mild conditions  

SciTech Connect

Herein, a one-step in situ plasma approach to synthesize the highly dispersed Pt nanoparticles on graphene under mild conditions is reported. The graphene oxide (GO) was transformed into graphene and H{sub 2}PtCl{sub 6} was simultaneously transformed into Pt nanoparticles under argon plasma conditions. The synthesized graphene-based Pt nanoparticles were characterized by scanning electron microscopy, atomic force microscopy, x-ray diffraction, and Fourier transform infrared spectroscopy. The analysis showed that the Pt nanoparticles were deposited on graphene as a form of face-centered cubical structure and the oxygen groups on graphene oxide were partially removed. The results of x-ray photoelectron spectroscopy analysis further confirmed the results.

Wang Qi; Song Mingming; Chen Changlun; Wei Yu; Zuo Xiao; Wang Xiangke [Key Laboratory of Novel Thin Film Solar Cells, Institute of Plasma Physics, Chinese Academy of Sciences, P.O. Box 1126, Hefei 230031 (China)

2012-07-16T23:59:59.000Z

423

Comparative study of the alloying effect on the initial oxidation of Cu-Au(100) and Cu-Pt(100)  

SciTech Connect

Using in situ transmission electron microscopy, we show that the oxidation of the Cu-Au(100) results in the formation of Cu{sub 2}O islands that deeply embed into the Cu-Au substrate while the oxidation of the Cu-Pt(100) leads to the formation of Cu{sub 2}O islands that highly protrude above the Cu-Pt substrate. Their difference is attributed to the different mobilities of Pt and Au in the Cu base alloys for which the sluggish mobility of Pt in Cu results in trapped Pt atoms at the oxide/alloy interface while the faster mobility of Au in Cu leads to enhanced rehomogenization of the alloy composition.

Luo, Langli; Zhou, Guangwen, E-mail: gzhou@binghamton.edu [Department of Mechanical Engineering and Multidisciplinary Program in Materials Science and Engineering, State University of New York, Binghamton, New York 13902 (United States); Kang, Yihong [Department of Mechanical Engineering and Materials Science, University of Pittsburgh, Pittsburgh, Pennsylvania 15261 (United States); Yang, Judith C. [Department of Chemical and Petroleum Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania 15261 (United States); Su, Dong; Stach, Eric A. [Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, New York 11973 (United States)

2014-03-24T23:59:59.000Z

424

Surface structures of cleaved icosahedral Al-Pd-Mn single quasicrystals after heat treatment  

Science Journals Connector (OSTI)

Surfaces produced by in situ cleavage fracture in ultrahigh vacuum of Czochralski-grown icosahedral Al-Pd-Mn single quasicrystals were investigated by scanning tunneling microscopy and by scanning electron microscopy at ambient temperature and after heat treatments of up to 670 °C. It is found that the evolution of the surface structure with temperature depends very sensitively on the local stoichiometry. In areas of suitable composition a cluster-subcluster structure similar to that observed at room temperature is maintained whereas in areas of slightly different composition a terrace structure atomically flat over relatively large areas develops. The results are discussed in the general framework provided by current models of quasicrystal formation.

Ph. Ebert, F. Yue, and K. Urban

1998-02-01T23:59:59.000Z

425

Refined Glauber model versus Faddeev calculations and experimental data for pd spin observables  

SciTech Connect

Spin-dependent observables in intermediate-energy pd elastic scattering within the framework of the refined Glauber model are considered. The improvements include an account of all ten pp and pn helicity amplitudes at respective energies constructed on the basis of modern phase-shift analysis, accurate deuteron wave functions taken from the modern NN force model and account of charge-exchange effects. Predictions of the refined diffraction model for differential cross section and analyzing powers are compared with exact three-body Faddeev calculations and the recent experimental data. An amazingly good agreement between the results of both theoretical approaches as well as between the refined Glauber model and experiment in a wide angular range not only for differential cross section but also for vector and tensor analyzing powers has been found for the first time. Possible reasons for this agreement are discussed.

Platonova, M. N.; Kukulin, V. I. [D.V. Skobeltsyn Institute of Nuclear Physics, M.V. Lomonosov Moscow State University, Moscow RU-119991 (Russian Federation)

2010-01-15T23:59:59.000Z

426

Bimetallic Fe-Ni Oxygen Carriers for Chemical Looping Combustion  

SciTech Connect

The relative abundance, low cost, and low toxicity of iron make Fe-based oxygen carriers of great interest for chemical looping combustion (CLC), an emerging technology for clean and efficient combustion of fossil and renewable fuels. However, Fe also shows much lower reactivity than other metals (such as Ni and Cu). Here, we demonstrate strong improvement of Fe-based carriers by alloying the metal phase with Ni. Through a combination of carrier synthesis and characterization with thermogravimetric and fixed-bed reactor studies, we demonstrate that the addition of Ni results in a significant enhancement in activity as well as an increase in selectivity for total oxidation. Furthermore, comparing alumina and ceria as support materials highlights the fact that reducible supports can result in a strong increase in oxygen carrier utilization.

Bhavsar, Saurabh; Veser, Goetz

2013-11-06T23:59:59.000Z

427

Superconductivity in SrNi2P2 single crystals  

SciTech Connect

Heat capacity, magnetic susceptibility, and resistivity of SrNi{sub 2}P{sub 2} single crystals are presented, illustrating the structural transition at 325 K, and bulk superconductivity at 1.4 K. The magnitude of {Tc}, fits to the heat capacity data, the small upper critical field H{sub c2} = 390 Oe, and {kappa} = 2.1 suggests a conventional fully gapped superconductor. With applied pressure we find that superconductivity persists into the so-called 'collapsed tetragonal' phase, although the transition temperature is monotonically suppressed with increasing pressure. This argues that reduced dimensionality can be a mechanism for increasing the transition temperatures of layered NiP, as well as layered FeAs and NiAs, superconductors.

