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Note: This page contains sample records for the topic "metal oxide chemical" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
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1

Aerosol chemical vapor deposition of metal oxide films  

DOE Patents (OSTI)

A process of preparing a film of a multicomponent metal oxide including: forming an aerosol from a solution comprised of a suitable solvent and at least two precursor compounds capable of volatilizing at temperatures lower than the decomposition temperature of said precursor compounds; passing said aerosol in combination with a suitable oxygen-containing carrier gas into a heated zone, said heated zone having a temperature sufficient to evaporate the solvent and volatilize said precursor compounds; and passing said volatilized precursor compounds against the surface of a substrate, said substrate having a sufficient temperature to decompose said volatilized precursor compounds whereby metal atoms contained within said volatilized precursor compounds are deposited as a metal oxide film upon the substrate is disclosed. In addition, a coated article comprising a multicomponent metal oxide film conforming to the surface of a substrate selected from the group consisting of silicon, magnesium oxide, yttrium-stabilized zirconium oxide, sapphire, or lanthanum gallate, said multicomponent metal oxide film characterized as having a substantially uniform thickness upon said substrate.

Ott, K.C.; Kodas, T.T.

1994-01-11T23:59:59.000Z

2

Evaluation of Novel Ceria-Supported Metal Oxides As Oxygen Carriers for Chemical-Looping Combustion  

E-Print Network (OSTI)

Evaluation of Novel Ceria-Supported Metal Oxides As Oxygen Carriers for Chemical-Looping Combustion and examined as oxygen carrier materials for chemical-looping combustion (CLC). Unlike conventional support agglomeration. 1. INTRODUCTION 1.1. Chemical-Looping Combustion. Chemical-looping combustion (CLC

Azad, Abdul-Majeed

3

Cyclic catalytic upgrading of chemical species using metal oxide materials  

DOE Patents (OSTI)

Processes are disclosure which comprise alternately contacting an oxygen-carrying catalyst with a reducing substance, or a lower partial pressure of an oxidizing gas, and then with the oxidizing gas or a higher partial pressure of the oxidizing gas, whereby the catalyst is alternately reduced and then regenerated to an oxygenated state. In certain embodiments, the oxygen-carrying catalyst comprises at least one metal oxide-containing material containing a composition having the following formulas: (a) Ce.sub.xB.sub.yB'.sub.zB''O.sub..delta., wherein B=Ba, Sr, Ca, or Zr; B'=Mn, Co, and/or Fe; B''=Cu; 0.01metal oxides.

White, James H; Schutte, Erick J; Rolfe, Sara L

2013-05-07T23:59:59.000Z

4

Cyclic catalytic upgrading of chemical species using metal oxide materials  

DOE Patents (OSTI)

Processes are disclosure which comprise alternately contacting an oxygen-carrying catalyst with a reducing substance, or a lower partial pressure of an oxidizing gas, and then with the oxidizing gas or a higher partial pressure of the oxidizing gas, whereby the catalyst is alternately reduced and then regenerated to an oxygenated state. In certain embodiments, the oxygen-carrying catalyst comprises at least one metal oxide-containing material containing a composition having one of the following formulas: (a) Ce.sub.xB.sub.yB'.sub.zB''O.sub..delta., wherein B=Ba, Sr, Ca, or Zr; B'=Mn, Co, or Fe; B''=Cu; 0.01

White, James H. (Boulder, CO); Schutte, Erick J. (Thornton, CO); Rolfe, Sara L. (Loveland, CO)

2010-11-02T23:59:59.000Z

5

Metal Oxides  

Science Journals Connector (OSTI)

Metal oxides are the class of materials having the widest application in gas sensors. This chapter presents information related to the application of various metal oxides in gas sensors designed on different p...

Ghenadii Korotcenkov

2013-01-01T23:59:59.000Z

6

Evaluation of reaction mechanism of coal-metal oxide interactions in chemical-looping combustion  

SciTech Connect

The knowledge of reaction mechanism is very important in designing reactors for chemical-looping combustion (CLC) of coal. Recent CLC studies have considered the more technically difficult problem of reactions between abundant solid fuels (i.e. coal and waste streams) and solid metal oxides. A definitive reaction mechanism has not been reported for CLC reaction of solid fuels. It has often been assumed that the solid/solid reaction is slow and therefore requires that reactions be conducted at temperatures high enough to gasify the solid fuel, or decompose the metal oxide. In contrast, data presented in this paper demonstrates that solid/solid reactions can be completed at much lower temperatures, with rates that are technically useful as long as adequate fuel/metal oxide contact is achieved. Density functional theory (DFT) simulations as well as experimental techniques such as thermo-gravimetric analysis (TGA), flow reactor studies, in situ X-ray photo electron spectroscopy (XPS), in situ X-ray diffraction (XRD) and scanning electron microscopy (SEM) are used to evaluate how the proximal interaction between solid phases proceeds. The data indicate that carbon induces the Cu-O bond breaking process to initiate the combustion of carbon at temperatures significantly lower than the spontaneous decomposition temperature of CuO, and the type of reducing medium in the vicinity of the metal oxide influences the temperature at which the oxygen release from the metal oxide takes place. Surface melting of Cu and wetting of carbon may contribute to the solid-solid contacts necessary for the reaction. (author)

Siriwardane, Ranjani; Richards, George; Poston, James [US Department of Energy, National Energy Technology Laboratory, 3610 Collins Ferry Road, P.O. Box 880, Morgantown, WV 26507-0880 (United States); Tian, Hanjing; Miller, Duane; Simonyi, Thomas [US Department of Energy, National Energy Technology Laboratory, 3610 Collins Ferry Road, P.O. Box 880, Morgantown, WV 26507-0880 (United States); URS, 3610 Collins Ferry Road, Morgantown, WV 26505 (United States)

2010-11-15T23:59:59.000Z

7

Chemical-looping combustion of coal with metal oxide oxygen carriers  

SciTech Connect

The combustion and reoxidation properties of direct coal chemical-looping combustion (CLC) over CuO, Fe{sub 2}O{sub 3}, CO{sub 3}O{sub 4}, NiO, and Mn{sub 2}O{sub 3} were investigated using thermogravimetric analysis (TGA) and bench-scale fixed-bed flow reactor studies. When coal is heated in either nitrogen or carbon dioxide (CO{sub 2}), 50% of weight loss was observed because of partial pyrolysis, consistent with the proximate analysis. Among various metal oxides evaluated, CuO showed the best reaction properties: CuO can initiate the reduction reaction as low as 500{sup o}C and complete the full combustion at 700{sup o}C. In addition, the reduced copper can be fully reoxidized by air at 700{sup o}C. The combustion products formed during the CLC reaction of the coal/metal oxide mixture are CO{sub 2} and water, while no carbon monoxide was observed. Multicycle TGA tests and bench-scale fixed-bed flow reactor tests strongly supported the feasibility of CLC of coal by using CuO as an oxygen carrier. Scanning electron microscopy (SEM) images of solid reaction products indicated some changes in the surface morphology of a CuO-coal sample after reduction/oxidation reactions at 800 {sup o}C. However, significant surface sintering was not observed. The interactions of fly ash with metal oxides were investigated by X-ray diffraction and thermodynamic analysis. Overall, the results indicated that it is feasible to develop CLC with coal by metal oxides as oxygen carriers. 22 refs., 12 figs., 2 tabs.

Ranjani Siriwardane; Hanjing Tian; George Richards; Thomas Simonyi; James Poston [United States Department of Energy, Morgantown, WN (United States). National Energy Technology Laboratory

2009-08-15T23:59:59.000Z

8

Synthesis of Metal Oxide Nanomaterials for Chemical Sensors by Molecular Beam Epitaxy  

SciTech Connect

Since the industrial revolution, detection and monitoring of toxic matter, chemical wastes, and air pollutants has become an important environmental issue. Thus, it leads to the development of chemical sensors for various environmental applications. The recent disastrous oil spills over the near-surface of ocean due to the offshore drilling emphasize the use of chemical sensors for prevention and monitoring of the processes that might lead to these mishaps.1, 2 Chemical sensors operated on a simple principle that the sensing platform undergoes a detectable change when exposed to the target substance to be sensed. Among all the types of chemical sensors, solid state gas sensors have attracted a great deal of attention due to their advantages such as high sensitivity, greater selectivity, portability, high stability and low cost.3, 4 Especially, semiconducting metal oxides such as SnO2, TiO2, and WO3 have been widely used as the active sensing platforms in solid state gas sensors.5 For the enhanced properties of solid state gas sensors, finding new sensing materials or development of existing materials will be needed. Thus, nanostructured materials such as nanotubes,6-8 nanowires,9-11 nanorods,12-15 nanobelts,16, 17 and nano-scale thin films18-23 have been synthesized and studied for chemical sensing applications.

Nandasiri, Manjula I.; Kuchibhatla, Satyanarayana V N T; Thevuthasan, Suntharampillai

2013-12-01T23:59:59.000Z

9

Regenerable MgO promoted metal oxide oxygen carriers for chemical looping combustion  

DOE Patents (OSTI)

The disclosure provides an oxygen carrier comprised of a plurality of metal oxide particles in contact with a plurality of MgO promoter particles. The MgO promoter particles increase the reaction rate and oxygen utilization of the metal oxide when contacting with a gaseous hydrocarbon at a temperature greater than about 725.degree. C. The promoted oxide solid is generally comprised of less than about 25 wt. % MgO, and may be prepared by physical mixing, incipient wetness impregnation, or other methods known in the art. The oxygen carrier exhibits a crystalline structure of the metal oxide and a crystalline structure of MgO under XRD crystallography, and retains these crystalline structures over subsequent redox cycles. In an embodiment, the metal oxide is Fe.sub.2O.sub.3, and the gaseous hydrocarbon is comprised of methane.

Siriwardane, Ranjani V.; Miller, Duane D.

2014-08-19T23:59:59.000Z

10

Metal oxide films on metal  

DOE Patents (OSTI)

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

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

1995-01-01T23:59:59.000Z

11

Lithium metal reduction of plutonium oxide to produce plutonium metal  

DOE Patents (OSTI)

A method is described for the chemical reduction of plutonium oxides to plutonium metal by the use of pure lithium metal. Lithium metal is used to reduce plutonium oxide to alpha plutonium metal (alpha-Pu). The lithium oxide by-product is reclaimed by sublimation and converted to the chloride salt, and after electrolysis, is removed as lithium metal. Zinc may be used as a solvent metal to improve thermodynamics of the reduction reaction at lower temperatures. Lithium metal reduction enables plutonium oxide reduction without the production of huge quantities of CaO--CaCl.sub.2 residues normally produced in conventional direct oxide reduction processes.

Coops, Melvin S. (Livermore, CA)

1992-01-01T23:59:59.000Z

12

Effect of hydrogen sulfide on chemical looping combustion of coal-derived synthesis gas over bentonite-supported metal-oxide oxygen carriers  

SciTech Connect

The effect of hydrogen sulfide (H{sub 2}S) on the chemical looping combustion of coal-derived synthesis gas with bentonite-supported metal oxides - such as iron oxide, nickel oxide, manganese oxide, and copper oxide - was investigated by thermogravimetric analysis, mass spectrometry, and X-ray photoelectron spectroscopy (XPS). During the reaction with synthesis gas containing H{sub 2}S, metal-oxide oxygen carriers were first reduced by carbon monoxide and hydrogen, and then interacted with H{sub 2}S to form metal sulfide, which resulted in a weight gain during the reduction/sulfidation step. The reduced/sulfurized compounds could be regenerated to form sulfur dioxide and oxides during the oxidation reaction with air. The reduction/oxidation capacities of iron oxide and nickel oxide were not affected by the presence of H{sub 2}S, but both manganese oxide and copper oxide showed decreased reduction/oxidation capacities. However, the rates of reduction and oxidation decreased in the presence of H{sub 2}S for all four metal oxides.

Tian, H.J.; Simonyi, T.; Poston, J.; Siriwardane, R. [US DOE, Morgantown, WV (United States). National Energy Technology Laboratory

2009-09-15T23:59:59.000Z

13

Effect of hydrogen sulfide on chemical looping of coal-derived synthesis gas over bentonite-supported metal---oxide oxygen carriers  

SciTech Connect

The effect of hydrogen sulfide (H2S) on the chemical looping combustion of coal-derived synthesis gas with bentonite-supported metal oxidesssuch as iron oxide, nickel oxide, manganese oxide, and copper oxideswas investigated by thermogravimetric analysis, mass spectrometry, and X-ray photoelectron spectroscopy (XPS). During the reaction with synthesis gas containing H2S, metal-oxide oxygen carriers were first reduced by carbon monoxide and hydrogen, and then interacted with H2S to form metal sulfide, which resulted in a weight gain during the reduction/sulfidation step. The reduced/sulfurized compounds could be regenerated to form sulfur dioxide and oxides during the oxidation reaction with air. The reduction/oxidation capacities of iron oxide and nickel oxide were not affected by the presence of H2S, but both manganese oxide and copper oxide showed decreased reduction/oxidation capacities. However, the rates of reduction and oxidation decreased in the presence of H2S for all four metal oxides.

Tian, H.; Simonyi, T.; Poston, J.; Siriwardane, R.

2009-01-01T23:59:59.000Z

14

METAL OXIDE NANOPARTICLES  

SciTech Connect

This chapter covers the fundamental science, synthesis, characterization, physicochemical properties and applications of oxide nanomaterials. Explains fundamental aspects that determine the growth and behavior of these systems, briefly examines synthetic procedures using bottom-up and top-down fabrication technologies, discusses the sophisticated experimental techniques and state of the art theory results used to characterize the physico-chemical properties of oxide solids and describe the current knowledge concerning key oxide materials with important technological applications.

FERNANDEZ-GARCIA,M.; RODGRIGUEZ, J.A.

2007-10-01T23:59:59.000Z

15

Evaluation of Novel Ceria-Supported Metal Oxides As Oxygen Carriers for Chemical-Looping Combustion  

Science Journals Connector (OSTI)

The equilibrium data were computed using the HSC Chemistry 6.1 software. ... Chuang, S. Y.; Dennis, J. S.; Hayhurst, A. N.; Scott, S. A.Development and performance of Cu-based oxygen carriers for chemical-looping combustion Combust. ...

Ali Hedayati; Abdul-Majeed Azad; Magnus Rydén; Henrik Leion; Tobias Mattisson

2012-08-24T23:59:59.000Z

16

Catalytic production of metal carbonyls from metal oxides  

DOE Patents (OSTI)

This invention relates to the formation of metal carbonyls from metal oxides and specially the formation of molybdenum carbonyl and iron carbonyl from their respective oxides. Copper is used here in admixed form or used in chemically combined form as copper molybdate. The copper/metal oxide combination or combined copper is utilized with a solvent, such as toluene and subjected to carbon monoxide pressure of 25 atmospheres or greater at about 150 to 260/sup 0/C. The reducing metal copper is employed in catalytic concentrations or combined concentrations as CuMoO/sub 4/ and both hydrogen and water present serve as promoters. It has been found that the yields by this process have been salutary and that additionally the catalytic metal may be reused in the process to good effect. 3 tables.

Sapienza, R.S.; Slegeir, W.A.; Foran, M.T.

1984-01-06T23:59:59.000Z

17

Decontamination of metals using chemical etching  

DOE Patents (OSTI)

The invention relates to chemical etching process for reclaiming contaminated equipment wherein a reduction-oxidation system is included in a solution of nitric acid to contact the metal to be decontaminated and effect reduction of the reduction-oxidation system, and includes disposing a pair of electrodes in the reduced solution to permit passage of an electrical current between said electrodes and effect oxidation of the reduction-oxidation system to thereby regenerate the solution and provide decontaminated equipment that is essentially radioactive contamination-free.

Lerch, Ronald E. (Kennewick, WA); Partridge, Jerry A. (Richland, WA)

1980-01-01T23:59:59.000Z

18

Reactor process using metal oxide ceramic membranes  

DOE Patents (OSTI)

A reaction vessel for use in photoelectrochemical reactions includes as its reactive surface a metal oxide porous ceramic membrane of a catalytic metal such as titanium. The reaction vessel includes a light source and a counter electrode. A provision for applying an electrical bias between the membrane and the counter electrode permits the Fermi levels of potential reaction to be favored so that certain reactions may be favored in the vessel. The electrical biasing is also useful for the cleaning of the catalytic membrane. Also disclosed is a method regenerating a porous metal oxide ceramic membrane used in a photoelectrochemical catalytic process by periodically removing the reactants and regenerating the membrane using a variety of chemical, thermal, and electrical techniques. 2 figures.

Anderson, M.A.

1994-05-03T23:59:59.000Z

19

NANO - "Green" metal oxides ... | ornl.gov  

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

NANO - "Green" metal oxides ... Water and nano-sized particles isolated from trees, plants and algae are the ingredients of a new recipe for low-cost metal oxides that are widely...

20

Structure, adhesion, and stability of metal/oxide and oxide/oxide interfaces  

SciTech Connect

Studies of structural, electronic, and chemical properties of metal/oxide and oxide/oxide interfaces were performed on well-defined interfaces that created by depositing ultra-thin potassium and aluminum films and their oxides onto single crystal TiO[sub 2] and NiO surfaces. Work focused on determining the structure, growth mechanisms, and morphologies of metal and oxide films as they are deposited an single crystal oxide surfaces using RHEED and atomic force microscopy probing electronic structure, bonding and chemical interactions at the interfaces using x-ray and uv photoelectron spectroscopies (XPS, UPS) and Auger electron spectroscopy (AES), and understanding factors affecting stability and reactivity of the interface regions including the role of defects and impurities. Results indicate that kinetic effects have an important influence on interface structure and composition, and they also show that defects in the oxide substrate induce new electronic states at the interface which play a major role in cation-anion bonding and interface interactions. The results establish a link between electronic and chemical bonding properties and the interface structure and morphology, which is required to successfully manipulate the interfacial properties of advanced ceramic materials.