Ronning, Filip [Los Alamos National Laboratory; Bauer, Eric D [Los Alamos National Laboratory; Park, Tuscon [Los Alamos National Laboratory; Thompson, Joe D [Los Alamos National Laboratory

2009-01-01T23:59:59.000Z

428

Preparation of Pt deposited nanotubular TiO{sub 2} as cathodes for enhanced photoelectrochemical hydrogen production using seawater electrolytes  

SciTech Connect

The purpose of this study was to develop effective cathodes to increase the production of hydrogen and use the seawater, an abundant resource in the earth as the electrolyte in photoelectrochemical systems. In order to fabricate the Pt/TiO{sub 2} cathodes, various contents of the Pt precursor (0-0.4 wt%) deposited by the electrodeposition method were used. On the basis of the hydrogen evolution rate, 0.2 wt% Pt/TiO{sub 2} was observed to exhibit the best performance among the various Pt/TiO{sub 2} cathodes with the natural seawater and two concentrated seawater electrolytes obtained from single (nanofiltration) and combined membrane (nanofiltration and reverse osmosis) processes. The surface characterizations exhibited that crystal structures and morphological properties of Pt and TiO{sub 2} found the results of XRD pattern and SEM/TEM images, respectively. - Graphical abstract: On the basis of photoelectrochemical hydrogen production, 0.2 wt% Pt/TiO{sub 2} was observed to exhibit the best performance among the various Pt/TIO{sub 2} cathodes with natural seawater. In comparison of hydrogen evolution rate with various seawater electrolytes, 0.2 wt% Pt/TiO{sub 2} was found to show the better performance as cathode with the concentrated seawater electrolytes obtained from membrane. Highlights: > Pt deposited TiO{sub 2} electrodes are used as cathode in PEC H{sub 2} production. > Natural and concentrated seawater by membranes are used as electrolytes in PEC. > Pt/TiO{sub 2} shows a good performance as cathode with seawater electrolytes. > H{sub 2} evolution rate increases with more concentrated seawater electrolyte. > Highly saline seawater is useful resource for H{sub 2} production.

Nam, Wonsik [Korea Institute of Energy Research, New and Renewable Energy Research Division, Hydrogen Energy Research Center, 71-2 Jang-dong, Yuseong-gu, Daejeon 305-343 (Korea, Republic of); Korea University of Technology and Education, Department of Applied Chemical Engineering, 1800 Chungjeollo, Byeongcheon-myun, Chungnam 330-708 (Korea, Republic of); Oh, Seichang [Korea Institute of Energy Research, New and Renewable Energy Research Division, Hydrogen Energy Research Center, 71-2 Jang-dong, Yuseong-gu, Daejeon 305-343 (Korea, Republic of); Yonsei University, Department of Chemical and Biomolecular Engineering, 134 Shinchon-dong, Seodaemun-gu, Seoul 120-749 (Korea, Republic of); Joo, Hyunku [Korea Institute of Energy Research, New and Renewable Energy Research Division, Hydrogen Energy Research Center, 71-2 Jang-dong, Yuseong-gu, Daejeon 305-343 (Korea, Republic of); Yoon, Jaekyung, E-mail: jyoon@kier.re.kr [Korea Institute of Energy Research, New and Renewable Energy Research Division, Hydrogen Energy Research Center, 71-2 Jang-dong, Yuseong-gu, Daejeon 305-343 (Korea, Republic of)

2011-11-15T23:59:59.000Z

429

Genesis and evolution of surface species during Pt atomic layer deposition on oxide supports characterized by in-situ XAFS analysis and water-gas shift reaction.  

SciTech Connect

Platinum atomic layer deposition (ALD) using MeCpPtMe{sub 3} was employed to prepare high loadings of uniform-sized, 1-2 nm Pt nanoparticles on high surface area Al{sub 2}O{sub 3}, TiO{sub 2}, and SrTiO{sub 3} supports. X-ray absorption fine structure was utilized to monitor the changes in the Pt species during each step of the synthesis. The temperature, precursor exposure time, treatment gas, and number of ALD cycles were found to affect the Pt particle size and density. Lower-temperature MeCpPtMe{sub 3} adsorption yielded smaller particles due to reduced thermal decomposition. A 300 C air treatment of the adsorbed MeCpPtMe{sub 3} leads to PtO. In subsequent ALD cycles, the MeCpPtMe{sub 3} reduces the PtO to metallic Pt in the ratio of one precursor molecule per PtO. A 200 C H{sub 2} treatment of the adsorbed MeCpPtMe{sub 3} leads to the formation of 1-2 nm, metallic Pt nanoparticles. During subsequent ALD cycles, MeCpPtMe{sub 3} adsorbs on the support, which, upon reduction, yields additional Pt nanoparticles with a minimal increase in size of the previously formed nanoparticles. The catalysts produced by ALD had identical water-gas shift reaction rates and reaction kinetics to those of Pt catalysts prepared by standard solution methods. ALD synthesis of catalytic nanoparticles is an attractive method for preparing novel model and practical catalysts.

Setthapun, W.; Williams, W.; Kim, S.; Feng, H.; Elam, J.; Rabuffetti, F.; Poeppelmeier, K.; Stair, P.; Stach, E.; Ribeiro, F.; Miller, J.; Marshall, C.; Northwestern Univ.; Purdue Univ.

2010-06-03T23:59:59.000Z

430

Journal of Magnetism and Magnetic Materials 266 (2003) 96101 Oxidation of FePt nanoparticles  

E-Print Network (OSTI)

on decomposition of iron pentacarbonyl and reduction of platinum acetylacetonate. The particle solution disordered FePt nanoparticles are synthesized using Sun's approach based on decomposition of iron pentacarbonyl and reduc- tion of platinum acetylacetonate. The particle solution is then washed and subsequently

Laughlin, David E.

431

Direct synthesis and easy axis alignment of L1{sub 0}-FePt nanoparticles  

SciTech Connect

Partially ordered Fe{sub 53}Pt{sub 47} nanoparticles with size around 8 nm were prepared by the simultaneous decomposition of iron pentacarbonyl and platinum acetylacetonate. The high boiling point chemical, hexadecylamine, was used as a solvent, and 1-adamantanecarboxylic acid was used as a stabilizer. The reflux temperature of the solution could exceed 360 deg. C, where disordered FePt particles could be partially transformed into the ordered L1{sub 0} phase. A nonmagnetic mechanical stirrer was used in order to avoid agglomeration of the fct-FePt particles during synthesis. The particles were dispersed in toluene and films of the particles were cast onto silicon wafers from the solution. X-ray diffraction patterns of as-made samples showed weak superlattice peaks, indicating partial chemical ordering of the Fe{sub 53}Pt{sub 47} particles. The room-temperature hysteresis loop of the as-made sample reveals a small coercivity ({approx}600 Oe) because of thermal fluctuations; however, the loop is wide open and hard to saturate. The remanence coercivity from the dcd curve is about 2.5 kOe, which is four times larger than the hysteresis coercivity. The large remanent to hysteresis coercivity ratio and the shapes of the hysteresis loop and dcd curve suggest a broad distribution of anisotropies in the partially ordered particles. By coating the ordered nanoparticles with a polymer binder, the easy axis of the particles could be aligned under an external field.

Kang Shishou; Jia Zhiyong; Shi Shifan; Nikles, David E.; Harrell, J.W. [Center for Materials for Information Technology, University of Alabama, Tuscaloosa, Alabama 35487-0209 (United States)

2005-05-15T23:59:59.000Z

432

Study of the atomic structure and morphology of the Pt3Co nanocatalyst  

Science Journals Connector (OSTI)

It has been shown that Pt3Co nanoparticles used as a catalyst for cathode of Proton Exchange Membrane Fuel Cells (PEMFC) enhance oxygen reduction reaction (ORR) activity even by a factor of two compared to pure Pt nanoparticles. The local structure and chemical disorder of a commercially available Pt3Co nanocatalyst supported on high surface area carbon were investigated. High-quality XAFS spectra were collected at the ELETTRA synchrotron XAFS 11.1 beamline. XAFS spectra analysis have been performed accounting for the reduction of the coordination number and degeneracy of three-body configurations, resulting from transmission electron microscopy (TEM) and x-ray diffraction (XRD) extracted mean particles diameter, size distribution and expected surface atom contributions. The presence of a Co-Co first neighbour EXAFS signal is shown to be related to the degree of the alloy's chemical disorder. This is a good starting point for analyzing the atomic structure of Pt3Co nanocrystalline system and their changes as a function of alloy preparation or working conditions when they operate as a catalyst in PEMFC.

G Greco; A Witkowska; Y Soldo; E Larquet; N Menguy; A Cognigni; M Minicucci; E Principi; A Di Cicco

2009-01-01T23:59:59.000Z

433

Effect of the preparation conditions of carbon-supported Pt catalyst on PEMFC performance  

Science Journals Connector (OSTI)

Carbon-supported Pt catalysts were prepared using NaBH4 as a reducing agent in either ethylene glycol or water for use as a cathode catalyst in PEMFCs (polymer electrolyte membrane fuel cells). Aqueous NaBH4 solu...

Ji Bong Joo; Pil Kim; Wooyoung Kim; Younghun Kim…

2009-01-01T23:59:59.000Z

434

A novel hierarchical Pt- and FTO-free counter electrode for dye-sensitized solar cell  

Science Journals Connector (OSTI)

Figure 3 presents the photocurrent density-voltage (J-V) curves of DSSCs using PEDOT:PSS/FTO CE, TiO2...-PEDOT:PSS/PEDOT:PSS/glass CE, and Pt/FTO CE, respectively, and the related photovolatic parameters are show...

Xing Zhao; Meicheng Li; Dandan Song; Peng Cui; Zhirong Zhang…

2014-05-01T23:59:59.000Z

435

Short- and medium-range order in Zr[subscript 80]Pt[subscript 20] liquids  

SciTech Connect

The atomic structures in equilibrium and supercooled liquids of Zr{sub 80}Pt{sub 20} were determined as a function of temperature by in situ high-energy synchrotron diffraction studies of the levitated liquids (containerless processing) using the beamline electrostatic levitation (BESL) technique. The presence of a pronounced pre-peak at q - 1.7 {angstrom}{sup -1} in the static structure factor indicates medium-range order (MRO) in the liquid. The position and intensity of the pre-peak remain constant with cooling, indicating that the MRO is already present in the liquid above its melting temperature. An analysis of the liquid atomic structures obtained using the Reverse Monte Carlo method utilizing both the structure factor S(q) from x-ray diffraction experiments and the partial pair-correlation functions from ab initio molecular dynamics simulations show that the pre-peak arises from a Pt-Pt correlation that can be identified with icosahedral short-range order around the Pt atoms. The local atomic ordering is dominated by icosahedral-like structures, raising the nucleation barrier between the liquid and these phases, thus assisting glass formation.

Mauro, N.A.; Wessels, V.; Bendert, J.C.; Klein, S.; Gangopadhyay, A.K.; Kramer, M.J.; Hao, S.G.; Rustan, G.E.; Kreyssig, A.; Goldman, A.I.; Kelton, K.F. (WU); (ETH Zurich); (Iowa State); (IMW-Germany)

2011-12-09T23:59:59.000Z

436

Body copy Arial 11pt black University of Birmingham opportunities for SMEs  

E-Print Network (OSTI)

Body copy ­ Arial 11pt black University of Birmingham opportunities for SMEs The University that of the individual employees; with the overall aim of improving long term profitability. Our services to SMEs internships and placements Student schemes cover a wide range of disciplines - technology, processing, finance

Birmingham, University of

437

Inactivation of Salmonella Enteritidis PT 30 on Almonds with a Fluidized Bed Atmospheric Pressure Plasma  

E-Print Network (OSTI)

investigated the use of a fluidized bed atmospheric pressure plasma (APP) as a possible pasteurization methodInactivation of Salmonella Enteritidis PT 30 on Almonds with a Fluidized Bed Atmospheric Pressure Plasma Kalyani Narayanan1, Nathan M. Anderson2, Gregory J. Fleischman2 and Susanne Keller2 1Institute

Heller, Barbara

438

Unidirectional Pt silicide nanowires grown on vicinal Si,,100... Do Kyung Lim,1  

E-Print Network (OSTI)

this limitation, we focused on noble metal silicide NWs be- cause noble metals rarely form insulating metal oxideUnidirectional Pt silicide nanowires grown on vicinal Si,,100... Do Kyung Lim,1 Sung-Soo Bae,1. In particular, rare-earth silicide NWs on silicon surfaces have attracted in- terest as candidate nanostructures

Kim, Sehun

439

Effect of deposition and treatment conditions on growth of nanometer PtSi heterostructure  

E-Print Network (OSTI)

-X I. INTRODUCTION Transition metal silicides have received a great deal of attention due to their use in a number of devices.1­4 Platinum silicide PtSi is an important metal silicide which is widely of silicides are intensely affected by the deposition and technological parameters. It is also confirmed

Zheng, Yufeng

440

Low resistivity of Pt silicide nanowires measured using double-scanning-probe tunneling microscope  

E-Print Network (OSTI)

experimentally shown to be conductive.8­10 However, RE metal silicide NWs are easily oxidized, so that inert NWs similarly to RE metal silicide NWs.11 It is essential to study the electrical properties, especiallyLow resistivity of Pt silicide nanowires measured using double-scanning- probe tunneling microscope

Kim, Sehun

Note: This page contains sample records for the topic "ni pd pt" 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

Supportless oxygen reduction electrocatalysts of CoCuPt hollow nanoparticles  

Science Journals Connector (OSTI)

...alternative fuel and storage materials to address both environmental...reaction (ORR) at the cathode region, if hydrogen...can be the choice of materials for improving the ORR...often several times more active than pure Pt metal...deposition of targeted materials, one can produce hollow...

2010-01-01T23:59:59.000Z

442

What performance would non-Pt cathode catalysts need to achieve  

E-Print Network (OSTI)

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

443

Instability of Pt/C Electrocatalysts in Proton Exchange Membrane Fuel Cells  

E-Print Network (OSTI)

catalysts. Catalyst durability during PEMFC operation remains a key challenge to developing PEMFCsInstability of Pt/C Electrocatalysts in Proton Exchange Membrane Fuel Cells A Mechanistic/C electrocatalyst sample in 0.5 M H2SO4 at 80°C were found to increase with applied potential from 0.9 to 1.1 V vs

Ferreira, Paulo J.