Lad, R.J.

1992-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "metal oxide chemical" 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

Metal-oxide-based energetic materials and synthesis thereof  

DOE Patents (OSTI)

A method of preparing energetic metal-oxide-based energetic materials using sol-gel chemistry has been invented. The wet chemical sol-gel processing provides an improvement in both safety and performance. Essentially, a metal-oxide oxidizer skeletal structure is prepared from hydrolyzable metals (metal salts or metal alkoxides) with fuel added to the sol prior to gelation or synthesized within the porosity metal-oxide gel matrix. With metal salt precursors a proton scavenger is used to destabilize the sol and induce gelation. With metal alkoxide precursors standard well-known sol-gel hydrolysis and condensation reactions are used. Drying is done by standard sol-gel practices, either by a slow evaporation of the liquid residing within the pores to produce a high density solid nanocomposite, or by supercritical extraction to produce a lower density, high porous nanocomposite. Other ingredients may be added to this basic nanostructure to change physical and chemical properties, which include organic constituents for binders or gas generators during reactions, burn rate modifiers, or spectral emitters.

Tillotson, Thomas M. (Tracy, CA), Simpson; Randall L. (Livermore, CA); Hrubesh, Lawrence W. (Pleasanton, CA)

2006-01-17T23:59:59.000Z

22

Nanocomposite of graphene and metal oxide materials  

SciTech Connect

Nanocomposite materials comprising a metal oxide bonded to at least one graphene material. The nanocomposite materials exhibit a specific capacity of at least twice that of the metal oxide material without the graphene at a charge/discharge rate greater than about 10C.

Liu, Jun; Aksay, Ilhan A.; Choi, Daiwon; Wang, Donghai; Yang, Zhenguo

2012-09-04T23:59:59.000Z

23

Methods of producing adsorption media including a metal oxide  

DOE Patents (OSTI)

Methods of producing a metal oxide are disclosed. The method comprises dissolving a metal salt in a reaction solvent to form a metal salt/reaction solvent solution. The metal salt is converted to a metal oxide and a caustic solution is added to the metal oxide/reaction solvent solution to adjust the pH of the metal oxide/reaction solvent solution to less than approximately 7.0. The metal oxide is precipitated and recovered. A method of producing adsorption media including the metal oxide is also disclosed, as is a precursor of an active component including particles of a metal oxide.

Mann, Nicholas R; Tranter, Troy J

2014-03-04T23:59:59.000Z

24

Chapter 14 - Metal oxide nanopowder  

Science Journals Connector (OSTI)

Research into soft chemical techniques has gained an importance for the synthesis of high quality advanced nanosized materials with desired properties at the low crystallization temperature. The closer interaction between the material chemists and alkoxide chemists has led to the molecular design of more suitable precursors, for fabrication of functional material has resulted in synergetic developments in both the fields. Metal alkoxide is a versatile precursor and is used for the synthesis of functional gradient nanomaterials, and characterization of materials was carried out in term of composition, microstructure and specific surface area. The write-up provides simple and convenient routes to many building blocks for assembling the structure with novel properties and its functional use in nanotechnology.

Taimur Athar

2015-01-01T23:59:59.000Z

25

Three-Electrode Metal Oxide Reduction Cell  

DOE Patents (OSTI)

A method of electrochemically reducing a metal oxide to the metal in an electrochemical cell is disclosed along with the cell. Each of the anode and cathode operate at their respective maximum reaction rates. An electrolyte and an anode at which oxygen can be evolved, and a cathode including a metal oxide to be reduced are included as is a third electrode with independent power supplies connecting the anode and the third electrode and the cathode and the third electrode.

Dees, Dennis W. (Downers Grove, IL); Ackerman, John P. (Downers Grove, IL)

2005-06-28T23:59:59.000Z

26

Three-electrode metal oxide reduction cell  

DOE Patents (OSTI)

A method of electrochemically reducing a metal oxide to the metal in an electrochemical cell is disclosed along with the cell. Each of the anode and cathode operate at their respective maximum reaction rates. An electrolyte and an anode at which oxygen can be evolved, and a cathode including a metal oxide to be reduced are included as is a third electrode with independent power supplies connecting the anode and the third electrode and the cathode and the third electrode.

Dees, Dennis W. (Downers Groves, IL); Ackerman, John P. (Downers Grove, IL)

2008-08-12T23:59:59.000Z

27

Direct electrochemical reduction of metal-oxides  

DOE Patents (OSTI)

A method of controlling the direct electrolytic reduction of a metal oxide or mixtures of metal oxides to the corresponding metal or metals. A non-consumable anode and a cathode and a salt electrolyte with a first reference electrode near the non-consumable anode and a second reference electrode near the cathode are used. Oxygen gas is produced and removed from the cell. The anode potential is compared to the first reference electrode to prevent anode dissolution and gas evolution other than oxygen, and the cathode potential is compared to the second reference electrode to prevent production of reductant metal from ions in the electrolyte.

Redey, Laszlo I. (Downers Grove, IL); Gourishankar, Karthick (Downers Grove, IL)

2003-01-01T23:59:59.000Z

28

Graphene/metal Oxide Nanocomposites for Li-ion Batteries  

Science Journals Connector (OSTI)

Our work focuses on preparing the graphene/metal oxide nanocomposites by facile methold and exploring the graphene/metal oxide composites with unique structural or compositions for...

Liang, Junfei; Li, Lidong; Guo, Lin

29

Understanding Atom Probe Tomography of Oxide-Supported Metal...  

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

Atom Probe Tomography of Oxide-Supported Metal Nanoparticles by Correlation with Atomic Resolution Electron Understanding Atom Probe Tomography of Oxide-Supported Metal...

30

High surface area, electrically conductive nanocarbon-supported metal oxide  

DOE Patents (OSTI)

A metal oxide-carbon composite includes a carbon aerogel with an oxide overcoat. The metal oxide-carbon composite is made by providing a carbon aerogel, immersing the carbon aerogel in a metal oxide sol under a vacuum, raising the carbon aerogel with the metal oxide sol to atmospheric pressure, curing the carbon aerogel with the metal oxide sol at room temperature, and drying the carbon aerogel with the metal oxide sol to produce the metal oxide-carbon composite. The step of providing a carbon aerogel can provide an activated carbon aerogel or provide a carbon aerogel with carbon nanotubes that make the carbon aerogel mechanically robust.

Worsley, Marcus A; Han, Thomas Yong-Jin; Kuntz, Joshua D; Cervanted, Octavio; Gash, Alexander E; Baumann, Theodore F; Satcher, Jr., Joe H

2014-03-04T23:59:59.000Z

31

Lithium metal oxide electrodes for lithium batteries  

DOE Patents (OSTI)

An uncycled electrode for a non-aqueous lithium electrochemical cell including a lithium metal oxide having the formula Li.sub.(2+2x)/(2+x)M'.sub.2x/(2+x)M.sub.(2-2x)/(2+x)O.sub.2-.delta., in which 0.ltoreq.x<1 and .delta. is less than 0.2, and in which M is a non-lithium metal ion with an average trivalent oxidation state selected from two or more of the first row transition metals or lighter metal elements in the periodic table, and M' is one or more ions with an average tetravalent oxidation state selected from the first and second row transition metal elements and Sn. Methods of preconditioning the electrodes are disclosed as are electrochemical cells and batteries containing the electrodes.

Thackeray, Michael M. (Naperville, IL); Kim, Jeom-Soo (Naperville, IL); Johnson, Christopher S. (Naperville, IL)

2008-01-01T23:59:59.000Z

32

Process for etching mixed metal oxides  

DOE Patents (OSTI)

An etching process using dicarboxylic and tricarboxylic acids as chelating etchants for mixed metal oxide films such as high temperature superconductors and ferroelectric materials. Undesirable differential etching rates between different metal oxides are avoided by selection of the proper acid or combination of acids. Feature sizes below one micron, excellent quality vertical edges, and film thicknesses in the 100 Angstom range may be achieved by this method.

Ashby, Carol I. H. (Edgewood, NM); Ginley, David S. (Evergreen, CO)

1994-01-01T23:59:59.000Z

33

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

SciTech Connect

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

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

1998-04-01T23:59:59.000Z

34

Growth of magnesium oxide thin lms using single molecular precursors by metalorganic chemical vapor deposition  

E-Print Network (OSTI)

Growth of magnesium oxide thin ®lms using single molecular precursors by metal±organic chemical precursors; Silicon; Sapphire 1. Introduction Magnesium oxide (MgO) thin ®lms have attracted much attention MgO ®lms on Si(100) above 6508C by thermal CVD. Murayama and Shionoya [12] used magnesium 2

Boo, Jin-Hyo

35

Chemical vapor deposition of group IIIB metals  

DOE Patents (OSTI)

Coatings of Group IIIB metals and compounds thereof are formed by chemical vapor deposition, in which a heat decomposable organometallic compound of the formula given in the patent where M is a Group IIIB metal, such as lanthanum or yttrium and R is a lower alkyl or alkenyl radical containing from 2 to about 6 carbon atoms, with a heated substrate which is above the decomposition temperature of the organometallic compound. The pure metal is obtained when the compound of the formula 1 is the sole heat decomposable compound present and deposition is carried out under nonoxidizing conditions. Intermetallic compounds such as lanthanum telluride can be deposited from a lanthanum compound of formula 1 and a heat decomposable tellurium compound under nonoxidizing conditions.

Erbil, A.

1989-11-21T23:59:59.000Z

36

Cerium Oxide Promoted Iron-based Oxygen Carrier for Chemical Looping Combustion  

Science Journals Connector (OSTI)

Cerium Oxide Promoted Iron-based Oxygen Carrier for Chemical Looping Combustion ... It entails the use of an oxygen carrier (OC), usually a metal oxide, to provide oxygen for combusting fuels in a fuel reactor (FR) and then the reoxidization of the OC in a separate air reactor (AR). ... Preprints of Symposia - American Chemical Society, Division of Fuel Chemistry (2004), 49 (2), 815-816 CODEN: PSADFZ; ISSN:1521-4648. ...

Fang Liu; Liangyong Chen; James K. Neathery; Kozo Saito; Kunlei Liu

2014-10-01T23:59:59.000Z

37

Designing Semiconductor Metal Oxides for Photoelectrochemical Energy Conversion  

Science Journals Connector (OSTI)

Innovative materials hold the key for renewable energy conversion. In this talk, we will introduce our recent progress in semiconducting metal oxides, which underpin a number of...

Wang, Lianzhou

38

Synergetic effects of mixed copper-iron oxides oxygen carriers in chemical looping combustion  

SciTech Connect

Chemical looping combustion (CLC) is an emerging technology for clean energy production from fuels. CLC produces sequestration-ready CO{sub 2}-streams without a significant energy penalty. Development of efficient oxygen carriers is essential to successfully operate a CLC system. Copper and iron oxides are promising candidates for CLC. Copper oxide possesses high reactivity but it has issues with particle agglomeration due to its low melting point. Even though iron oxide is an inexpensive oxygen carrier it has a slower reactivity. In this study, mixed metal oxide carriers containing iron and copper oxides were evaluated for coal and methane CLC. The components of CuO and Fe{sub 2}O{sub 3} were optimized to obtain good reactivity while maintaining physical and chemical stability during cyclic reactions for methane-CLC and solid-fuel CLC. Compared with single metal oxygen carriers, the optimized Cu–Fe mixed oxide oxygen carriers demonstrated high reaction rate, better combustion conversion, greater oxygen usage and improved physical stability. Thermodynamic calculations, XRD, TGA, flow reactor studies and TPR experiments suggested that there is a strong interaction between CuO and Fe{sub 2}O{sub 3} contributing to a synergistic effect during CLC reactions. The amount of oxygen release of the mixed oxide carrier in the absence of a fuel was similar to that of the single metal oxides. However, in the presence of fuels, the oxygen consumption and the reaction profiles of the mixed oxide carriers were significantly better than that of the single metal oxides. The nature of the fuel not only influenced the reactivity, but also the final reduction status of the oxygen carriers during chemical looping combustion. Cu oxide of the mixed oxide was fully reduced metallic copper with both coal and methane. Fe oxide of the mixed oxide was fully reduced Fe metal with methane but it was reduced to only FeO with coal. Possible mechanisms of how the presence of CuO enhances the reduction of Fe{sub 2}O{sub 3} are discussed.

Siriwardane, Ranjani; Tian, Hanjing; Simonyi, Thomas; Poston, James

2013-06-01T23:59:59.000Z

39

Structure, adhesion, and stability of metal/oxide and oxide/oxide interfaces. Technical progress report, August 1, 1992--July 31, 1993  

SciTech Connect

Studies of structural, electronic, and chemical properties of metal/oxide and oxide/oxide interfaces were performed on well-defined interfaces that created by depositing ultra-thin potassium and aluminum films and their oxides onto single crystal TiO{sub 2} and NiO surfaces. Work focused on determining the structure, growth mechanisms, and morphologies of metal and oxide films as they are deposited an single crystal oxide surfaces using RHEED and atomic force microscopy probing electronic structure, bonding and chemical interactions at the interfaces using x-ray and uv photoelectron spectroscopies (XPS, UPS) and Auger electron spectroscopy (AES), and understanding factors affecting stability and reactivity of the interface regions including the role of defects and impurities. Results indicate that kinetic effects have an important influence on interface structure and composition, and they also show that defects in the oxide substrate induce new electronic states at the interface which play a major role in cation-anion bonding and interface interactions. The results establish a link between electronic and chemical bonding properties and the interface structure and morphology, which is required to successfully manipulate the interfacial properties of advanced ceramic materials.

Lad, R.J.

1992-11-01T23:59:59.000Z

40

Transition metal-promoted oxygen ion conductors as oxidation catalyst  

SciTech Connect

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

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

1994-12-31T23:59:59.000Z

Note: This page contains sample records for the topic "metal oxide chemical" 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

REVIEW ARTICLE Heavy Metal Pollutants and Chemical Ecology: Exploring  

E-Print Network (OSTI)

REVIEW ARTICLE Heavy Metal Pollutants and Chemical Ecology: Exploring New Frontiers Robert S. Boyd to be learned about how heavy metal pollution impacts organisms, and that exciting new research frontiers as pollutants (Han et al. 2002), including Cd, Cu, Cr, Hg, Pb, Ni, and Zn. Much research on heavy metal

Boyd, Robert S.

42

Route to transition metal carbide nanoparticles through cyanamide and metal oxides  

SciTech Connect

We have designed an efficient route to the synthesis of transition metal carbide nanoparticles starting from an organic reagent cyanamide and transition metal oxides. Four technologically important metal carbide nanoparticles such as tungsten carbide, niobium carbide, tantalum carbide and vanadium carbide were synthesized successfully at moderate temperatures. It is found that cyanamide is an efficient carburization reagent and that the metal oxides are completely transmitted into the corresponding carbide nanoparticles. A possible mechanism is proposed to explain the results of the reaction between cyanamide and the metal oxides.

Li, P.G. [Department of Physics, Center for Optoelectronics Materials and Devices, Zhejiang Sci-Tech University, Xiasha College Park, Hangzhou 310018 (China)], E-mail: peigangiphy@yahoo.com.cn; Lei, M.; Tang, W.H. [Department of Physics, Center for Optoelectronics Materials and Devices, Zhejiang Sci-Tech University, Xiasha College Park, Hangzhou 310018 (China)

2008-12-01T23:59:59.000Z

43

Structure, adhesion, and stability of metal/oxide and oxide/oxide interfaces  

SciTech Connect

During the past six months, we have begun our studies of the fundamental properties of metal/oxide and oxide/oxide heterogeneous interfaces which are being prepared by epitaxial growth of ultra-thin-films on single crystal TiO{sub 2} and NiO surfaces. A new ultra-high vacuum film growth chamber was assembled and coupled to an existing surface analysis chamber; a sample transfer system, metal deposition sources, and a RHEED systems with microchannel plate detection were constructed and implemented. Atomic Force Microscopy was used to characterize and refine the preparation procedures for the single crystal surfaces. The electronic structure of stoichiometric, oxygen-deficient, and potassium-covered TiO{sub 2} (110) surfaces was investigated. Preliminary results on the Al/TiO{sub 2} (110) system have been obtained. Two graduate students have begun thesis research on the project. 6 figs.

Lad, R.J.

1991-01-01T23:59:59.000Z

44

EMPTY CHEMICAL BOTTLES RECYCLING PROGRAM Empty Chemical Bottles Recycling includes all glass, plastic and metal bottles and containers that previously  

E-Print Network (OSTI)

, plastic and metal bottles and containers that previously contained hazardous or non-hazardous chemicals

Baker, Chris I.

45

Method and apparatus for the production of metal oxide powder  

DOE Patents (OSTI)

The present invention provides a method for preparing metal oxide powder. A first solution, which is substantially organic, is prepared. A second solution, which is an aqueous solution substantially immiscible in the first solution, is prepared and delivered as drops to the first solution. The drops of the second solution are atomized by a pulsed electric field forming micro-drops of the second solution. Reagents in the first solution diffuse into and react with reactants in the micro-drops of the second solution forming metal hydroxide or oxalate particles. The metal hydroxide or metal oxalate particles are then recovered and dried to produce the metal oxide powder. An apparatus for preparing a metal oxide powder is also disclosed.

Harris, Michael T. (Knoxville, TN); Scott, Timothy C. (Knoxville, TN); Byers, Charles H. (Oak Ridge, TN)

1993-01-01T23:59:59.000Z

46

Method and apparatus for the production of metal oxide powder  

DOE Patents (OSTI)

The present invention provides a method for preparing metal oxide powder. A first solution, which is substantially organic, is prepared. A second solution, which is an aqueous solution substantially immiscible in the first solution, is prepared and delivered as drops to the first solution. The drops of the second solution are atomized by a pulsed electric field forming micro-drops of the second solution. Reagents in the first solution diffuse into and react with reactants in the micro-drops of the second solution forming metal hydroxide or oxalate particles. The metal hydroxide or metal oxalate particles are then recovered and dried to produce the metal oxide powder. An apparatus for preparing a metal oxide powder is also disclosed.

Harris, Michael T. (Knoxville, TN); Scott, Timothy C. (Knoxville, TN); Byers, Charles H. (Oak Ridge, TN)

1992-01-01T23:59:59.000Z

47

Method and apparatus for the production of metal oxide powder  

DOE Patents (OSTI)

The present invention provides a method for preparing metal oxide powder. A first solution, which is substantially organic, is prepared. A second solution, which is an aqueous solution substantially immiscible in the first solution, is prepared and delivered as drops to the first solution. The drops of the second solution are atomized by a pulsed electric field forming micro-drops of the second solution. Reagents in the first solution diffuse into and react with reactants in the micro-drops of the second solution forming metal hydroxide or oxalate particles. The metal hydroxide or metal oxalate particles are then recovered and dried to produce the metal oxide powder. An apparatus for preparing a metal oxide powder is also disclosed. 2 figs.

Harris, M.T.; Scott, T.C.; Byers, C.H.

1992-06-16T23:59:59.000Z

48

Plasmonic transparent conducting metal oxide nanoparticles and films for optical sensing applications  

DOE Patents (OSTI)

The disclosure relates to a method of detecting a change in a chemical composition by contacting a doped oxide material with a monitored stream, illuminating the doped oxide material with incident light, collecting exiting light, monitoring an optical signal based on a comparison of the incident light and the exiting light, and detecting a shift in the optical signal. The doped metal oxide has a carrier concentration of at least 10.sup.18/cm.sup.3, a bandgap of at least 2 eV, and an electronic conductivity of at least 10.sup.1 S/cm, where parameters are specified at a temperature of 25.degree. C. The optical response of the doped oxide materials results from the high carrier concentration of the doped metal oxide, and the resulting impact of changing gas atmospheres on that relatively high carrier concentration. These changes in effective carrier densities of conducting metal oxide nanoparticles are postulated to be responsible for the change in measured optical absorption associated with free carriers. Exemplary doped metal oxides include but are not limited to Al-doped ZnO, Sn-doped In.sub.2O.sub.3, Nb-doped TiO.sub.2, and F-doped SnO.sub.2.

Ohodnicki, Jr., Paul R; Wang, Congjun; Andio, Mark A

2014-01-28T23:59:59.000Z

49

Electronically conducting metal oxide nanoparticles and films for optical sensing applications  

DOE Patents (OSTI)

The disclosure relates to a method of detecting a change in a chemical composition by contacting a conducting oxide material with a monitored stream, illuminating the conducting oxide material with incident light, collecting exiting light, monitoring an optical signal based on a comparison of the incident light and the exiting light, and detecting a shift in the optical signal. The conducting metal oxide has a carrier concentration of at least 10.sup.17/cm.sup.3, a bandgap of at least 2 eV, and an electronic conductivity of at least 10.sup.-1 S/cm, where parameters are specified at the gas stream temperature. The optical response of the conducting oxide materials is proposed to result from the high carrier concentration and electronic conductivity of the conducting metal oxide, and the resulting impact of changing gas atmospheres on that relatively high carrier concentration and electronic conductivity. These changes in effective carrier densities and electronic conductivity of conducting metal oxide films and nanoparticles are postulated to be responsible for the change in measured optical absorption associated with free carriers. Exemplary conducting metal oxides include but are not limited to Al-doped ZnO, Sn-doped In.sub.2O.sub.3, Nb-doped TiO.sub.2, and F-doped SnO.sub.2.

Ohodnicki, Jr., Paul R.; Wang, Congjun; Andio, Mark A

2014-09-16T23:59:59.000Z

50

Method of physical vapor deposition of metal oxides on semiconductors  

DOE Patents (OSTI)

A process for growing a metal oxide thin film upon a semiconductor surface with a physical vapor deposition technique in a high-vacuum environment and a structure formed with the process involves the steps of heating the semiconductor surface and introducing hydrogen gas into the high-vacuum environment to develop conditions at the semiconductor surface which are favorable for growing the desired metal oxide upon the semiconductor surface yet is unfavorable for the formation of any native oxides upon the semiconductor. More specifically, the temperature of the semiconductor surface and the ratio of hydrogen partial pressure to water pressure within the vacuum environment are high enough to render the formation of native oxides on the semiconductor surface thermodynamically unstable yet are not so high that the formation of the desired metal oxide on the semiconductor surface is thermodynamically unstable. Having established these conditions, constituent atoms of the metal oxide to be deposited upon the semiconductor surface are directed toward the surface of the semiconductor by a physical vapor deposition technique so that the atoms come to rest upon the semiconductor surface as a thin film of metal oxide with no native oxide at the semiconductor surface/thin film interface. An example of a structure formed by this method includes an epitaxial thin film of (001)-oriented CeO.sub.2 overlying a substrate of (001) Ge.

Norton, David P. (Knoxville, TN)

2001-01-01T23:59:59.000Z

51

DOE - Office of Legacy Management -- Ferro Metal and Chemical...  

Office of Legacy Management (LM)

- Ferro Metal & Chemical Corp. Letter; Schloss to the Vitro Mfg. Co.; Request for Price Quote; November 15, 1944 NY.42-2 - DOE MemorandumChecklist; Wallo to File; Subject:...

52

Plutonium metal and oxide container weld development and qualification  

SciTech Connect

Welds were qualified for a container system to be used for long-term storage of plutonium metal and oxide. Inner and outer containers are formed of standard tubing with stamped end pieces gas-tungsten-arc (GTA) welded onto both ends. The weld qualification identified GTA parameters to produce a robust weld that meets the requirements of the Department of Energy standard DOE-STD-3013-94, ``Criteria for the Safe Storage of Plutonium Metals and Oxides.``

Fernandez, R.; Horrell, D.R.; Hoth, C.W.; Pierce, S.W.; Rink, N.A.; Rivera, Y.M.; Sandoval, V.D.

1996-01-01T23:59:59.000Z

53

Inert electrode containing metal oxides, copper and noble metal  

DOE Patents (OSTI)

A cermet composite material is made by treating at an elevated temperature a mixture comprising a compound of iron and a compound of at least one other metal, together with an alloy or mixture of copper and a noble metal. The alloy or mixture preferably comprises particles having an interior portion containing more copper than noble metal and an exterior portion containing more noble metal than copper. The noble metal is preferably silver. The cermet composite material preferably includes alloy phase portions and a ceramic phase portion. At least part of the ceramic phase portion preferably has a spinel structure.

Ray, Siba P. (Murrysville, PA); Woods, Robert W. (New Kensington, PA); Dawless, Robert K. (Monroeville, PA); Hosler, Robert B. (Sarver, PA)

2001-01-01T23:59:59.000Z

54

Inert electrode containing metal oxides, copper and noble metal  

DOE Patents (OSTI)

A cermet composite material is made by treating at an elevated temperature a mixture comprising a compound of iron and a compound of at least one other metal, together with an alloy or mixture of copper and a noble metal. The alloy or mixture preferably comprises particles having an interior portion containing more copper than noble metal and an exterior portion containing more noble metal than copper. The noble metal is preferably silver. The cermet composite material preferably includes alloy phase portions and a ceramic phase portion. At least part of the ceramic phase portion preferably has a spinel structure.

Ray, Siba P. (Murrysville, PA); Woods, Robert W. (New Kensington, PA); Dawless, Robert K. (Monroeville, PA); Hosler, Robert B. (Sarver, PA)

2000-01-01T23:59:59.000Z

55

Enhanced Half-Metallicity in Edge-Oxidized Zigzag Graphene  

E-Print Network (OSTI)

Enhanced Half-Metallicity in Edge-Oxidized Zigzag Graphene Nanoribbons Oded Hod,* Vero´nica Barone theoretical study of the electronic properties and relative stabilities of edge-oxidized zigzag graphene with nanometer scale dimen- sions. Recently, a new type of graphene-based material was experimentally realized.12

Hod, Oded

56

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

SciTech Connect

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

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

2000-07-09T23:59:59.000Z

57

Characterization of metal oxide layers grown on CVD graphene  

SciTech Connect

Growth of a fully oxidized aluminum oxide layer with low surface roughness on graphene grown by chemical vapor deposition is demonstrated. This is accomplished by the deposition of a 0.2 nm thick titanium seed layer on the graphene prior to the deposition of the aluminum under ultra high vacuum conditions, which was subsequently oxidized. The stoichiometry and surface roughness of the oxide layers were measured for a range of titanium and aluminum depositions utilizing ex situ x-ray photoelectron spectrometry and atomic force microscopy. These fully oxidized films are expected to produce good dielectric layers for use in graphene based electronic devices.

Matsubayashi, Akitomo; Abel, Joseph; Prasad Sinha, Dhiraj; Lee, Ji Ung; LaBella, Vincent P. [College of Nanoscale Science and Engineering, University at Albany, SUNY, Albany, New York 12203 (United States)

2013-03-15T23:59:59.000Z

58

Chemicl-looping combustion of coal with metal oxide oxygen carriers  

SciTech Connect

The combustion and reoxidation properties of direct coal chemical-looping combustion (CLC) over CuO, Fe2O3, Co3O4, NiO, and Mn2O3 were investigated using thermogravimetric analysis (TGA) and bench-scale fixed-bed flow reactor studies. When coal is heated in either nitrogen or carbon dioxide (CO2), 50% of weight loss was observed because of partial pyrolysis, consistent with the proximate analysis. Among various metal oxides evaluated, CuO showed the best reaction properties: CuO can initiate the reduction reaction as low as 500 °C and complete the full combustion at 700 °C. In addition, the reduced copper can be fully reoxidized by air at 700 °C. The combustion products formed during the CLC reaction of the coal/metal oxide mixture are CO2 and water, while no carbon monoxide was observed. Multicycle TGA tests and bench-scale fixed-bed flow reactor tests strongly supported the feasibility of CLC of coal by using CuO as an oxygen carrier. Scanning electron microscopy (SEM) images of solid reaction products indicated some changes in the surface morphology of a CuO-coal sample after reduction/oxidation reactions at 800 °C. However, significant surface sintering was not observed. The interactions of fly ash with metal oxides were investigated by X-ray diffraction and thermodynamic analysis. Overall, the results indicated that it is feasible to develop CLC with coal by metal oxides as oxygen carriers.

Siriwardane, R.; Tian, H.; Richards, G.; Simonyi, T.; Poston, J.

2009-01-01T23:59:59.000Z

59

Composite materials with metal oxide attached to lead chalcogenide nanocrystal quantum dots with linkers  

DOE Patents (OSTI)

Composite materials useful for devices such as photoelectrochemical solar cells include a substrate, a metal oxide film on the substrate, nanocrystalline quantum dots (NQDs) of lead sulfide, lead selenide, and lead telluride, and linkers that attach the NQDs to the metal oxide film. Suitable linkers preserve the 1s absorption peak of the NQDs. A suitable linker has a general structure A-B-C where A is a chemical group adapted for binding to a MO.sub.x and C is a chemical group adapted for binding to a NQD and B is a divalent, rigid, or semi-rigid organic spacer moiety. Other linkers that preserve the 1s absorption peak may also be used.

Fuke, Nobuhiro; Koposov, Alexey Y; Sykora, Milan; Hoch, Laura

2014-12-16T23:59:59.000Z

60

Chemical vapor deposition of aluminum oxide  

DOE Patents (OSTI)

An aluminum oxide film is deposited on a heated substrate by CVD from one or more alkylaluminum alkoxide compounds having composition R.sub.n Al.sub.2 (OR').sub.6-n, wherein R and R' are alkyl groups and n is in the range of 1 to 5.

Gordon, Roy (Cambridge, MA); Kramer, Keith (Cleveland, OH); Liu, Xinye (Cambridge, MA)

2000-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "metal oxide chemical" 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

Metallic Materials in Solid Oxide Fuel Cells  

Science Journals Connector (OSTI)

Fe-Cr alloys with variations in chromium content and additions of different elements were studied for potential application in intermediate temperature Solid Oxide Fuel Cell (SOFC). Recently, a new type of FeC...

V. Shemet; J. Piron-Abellan; W.J. Quadakkers…

2005-01-01T23:59:59.000Z

62

Modifications of the surface properties of metals by oxide overlayers: 1, Oxidized zirconium deposited on the Pt(100) single crystal surface  

SciTech Connect

Metallic zirconium was deposited on a single crystal Pt(100) surface by thermal evaporation in UHV conditions. The deposit was oxidized by exposure to oxygen immediately after deposition. Oxidized zirconium was found to grow on the platinum ace by the layer-by-layer mechanism. The adsorption of carbon monoxide on the surface was studied as a function of the zirconium coverage. The results show that oxidized zirconium forms a chemically inert layer which blocks the adsorptive sites of the underlying platinum substrate. The properties of the free Pt surface were unaffected by the presence of the oxidized zirconium layer.

Bardi, U.; Ross, P.N.

1986-06-01T23:59:59.000Z

63

Electrospun and oxidized cellulose materials for environmental remediation of heavy metals in groundwater  

SciTech Connect

This chapter focuses on the use of modified cellulosic materials in the field of environmental remediation. Two different chemical methods were involved in fabricating oxidized cellulose (OC), which has shown promise as a metal ion chelator in environmental applications. Electrospinning was utilized to introduce a more porous structure into an oxidized cellulose matrix. FTIR and Raman spectroscopy were used to study both the formation of OC and its surface complexation with metal ions. IR and Raman spectroscopic data demonstrate the formation of characteristic carboxylic groups in the structure of the final products and the successful formation of OC-metal complexes. Subsequent field tests at the Field Research Site at Oak Ridge National Laboratory confirmed the value of OC for sorption of both U and Th ions.

Han, Dong [Stony Brook University (SUNY); Halada, Gary P. [Stony Brook University (SUNY); Spalding, Brian Patrick [ORNL; Brooks, Scott C [ORNL

2009-12-01T23:59:59.000Z

64

Flame Synthesis of One-Dimensional Metal Oxide Nanomaterials  

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

Synthesis of One-Dimensional Metal Oxide Nanomaterials Synthesis of One-Dimensional Metal Oxide Nanomaterials Alexei V. Saveliev Dept. of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, NC 27695, USA Robust, scalable, and energy efficient methods of nanomaterial synthesis are needed to meet the demands of current and potential applications. Flames have been successfully applied for the synthesis of metal oxide and ceramic nanopowders largely composed of spherical particles and their aggregates. In recent years, premixed and diffusion flames have been employed for the synthesis of 1-D carbon nanoforms such as carbon fibers and carbon nanotubes. The extension of flame methods to gas phase and solid support synthesis of 1-D inorganic nanoforms is of great interest and significance. This talk presents

65

Applications of direct chemical oxidation to demilitarization  

SciTech Connect

Research is reported concerning an aqueous process for oxidative destruction of solid- and liquid organic wastes, including ongoing work relevant to demilitarization This process uses acidified ammonium- or sodium peroxydisulfate and operates at ambient pressure and at temperatures of 80- 100 C The oxidant may be regenerated by electrolysis of the sulfate by- product at Pt anodes at roughly 80% coulombic efficiency, even in the presence of inorganic contaminants (e g , nitrate, phosphate or chloride) found in the original waste and entrained in the recycle stream Integral rate constants have been determined for the oxidation of diverse organic compounds at low concentrations (50 ppm, C), with rate constants (based on equivalents) of 0 004-O 02 miri Higher concentrations generally react at a 2-4X higher rate. The process has been carried through full- scale laboratory tests and initial pilot plant tests on chlorinated solvents, using a hydrolysis pretreatment Integral rate data indicate throughput rates of about 200 kg- C/m3-day The process may benefit the demilitarization efforts in various specialized applications destruction of solvents; destruction of trace propellants and explosives in shell casings remaining after bulk removal, destruction of red and pink waters, in situ remediation of soils at open pit burning/detonation sites; and as a regenerative filter for offgas carrying toxic or explosive substances.

Cooper, J.F., LLNL

1998-06-01T23:59:59.000Z

66

Chemical Tuning of Metal-Semiconductor Interfaces  

Science Journals Connector (OSTI)

We report a study of the Schottky barrier for Pb films grown on Si surfaces terminated by various metals (Ag, In, Au, and Pb) to explore the atomic-scale physics of the interface barrier and a means to control the barrier height. Electronic confinement by the Schottky barrier results in quantum well states in the Pb films, which are measured by angle-resolved photoemission. The barrier height is determined from the atomic-layer-resolved energy levels and the line widths. A calculation based on the known interface chemistry and the electronegativity yields predicted barrier heights in good agreement with the experiment.

D. A. Ricci; T. Miller; T.-C. Chiang

2004-09-20T23:59:59.000Z

67

Metal current collect protected by oxide film  

DOE Patents (OSTI)

Provided are low-cost, mechanically strong, highly electronically conductive current collects and associated structures for solid-state electrochemical devices, techniques for forming these structures, and devices incorporating the structures. The invention provides solid state electrochemical devices having as current interconnects a ferritic steel felt or screen coated with a protective oxide film.

Jacobson, Craig P. (Lafayette, CA); Visco, Steven J. (Berkeley, CA); DeJonghe, Lutgard C. (Lafayette, CA)

2004-05-25T23:59:59.000Z

68

Amorphous semiconducting and conducting transparent metal oxide thin films and production thereof  

DOE Patents (OSTI)

Metal oxide thin films and production thereof are disclosed. An exemplary method of producing a metal oxide thin film may comprise introducing at least two metallic elements and oxygen into a process chamber to form a metal oxide. The method may also comprise depositing the metal oxide on a substrate in the process chamber. The method may also comprise simultaneously controlling a ratio of the at least two metallic elements and a stoichiometry of the oxygen during deposition. Exemplary amorphous metal oxide thin films produced according to the methods herein may exhibit highly transparent properties, highly conductive properties, and/or other opto-electronic properties.