444

Characterization of Pt/SiO2 Model Catalysts at UHV and Near Atmospheric Pressures  

E-Print Network (OSTI)

catalyst samples, prepared under UHV conditions in a contiguous high pressure reactor cell surface analysis with measurements on a Pt(110) single crystal for direct com- parison. CO desorption measurements and STM measure, turnover frequency (TOF, product molecules produced/site/s) is a standard metric used for comparison

Goodman, Wayne

445

Metal-assisted hydrogen storage on Pt-decorated single-walled carbon nanohorns  

E-Print Network (OSTI)

Metal-assisted hydrogen storage on Pt-decorated single-walled carbon nanohorns Yun Liu a,b,*, Craig nanoparticles can assist in enhanced hydrogen storage on high-surface area supports are still under debate. Experimental mea- surements of metal-assisted hydrogen storage have been hampered by inaccurate estima- tion

Geohegan, David B.

446

P0616-Nielsen Platinum Migration at the Pt/YSZ Interface  

E-Print Network (OSTI)

. The oxygen electrode on YSZ surfaces is studied at Pt micro-electrodes prepared by electrochemical etching polarization is confirmed, but furthermore, a very accentuated noise pattern is seen during cathodic step structures from the TPB. The formation of these may explain the observed noise and contribute

447

Correlating Catalytic Methanol Oxidation with the Structure and Oxidation State of Size-Selected Pt Nanoparticles  

E-Print Network (OSTI)

of this process is a limiting factor in the performance of direct methanol fuel cells, which produce electricityCorrelating Catalytic Methanol Oxidation with the Structure and Oxidation State of Size-Selected Pt nanoparticles (NPs) prepared by micelle encapsulation and supported on -Al2O3 during the oxidation of methanol

Kik, Pieter

448

High Power Impulse Magnetron Sputtering deposition of Pt inside fuel cell electrodes  

E-Print Network (OSTI)

1 High Power Impulse Magnetron Sputtering deposition of Pt inside fuel cell electrodes S Cuynet1 as a cathode of a proton exchange membrane fuel cell. An increase of 80 % at 0.65 V of the PEMFC power density) 272001" #12;2 Proton exchange membrane fuel cells (PEMFC) have the potential to provide

Paris-Sud XI, Université de

449

Quasi-model-independent search for new high p(T) physics at D0  

E-Print Network (OSTI)

We apply a quasi-model-independent strategy ("Sleuth") to search for new high p(T) physics in approximate to 100 pb(-1) of p (p) over bar collisions at roots = 1.8 TeV collected by the D0 experiment during 1992-1990 at the ...

Baringer, Philip S.; Bean, Alice; Coppage, Don; Hebert, C.

2001-04-01T23:59:59.000Z

450

Pt/CARBON XEROGEL CATALYSTS FOR PEM FUEL CELLS Nathalie JOBa  

E-Print Network (OSTI)

Pt/CARBON XEROGEL CATALYSTS FOR PEM FUEL CELLS Nathalie JOBa , Frédéric MAILLARDb , Jean of proton exchange membrane (PEM) fuel cells in order to decrease the mass transport limitations The catalytic layer configuration is a key-element in the design of PEM fuel cells [1]. Indeed, besides

Paris-Sud XI, Université de

451

Full Name: Vicki Gray, PT, PhD Title(s): UMANRRT PostDoctoral Fellow  

E-Print Network (OSTI)

Full Name: Vicki Gray, PT, PhD Title(s): UMANRRT PostDoctoral Fellow Email: vgray and Rehabilitation Sciences in the field of Physical Therapy. Her Ph.D. thesis focused on the motor control of fast continued to work in Dr Jayne Garland's Neural Control of Force Production and Movement Lab

Weber, David J.

452

Temperature dependent surface electrochemistry on Pt singlecrystals in alkaline electrolyte: Part 3: The oxygen reductionreaction  

SciTech Connect

The kinetics of the oxygen reduction reaction (ORR) was studied in alkaline electrolyte at 293-333K on Pt(hkl) surfaces by means of the rotating ring-disk electrode technique with solution phase peroxide detected at the ring electrode. The ORR on Pt(hkl) was found to be highly structure sensitive with activities increasing in the sequence (111) > (100) > (110)(1x2). Very similar apparent activation energies (37-45 {+-} 5 kJmol-1, {eta} = 0.35 V) were found on all three surfaces. Furthermore, at elevated temperature, significantly smaller amounts of peroxide are formed in agreement with enhanced peroxide reduction rates by increasing temperature. We found that the Tafel slopes on all three single crystal surfaces decrease with increasing temperature, indicating that the logi-E relationship is not represented by a classical Butler-Volmer expression. Based on the kinetic analysis of the polarization curves and from simulations of logi-E curves, we propose that the rate of the ORR on Pt(hkl) in alkaline solution is mainly determined by the potential/temperature dependent surface coverage by OH{sub ad}. We propose two modes of action of the OH{sub ad}: (i) OH{sub ad} blocks the adsorption of O{sub 2} on active platinum sites; and (ii) OH{sub ad} alters the adsorption energy of intermediates which are formed during the ORR on Pt sites.

tom.schmidt@psi.ch

2002-08-01T23:59:59.000Z

453

Oxygen reduction on Pt in aqueous K sub 2 CO sub 3 and KOH  

SciTech Connect

This paper reports on the electrolyte concentration dependences of platinum oxidation and oxygen reduction (OR) on Pt investigated in KOH and K{sub 2}CO{sub 3} electrolytes. Cyclic voltammetry was used to characterize the oxidation processes on the Pt electrode, and the rotating ring-disk electrode (RRDE) technique was used to evaluate the kinetic processes for OR in 0.1--6.9 {ital M} KOH and 0.1--4.0 {ital M} K{sub 2}CO{sub 3}, at room temperature. The charge due to Pt oxidation reached a maximum at a KOH concentration of about 2--3 {ital M} for a range of electrode potentials. This is consistent with changes in the rates and the relative importances of the reversible and aging processes with changes in hydroxide-ion activity. No maxima were observed with carbonate electrolytes at comparable ionic strengths. At high overpotentials, in both electrolytes, current densities were limited by the rate of O{sub 2} adsorption onto Pt. The Tafel slope for this process was essentially infinite for the more-oxidized surfaces. At lower overpotentials, the observed Tafel slope decreased and the fraction of current passing through the 2-electron pathway increased with increasing hydroxide-ion activity.

Striebel, K.; McLarnon, F.R.; Cairns, E.J. (Applied Science Div., Lawrence Berkeley Lab., Dept. of Chemical Engineering, Univ. of California, Berkeley, CA (US))

1990-11-01T23:59:59.000Z

454

Acceptability of Four Transformer Top-Oil Thermal Models: Pt. 2: Comparing Metrics  

E-Print Network (OSTI)

1 Acceptability of Four Transformer Top-Oil Thermal Models: Pt. 2: Comparing Metrics Lida Jauregui transformer top-oil thermal models are examined vis-à-vis training with measured data. Acceptability is unacceptable for model identification purposes. The linear top-oil model is acceptable for FOFA transformers

455

Femtosecond Near-Infrared Laser Desorption of Multilayer Benzene on Pt{111}: A Molecular Newton's Cradle?  