Perkins, John (Boulder, CO); Van Hest, Marinus Franciscus Antonius Maria (Lakewood, CO); Ginley, David (Evergreen, CO); Taylor, Matthew (Golden, CO); Neuman, George A. (Holland, MI); Luten, Henry A. (Holland, MI); Forgette, Jeffrey A. (Hudsonville, MI); Anderson, John S. (Holland, MI)

2010-07-13T23:59:59.000Z

69

New Chemical Systems for Solid Oxide Fuel Cells  

Science Journals Connector (OSTI)

New Chemical Systems for Solid Oxide Fuel Cells† ... (238) This, however, represented a significant improvement over earlier work with the use of Pt electrodes, suggesting that further improvements can be made through electrode optimization and, hence, identifying the need for more work in optimizing electrodes for use with apatite electrolytes. ... cond., the optimized compn. ...

A. Orera; P. R. Slater

2009-11-05T23:59:59.000Z

70

Nonprecious Metal Catalysts for Low Temperature Solid Oxide Fuel Cells  

Science Journals Connector (OSTI)

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

Timothy P. Holme; Fritz B. Prinz

2011-05-24T23:59:59.000Z

71

Metal complexes of substituted Gable porphyrins as oxidation catalysts  

DOE Patents (OSTI)

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

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

1996-01-01T23:59:59.000Z

72

Metal complexes of substituted Gable porphyrins as oxidation catalysts  

DOE Patents (OSTI)

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

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

1996-01-02T23:59:59.000Z

73

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

SciTech Connect

Ferroelectric hafnium oxide films were fabricated by chemical solution deposition with a remnant polarization of >13 ?C/cm{sup 2}. The samples were prepared with 5.2?mol.?% yttrium-doping and the thickness varied from 18?nm to 70?nm. The hafnium oxide layer was integrated into a metal-insulator-metal capacitor using platinum electrodes. Due to the processing procedure, no thickness dependence of the ferroelectric properties was observed. To confirm the ferroelectric nature of the deposited samples, polarization, capacitance, and piezoelectric displacement measurements were performed. However, no evidence of the orthorhombic phase was found which has been proposed to be the non-centrosymmetric, ferroelectric phase in HfO{sub 2}.

Starschich, S.; Griesche, D.; Schneller, T.; Böttger, U. [Institut für Werkstoffe der Elektrotechnik 2, RWTH Aachen University, Sommerfeldstraße 24, D-52074 Aachen (Germany); Waser, R. [Institut für Werkstoffe der Elektrotechnik 2, RWTH Aachen University, Sommerfeldstraße 24, D-52074 Aachen (Germany); Peter Grünberg Institut 7, Forschungszentrum Jülich GmbH, D-52425 Jülich (Germany)

2014-05-19T23:59:59.000Z

74

Metal Oxide Nanoparticles as Bactericidal Agents  

Science Journals Connector (OSTI)

8 Magnesium oxide prepared through an aerogel procedure (AP-MgO)9 yields square and polyhedral shaped nanoparticles with diameters varying slightly around 4 nm, arranged in an extensive porous structure with considerable pore volume. ... Approximately 106 CFU (colony forming units) of bacteria or spores were deposited on water filtration membranes with pore size 0.45 ?m (Millipore Corp.). ... The filters were dried at ambient conditions for 30 min and then completely covered with 0.25 g of AP-MgO/X2 (X = Cl, Br, none). ...

Peter K. Stoimenov; Rosalyn L. Klinger; George L. Marchin; Kenneth J. Klabunde

2002-07-04T23:59:59.000Z

75

Reduction of Metal Oxides by Microwave Heating of Multi-walled...  

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

Reduction of Metal Oxides by Microwave Heating of Multi-walled Carbon Nanotubes Microwave heating of a metal oxide in the presence of multi-walled carbon nanotubes may result in...

76

Electrical excitation of colloidally synthesized quantum dots in metal oxide structures  

E-Print Network (OSTI)

This thesis develops methods for integrating colloidally synthesized quantum dots (QDs) and metal oxides in optoelectronic devices, presents three distinct light emitting devices (LEDs) with metal oxides surrounding a QD ...

Wood, Vanessa Claire

2010-01-01T23:59:59.000Z

77

Purifying metallurgical silicon to solar grade silicon by metal-assisted chemical etching  

Science Journals Connector (OSTI)

Metal impurities have detrimental effects on the performance of Si solar cells. Through metal assisted chemical etching, we fabricate Si nanowires from metallurgical Si while purifying...

Li, Xiaopeng; Sprafke, Alexander N; Schweizer, Stefan L; Wehrspohn, Ralf

78

An experimental study of steam explosions involving chemically reactive metal  

SciTech Connect

An experimental study of molten zirconium-water explosions was conducted. A 1-kg mass of zirconium melt was dropped into a column of water. Explosions took place only when an external trigger was used. In the triggered tests, the extent of oxidation of the zirconium melt was very extensive. However, the explosion energetics estimated were found to be very small compared to the potential chemical energy available from the oxidation reaction. Zirconium is of particular interest, since it is a component of the core materials of the current nuclear power reactors. This paper describes the test apparatus and summarizes the results of four tests conducted using pure zirconium melt.

Cho, D.H.; Armstrong, D.R.; Gunther, W.H. [Argonne National Lab., IL (United States); Basu, S. [Nuclear Regulatory Commission, Washington, DC (United States). Office of Nuclear Regulatory Research

1997-07-01T23:59:59.000Z

79

Electrolytic photodissociation of chemical compounds by iron oxide photochemical diodes  

DOE Patents (OSTI)

Chemical compounds can be dissociated by contacting the same with a p/n type semi-conductor photochemical diode having visible light as its sole source of energy. The photochemical diode consists of low cost, readily available materials, specifically polycrystalline iron oxide doped with silicon in the case of the n-type semi-conductor electrode, and polycrystalline iron oxide doped with magnesium in the case of the p-type electrode. So long as the light source has an energy greater than 2.2 electron volts, no added energy source is needed to achieve dissociation.

Somorjai, Gabor A. (Berkeley, CA); Leygraf, Christofer H. (Berkeley, CA)

1985-01-01T23:59:59.000Z

80

Electrolytic photodissociation of chemical compounds by iron oxide electrodes  

DOE Patents (OSTI)

Chemical compounds can be dissociated by contacting the same with a p/n type semi-conductor diode having visible light as its sole source of energy. The diode consists of low cost, readily available materials, specifically polycrystalline iron oxide doped with silicon in the case of the n-type semi-conductor electrode, and polycrystalline iron oxide doped with magnesium in the case of the p-type electrode. So long as the light source has an energy greater than 2.2 electron volts, no added energy source is needed to achieve dissociation.

Somorjai, Gabor A. (Berkeley, CA); Leygraf, Christofer H. (Berkeley, CA)

1984-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "metal oxide chemical" 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

Influence of uranium hydride oxidation on uranium metal behaviour  

SciTech Connect

This work addresses concerns that the rapid, exothermic oxidation of active uranium hydride in air could stimulate an exothermic reaction (burning) involving any adjacent uranium metal, so as to increase the potential hazard arising from a hydride reaction. The effect of the thermal reaction of active uranium hydride, especially in contact with uranium metal, does not increase in proportion with hydride mass, particularly when considering large quantities of hydride. Whether uranium metal continues to burn in the long term is a function of the uranium metal and its surroundings. The source of the initial heat input to the uranium, if sufficient to cause ignition, is not important. Sustained burning of uranium requires the rate of heat generation to be sufficient to offset the total rate of heat loss so as to maintain an elevated temperature. For dense uranium, this is very difficult to achieve in naturally occurring circumstances. Areas of the uranium surface can lose heat but not generate heat. Heat can be lost by conduction, through contact with other materials, and by convection and radiation, e.g. from areas where the uranium surface is covered with a layer of oxidised material, such as burned-out hydride or from fuel cladding. These rates of heat loss are highly significant in relation to the rate of heat generation by sustained oxidation of uranium in air. Finite volume modelling has been used to examine the behaviour of a magnesium-clad uranium metal fuel element within a bottle surrounded by other un-bottled fuel elements. In the event that the bottle is breached, suddenly, in air, it can be concluded that the bulk uranium metal oxidation reaction will not reach a self-sustaining level and the mass of uranium oxidised will likely to be small in relation to mass of uranium hydride oxidised. (authors)

Patel, N.; Hambley, D. [National Nuclear Laboratory (United Kingdom); Clarke, S.A. [Sellafield Ltd (United Kingdom); Simpson, K.

2013-07-01T23:59:59.000Z

82

Microstructural characteristics of chemically processed manganese oxide nanofibers  

SciTech Connect

Nanostructured fibrous manganese oxide cryptomelane-type hollandite powders were prepared via a chemical route. Powders were obtained by the chemical reaction of the aqueous solutions of potassium permanganate and manganese sulfate in the presence of a strong acid, followed by crystalline growth at elevated temperatures. These powders were characterized by powder X-ray diffraction (XRD), Rietveld refinement, analytical scanning electron microscopy (SEM), transmission electron microscopy (TEM) combined with micro-micro diffraction ({mu}{mu}d), and high resolution transmission electron microscopy (HRTEM). The crystalline structure, morphology, crystallite size, fiber growth direction, and structural defects are discussed.

Xiao, T.D. [CIMAV, Chihuahua (Mexico). Centro de Investigacion en Materiales Avanzados] [CIMAV, Chihuahua (Mexico). Centro de Investigacion en Materiales Avanzados; [Univ. of Connecticut, Storrs, CT (United States). Connecticut Advanced Technology Center for Precision Manufacturing; Bokhimi; Benaissa, M.; Perez, R.; Yacaman, M.J. [Univ. Nacional Autonoma de Mexico, Mexico City (Mexico). Inst. de Fisica] [Univ. Nacional Autonoma de Mexico, Mexico City (Mexico). Inst. de Fisica; Strutt, P.R. [Univ. of Connecticut, Storrs, CT (United States). Connecticut Advanced Technology Center for Precision Manufacturing] [Univ. of Connecticut, Storrs, CT (United States). Connecticut Advanced Technology Center for Precision Manufacturing

1997-04-01T23:59:59.000Z

83

Strengthening of metallic alloys with nanometer-size oxide dispersions  

DOE Patents (OSTI)

Austenitic stainless steels and nickel-base alloys containing, by wt. %, 0.1 to 3.0% V, 0.01 to 0.08% C, 0.01 to 0.5% N, 0.05% max. each of Al and Ti, and 0.005 to 0.10% O, are strengthened and ductility retained by atomization of a metal melt under cover of an inert gas with added oxygen to form approximately 8 nanometer-size hollow oxides within the alloy grains and, when the alloy is aged, strengthened by precipitation of carbides and nitrides nucleated by the hollow oxides. Added strengthening is achieved by nitrogen solid solution strengthening and by the effect of solid oxides precipitated along and pinning grain boundaries to provide temperature-stabilization and refinement of the alloy grains.

Flinn, John E. (Idaho Falls, ID); Kelly, Thomas F. (Madison, WI)

1999-01-01T23:59:59.000Z

84

Strengthening of metallic alloys with nanometer-size oxide dispersions  

DOE Patents (OSTI)

Austenitic stainless steels and nickel-base alloys containing, by wt. %, 0.1 to 3.0% V, 0.01 to 0.08% C, 0.01 to 0.5% N, 0.05% max. each of Al and Ti, and 0.005 to 0.10% O, are strengthened and ductility retained by atomization of a metal melt under cover of an inert gas with added oxygen to form approximately 8 nanometer-size hollow oxides within the alloy grains and, when the alloy is aged, strengthened by precipitation of carbides and nitrides nucleated by the hollow oxides. Added strengthening is achieved by nitrogen solid solution strengthening and by the effect of solid oxides precipitated along and pinning grain boundaries to provide temperature-stabilization and refinement of the alloy grains. 20 figs.

Flinn, J.E.; Kelly, T.F.

1999-06-01T23:59:59.000Z

85

Lithium Metal Oxide Electrodes For Lithium Cells And Batteries  

DOE Patents (OSTI)

A lithium metal oxide positive electrode for a non-aqueous lithium cell is disclosed. The cell is prepared in its initial discharged state and has a general formula xLiMO.sub.2.(1-x)Li.sub.2 M'O.sub.3 in which 0oxidation state and with at least one ion being Mn or Ni, and where M' is one or more ion with an average tetravalent oxidation state. Complete cells or batteries are disclosed with anode, cathode and electrolyte as are batteries of several cells connected in parallel or series or both.

Thackeray, Michael M. (Naperville, IL); Johnson, Christopher S. (Naperville, IL); Amine, Khalil (Downers Grove, IL); Kim, Jaekook (Naperville, IL)

2004-01-20T23:59:59.000Z

86

Lithium metal oxide electrodes for lithium cells and batteries  

DOE Patents (OSTI)

A lithium metal oxide positive electrode for a non-aqueous lithium cell is disclosed. The cell is prepared in its initial discharged state and has a general formula xLiMO.sub.2.(1-x)Li.sub.2M'O.sub.3 in which 0oxidation state and with at least one ion being Mn or Ni, and where M' is one or more ion with an average tetravalent oxidation state. Complete cells or batteries are disclosed with anode, cathode and electrolyte as are batteries of several cells connected in parallel or series or both.

Thackeray, Michael M. (Naperville, IL); Johnson, Christopher S. (Naperville, IL); Amine, Khalil (Oakbrook, IL)

2008-12-23T23:59:59.000Z

87

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

SciTech Connect

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

Rodriguez J. A.; Illas, F.

2012-01-01T23:59:59.000Z

88

Beyond the Lone-Pair Model for Structurally Distorted Metal Oxides  

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

Beyond the Lone-Pair Model for Structurally Distorted Metal Oxides Print Beyond the Lone-Pair Model for Structurally Distorted Metal Oxides Print "Ferroelectricity," by analogy to ferromagnetism, is defined as the presence of spontaneous electrical polarization in a material, often arising from distortions in the material's crystal structure. In oxides of the metals lead and bismuth, such distortions were for many years attributed to the existence of "lone pair" electrons: pairs of chemically inert, nonbonding valence electrons in hybrid orbitals that leave noticeable voids in the crystal structure. At the ALS, researchers from the U.K., Ireland, and the U.S. have now obtained definitive experimental evidence that this lone-pair model must be revised. High-resolution x-ray photoemission spectroscopy (XPS) and soft x-ray emission spectroscopy (XES) have clarified the subtle electronic origins of the prototypical distortions in these crystal structures. The results have important implications for the tantalizing possibility of spintronic or superconducting devices combining ferroelectric and ferromagnetic properties.

89

Beyond the Lone-Pair Model for Structurally Distorted Metal Oxides  

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

Beyond the Lone-Pair Model for Structurally Distorted Metal Oxides Print Beyond the Lone-Pair Model for Structurally Distorted Metal Oxides Print "Ferroelectricity," by analogy to ferromagnetism, is defined as the presence of spontaneous electrical polarization in a material, often arising from distortions in the material's crystal structure. In oxides of the metals lead and bismuth, such distortions were for many years attributed to the existence of "lone pair" electrons: pairs of chemically inert, nonbonding valence electrons in hybrid orbitals that leave noticeable voids in the crystal structure. At the ALS, researchers from the U.K., Ireland, and the U.S. have now obtained definitive experimental evidence that this lone-pair model must be revised. High-resolution x-ray photoemission spectroscopy (XPS) and soft x-ray emission spectroscopy (XES) have clarified the subtle electronic origins of the prototypical distortions in these crystal structures. The results have important implications for the tantalizing possibility of spintronic or superconducting devices combining ferroelectric and ferromagnetic properties.

90

Atomic polar tensors and acid-base properties of metal-oxide building blocks  

SciTech Connect

The sensitivity of the atomic polar tensor to compositional substituents is reported for the alkali silicate series. Rotational invariants, effective atomic charge (GAPT) and charge normalized anisotropy and dipole ({alpha}{sub n} and {gamma}{sub n}) are used to characterize the charge distribution and chemical environment of the atomic sites. Comparison of {alpha}{sub n} and {gamma}{sub n} with a series of known Bronsted and Lewis acids and bases suggests that these rotational invariants may act as indicators for metal-oxide site acidities. Basis set and electron correlation particularly affect the determined effective charge, but show minimal effect on {alpha} and {gamma} quantities.

Ferris, K.F.

1993-02-01T23:59:59.000Z

91

Atomic polar tensors and acid-base properties of metal-oxide building blocks  

SciTech Connect

The sensitivity of the atomic polar tensor to compositional substituents is reported for the alkali silicate series. Rotational invariants, effective atomic charge (GAPT) and charge normalized anisotropy and dipole ([alpha][sub n] and [gamma][sub n]) are used to characterize the charge distribution and chemical environment of the atomic sites. Comparison of [alpha][sub n] and [gamma][sub n] with a series of known Bronsted and Lewis acids and bases suggests that these rotational invariants may act as indicators for metal-oxide site acidities. Basis set and electron correlation particularly affect the determined effective charge, but show minimal effect on [alpha] and [gamma] quantities.

Ferris, K.F.

1993-02-01T23:59:59.000Z

92

Nonpolar resistance switching of metal/binary-transition-metal oxides/metal sandwiches: Homogeneous/inhomogeneous transition of current distribution  

Science Journals Connector (OSTI)

Exotic features of a metal/oxide/metal sandwich, which will be the basis for a drastically innovative nonvolatile memory device, is brought to light from a physical point of view. Here the insulator is one of the ubiquitous and classic binary-transition-metal oxides (TMO), such as Fe2O3, NiO, and CoO. The sandwich exhibits a resistance that reversibly switches between two states: one is a highly resistive off state and the other is a conductive on state. Several distinct features were universally observed in these binary TMO sandwiches: namely, nonpolar switching, nonvolatile threshold switching, and current-voltage duality. From the systematic sample-size dependence of the resistance in on and off states, we conclude that the resistance switching is due to the formation of “electric faucet” at the interface, which shows up as a homogeneous to inhomogeneous transition of the current distribution.

I. H. Inoue; S. Yasuda; H. Akinaga; H. Takagi

2008-01-03T23:59:59.000Z

93

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

SciTech Connect

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

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

1994-07-01T23:59:59.000Z

94

Magnetic preferential orientation of metal oxide superconducting materials  

DOE Patents (OSTI)

A superconductor comprised of a polycrystalline metal oxide such as YBa[sub 2]Cu[sub 3]O[sub 7[minus]X] (where 0 < X < 0.5) exhibits superconducting properties and is capable of conducting very large current densities. By aligning the two-dimensional Cu-O layers which carry the current in the superconducting state in the a- and b-directions, i.e., within the basal plane, a high degree of crystalline axes alignment is provided between adjacent grains permitting the conduction of high current densities. The highly anisotropic diamagnetic susceptibility of the polycrystalline metal oxide material permits the use of an applied magnetic field to orient the individual crystals when in the superconducting state to substantially increase current transport between adjacent grains. In another embodiment, the anisotropic paramagnetic susceptibility of rare-earth ions substituted into the oxide material is made use of as an applied magnetic field orients the particles in a preferential direction. This latter operation can be performed with the material in the normal (non-superconducting) state. 4 figs.

Capone, D.W.; Dunlap, B.D.; Veal, B.W.

1990-07-17T23:59:59.000Z

95

Magnetic preferential orientation of metal oxide superconducting materials  

DOE Patents (OSTI)

A superconductor comprised of a polycrystalline metal oxide such as YBa.sub.2 Cu.sub.3 O.sub.7-X (where 0metal oxide material permits the use of an applied magnetic field to orient the individual crystals when in the superconducting state to substantially increase current transport between adjacent grains. In another embodiment, the anisotropic paramagnetic susceptibility of rare-earth ions substituted into the oxide material is made use of as an applied magnetic field orients the particles in a preferential direction. This latter operation can be performed with the material in the normal (non-superconducting) state.

Capone, Donald W. (Bolingbrook, IL); Dunlap, Bobby D. (Bolingbrook, IL); Veal, Boyd W. (Downers Grove, IL)

1990-01-01T23:59:59.000Z

96

Electrodepositionof Metal Alloyand Mixed Oxide Films Usinga Single-PrecursorTetranuclearCopper-NickelComplex  

E-Print Network (OSTI)

Compositionally uniform mixed metals, metal oxides, and alloys are used extensively as corrosion protective and catalysts. I-~For example, nickel-containing oxides and alloys are used for oxidative protection of very. Although Cu-Ni alloy deposition has been stud- ied for many years, none of the previous approaches has led

Kounaves, Samuel P.

97

Stochastic chemical enrichment in metal-poor systems I. Theory  

E-Print Network (OSTI)

A stochastic model of the chemical enrichment of metal-poor systems by core-collapse (Type II) supernovae is presented, allowing for large-scale mixing of the enriched material by turbulent motions and cloud collisions in the interstellar medium. Infall of pristine material is taken into account by following the evolution of the gas density in the medium. Analytical expressions were derived for the number of stars enriched by a given number of supernovae, as well as for the amount of mass with which the ejected material from a supernova is mixed before being locked up in a subsequently formed star. It is shown that for reasonable values of the gas density (~0.1 cm-3) and of the supernova rate (~0.25 kpc-3 Myr-1) of the Galactic halo, the resulting metallicity distributions of the extreme Population II stars show a distinct cut-off at [Fe/H] ~= -4. In fact, by assuming no low-mass Population III stars were able to form out of the primordial interstellar medium, the derived fraction of stars below [Fe/H] = -4 is in agreement with observations. Moreover, the probability is high that even the most metal-poor stars observed to date have been enriched by several contributing supernovae. This partly explains the relatively small star-to-star scatter in many chemical-abundance ratios for stars down to [Fe/H] = -4, as recently found in several observational studies. Contribution from the thermonuclear (Type Ia) supernovae is found to be negligible over almost the entire extremely metal-poor regime. (***abridged***)

T. Karlsson

2005-04-27T23:59:59.000Z

98

Synthesis of Metallic Nanostructures Using Chemical Fluid Deposition  

Science Journals Connector (OSTI)

Department of Chemical Engineering, and Department of Physics and Institute of Nano Science and Technology, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China ... A solubility study of the platinum precursor, platinum(II) dimethylcyclooctadiene, in the supercritical carbon dioxide was carried out to obtain a phase diagram in order to optimize the operating parameters required for the metal deposition process. ... Korgel and Hanrath and co-workers had also published work on synthesizing nanowires of semiconducting materials, such as silicon, germanium, and gallium arsenide(22-25) using gold seeding particles. ...

Candy S. Lin; Frank Leung-Yuk Lam; Xijun Hu; Wing Yim Tam; Ka M. Ng

2008-06-18T23:59:59.000Z

99

Interfacial oxide re-growth in thin film metal oxide III-V semiconductor systems  

SciTech Connect

The Al{sub 2}O{sub 3}/GaAs and HfO{sub 2}/GaAs interfaces after atomic layer deposition are studied using in situ monochromatic x-ray photoelectron spectroscopy. Samples are deliberately exposed to atmospheric conditions and interfacial oxide re-growth is observed. The extent of this re-growth is found to depend on the dielectric material and the exposure temperature. Comparisons with previous studies show that ex situ characterization can result in misleading conclusions about the interface reactions occurring during the metal oxide deposition process.

McDonnell, S.; Dong, H.; Hawkins, J. M.; Brennan, B.; Milojevic, M.; Aguirre-Tostado, F. S.; Zhernokletov, D. M.; Hinkle, C. L.; Kim, J.; Wallace, R. M.

2012-04-02T23:59:59.000Z

100

Ductility and chemical reactions at the interface between nickel and magnesium oxide single crystals.  

E-Print Network (OSTI)

??An investigation was conducted on the interaction between nickel metal and single crystals of magnesium oxide. The nickel was cleaned with purified hydrogen gas at… (more)

Hasselman, Didericus Petrus Hermannus

2011-01-01T23:59:59.000Z

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


101

Lithium metal oxide electrodes for lithium cells and batteries  

DOE Patents (OSTI)

A lithium metal oxide positive electrode for a non-aqueous lithium cell is disclosed. The cell is prepared in its initial discharged state and has a general formula xLiMO.sub.2.(1-x)Li.sub.2 M'O.sub.3 in which 0

Thackeray, Michael M. (Naperville, IL); Johnson, Christopher S. (Naperville, IL); Amine, Khalil (Downers Grove, IL); Kim, Jaekook (Naperville, IL)

2004-01-13T23:59:59.000Z

102

In-situ ductile metal/bulk metallic glass matrix composites formed by chemical partitioning  

DOE Patents (OSTI)

A composite metal object comprises ductile crystalline metal particles in an amorphous metal matrix. An alloy is heated above its liquidus temperature. Upon cooling from the high temperature melt, the alloy chemically partitions, forming dendrites in the melt. Upon cooling the remaining liquid below the glass transition temperature it freezes to the amorphous state, producing a two-phase microstructure containing crystalline particles in an amorphous metal matrix. The ductile metal particles have a size in the range of from 0.1 to 15 micrometers and spacing in the range of from 0.1 to 20 micrometers. Preferably, the particle size is in the range of from 0.5 to 8 micrometers and spacing is in the range of from 1 to 10 micrometers. The volume proportion of particles is in the range of from 5 to 50% and preferably 15 to 35%. Differential cooling can produce oriented dendrites of ductile metal phase in an amorphous matrix. Examples are given in the Zr--Ti--Cu--Ni--Be alloy bulk glass forming system with added niobium.

Kim, Choong Paul (Northridge, CA); Hays, Charles C. (Pasadena, CA); Johnson, William L. (Pasadena, CA)

2007-07-17T23:59:59.000Z

103

A Low Temperature Fully Lithographic Process For Metal–Oxide Field-Effect Transistors  

E-Print Network (OSTI)

We report a low temperature ( ~ 100à °C) lithographic method for fabricating hybrid metal oxide/organic field-effect transistors (FETs) that combine a zinc-indium-oxide (ZIO) semiconductor channel and organic, parylene, ...

Sodini, Charles G.

104

E-Print Network 3.0 - alkaline-earth metal oxides Sample Search...  

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

differ in the nature of the angle... ). Weidner and Hamaya (1983) observed that the transition-metal oxides and the alkaline-earth oxides fail... ... Source: Price, G. David -...

105

Development of metallic substrate supported planar solid oxide fuel cells fabricated by atmospheric plasma spraying  

Science Journals Connector (OSTI)

A planar solid oxide fuel cell (SOFC) consisting of a cell supported with a porous metallic substrate and a metallic separator has been developed. In the fabrication of the cell, anodes and electrolytes were form...

Shunji Takenoiri; Naruaki Kadokawa; Kazuo Koseki

2000-09-01T23:59:59.000Z

106

Detailed chemical kinetic oxidation mechanism for a biodiesel surrogate  

SciTech Connect

A detailed chemical kinetic mechanism has been developed and used to study the oxidation of methyl decanoate, a surrogate for biodiesel fuels. This model has been built by following the rules established by Curran et al. for the oxidation of n-heptane and it includes all the reactions known to be pertinent to both low and high temperatures. Computed results have been compared with methyl decanoate experiments in an engine and oxidation of rapeseed oil methyl esters in a jet stirred reactor. An important feature of this mechanism is its ability to reproduce the early formation of carbon dioxide that is unique to biofuels and due to the presence of the ester group in the reactant. The model also predicts ignition delay times and OH profiles very close to observed values in shock tube experiments fueled by n-decane. These model capabilities indicate that large n-alkanes can be good surrogates for large methyl esters and biodiesel fuels to predict overall reactivity, but some kinetic details, including early CO{sub 2} production from biodiesel fuels, can be predicted only by a detailed kinetic mechanism for a true methyl ester fuel. The present methyl decanoate mechanism provides a realistic kinetic tool for simulation of biodiesel fuels.

Herbinet, O; Pitz, W J; Westbrook, C K

2007-09-20T23:59:59.000Z

107

Detailed chemical kinetic oxidation mechanism for a biodiesel surrogate  

SciTech Connect

A detailed chemical kinetic mechanism has been developed and used to study the oxidation of methyl decanoate, a surrogate for biodiesel fuels. This model has been built by following the rules established by Curran et al. for the oxidation of n-heptane and it includes all the reactions known to be pertinent to both low and high temperatures. Computed results have been compared with methyl decanoate experiments in an engine and oxidation of rapeseed oil methyl esters in a jet stirred reactor. An important feature of this mechanism is its ability to reproduce the early formation of carbon dioxide that is unique to biofuels and due to the presence of the ester group in the reactant. The model also predicts ignition delay times and OH profiles very close to observed values in shock tube experiments fueled by n-decane. These model capabilities indicate that large n-alkanes can be good surrogates for large methyl esters and biodiesel fuels to predict overall reactivity, but some kinetic details, including early CO2 production from biodiesel fuels, can be predicted only by a detailed kinetic mechanism for a true methyl ester fuel. The present methyl decanoate mechanism provides a realistic kinetic tool for simulation of biodiesel fuels.

Herbinet, O; Pitz, W J; Westbrook, C K

2007-09-17T23:59:59.000Z

108

Bipolar plating of metal contacts onto oxide interconnection for solid oxide electrochemical cell  

DOE Patents (OSTI)

Disclosed is a method of forming an adherent metal deposit on a conducting layer of a tube sealed at one end. The tube is immersed with the sealed end down into an aqueous solution containing ions of the metal to be deposited. An ionically conducting aqueous fluid is placed inside the tube and a direct current is passed from a cathode inside the tube to an anode outside the tube. Also disclosed is a multi-layered solid oxide fuel cell tube which consists of an inner porous ceramic support tube, a porous air electrode covering the support tube, a non-porous electrolyte covering a portion of the air electrode, a non-porous conducting interconnection covering the remaining portion of the electrode, and a metal deposit on the interconnection.

Isenberg, Arnold O. (Forest Hills Boro, PA)

1987-01-01T23:59:59.000Z

109

High-throughput synthesis and characterization of vanadium mixed metal oxide pigments using synchroton radiation.  

E-Print Network (OSTI)

??UNA range of inorganic vanadium mixed metal oxides, with potential applications as inorganic pigments, have been synthesised and characterised in terms of their crystal structure,… (more)

Russu, Sergio

2008-01-01T23:59:59.000Z

110

E-Print Network 3.0 - active complementary metal-oxide-semiconductor...  

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

ion-implanted p and n dopants in germanium Summary: wavelength spectrum allowing optoelectronic integra- tion to enhance complementary-metal-oxide- semiconductor... lim- its in...

111

E-Print Network 3.0 - area metal-oxide-semiconductor electron...  

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

inversion layer mobility Joo-Hiuk Son,a) Seongtae... measured absorption of terahertz radiation pulses by metal-oxide-semiconductor MOS inversion layers... of the...

112

Project Profile: Thermochemical Heat Storage for CSP Based on Multivalent Metal Oxides  

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

General Atomics (GA), under the Thermal Storage FOA, is developing a high-density thermochemical heat storage system based on solid metal oxides.

113

Two-step fuel oxidation to improve efficiency in the conversion of chemical energy into work  

SciTech Connect

It is well known that in the conversion of chemical exergy into work a remarkable percentage of exergy is destroyed during the combustion process. Obviously, hypothetical reversible combustions, as proposed in some papers, are not to be taken into account. On the contrary, recent studies of a new system to increase the efficiency of the conversion of chemical exergy into work appear interesting. The proposed system includes a gas turbine system with chemical-looping combustion where a metal oxide is used as an oxygen carrier. Instead of conventional combustion, the oxidation of fuel is carried out in a two-step reaction. The first step is an endothermic reaction in which a metal oxide is reduced by fuel at low temperature and the second step an exothermic reaction in which the products of the former reaction are subjected to oxidation. The thermal energy of low exergy value in the exhaust gas is employed to drive the endothermic reaction. Various systems have been proposed and tested. The power-generation system (called CLSA), with chemical-looping combustion and air saturation seems the most convenient. When only saturated air is used, exergy destruction becomes small in the middle- and low temperature range. However, the inefficiency in the high temperature range remains. On the other hand, when only chemical-looping combustion is used, exergy destruction becomes small in the high- and middle temperature range. However, the inefficiency in the low-temperature range is now not removed. When both technologies are combined, exergy efficiency may become much greater than that obtained from each individual process. The synergistic effect of combining these two technologies is analogous to the improvement achieved when a combined system was designed as a new power-generation system by combining a gas turbine with a steam turbine. For a model system, an exergy efficiency of 53.3% is obtained when the process water is recovered and a value of about 55% is obtained when water is not recovered. A significant advantage of the CLSA system is that CO{sub 2} can be easily recovered. The CO{sub 2} produced in the reduction reactor is not diluted by air since air and fuel enter different reactors. This is quite different from a traditional combustor in which CO{sub 2} is diluted in air and hence cannot be concentrated and separated economically. In the CLSA system, since the exhaust gas from the reduction reactor is composed only of high-concentration CO{sub 2} and water vapor, CO{sub 2} can be easily recovered by cooling the exhaust gas and removing the liquid water, i.e. very little energy expenditure is required for recovering CO{sub 2} from the exhaust gas. The recovered CO{sub 2} may be utilized, e.g., in artificial photosynthesis, whereas a simple recovery without any utilization but only to reduce greenhouse effect seems questionable. Another significant characteristic of CLSA system is that the most of the water vapor in the exhaust gas can be recovered by cooling the exhaust gas from the oxidation reactor. In chemical-looping combustion, fuel is not burned directly and the gas discharged from the oxidation reactor has no impurities from the fuel. Hence, there will be no corrosion of the apparatus when the exhaust gas is cooled to a very low temperature and low cost materials can be utilized for the heat exchangers. Because of the recycling of the most part of water, the CLSA system can be used in locations with limited water resources. Chemical-looping combustion system can be also combined with an integrated coal gasification and this topic appears very interesting. Indeed, to achieve better conversion efficiencies and lower pollutant emissions in power plants, new technologies that combines coal gasification with a gas turbine based combined cycle have been extensively studied worldwide.

Bisio, G.; Rubatto, R.; Marletta, L.

1998-07-01T23:59:59.000Z

114

Synergistic Metal–Metal Oxide Nanoparticles Supported Electrocatalytic Graphene for Improved Photoelectrochemical Glucose Oxidation  

Science Journals Connector (OSTI)

Panels a and b in Figure 1 depict the schematic representation of mechanism of glucose oxidation at the graphene–WO3–Au hybrid membrane modified with glucose oxidase (GOD) enzyme. ... The efficiency improvement seems to be due to (1) the enhancement of electron transport through the TiO2 layer by inter-particle necking of primary TiO2 particles and (2) an increase in the recombination resistance at TiO2/QD/electrolyte interfaces by healing the surface states or managing the oxygen vacancies upon N-ion doping. ...

Anitha Devadoss; P. Sudhagar; Santanu Das; Sang Yun Lee; C. Terashima; K. Nakata; A. Fujishima; Wonbong Choi; Yong Soo Kang; Ungyu Paik

2014-03-09T23:59:59.000Z

115

Enrichment of Fe and Ni at metal and oxide grain boundaries in corroded Zircaloy-2  

Science Journals Connector (OSTI)

Atom probe tomography has been used to study for the first time the metal–oxide interface region in Zircaloy-2. Segregation of Fe and Ni to both deformation-induced sub-grain boundaries in the metal and planar features in the oxide has been found. Apparently, the oxide inherits the chemistry of the sub-grain boundaries as the material oxidizes, which may have implications for the waterside corrosion kinetics of the alloy.