E-Print Network (OSTI)

Femtosecond Near-Infrared Laser Desorption of Multilayer Benzene on Pt{111}: A Molecular Newton Recently, the intense near-infrared laser desorption of intact benzene molecules has been reported.1 Three, 1999; In Final Form: February 11, 2000 Velocity distributions resulting from the intense, near-IR laser

Levis, Robert J.

456

Shape coexistence from the structure of the yrast band in Pt174  

Science Journals Connector (OSTI)

Excited states in the very neutron-deficient nucleus Pt174 have been identified up to spin 14. An irregular yrast sequence was observed beginning with a high 2+?0+ energy. It can be interpreted as the result of a change from a weakly deformed ground-state band, to a well-deformed rotor, near spin 6.

G. D. Dracoulis; B. Fabricius; A. E. Stuchbery; A. O. Macchiavelli; W. Korten; F. Azaiez; E. Rubel; M. A. Deleplanque; R. M. Diamond; F. S. Stephens

1991-10-01T23:59:59.000Z

457

Effect of nickel loading on the activity of Ni/ZrO2 for methane steam reforming at low temperature  

Science Journals Connector (OSTI)

The effect of Ni loading on the catalytic activity of Ni/ZrO2 catalyst for methane steam reforming was investigated. The sample containing 15 wt...

Long Q. Nguyen; Leonila C. Abella…

2008-04-01T23:59:59.000Z

458

Effect of Aging Heat Treatments on Ni52Ti48 Shape Memory Alloy  

E-Print Network (OSTI)

Ni-rich NiTi shape memory alloys (SMAs) are capable of attaining a wide range of transformation temperatures depending on the heat treatment conditions and superior thermo-mechanical cycling stability, which are desired for repeated solid...

Akin, Erhan

2011-10-21T23:59:59.000Z

459

SciTech Connect: Neutron Scattering of CeNi at the SNS-ORNL:...  

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

Conference: Neutron Scattering of CeNi at the SNS-ORNL: A Preliminary Report Citation Details In-Document Search Title: Neutron Scattering of CeNi at the SNS-ORNL: A Preliminary...

460

Textural Characterization of Pilc Montmorillonite Pillared with Binary Oxides LaNiOx  

Science Journals Connector (OSTI)

Montmorillonite pillared clay was synthesized by intercalation of binuclear complex of the form NiLa(fsaen)NO3 and subsequent calcination at 500°C. The binary oxides of the form NiLaOx thus created inside the lay...

S. P. Skaribas; P. J. Pomonis; P. Grange…

1993-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "ni pd pt" 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

E-Print Network 3.0 - alloy fracture cu-ni Sample Search Results  

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

fracture cu-ni Search Powered by Explorit Topic List Advanced Search Sample search results for: alloy fracture cu-ni Page: << < 1 2 3 4 5 > >> 1 Ris-R-1276(EN) Final Report...

462

X-ray absorption spectroscopy at the Ni-K edge in Stackhousia tryonii Bailey hyperaccumulator  

E-Print Network (OSTI)

X-ray absorption spectroscopy at the Ni–K edge inin vivo by micro x-ray absorption spectroscopy (XAS) at theNi–K edge. Both x-ray absorption near edge structure and

Kachenko, A.

2009-01-01T23:59:59.000Z

463

Piezospectroscopic study of substitutional Ni in ZnO  

SciTech Connect

The effect of uniaxial stress on the electronic {sup 3}T{sub 1}(F)?{sup 3}T{sub 2}(F) transitions of Ni{sup 2+} in ZnO at 4216, 4240, and 4247 cm{sup ?1} is investigated by means of Fourier transform IR absorption spectroscopy. A stress Hamiltonian is constructed which accounts for the behavior of these transitions under uniaxial stress. It is shown that the split pattern and polarization properties of these IR absorption lines are consistent with a dynamic Jahn-Teller effect in the {sup 3}T{sub 2}(F) state of Ni.

Lavrov, E. V.; Herklotz, F. [Technische Universität Dresden, 01062 Dresden (Germany); Kutin, Y. S. [Kazan Federal University, Federal Center of Shared Facilities, 420008 Kazan (Russian Federation)

2014-02-21T23:59:59.000Z

464

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

465

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

466

Kinetics of Mixed Ni-Al Precipitate Formation on a Soil Clay Fraction  

E-Print Network (OSTI)

Kinetics of Mixed Ni-Al Precipitate Formation on a Soil Clay Fraction D A R R Y L R . R O B E R Management Laboratory, Paul Scherrer Institute, CH-5232 Villigen PSI, Switzerland The kinetics of mixed Ni-Al Ni- Al LDH formation. The initial Ni concentration was 3 mM with a solid/solution ratio of 10 g L-1

Sparks, Donald L.

467

Is Hydrogen Storage Possible in Metal-Doped Graphite 2D Systems in Conditions Found on Earth?  

Science Journals Connector (OSTI)

Density functional theory (DFT) calculations are performed for the adsorption energy of hydrogen and oxygen on graphene decorated with a wide set of metals (Li, Na, K, Al, Ti, V, Ni, Cu, Pd, Pt). It is found that oxygen interferes with hydrogen adsorption by either blocking the adsorption site or by the irreversible oxidation of the metal decoration. The most promising decorations are Ni, Pd, and Pt due to a reasonable relationship of adsorption energies which minimize the oxygen interference. The DFT results are used to parametrize a statistical mechanical model which allows evaluation of the effect of partial pressures in the gas phase during storage. According to this model, even in the most promising case, it is necessary to reduce the oxygen partial pressure close to ultrahigh vacuum conditions to allow hydrogen storage.

A. Sigal; M. I. Rojas; E. P. M. Leiva

2011-10-06T23:59:59.000Z

468

Potential of producing various hydrocarbons from canola oil by catalytic treatment over Pt-ZSM-5  

SciTech Connect

Canola oil conversion was studied at atmospheric pressure over Pt-ZSM-5 catalyst (0.5 wt% Pt) in a fixed bed micro-reactor. The operating conditions were: temperature range of 400--500 C, weight hourly space velocity (WHSV) of 1.8 and 3.6 h{sup {minus}1} and steam/oil ratio of 4:1. The products were coke, gas, an organic liquid product (OLP) and residue. The gas and OLP consisted mainly of hydrocarbons. The objective of this study was to maximize the amount of gasoline range hydrocarbons in the OLP and the selectivity to isohydrocarbons in the gas. The gas yields varied between 22--65 wt% and were higher in the presence of steam compared to the operation without steam. Also, the gas fraction decreased with increase in space velocity. The olefin/paraffin ratio of C{sub 2}-C{sub 4} hydrocarbon gases varied between 0.31--0.79. The amount of isohydrocarbons relative to n-hydrocarbons were higher with Pt-ZSM-5 (1.6--4.8) compared to pure HZSM-5 catalyst (0.2--0.3). The OLP yields with Pt-ZSM-5 (20--55wt% of canola oil) were slightly lower compared to HZSM-5 (40--63wt% of canola oil) under similar conditions. The major components of OLP were aliphatic and aromatic hydrocarbons. The main aromatic hydrocarbons were benzene, toluene, xylenes and trimethylbenzenes. Alkylated pentane and hexane were the main aliphatic hydrocarbons. In the presence of steam, Pt-ZSM-5 gave higher yields of liquid hydrocarbons within the gasoline boiling range than HZSM-5.

Katikaneni, S.P.R.; Adjaye, J.D.; Bakhshi, N.N. [Univ. of Saskatchewan, Saskatoon (Canada)

1995-12-31T23:59:59.000Z

469

INVESTIGATION OF NOVEL ALLOY TiC-Ni-Ni3Al FOR SOLID OXIDE FUEL CELL INTERCONNECT APPLICATIONS  

SciTech Connect

Solid oxide fuel cell interconnect materials must meet stringent requirements. Such interconnects must operate at temperatures approaching 800 C while resisting oxidation and reduction, which can occur from the anode and cathode materials and the operating environment. They also must retain their electrical conductivity under these conditions and possess compatible coefficients of thermal expansion as the anode and cathode. Results are presented in this report for fuel cell interconnect candidate materials currently under investigation based upon nano-size titanium carbide (TiC) powders. The TiC is liquid phase sintered with either nickel (Ni) or nickel-aluminide (Ni{sub 3}Al) in varying concentrations. The oxidation resistance of the submicron grain TiC-metal materials is presented as a function weight change versus time at 700 C and 800 C for varying content of metal/intermetallic in the system. Electrical conductivity at 800 C as a function of time is also presented for TiC-Ni to demonstrate the vitality of these materials for interconnect applications. TGA studies showed that the weight gain was 0.8 mg/cm{sup 2} for TiC(30)-Ni(30wt.%) after 100 hours in wet air at 800 C and the weight gain was calculated to be 0.5205 mg/cm{sup 2} for TiC(30)- Ni(10 wt.%) after 100 hours at 700 C and 100 hours at 800 C. At room temperature the electrical conductivity was measured to be 2444 1/[ohm.cm] for TiC-Ni compositions. The electrical conductivities at 800 C in air was recorded to be 19 1/[ohm.cm] after 125 hours. Two identical samples were supplied to PNNL (Dr. Jeff Stevenson) for ASR testing during the pre-decision period and currently they are being tested there. Fabrication, oxidation resistance and electrical conductivity studies indicate that TiC-Ni-Ni{sub 3}Al ternary appears to be a very important system for the development of interconnect composition for solid oxide fuel cells.

Rasit Koc; Geoffrey Swift; Hua Xie

2005-01-25T23:59:59.000Z

470

Shape memory response of ni2mnga and nimncoin magnetic shape memory alloys under compression  

E-Print Network (OSTI)

In this study, the shape memory response of Ni2MnGa and NiMnCoIn magnetic shape memory alloys was observed under compressive stresses. Ni2MnGa is a magnetic shape memory alloy (MSMA) that has been shown to exhibit fully reversible, stressassisted...

Brewer, Andrew Lee

2009-05-15T23:59:59.000Z

471

Vacancy-Vacancy Interactions in NiAl Matthew O. Zacate and Gary S. Collins  

E-Print Network (OSTI)

Vacancy-Vacancy Interactions in NiAl Matthew O. Zacate and Gary S. Collins Department of Physics, Washington State University, Pullman, WA 99164, USA Keywords: point defect, vacancy, defect interaction, intermetallic compound, perturbed angular correlation, PAC, NiAl Abstract. Interactions between Ni vacancies

Collins, Gary S.

472

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

473

Monopole resonance strengths in Ni-58 and Pb-208  

E-Print Network (OSTI)

Giant monopole resonance strengths were obtained from small angle inelastic alpha scattering on Ni-58 and Pb-208 using deformed potential and folding models. Folding model analyses increase the sum rule strength in both nuclei, with 160% of the E0...

Youngblood, David H.

1997-01-01T23:59:59.000Z

474

Precipitation in 9Ni-12Cr-2Cu maraging steels  

SciTech Connect

Two maraging steels with the compositions 9Ni-12Cr-2Cu-4Mo (wt%) and 9Ni-12Cr-2Cu and with small additions of Al and Ti were investigated using atom probe field ion microscopy. Tomographic atom probe investigations were performed to clarify the spatial distribution of elements in and close to the precipitates. Materials heat treated at 475 C for 5, 25 min, 1, 2, 4 and 400 h were analyzed. Precipitates in the Mo-rich material were observed already after 5 min of aging, while in the material without MO, precipitation started later. In both materials precipitation begins with the formation of Cu-rich particles which work as nucleation sites for a Ni-rich phase of type Ni{sub 3}(Ti,Al). A Mo-rich phase was detected in the Mo-rich steel after 2 h of aging. The distribution of alloying elements in the precipitates, their role in the precipitation process, and the mechanism of hardening in the two materials are discussed.

Stiller, K.; Haettestrand, M. [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Physics] [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Physics; Danoix, F. [Univ. de Rouen, Mont Saint Aignan (France). Lab. de Microscopie Ionique] [Univ. de Rouen, Mont Saint Aignan (France). Lab. de Microscopie Ionique

1998-11-02T23:59:59.000Z

475

Metal-to-Semiconductor Transition in Hexagonal NiS  

Science Journals Connector (OSTI)

Recent electrical resistivity measurements have shown that the hexagonal form of stoichiometric NiS exhibits an abrupt metal-to-semiconductor transition at 264°K. Neutron diffraction studies have shown that a first-order paramagnetic-to-antiferromagnetic transition also occurs at 264°K. No crystal lattice distortion is observed at the transition nor detected at 4.2°K, suggesting that this may be a transition of the kind considered by Adler and Brooks. The measured magnetic moment at 4.2°K is 1.66±0.08 ?? and at 260°K it is 150.±0.10 ?? indicating that the sublattice magnetization is within 10% of saturation immediately upon ordering. The neutron data also shown that no more than about 1% of the Ni atoms migrate to tetragonal interstitial sites on warming from 4.2°K to room temperature. Thus, Ni atom migration apparently plays no part in this transition. The powder magnetic susceptibility is 2.24×10-6 emu/g at 300°K and is virtually temperature-independent above the transition. ? increases abruptly at 264°K by about 15% and exhibits some field-cooling effects. Studies on the compounds NiXS, for X=1.01, 0.99, 0.97, and 0.94 show that excess sulfur lowers the transition temperature.