G. Sundell; M. Thuvander; H.-O. Andrén

2012-01-01T23:59:59.000Z

116

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

SciTech Connect

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

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

1995-05-01T23:59:59.000Z

117

Studies on supported metal oxide-oxide support interactions (an incorporation model)  

SciTech Connect

XRD, XPS, SSIMS, LRS, and FT-IR are used to explore the valency, composition and structure of the dispersed metal oxide species on supports with different structures, i.e., on ceria and {gamma}-alumina. The results indicated that the dispersion of various ionic compounds are proceeded by the incorporation of the metal cations into the surface vacant sites on the support provided that the loading amounts of the compounds are not higher than their dispersion capacities. The key factors determining the dispersion capacities of the ionic compounds are: (1) the surface structure of the support which determines the size and number of the vacant sites available. (2) the valency of the dispersed ionic compound and the size of the anion, from which the shielding effect of the capping anion(s) can be evaluated, and (3) the sizes of the dispersed cations and the vacant sites on the surface, from which the sites can be used for incorporation can be identified. The Quantitative results deduced from the incorporation model and from the independent experiments are consistent, providing further evidence that the model captures the essentials of the interactions between the dispersed metal oxide and support.

Yi Chen; Lin Dong; Y.S. Jin; Bing Xu; Weijie Ji [Nanjing Univ. (China)

1996-12-31T23:59:59.000Z

118

Trending: Metal Oxo Bonds  

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

Trending: Metal Oxo Bonds Trending: Metal Oxo Bonds Trending: Metal Oxo Bonds Print Wednesday, 29 May 2013 00:00 Metal oxides are important for scientific and technical applications in a variety of disciplines, including materials science, chemistry, and biology. Highly covalent metal-oxygen multiple bonds (metal oxos) are the building blocks of metal oxides and have a bearing on the oxide's desirable chemical, magnetic, electronic, and thermal properties. The lack of a more sophisticated grasp of bonding in metal oxides constitutes a roadblock to innovation in a wide variety of important emergent technologies, including industrial catalysis, biomimetic transformations, and artificial photosynthesis. To address this problem, a research team from four national laboratories, three Department of Energy synchrotron user facilities, and the University of Washington has applied spectroscopic and computational analyses to a number of metal oxides, quantifying trends in metal oxo bonding for groups of metals across the periodic table.

119

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

DOE Patents (OSTI)

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

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

2008-10-28T23:59:59.000Z

120

Self assembled multi-layer nanocomposite of graphene and metal oxide materials  

DOE Patents (OSTI)

Nanocomposite materials having at least two layers, each layer consisting of one metal oxide bonded to at least one graphene layer were developed. The nanocomposite materials will typically have many alternating layers of metal oxides and graphene layers, bonded in a sandwich type construction and will be incorporated into an electrochemical or energy storage device.

Liu, Jun; Aksay, Ilhan A; Choi, Daiwon; Kou, Rong; Nie, Zimin; Wang, Donghai; Yang, Zhenguo

2013-10-22T23:59:59.000Z

Note: This page contains sample records for the topic "metal oxide chemical" from the National Library of EnergyBeta (NLEBeta).
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121

Self assembled multi-layer nanocomposite of graphene and metal oxide materials  

SciTech Connect

Nanocomposite materials having at least two layers, each layer consisting of one metal oxide bonded to at least one graphene layer were developed. The nanocomposite materials will typically have many alternating layers of metal oxides and graphene layers, bonded in a sandwich type construction and will be incorporated into an electrochemical or energy storage device.

Liu, Jun; Choi, Daiwon; Kou, Rong; Nie, Zimin; Wang, Donghai; Yang, Zhenguo

2014-09-16T23:59:59.000Z

122

Development of a Plasma Arc Manufacturing Process and Machine to Create Metal Oxide Particles in Water From Wire Feedstock.  

E-Print Network (OSTI)

??A plasma arc erosion process can be used to create metal and metal oxide particles in the ultra-fine size range (<70 um). An electric arc… (more)

George, Jonathan Alan 1983-

2010-01-01T23:59:59.000Z

123

Stabilization of Electrocatalytic Metal Nanoparticles at Metal...  

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

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

124

Superconductors and Complex Transition Metal Oxides for Tunable THz Plasmonic Metamaterials  

SciTech Connect

The outline of this presentation are: (1) Motivation - Non-tunability of metal metamaterials; (2) Superconductors for temperature tunable metamaterials; (3) Ultrafast optical switching in superconductor metamaterials; (4) Controlling the conductivity with infrared pump beam; (5) Complex metal oxides as active substrates - Strontium Titanate; and (6) Conclusion. Conclusions are: (1) High Tc superconductors good for tunable and ultrafast metamaterials; (2) Large frequency and amplitude tunability in ultrathin superconductor films; (3) Such tunable properties cannot be accessed using metals; (4) Complex metal oxides can be used as active substrates - large tunability; (5) Complex oxides fail to address the issue of radiation losses in THz metamaterials.

Singh, Ranjan [Los Alamos National Laboratory; Xiong, Jie [Los Alamos National Laboratory; Azad, Md A. [Los Alamos National Laboratory; Yang, Hao [Los Alamos National Laboratory; Trugman, Stuart A. [Los Alamos National Laboratory; Jia, Quanxi [Los Alamos National Laboratory; Taylor, Antoinette [Los Alamos National Laboratory; Chen, Houtong [Los Alamos National Laboratory

2012-07-13T23:59:59.000Z

125

Copper-induced oxidative stress in three-spined stickleback : relationship with hepatic metal levels  

E-Print Network (OSTI)

contamination of aquatic ecosystems by heavy metals. Among them, copper is a widespread pollutant found, 1999). Although this metal is a required element, high concentrations appear to be toxic to freshwater1 Copper-induced oxidative stress in three-spined stickleback : relationship with hepatic metal

Paris-Sud XI, Université de

126

Trending: Metal Oxo Bonds  

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

Trending: Metal Oxo Bonds Print Trending: Metal Oxo Bonds Print Metal oxides are important for scientific and technical applications in a variety of disciplines, including materials science, chemistry, and biology. Highly covalent metal-oxygen multiple bonds (metal oxos) are the building blocks of metal oxides and have a bearing on the oxide's desirable chemical, magnetic, electronic, and thermal properties. The lack of a more sophisticated grasp of bonding in metal oxides constitutes a roadblock to innovation in a wide variety of important emergent technologies, including industrial catalysis, biomimetic transformations, and artificial photosynthesis. To address this problem, a research team from four national laboratories, three Department of Energy synchrotron user facilities, and the University of Washington has applied spectroscopic and computational analyses to a number of metal oxides, quantifying trends in metal oxo bonding for groups of metals across the periodic table.

127

Trending: Metal Oxo Bonds  

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

Trending: Metal Oxo Bonds Print Trending: Metal Oxo Bonds Print Metal oxides are important for scientific and technical applications in a variety of disciplines, including materials science, chemistry, and biology. Highly covalent metal-oxygen multiple bonds (metal oxos) are the building blocks of metal oxides and have a bearing on the oxide's desirable chemical, magnetic, electronic, and thermal properties. The lack of a more sophisticated grasp of bonding in metal oxides constitutes a roadblock to innovation in a wide variety of important emergent technologies, including industrial catalysis, biomimetic transformations, and artificial photosynthesis. To address this problem, a research team from four national laboratories, three Department of Energy synchrotron user facilities, and the University of Washington has applied spectroscopic and computational analyses to a number of metal oxides, quantifying trends in metal oxo bonding for groups of metals across the periodic table.

128

Trending: Metal Oxo Bonds  

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

Trending: Metal Oxo Bonds Print Trending: Metal Oxo Bonds Print Metal oxides are important for scientific and technical applications in a variety of disciplines, including materials science, chemistry, and biology. Highly covalent metal-oxygen multiple bonds (metal oxos) are the building blocks of metal oxides and have a bearing on the oxide's desirable chemical, magnetic, electronic, and thermal properties. The lack of a more sophisticated grasp of bonding in metal oxides constitutes a roadblock to innovation in a wide variety of important emergent technologies, including industrial catalysis, biomimetic transformations, and artificial photosynthesis. To address this problem, a research team from four national laboratories, three Department of Energy synchrotron user facilities, and the University of Washington has applied spectroscopic and computational analyses to a number of metal oxides, quantifying trends in metal oxo bonding for groups of metals across the periodic table.

129

Trending: Metal Oxo Bonds  

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

Trending: Metal Oxo Bonds Print Trending: Metal Oxo Bonds Print Metal oxides are important for scientific and technical applications in a variety of disciplines, including materials science, chemistry, and biology. Highly covalent metal-oxygen multiple bonds (metal oxos) are the building blocks of metal oxides and have a bearing on the oxide's desirable chemical, magnetic, electronic, and thermal properties. The lack of a more sophisticated grasp of bonding in metal oxides constitutes a roadblock to innovation in a wide variety of important emergent technologies, including industrial catalysis, biomimetic transformations, and artificial photosynthesis. To address this problem, a research team from four national laboratories, three Department of Energy synchrotron user facilities, and the University of Washington has applied spectroscopic and computational analyses to a number of metal oxides, quantifying trends in metal oxo bonding for groups of metals across the periodic table.

130

Hydrogen Production via Chemical Looping Redox Cycles Using Atomic Layer Deposition-Synthesized Iron Oxide and Cobalt Ferrites  

Science Journals Connector (OSTI)

Hydrogen Production via Chemical Looping Redox Cycles Using Atomic Layer Deposition-Synthesized Iron Oxide and Cobalt Ferrites ... Unlike solution and line-of-sight methods used to synthesize metal-substituted ferrites, including solution combustion synthesis,(6) aerial oxidation of aqueous suspensions,(5) sol?gel process,(8) laser molecular beam epitaxy,(21) sputtering,(22) and chemical vapor deposition (CVD),(23) ALD can produce conformal thin films on porous materials. ... The drop in peak H2 production rate is accompanied by a ?55% decrease in the total amount of H2 produced (see Table 1) and a similar decrease in the time required to achieve 95% conversion, suggesting a loss of accessible iron in this material. ...

Jonathan R. Scheffe; Mark D. Allendorf; Eric N. Coker; Benjamin W. Jacobs; Anthony H. McDaniel; Alan W. Weimer

2011-03-24T23:59:59.000Z

131

Gate Metal-Induced Diffusion and Interface Reactions in Hf Oxide Films on Si  

SciTech Connect

When metal electrodes are deposited on a high-{kappa} metal-oxide/SiO{sub 2}/Si stack, chemical interactions may occur both at the metal/high-{kappa} and the high-{kappa}/Si interfaces, causing changes in electrical performance. We report here results from medium energy ion scattering (MEIS) and x-ray photoelectron (XPS) studies of oxygen and silicon transport and interfacial layer reactions in multilayer gate stacks. Our results show that Ti deposition on HfO{sub 2}/SiO{sub 2}/Si stacks causes reduction of the SiO{sub 2} interfacial layer and (to a lesser extent) the HfO{sub 2} layer. Silicon atoms initially present in the interfacial SiO{sub 2} layer incorporate into the bottom of the high-{kappa} layer. Some evidence for titanium-silicon interdiffusion through the high-{kappa} film in the presence of a titanium gate in crystalline HfO{sub 2} films is also reported.

Goncharova, Lyudmila V.; Dalponte, Mateus; Celik, Ozgur; Garfunkel, Eric; Gustafsson, Torgny [Departments of Physics and Chemistry, and Laboratory for Surface Modification, Rutgers University, Piscataway, NJ 08854 (United States); Lysaght, Pat S.; Bersuker, Gennadi I. [Sematech, Austin, Texas 78741 (United States)

2007-09-26T23:59:59.000Z

132

Spectroscopic Studies of O-Vacancy Defects in Transition Metal Oxides  

SciTech Connect

Dielectrics comprised of nano-crystalline HfO{sub 2} in gate stacks with thin SiO{sub 2}/SiON interfacial transition regions display significant asymmetries with respect to trapping of Si substrate injected holes and electrons. Based on spectroscopic studies, and guided by ab initio theory, electron and hole traps in HfO{sub 2} and other transition metal elemental oxides are assigned to O-atom divacancies clustered at internal grain boundaries of nano-crystalline films. Engineering solutions in which grain boundary defects are suppressed include: (i) ultra-thin, <2 nm, HfO{sub 2} fims, (ii) chemically phase separated high HfO2 content silicate films, and (iii) non-crystalline Zr/Hf Si oxynitride films.

Lucovsky, G.; Luning, J.; Fleming, L.B.; Ulrich, M.D.; Rowe, J.E.; Seo, H.; Lee, S.; Lysaght, P.; Bersuker, G.

2009-06-03T23:59:59.000Z

133

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

SciTech Connect

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

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

1991-06-26T23:59:59.000Z

134

Chemically Modified Metal Oxide Nanostructure for Photoelectrochemical Water Splitting  

E-Print Network (OSTI)

and the widespread use of hydrogen powered fuel cells is theHydrogen is an energy carrier, which combines oxygen in a fuel cell

Wang, Gongming

2013-01-01T23:59:59.000Z

135

Final LDRD report : metal oxide films, nanostructures, and heterostructures for solar hydrogen production.  

SciTech Connect

The distinction between electricity and fuel use in analyses of global power consumption statistics highlights the critical importance of establishing efficient synthesis techniques for solar fuels-those chemicals whose bond energies are obtained through conversion processes driven by solar energy. Photoelectrochemical (PEC) processes show potential for the production of solar fuels because of their demonstrated versatility in facilitating optoelectronic and chemical conversion processes. Tandem PEC-photovoltaic modular configurations for the generation of hydrogen from water and sunlight (solar water splitting) provide an opportunity to develop a low-cost and efficient energy conversion scheme. The critical component in devices of this type is the PEC photoelectrode, which must be optically absorptive, chemically stable, and possess the required electronic band alignment with the electrochemical scale for its charge carriers to have sufficient potential to drive the hydrogen and oxygen evolution reactions. After many decades of investigation, the primary technological obstacle remains the development of photoelectrode structures capable of efficient conversion of light with visible frequencies, which is abundant in the solar spectrum. Metal oxides represent one of the few material classes that can be made photoactive and remain stable to perform the required functions.

Kronawitter, Coleman X. [Lawrence Berkeley National Laboratory, Berkeley, CA; Antoun, Bonnie R.; Mao, Samuel S. [Lawrence Berkeley National Laboratory, Berkeley, CA

2012-01-01T23:59:59.000Z

136

An experimental and detailed chemical kinetic modelling study of 2methyl furan oxidation  

E-Print Network (OSTI)

platform chemical 5hydroxymethylfurfural now a possibility [4], [5], [6] and [7]. 25DMF offers significantAn experimental and detailed chemical kinetic modelling study of 2methyl furan oxidation.55­1.65, initial temperatures of 298­398 K and atmospheric pressure. A detailed chemical kinetic mechanism

Paris-Sud XI, Université de

137

Reactivity of biogenic manganese oxide for metal sequestration and photochemistry: Computational solid state physics study  

SciTech Connect

Many microbes, including both bacteria and fungi, produce manganese (Mn) oxides by oxidizing soluble Mn(II) to form insoluble Mn(IV) oxide minerals, a kinetically much faster process than abiotic oxidation. These biogenic Mn oxides drive the Mn cycle, coupling it with diverse biogeochemical cycles and determining the bioavailability of environmental contaminants, mainly through strong adsorption and redox reactions. This mini review introduces recent findings based on quantum mechanical density functional theory that reveal the detailed mechanisms of toxic metal adsorption at Mn oxide surfaces and the remarkable role of Mn vacancies in the photochemistry of these minerals.

Kwon, K.D.; Sposito, G.

2010-02-01T23:59:59.000Z

138

Oxidative Dissolution of Nickel Metal in Hydrogenated Hydrothermal Solutions  

SciTech Connect

A platinum-lined, flowing autoclave facility is used to investigate the solubility behavior of metallic nickel in hydrogenated ammonia and sodium hydroxide solutions between 175 and 315 C. The solubility measurements were interpreted by means of an oxidative dissolution reaction followed by a sequence of Ni(II) ion hydrolysis reactions: Ni(s) + 2H+(aq) = Ni2+(aq) + H2(g) and Ni{sup 2+}(aq) + nH{sub 2}O = Ni(OH){sub n}{sup 2-n}(aq) + nH{sup +}(aq) where n = 1 and 2. Gibbs energies associated with these reaction equilibria were determined from a least-squares analysis of the data. The extracted thermochemical properties ({Delta}fG{sup 0}, {Delta}fH{sup 0} and S{sup 0}) for Ni2{sup +}(aq), Ni(OH){sup +}(aq) and Ni(OH){sub 2}(aq) were found to be consistent with those determined in a previous solubility study of NiO/Ni(OH){sub 2} conducted in our laboratory. The thermodynamic basis of the Ni/NiO phase boundary in aqueous solutions is examined to show that Ni(s) is stable relative to NiO(s) in solutions saturated at 25 C with 1 atm H{sub 2} for temperatures below 309 C.

Ziemniak SE, Guilmette PA, Turcotte RA, Tunison HM

2007-03-27T23:59:59.000Z

139

Studies on transparent spinel magnesium indium oxide thin films prepared by chemical spray pyrolysis  

Science Journals Connector (OSTI)

Ternary semiconducting oxide compound magnesium indium oxide films (MgIn2O4), manifesting high transparency were prepared by metal organic chemical spray pyrolysis technique. Precursors prepared for various cationic ratios of Mg/In = 0.35, 0.40, 0.45 and 0.50 were thermally sprayed onto quartz substrates, decomposed at 450 °C and the spinel phase evolution was studied. X-ray diffraction, Rutherford backscattering and X-ray photoelectron spectroscopy studies have been conducted to confirm the formation of single-phase MgIn2O4 films with Mg/In ratio 0.50. From optical transmission studies, the observed optical band gaps varied from 3.18 to 3.86 eV (0.35 < Mg/In < 0.5). The electrical conductivity variations of these films were measured in the temperature range between 30 and 150 °C by four-probe technique (34.07–1.44 × 10? 5 S cm? 1) and the Hall coefficient showed n-type electrical conduction and high carrier concentration (0.16 × 1020–0.89 × 17 cm? 3).