JOSEPH T. SPARKS and TED KOMOTO

1968-10-01T23:59:59.000Z

476

Directional solidification studies in Ni-Al alloys  

SciTech Connect

Three solid phases are involved in the phase equilibria of the intermetallic compound Ni{sub 3}Al near its melting point, {beta}, {gamma}{prime}(Ni{sub 3}Al), and {gamma}. The generally-accepted phase diagram involves a eutectic reaction between {beta}{prime} and {gamma}, but some recent studies agree with an older diagram due to Schramm, which has a eutectic reaction between the {beta} and {gamma}{prime} phases. The phase equilibria near Ni{sub 3}Al compositions was evaluated using quenched directional solidification experiments, that preserve the microstructures tonned at the solidification front, and using diffusion couple experiments. These experiments show that eutectic forms between {beta} and {gamma}{prime} phases, as in the Schramm diagram. Growth and phase transformations of these three phases are also studied in the directional solidification experiments. Microstructure analysis shows that etching of Ni{sub 3}Al({gamma}{prime}) is very sensitive to small composition variations and crystallographic orientation changes. The eutectic solidification study confirms that the equilibrium eutectic is {gamma}{prime}+{beta}, and that the metastable {gamma}+{beta} eutectic might be also produced in this system according to the impurities, solidification rates, and composition variations.

Lee, Je-hyun

1993-05-01T23:59:59.000Z

477

NTS-2 Ni-H/sub 2/ battery - an update  

SciTech Connect

This paper presents an extensive data base for future Ni-H/sub 2/ spacecraft batteries. End of-discharge (EOD) voltages for the eight eclipse seasons are presented along with long-term pressure data derived from a strain gauge mounted on the dome of a cell. The use of temperature for charge control is also evaluated. 5 refs.

Stockel, J.F.

1981-01-01T23:59:59.000Z

478

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

Science Journals Connector (OSTI)

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

T Sarakonsri; S Thungprasert; W Klysubun; T Vilaithong

2010-01-01T23:59:59.000Z

479

(Electronic structure and reactivities of transition metal clusters)  

SciTech Connect

The following are reported: theoretical calculations (configuration interaction, relativistic effective core potentials, polyatomics, CASSCF); proposed theoretical studies (clusters of Cu, Ag, Au, Ni, Pt, Pd, Rh, Ir, Os, Ru; transition metal cluster ions; transition metal carbide clusters; bimetallic mixed transition metal clusters); reactivity studies on transition metal clusters (reactivity with H{sub 2}, C{sub 2}H{sub 4}, hydrocarbons; NO and CO chemisorption on surfaces). Computer facilities and codes to be used, are described. 192 refs, 13 figs.

Not Available

1992-01-01T23:59:59.000Z

480

Large pT from the fragmentation of 1.2-GeV/nucleon La139 nuclei  

Science Journals Connector (OSTI)

The first measurements of the transverse momenta (pT) of heavy projectile fragments produced by fragmentation of 1.2-GeV/nucleon La are presented. The momentum distributions of the fragments (Z?26–56) are Gaussians and broader than predicted by models based on internal momenta of the projectile nucleons. The larger pT observed do not appear to be due solely to Coulomb effects, but are consistent with a simple model whereby nucleons from the (hot) overlap region recoil collectively into the (colder) projectile fragments. Thus, pT and the fragment mass may provide a good indication of the vector impact parameter b.

F. P. Brady; W. B. Christie; J. L. Romero; C. E. Tull; B. McEachern; M. L. Webb; J. C. Young; H. J. Crawford; D. E. Greiner; P. J. Lindstrom; H. Sann

1988-04-25T23:59:59.000Z

Note: This page contains sample records for the topic "ni pd pt" 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

Morphology of Carbon Supported Pt?Ru Electrocatalyst and the CO Tolerance of Anodes for PEM Fuel Cells  

Science Journals Connector (OSTI)

Thus, the development of CO-tolerant electrocatalysts is necessary before hydrogen?oxygen PEFCs can be widely applied. ... Figure 3 PEMFC single-cell CO tolerance test of (A) the commercial Pt?Ru/C catalyst, (B) the commercial 20% Pt/C catalyst, and (C) the YZU Pt?Ru/C catalyst under pure H2 (open symbols) and 100 ppm of CO in H2 for 60 min (filled symbols). ... This indicates that there is still a long distance to the development of a practical CO tolerant electrocatalyst. ...

Shawn D. Lin; Ting-Chou Hsiao; Jen-Ray Chang; Andrew S. Lin

1998-12-15T23:59:59.000Z

482

New-Concept CO-Tolerant Anode Catalysts Using a Rh Porphyrin-Deposited PtRu/C  

Science Journals Connector (OSTI)

We tried to counteract this problem using a CO oxidation electrocatalyst. ... In the development of a stationary proton exchange membrane fuel cell (PEMFC), CO in reformed gas remains a severe problem because it dramatically poisons the Pt anodes of PEMFC even at very low concentrations of less than 100 ppm. ... In the CO tolerance of conventional PtRu catalysts, this reaction has a less significant role than electronic effects of Ru on Pt.(39) Electrocatalysts that can oxidize CO at low potentials would be useful for the development of CO-tolerant anode catalysts for reformate gas. ...

Shin-ichi Yamazaki; Masaru Yao; Zyun Siroma; Tsutomu Ioroi; Kazuaki Yasuda

2010-11-16T23:59:59.000Z

483

Effect of particle size on the activity and durability of the Pt/C electrocatalyst for proton exchange membrane fuel cells  

Science Journals Connector (OSTI)

Carbon supported Pt (Pt/C) with various average particle sizes ranging from sub 3 nm to 6.5 nm were in situ prepared and characterized at the cathode of proton exchange membrane fuel cells (PEMFCs). A clear Pt particle size effect on both the catalytic activity for oxygen reduction reaction (ORR) and the durability of the electrocatalyst was revealed. With the Pt particle size increase, both the surface specific activity and the electrochemical stability of Pt/C improved; however, the mass specific activity of Pt/C is balanced by the electrochemical surface area loss. The reduced occupation of corner and edge atoms on the Pt surface during the Pt particle size increase is believed to weaken the adsorption of the oxygenated species on Pt, and thereafter releases more available active sites for ORR and also renders the Pt surface a stronger resistance against potential cycling. It is therefore proposed that by designing the Pt microstructure with more face atoms on the surface, cathode electrocatalyst with both improved activity and enhanced durability would be developed for PEMFCs.

Zhuang Xu; Huamin Zhang; Hexiang Zhong; Qiuhong Lu; Yunfeng Wang; Dangsheng Su

2012-01-01T23:59:59.000Z

484

Interdiffusion in NiMnSb/V/NiMnSb: X-ray and neutron reflectivity investigation of ion beam sputtered trilayer systems  

SciTech Connect

The new trilayer system NiMnSb/V/NiMnSb on MgO(001) was investigated by means of vibrating sample magnetometry (VSM), x-ray, and neutron reflectivity. VSM revealed a coercive field H{sub c}=23 Oe and a hysteresis loop similar to that of an uncoupled ferromagnet. The x-ray and neutron reflectivity data proved that interface roughnesses of 10 {Angstrom} are present. A detailed analysis yielded significant interdiffusion at the NiMnSb/V interfaces which is one possible explanation for the weak magnetoresistance effect measured in similar NiMnSb-based multilayer systems. {copyright} {ital 1999 American Institute of Physics.}

Schlomka, J.; Tolan, M.; Press, W. [Institut fuer Experimentelle und Angewandte Physik, Christian-Albrechts-Universitaet zu Kiel, 24098 Leibnizstrasse 17-19, Kiel (Germany)] [Institut fuer Experimentelle und Angewandte Physik, Christian-Albrechts-Universitaet zu Kiel, 24098 Leibnizstrasse 17-19, Kiel (Germany); Fitzsimmons, M.R. [Manuel Lujan, Jr. Neutron Scattering Center, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)] [Manuel Lujan, Jr. Neutron Scattering Center, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Siebrecht, R. [Institut Laue-Langevin, 38042 Grenoble, Cedex 9 (France)] [Institut Laue-Langevin, 38042 Grenoble, Cedex 9 (France); Schubert, D.W. [GKSS Forschungszentrum, 21502 Geesthacht (Germany)] [GKSS Forschungszentrum, 21502 Geesthacht (Germany); Simon, P. [Max Planck Institut fuer Polymerforschung, 55021 Mainz (Germany)] [Max Planck Institut fuer Polymerforschung, 55021 Mainz (Germany)

1999-11-01T23:59:59.000Z

485

First-principles investigations of Ni3Al(111) and NiAl(110) surfaces at metal dusting conditions  

SciTech Connect

We investigate the structure and surface composition of the {gamma}{prime}-Ni{sub 3}Al(111) and {beta}-NiAl(110) alloy surfaces at conditions relevant for metal dusting corrosion related to catalytic steam reforming of natural gas. In regular service as protective coatings, nickel-aluminum alloys are protected by an oxide scale, but in case of oxide scale spallation, the alloy surface may be directly exposed to the reactive gas environment and vulnerable to metal dusting. By means of density functional theory and thermochemical calculations for both the Ni{sub 3}Al and NiAl surfaces, the conditions under which CO and OH adsorption is to be expected and under which it is inhibited, are mapped out. Because CO and OH are regarded as precursors for nucleating graphite or oxide on the surfaces, phase diagrams for the surfaces provide a simple description of their stability. Specifically, this study shows how the CO and OH coverages depend on the steam to carbon ratio (S/C) in the gas and thereby provide a ranking of the carbon limits on the different surface phases.

Saadi, Souheil

2011-03-01T23:59:59.000Z

486

Low-temperature magnetization in Ni-rich gamma-Ni100-x-yFexVy alloys  

E-Print Network (OSTI)

is antiferromagnetic) suppresses the ferromagnetic order in the NiFe binary alloys. The magnetization of the alloys with low V (y less than or equal to 11 at. %) has shown a good fit to only the spin-wave T-3/2 term whereas the data for the high V (gamma greater than...

Chakraborty, S.; Mukherjee, GD; Rathnayaka, KDD; Naugle, Donald G.; Majumdar, AK.

2000-01-01T23:59:59.000Z

487

Effect of Composition on the Solidification Behavior of Several Ni-Cr-Mo and Fe-Ni-Cr-Mo Alloys  

E-Print Network (OSTI)

simulate the solidifi- cation behavior of dissimilar welds made between AL-6XN and Ni-base filler metals.[3 differential thermal analysis (DTA) samples and welded specimens. This explains the in- variance of the amount of eutectic constituent observed in the microstructure in the welded and DTA conditions. Multicomponent

DuPont, John N.

488

El Ni~no and La Ni~na: Causes and Global Consequences Michael J McPhaden  

E-Print Network (OSTI)

releases heat into the middle and upper troposphere. This heat provides a source of energy to drive global wind fields that extend El Ni~no's influence to remote parts of the planet. Altered circulation patterns produce droughts, floods, unusual storminess, heat waves, and other weather extremes that have

489

High Permeability Ternary Palladium Alloy Membranes with Improved Sulfur and Halide Tolerances  

SciTech Connect

The project team consisting of Southwest Research Institute{reg_sign} (SwRI{reg_sign}), Georgia Institute of Technology (GT), the Colorado School of Mines (CSM), TDA Research, and IdaTech LLC was focused on developing a robust, poison-tolerant, hydrogen selective free standing membrane to produce clean hydrogen. The project completed on schedule and on budget with SwRI, GT, CSM, TDA and IdaTech all operating independently and concurrently. GT has developed a robust platform for performing extensive DFT calculations for H in bulk palladium (Pd), binary alloys, and ternary alloys of Pd. Binary alloys investigated included Pd96M4 where M = Li, Na, Mg, Al, Si, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Y, Zr, Nb, Mo, Tc, Ru, Rh, Ag, Cd, In, Sn, Sb, Te, Hf, Ta, W, Re, Os, Ir, Pt, Au, Tl, Pb, Bi, Ce, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu. They have also performed a series of calculations on Pd{sub 70}Cu{sub 26}Ag{sub 4}, Pd{sub 70}Cu{sub 26}Au{sub 4}, Pd{sub 70}Cu{sub 26}Ni{sub 4}, Pd{sub 70}Cu{sub 26}Pt{sub 4}, and Pd{sub 70}Cu{sub 26}Y{sub 4}. SwRI deposited and released over 160 foils of binary and ternary Pd alloys. There was considerable work on characterizing and improving the durability of the deposited foils using new alloy compositions, post annealing and ion bombardment. The 10 and 25 {micro}m thick films were sent to CSM, TDA and IdaTech for characterization and permeation testing. CSM conducted over 60 pure gas permeation tests with SwRI binary and ternary alloy membranes. To date the PdAu and PdAuPt membranes have exhibited the best performance at temperatures in the range of 423-773 C and their performance correlates well with the predictions from GT. TDA completed testing under the Department of Energy (DOE) WGS conditions on over 16 membranes. Of particular interest are the PdAuPt alloys that exhibited only a 20% drop in flux when sulfur was added to the gas mixture and the flux was completely recovered when the sulfur flow was stopped. IdaTech tested binary and ternary membranes on a simulated flue gas stream and experienced significant difficulty in mounting and testing the sputter deposited membranes. IdaTech was able to successfully test PdAu and PdAuPt membranes and saw similar sulfur tolerance to what TDA found. The Program met all the deliverables on schedule and on budget. Over ten presentations at national and international conferences were made, four papers were published (two in progress) in technical journals, and three students (2 at GT and 1 at CSM) completed their doctorates using results generated during the course of the program. The three major findings of program were; (1) the DFT modeling was verified as a predictive tool for the permeability of