A. Moses Ezhil Raj; V. Senthilkumar; V. Swaminathan; Joachim Wollschläger; M. Suendorf; M. Neumann; M. Jayachandran; C. Sanjeeviraja

2008-01-01T23:59:59.000Z

140

Alkane oxidation with porphyrins and metal complexes thereof having haloalkyl side chains  

DOE Patents (OSTI)

Transition metal complexes of meso-haloalkylporphyrins are disclosed, wherein the haloalkyl groups contain 2 to 8 carbon atoms have been found to be highly effective catalysts for oxidation of alkanes and for the decomposition of hydroperoxides. 7 figs.

Wijesekera, T.; Lyons, J.E.; Ellis, P.E. Jr.; Bhinde, M.V.

1998-06-23T23:59:59.000Z

Note: This page contains sample records for the topic "metal oxide chemical" 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

Near-infrared photodetector consisting of J-aggregating cyanine dye and metal oxide thin films  

E-Print Network (OSTI)

We demonstrate a near-infrared photodetector that consists of a thin film of the J-aggregating cyanine dye, U3, and transparent metal-oxide charge transport layers. The high absorption coefficient of the U3 film, combined ...

Osedach, Timothy P.

142

Low temperature lithographically patterned metal oxide transistors for large area electronics  

E-Print Network (OSTI)

Optically transparent, wide bandgap metal oxide semiconductors are a promising candidate for large-area electronics technologies that require lightweight, temperature-sensitive flexible substrates. Because these thin films ...

Wang, Annie I. (Annie I-Jen), 1981-

2011-01-01T23:59:59.000Z

143

Alkane oxidation with porphyrins and metal complexes thereof having haloalkyl side chains  

DOE Patents (OSTI)

Transition metal complexes of meso-haloalkylporphyrins, wherein the haloalkyl groups contain 2 to 8 carbon atoms have been found to be highly effective catalysts for oxidation of alkanes and for the decomposition of hydroperoxides.

Wijesekera, Tilak (Glen Mills, PA); Lyons, James E. (Wallingford, PA); Ellis, Jr., Paul E. (Downingtown, PA); Bhinde, Manoj V. (Boothwyn, PA)

1998-01-01T23:59:59.000Z

144

Long-term research in Japan: amorphous metals, metal oxide varistors, high-power semiconductors and superconducting generators  

SciTech Connect

The review revealed that significant activity is under way in the research of amorphous metals, but that little fundamental work is being pursued on metal oxide varistors and high-power semiconductors. Also, the investigation of long-term research program plans for superconducting generators reveals that activity is at a low level, pending the recommendations of a study currently being conducted through Japan's Central Electric Power Council.

Hane, G.J.; Yorozu, M.; Sogabe, T.; Suzuki, S.

1985-04-01T23:59:59.000Z

145

Thermal conversion of biomass to valuable fuels, chemical feedstocks and chemicals  

DOE Patents (OSTI)

A continuous process for the conversion of biomass to form a chemical feedstock is described. The biomass and an exogenous metal oxide, preferably calcium oxide, or metal oxide precursor are continuously fed into a reaction chamber that is operated at a temperature of at least 1400.degree. C. to form reaction products including metal carbide. The metal oxide or metal oxide precursor is capable of forming a hydrolizable metal carbide. The reaction products are quenched to a temperature of 800.degree. C. or less. The resulting metal carbide is separated from the reaction products or, alternatively, when quenched with water, hydolyzed to provide a recoverable hydrocarbon gas feedstock.

Peters, William A. (Lexington, MA); Howard, Jack B. (Winchester, MA); Modestino, Anthony J. (Hanson, MA); Vogel, Fredreric (Villigen PSI, CH); Steffin, Carsten R. (Herne, DE)

2009-02-24T23:59:59.000Z

146

Oxidative chemical vapor deposition of conductive polymers for use in novel photovoltaic device architectures  

E-Print Network (OSTI)

The conductive polymer poly(3,4-ethylenedioxythiophene), (PEDOT), deposited via oxidative chemical vapor deposition (oCVD) has been investigated for use in organic electronic devices. The oCVD process as well as the ...

Howden, Rachel M. (Rachel Mary)

2013-01-01T23:59:59.000Z

147

Antireflective silicon nanostructures with hydrophobicity by metal-assisted chemical etching for solar cell applications  

Science Journals Connector (OSTI)

We present broadband antireflective silicon (Si) nanostructures with hydrophobicity using a spin-coated Ag ink and by subsequent metal-assisted chemical etching (MaCE). Improved understanding of ... reveals a des...

ChanIl Yeo; Joon Beom Kim; Young Min Song; Yong Tak Lee

2013-04-01T23:59:59.000Z

148

Metal enrichment of the intracluster medium: a three-dimensional picture of chemical and dynamical properties  

Science Journals Connector (OSTI)

......supply of this enriched gas include galactic winds...baryonic component due to gas cooling, star formation, metal production and energetic and chemical...of the intracluster gas through radial velocity...smaller computational cost. In particular, it......

Sofía A Cora

2006-06-01T23:59:59.000Z

149

Geochemical, metagenomic and metaproteomic insights into trace metal utilization by methane-oxidizing microbial consortia in sulfidic marine sediments  

SciTech Connect

Microbes have obligate requirements for trace metals in metalloenzymes that catalyze important biogeochemical reactions. In anoxic methane- and sulfide-rich environments, microbes may have unique adaptations for metal acquisition and utilization due to decreased bioavailability as a result of metal sulfide precipitation. However, micronutrient cycling is largely unexplored in cold ( 10 C) and sulfidic (>1 mM H2S) deep-sea methane seep ecosystems. We investigated trace metal geochemistry and microbial metal utilization in methane seeps offshore Oregon and California, USA, and report dissolved concentrations of nickel (0.5-270 nM), cobalt (0.5-6 nM), molybdenum (10-5,600 nM) and tungsten (0.3-8 nM) in Hydrate Ridge sediment porewaters. Despite low levels of cobalt and tungsten, metagenomic and metaproteomic data suggest that microbial consortia catalyzing anaerobic oxidation of methane utilize both scarce micronutrients in addition to nickel and molybdenum. Genetic machinery for cobalt-containing vitamin B12 biosynthesis was present in both anaerobic methanotrophic archaea (ANME) and sulfate-reducing bacteria (SRB). Proteins affiliated with the tungsten-containing form of formylmethanofuran dehydrogenase were expressed in ANME from two seep ecosystems, the first evidence for expression of a tungstoenzyme in psychrotolerant microorganisms. Finally, our data suggest that chemical speciation of metals in highly sulfidic porewaters may exert a stronger influence on microbial bioavailability than total concentration

Glass, DR. Jennifer [California Institute of Technology, Pasadena; Yu, DR. Hang [California Institute of Technology, Pasadena; Steele, Joshua [California Institute of Technology, Pasadena; Dawson, Katherine [California Institute of Technology, Pasadena; Sun, S [University of California, San Diego; Chourey, Karuna [ORNL; Hettich, Robert {Bob} L [ORNL; Orphan, V [California Institute of Technology, Pasadena

2014-01-01T23:59:59.000Z

150

Emerging Applications of Liquid Metals Featuring Surface Oxides  

Science Journals Connector (OSTI)

Figure 4. 3D printing of free-standing liquid metal structures. ... Ladd, C.; So, J.-H.; Muth, J.; Dickey, M. D.3D Printing of Free Standing Liquid Metal Microstructures Adv. ... 3D Printing of Free Standing Liquid Metal Microstructures ...

Michael D. Dickey

2014-10-06T23:59:59.000Z

151

Evaluation of iron- and manganese-based mono- and mixed-metallic oxygen carriers for chemical looping combustion  

Science Journals Connector (OSTI)

Abstract Chemical looping combustion (CLC) is an emerging technology for clean combustion of fossil fuels with inherent CO2 capture. In the present work, we investigate the use of iron and manganese based mixed oxides (MnxFe1?x–CeO2) supported on CeO2 as oxygen carriers in CLC. The low cost and low toxicity of iron and manganese make them interesting candidates for CLC, but both mono-metallic carriers suffer from issues of low reactivity, and manganese is additionally prone to form undesired spinel structures with typical oxide supports. Mono- and bimetallic oxygen carriers were synthesized across the entire spectrum of compositions from pure Mn to pure Fe (with x = 0, 0.1, 0.33, 0.5, 0.8, 0.9, 1), characterized, and tested in thermogravimetric and fixed-bed reactor studies using H2 and CH4 as fuels. We find that the use of ceria as support results in stable operation for all compositions of the metal phase, including pure Mn. Bimetallic carriers with high Fe content, which contain a FeMnO3 phase, exhibit an unusual, reversible de-alloying/re-alloying behavior during cyclic redox operation, which precludes any synergistic effects between the two metals and results in slowed reduction kinetics. However, Mn-rich carriers show a pronounced increase in carrier reactivity and selectivity for total oxidation of methane due to the addition of small amounts of Fe, indicating the promise of appropriately designed FeMn carriers as low-cost, environmentally benign oxygen carrier materials for chemical looping combustion.

Saurabh Bhavsar; Brian Tackett; Götz Veser

2014-01-01T23:59:59.000Z

152

Development of Iron Oxide Carriers for Chemical Looping Combustion Using Sol?Gel  

Science Journals Connector (OSTI)

Development of Iron Oxide Carriers for Chemical Looping Combustion Using Sol?Gel ... Industrial & Engineering Chemistry Research (2008), 47 (6), 1747-1754 CODEN: IECRED; ISSN:0888-5885. ... Ishida, M.; Takeshita, K.; Suzuki, K.; Ohba, T. Application of FeO?AlO composite particles as solid looping material of the chemical-loop combustor Energy Fuels 2005, 19, 2514– 2518 ...

A. M. Kierzkowska; C. D. Bohn; S. A. Scott; J. P. Cleeton; J. S. Dennis; C. R. Müller

2010-04-30T23:59:59.000Z

153

A Diode Laser Chemical Sensor Utilizing an Oxidized Lower Cladding Layer for High Sensitivity  

E-Print Network (OSTI)

A Diode Laser Chemical Sensor Utilizing an Oxidized Lower Cladding Layer for High Sensitivity Chad@engineering.ucsb.edu Tel: 805.893.7065 Abstract: We demonstrate a novel chemical sensor incorporating a symmetrically-clad clad, and have tight optical confinement [4]. Symmetrically clad dielectric waveguides have been

Coldren, Larry A.

154

Metal Hydride Chemical Heat Pumps for Industrial Use  

E-Print Network (OSTI)

Hydriding alloys are intermetallic absorbent compounds which have the remarkable quality of absorbing very large quantities of hydrogen gas per unit volume of metallic powder. The absorption and desorption of hydrogen are exothermic and endothermic...

Ally, M. R.; Rebello, W. J.; Rosso, M. J., Jr.

1984-01-01T23:59:59.000Z

155

Thermal resistance of contact with oxidized metal surfaces  

Science Journals Connector (OSTI)

A model of an elementary heat channel is analyzed which simulates the ... is derived which describes the increment of contact resistance due to the presence of an oxide...

V. M. Popov; A. I. Krasnoborod'ko

1973-10-01T23:59:59.000Z

156

Detailed chemical kinetic oxidation mechanism for a biodiesel Olivier Herbineta  

E-Print Network (OSTI)

experiments in an engine and oxidation of rapeseed oil methyl esters in a jet- stirred reactor. An important to biofuels and due to the presence of the ester group in the reactant. The model also predicts ignition delay

Paris-Sud XI, Université de

157

Photoelectron Imaging Spectroscopic Investigations of Transition Metal Silicides and Oxides.  

E-Print Network (OSTI)

??This dissertation presents the experimental progress in the use of photoelectron imaging spectroscopy to probe the electronic structure of negatively charged transition metal silicides and… (more)

Gunaratne, K. Don

2012-01-01T23:59:59.000Z

158

Effect of Carbon Deposition on the Oxidation Rate of Copper/Bentonite in the Chemical Looping Process  

SciTech Connect

The presented work is part of the Industrial Carbon Management Initiative (ICMI) on the development of metal oxide oxygen carriers for use in the chemical looping combustion process. An oxygen carrier, CuO/bentonite (60:40%), was reacted with methane gas and then oxidized in air. The change in weight and reaction gas concentrations were measured using a thermogravimetric analyzer (TGA) equipped with a real-time gas analyzer. The reduction–oxidation cycle was conducted within the temperature range of 750–900 °C for 10 cycles, using 20, 50, and100% CH{sub 4} concentrations in N{sub 2} for the reduction segment and dry air for the oxidation segment. Several analysis methods were evaluated to fit the oxidation of reduced CuO (i.e., Cu) data over the complete conversion range with suitable rate expressions derived from existing models for oxidation, including the shrinking core model (diffusion and reaction control), first- and second-order reaction rates, parallel and series reaction mechanisms, and Johnson–Mehl–Avrami (JMA) rate. The best agreement between the experimental data and the models of the Cu oxidation was accomplished using the JMA model. The reactivity of the oxygen carrier during the oxidation reactions was affected by the CH{sub 4} concentration as well as the temperature. The rate of fractional uptake of oxygen onto the carrier decreased as the temperature increased, contrary to expectations and indicative that the mechanism is changing during the test. Analysis of the exit gas provided evidence of carbon deposition on the reduced sorbent particle and resulted in the CO{sub 2} product upon oxidation. The oxidation of this carbon releases significant heat that is capable of changing the particle morphology (Zhu, Y.; Mimura, K.; Isshiki, M. Oxid. Met. 2004, 62, 207?222). On the basis of experimental results, the overall reaction process in the fuel reactor may be considered to consist of the decomposition of CH{sub 4} into C and H{sub 2} and reduction of CuO/bentonite by the resulting H{sub 2} and the parallel reaction of CH{sub 4} with CuO/bentonite. The extent of carbon deposition in the carrier particle increased with an increasing temperature and CH{sub 4} concentration. This deposited carbon not only leads to CO{sub 2} release from the oxidation reactor but, more importantly, causes degredation of the carrier capacity and its reactivity.

Monazam, Esmail R.; Breault, Ronald W.; Siriwardane, Ranjani

2012-11-01T23:59:59.000Z

159

Plasma enhanced chemical vapor deposition (PECVD) method of forming vanadium oxide films and vanadium oxide thin-films prepared thereby  

DOE Patents (OSTI)

A method is disclosed of forming a vanadium oxide film on a substrate utilizing plasma enhanced chemical vapor deposition. The method includes positioning a substrate within a plasma reaction chamber and then forming a precursor gas comprised of a vanadium-containing chloride gas in an inert carrier gas. This precursor gas is then mixed with selected amounts of hydrogen and oxygen and directed into the reaction chamber. The amounts of precursor gas, oxygen and hydrogen are selected to optimize the final properties of the vanadium oxide film An rf plasma is generated within the reaction chamber to chemically react the precursor gas with the hydrogen and the oxygen to cause deposition of a vanadium oxide film on the substrate while the chamber deposition pressure is maintained at about one torr or less. Finally, the byproduct gases are removed from the plasma reaction chamber.

Zhang, Ji-Guang (Golden, CO); Tracy, C. Edwin (Golden, CO); Benson, David K. (Golden, CO); Turner, John A. (Littleton, CO); Liu, Ping (Lakewood, CO)

2000-01-01T23:59:59.000Z

160

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

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

Tuning the Metal-Adsorbate Chemical Bond through the Ligand Effect on Tuning the Metal-Adsorbate Chemical Bond through the Ligand Effect on Platinum Subsurface Alloys Tuesday, July 31, 2012 The ability to design and control the activities of transition metal catalysts, which are scarce in nature and thus expensive, has been of great importance to the development of economical industrial and energy-saving processes. Over the years several methods have been suggested, especially for processes using platinum, which is the most active metal catalyst for many important reactions, including the reduction of oxygen in fuel cells. Figure 1. Figure 1. Schematic representation of Pt subsurface alloys and corresponding shifts in Pt d-band center. Tuning chemical functionality by implementing a ligand effect - in other words, by changing the atomic nearest neighbor environment - is a

Note: This page contains sample records for the topic "metal oxide chemical" 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

Method of nitriding, carburizing, or oxidizing refractory metal articles using microwaves  

DOE Patents (OSTI)

A method of nitriding an article of refractory-nitride-forming metal or metalloids. A consolidated metal or metalloid article is placed inside a microwave oven and nitrogen containing gas is introduced into the microwave oven. The metal or metalloid article is heated to a temperature sufficient to react the metal or metalloid with the nitrogen by applying a microwave energy within the microwave oven. The metal or metalloid article is maintained at that temperature for a period of time sufficient to convert the article of metal or metalloid to an article of refractory nitride. in addition, a method of applying a coating, such as a coating of an oxide, a carbide, or a carbo-nitride, to an article of metal or metalloid by microwave heating.

Holcombe, C.E.; Dykes, N.L.; Tiegs, T.N.

1992-10-13T23:59:59.000Z

162

Method of nitriding, carburizing, or oxidizing refractory metal articles using microwaves  

DOE Patents (OSTI)

A method of nitriding an article of refractory-nitride-forming metal or metalloids. A consolidated metal or metalloid article is placed inside a microwave oven and nitrogen containing gas is introduced into the microwave oven. The metal or metalloid article is heated to a temperature sufficient to react the metal or metalloid with the nitrogen by applying a microwave energy within the microwave oven. The metal or metalloid article is maintained at that temperature for a period of time sufficient to convert the article of metal or metalloid to an article of refractory nitride. in addition, a method of applying a coating, such as a coating of an oxide, a carbide, or a carbo-nitride, to an article of metal or metalloid by microwave heating.

Holcombe, Cressie E. (Knoxville, TN); Dykes, Norman L. (Oak Ridge, TN); Tiegs, Terry N. (Lenoir City, TN)

1992-01-01T23:59:59.000Z

163

Fabrication of superconducting metal-oxide textiles by heating impregnated polymeric material in a weakly oxidizing atmosphere  

SciTech Connect

A process is described for producing crystalline fibers, textiles or shapes comprised of YBa[sub 2]Cu[sub 3]O[sub 7[minus]x] where x varies from about 0 to about 0.4, said process comprising: (a) impregnating a preformed organic polymeric material with three metal compounds to provide metal elements in said material in substantially the atomic ratio occurring in said YBa[sub 2]Cu[sub 3]O[sub 7[minus]x]; (b) heating said impregnated material in a weakly oxidizing atmosphere containing from about 0.05% to about 2% oxygen by volume to a temperature sufficiently high to at least partially pyrolize and oxidize said organic material and at least partially oxidize said metal compounds substantially without ignition of said organic material and without formation of a molten phase or reaching a decomposition temperature of said YBa[sub 2]Cu[sub 3]O[sub 7[minus]x]; and (c) cooling the resulting material in at least a moderately oxidizing atmosphere to room temperature so as to obtain said fibers, textiles or shapes.

Van den Sype, J.S.

1993-07-13T23:59:59.000Z

164

Nonlithographic Patterning and Metal-Assisted Chemical Etching for  

E-Print Network (OSTI)

,14 Recent innovative techniques such as the cooling of laser ablated Si in supercritical CO2 and metal on the design and performance of many types of devices, including batteries, solar cells, detectors nanowire arrays for solar cell applications has also been demonstrated with promising results, owing

Li, Xiuling

165

Perspectives on the metallic interconnects for solid oxide fuel cells  

Science Journals Connector (OSTI)

The various stages and progress in the development of interconnect materials for solid oxide fuel cells (SOFCs) over the last two decades are reviewed. The criteria for the application of materials as intercon...

Wei-zhong Zhu; Mi Yan

2004-12-01T23:59:59.000Z

166

Electrostatic Cooperativity of Hydroxyl Groups at Metal Oxide...  

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

Oxide Surfaces. Abstract: The O-H bond distribution of hydroxyl groups at the 110 goethite (R-FeOOH) surface was investigated by molecular dynamics. This distribution was...

167

Measuring the Kinetics of the Reduction of Iron Oxide with Carbon Monoxide in a Fluidized Bed  

Science Journals Connector (OSTI)

Combusting a solid fuel in the presence of a metal oxide rather than air, chemical looping combustion, generates CO2suitable for sequestration and the reduced metal. For the case of iron, the reduced oxide can be...

C. D. Bohnt; J. P. Cleeton; C. M. Miiller…

2010-01-01T23:59:59.000Z

168

Use of amine oxide surfactants for chemical flooding EOR (enhanced oil recovery)  

SciTech Connect

The use of amine oxides with and without alcohols as cosolvents, and in combination with other surfactants as mixed micellar formulations for enhanced oil recovery by surfactant flooding was investigated. Amine oxides are a salt-tolerant class of surfactants that produce low interfacial tension and can develop viscosity without the addition of polymers. These salt-tolerant formulations generate three-phase regions with hydrocarbons over a broad salinity range, develop moderate solubilization, and produce low interfacial tensions, however oil recovery from amine oxide-alcohol phase behavior optimized formulations was directly dependent upon the quantity of surfactant injected. The large pore volume and high concentration of surfactant required prohibits their economic use as the primary surfactant in chemical flooding EOR. Dimethylalkylamine oxides are useful as cosurfactants and viscosifiers in formulations with other surfactants for chemical flooding EOR but the use of ethoxylated and propoxylated amine oxides should be avoided due to the decomposition of these amine oxides under reservoir conditions. Phase behavior, phase inversion temperatures, and viscosity scans have been correlated with surfactant structures to provide a guide for amine oxide applications in chemical flooding. 36 refs., 5 figs., 6 tabs.

Olsen, D.K.

1989-11-01T23:59:59.000Z

169

Mesoporous metal oxide microsphere electrode compositions and their methods of making  

SciTech Connect

Compositions and methods of making are provided for treated mesoporous metal oxide microspheres electrodes. The compositions comprise (a) microspheres with an average diameter between 200 nanometers (nm) and 10 micrometers (.mu.m); (b) mesopores on the surface and interior of the microspheres, wherein the mesopores have an average diameter between 1 nm and 50 nm and the microspheres have a surface area between 50 m.sup.2/g and 500 m.sup.2/g, and wherein the composition has an electrical conductivity of at least 1.times.10.sup.-7 S/cm at 25.degree. C. and 60 MPa. The methods of making comprise forming a mesoporous metal oxide microsphere composition and treating the mesoporous metal oxide microspheres by at least one method selected from the group consisting of: (i) annealing in a reducing atmosphere, (ii) doping with an aliovalent element, and (iii) coating with a coating composition.

Parans Paranthaman, Mariappan; Bi, Zhonghe; Bridges, Craig A; Brown, Gilbert M

2014-12-16T23:59:59.000Z

170

Formation of amorphous metal alloys by chemical vapor deposition  

DOE Patents (OSTI)

Amorphous alloys are deposited by a process of thermal dissociation of mixtures of organometallic compounds and metalloid hydrides,e.g., transition metal carbonyl, such as nickel carbonyl and diborane. Various sizes and shapes of deposits can be achieved, including near-net-shape free standing articles, multilayer deposits, and the like. Manipulation or absence of a magnetic field affects the nature and the structure of the deposit. 1 fig.

Mullendore, A.W.

1988-03-18T23:59:59.000Z

171

Determination of Interfacial Adhesion Strength between Oxide Scale and Substrate for Metallic SOFC Interconnects  

SciTech Connect

The interfacial adhesion strength between the oxide scale and the substrate is crucial to the reliability and durability of metallic interconnects in SOFC operating environments. It is necessary, therefore, to establish a methodology to quantify the interfacial adhesion strength between the oxide scale and the metallic interconnect substrate, and furthermore to design and optimize the interconnect material as well as the coating materials to meet the design life of an SOFC system. In this paper, we present an integrated experimental/analytical methodology for quantifying the interfacial adhesion strength between oxide scale and a ferritic stainless steel interconnect. Stair-stepping indentation tests are used in conjunction with subsequent finite element analyses to predict the interfacial strength between the oxide scale and Crofer 22 APU substrate.

Sun, Xin; Liu, Wenning N.; Stephens, Elizabeth V.; Khaleel, Mohammad A.

2008-01-21T23:59:59.000Z

172

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

Science Journals Connector (OSTI)

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

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

2014-04-24T23:59:59.000Z

173

Metal oxide coating on first mirror in fusion reactor with carbon wall  

Science Journals Connector (OSTI)

Abstract The lifetime of diagnostic equipment in a fusion reactor is typically very short. The first mirror used to reflect optical signals for diagnostics plays a crucial role in the reactor, and it is highly important to develop a more durable first mirror which can survive in the hostile environment. In this work, by conducting electron beam deposition on molybdenum substrates, metallic oxide mirrors are prepared and studied in the simulated environment. The multi-layered metal oxide mirror exhibits much higher reflectivity than the original molybdenum one and the in situ technique to monitor the performance of the first mirror is developed and described.

Xirui Hou; Zhengwei Wu; Paul K. Chu

2014-01-01T23:59:59.000Z

174

Chemical probes of metal cluster structure--Fe, Co, Ni, and Cu  

SciTech Connect

Chemical reactivity is one of the few methods currently available for investigating the geometrical structure of isolated transition metal clusters. In this paper we summarize what is currently known about the structures of clusters of four transition metals, Fe, Co, Ni, and Cu, in the size range from 13 to 180 atoms. Chemical probes used to determine structural information include reactions with H{sub 2}(D{sub 2}), H{sub 2}0, NH{sub 3} and N{sub 2}. Measurements at both low coverage and at saturation are discussed.

Parks, E.K.; Zhu, L.; Ho, J.; Riley, S.J.

1992-09-01T23:59:59.000Z

175

Chemical probes of metal cluster structure--Fe, Co, Ni, and Cu  

SciTech Connect

Chemical reactivity is one of the few methods currently available for investigating the geometrical structure of isolated transition metal clusters. In this paper we summarize what is currently known about the structures of clusters of four transition metals, Fe, Co, Ni, and Cu, in the size range from 13 to 180 atoms. Chemical probes used to determine structural information include reactions with H{sub 2}(D{sub 2}), H{sub 2}0, NH{sub 3} and N{sub 2}. Measurements at both low coverage and at saturation are discussed.

Parks, E.K.; Zhu, L.; Ho, J.; Riley, S.J.

1992-01-01T23:59:59.000Z

176

Atomic-scale chemical quantification of oxide interfaces using energy-dispersive X-ray spectroscopy  

SciTech Connect

Atomic-scale quantification of chemical composition across oxide interfaces is important for understanding physical properties of epitaxial oxide nanostructures. Energy-dispersive X-ray spectroscopy (EDS) in an aberration-corrected scanning transmission electron microscope was used to quantify chemical composition across the interface of ferromagnetic La{sub 0.7}Sr{sub 0.3}MnO{sub 3} and antiferromagnetic BiFeO{sub 3} quantum structure. This research demonstrates that chemical composition at atomic columns can be quantified by Gaussian peak-fitting of EDS compositional profiles across the interface. Cation diffusion was observed at both A- and B-sublattice sites; and asymmetric chemical profiles exist across the interface, consistent with the previous studies.

Lu, Ping; Van Benthem, Mark [Sandia National Laboratories, P.O. Box 5800, MS 1411, Albuquerque, New Mexico 87185-1411 (United States)] [Sandia National Laboratories, P.O. Box 5800, MS 1411, Albuquerque, New Mexico 87185-1411 (United States); Xiong, Jie; Jia, Quanxi [Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)] [Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

2013-04-29T23:59:59.000Z

177

Reducible Oxide Based Oxygen Carriers for Chemical Looping Combustion and Partial Oxidation of Methane.  

E-Print Network (OSTI)

??Chemical looping combustion (CLC) is a novel combustion technology that offers a highly efficient route towards clean combustion of fuel with inherent CO2 capture. In… (more)

Bhavsar, Saurabh

2014-01-01T23:59:59.000Z

178

Metal oxide/organic interface investigations for photovoltaic devices  

E-Print Network (OSTI)

summarises work I have carried out as a PhD student of the Optoelectronics Group at Cavendish Laboratory of the University of Cambridge since October 2010. I am thankful to the Engineering and Physical Sciences Research Council and the A.G. Leventis... are often used in many other optoelectronic devices such as photovoltaics and light emitting diodes. Sufficiently conducting oxides with the appropriate electron affinities and ionisation potentials, can be employed as charge transport and injection layers...

Pachoumi, Olympia

2014-10-07T23:59:59.000Z

179

Transition metal oxide improves overall efficiency and maintains performance with inexpensive metals.  

E-Print Network (OSTI)

of a typical device (middle); schematic energy diagram of interfacial layers PbS/MoOx, indicating carrier metals. A research team at the National Renewable Energy Laboratory (NREL) has demonstrated the overall conversion efficiency. This allows for inexpensive metals such as Al to be employed without loss

180

Criteria for Preparing and Packaging Plutonium Metals and Oxides for Long-Term Storage  

SciTech Connect

This Standard provides criteria for packaging of plutonium metals and stabilized oxides for storage periods of at least 50 years. To meet the criteria, plutonium-bearing materials must be in stable forms and be packaged in containers designed to maintain their integrity both under normal storage conditions and during anticipated handling accidents.

NONE

1994-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "metal oxide chemical" 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

Understanding the NMR shifts in paramagnetic transition metal oxides using density functional theory calculations  

E-Print Network (OSTI)

obvious. In this paper, we show by means of density functional theory DFT calcula- tions that a rationalUnderstanding the NMR shifts in paramagnetic transition metal oxides using density functional functional theory DFT calculations in the generalized gradient approximation. For each compound, we calculate

Ceder, Gerbrand

182

Nanotube Formation: Researchers Learn To Control The Dimensions Of Metal Oxide Nanotubes  

E-Print Network (OSTI)

Nanotube Formation: Researchers Learn To Control The Dimensions Of Metal Oxide Nanotubes ScienceDaily (Aug. 29, 2007) -- Moving beyond carbon nanotubes, researchers are developing insights-walled inorganic nanotubes could be useful in a range of nanotechnology applications that require precise control

Nair, Sankar

183

Methane-to-Methanol Conversion by Gas-Phase Transition Metal Oxide Cations: Experiment and Theory  

E-Print Network (OSTI)

Methane-to-Methanol Conversion by Gas-Phase Transition Metal Oxide Cations: Experiment and Theory Ricardo B. Metz Department of Chemistry, University of Massachusetts, Amherst, MA 01003 USA Abstract Gas such as methanol has attracted great experimental and theoretical interest due to its importance as an industrial

Metz, Ricardo B.

184

Transition metal-catalyzed oxidation of atmospheric sulfur: Global implications for the sulfur budget  

E-Print Network (OSTI)

of the oxygen-17 excess (D17 O) of sulfate in the Arctic to quantify the sulfate source from aqueous SO2 (S concentrations, respectively. The solubility and oxidation state of these metals is determined by cloud liquid discrepancies with surface SO2 and sulfate observations in Europe. Oxygen isotope measurements of sulfate

Alexander, Becky

185

Self-assembly of oxide-supported metal clusters into ring-like Kristoffer Meinander,  

E-Print Network (OSTI)

Self-assembly of oxide-supported metal clusters into ring-like structures Kristoffer Meinander, Kai, Finland Abstract Self-assembly is a phenomenon that continuously occurs at the nanoscale, as atoms form of these organized systems, but the precise mechanism, with which this self-assembly progresses, is seldom known

Nordlund, Kai

186

Electrochromic nickel oxide simultaneously doped with lithium and a metal dopant  

DOE Patents (OSTI)

An electrochromic device comprising a counter electrode layer comprised of lithium metal oxide which provides a high transmission in the fully intercalated state and which is capable of long-term stability, is disclosed. Methods of making an electrochromic device comprising such a counter electrode are also disclosed.

Gillaspie, Dane T; Weir, Douglas G

2014-04-01T23:59:59.000Z

187

AC conductivity of nanoporous metal-oxide photoanodes for solar energy conversion  

E-Print Network (OSTI)

AC conductivity of nanoporous metal-oxide photoanodes for solar energy conversion Steven J. Konezny% solar-to-electric energy conversion efficiency) exploited the large surface area of nanoporous thin of nanoporous thin films without increasing the recombination rate. To ensure efficient charge carrier

Konezny, Steven J.

188

Borohydride reduction: A technique to synthesize nanosize transition metal oxides and nanocomposites  

SciTech Connect

This paper summarizes recent studies of using borohydride reduction to synthesize W, transition metal oxides such as WO{sub 2} and MoO{sub 2}, and Fe-Al{sub x}B{sub y}O{sub z}

Zhu, Yuntian T.; Lowe, T.C.; Stout, M.G. [Los Alamos National Lab., NM (United States); Manthiram, A.; Guggilla, S. [Texas Univ., Austin, TX (United States). Center for Materials Science and Engineering

1996-06-01T23:59:59.000Z

189

High density adsorbed oxygen on Rh,,111... and enhanced routes to metallic oxidation using atomic oxygen  

E-Print Network (OSTI)

High density adsorbed oxygen on Rh,,111... and enhanced routes to metallic oxidation using atomic oxygen K. D. Gibson, Mark Viste, Errol C. Sanchez, and S. J. Sibener The James Franck Institute; accepted 30 November 1998 Exposure of Rh 111 to atomic oxygen leads to the facile formation of a full

Sibener, Steven

190

Surfactant Organic Molecules Restore Magnetism in Metal-Oxide Nanoparticle Surfaces  

E-Print Network (OSTI)

Surfactant Organic Molecules Restore Magnetism in Metal-Oxide Nanoparticle Surfaces Juan Salafranca, Nashville, Tennessee 37235, United States *S Supporting Information ABSTRACT: The properties of magnetic nanoparticles tend to be depressed by the unavoidable presence of a magnetically inactive surface layer. However

Pennycook, Steve

191

Chemical Reaction of Metal-Carbon Binary Cluster Anions by FT-ICR Mass Spectrometer  

E-Print Network (OSTI)

45 48 51 54 57 60 Number of Carbon Atoms Intensity(arbitrary) (a) as injected (b) SWIFTed (c) NO 1sChemical Reaction of Metal-Carbon Binary Cluster Anions by FT-ICR Mass Spectrometer S. Maruyama, M- fullerene and single walled carbon nanotubes are investigated through experimental studies of interaction

Maruyama, Shigeo

192

Observing single molecule chemical reactions on metal nanoparticles.  

SciTech Connect

We report the study of the photodecomposition of single Rhodamine 6G (R6G) dye molecules adsorbed on silver nanoparticles. The nanoparticles were immobilized and spatially isolated on polylysine-derivatized glass coverslips, and confocal laser microspectroscopy was used to obtain surface-enhanced Raman scattering (SERS) spectra from individual R6G molecules. The photodecomposition of these molecules was observed with 150-ms temporal resolution. The photoproduct was identified as graphitic carbon based on the appearance of broad SERS vibrational bands at 1592 cm{sup -1} and 1340 cm{sup -1} observed in both bulk and averaged single-molecule photoproduct spectra. In contrast, when observed at the single-molecule level, the photoproduct yielded sharp SERS spectra. The inhomogeneous broadening of the bulk SERS spectra is due to a variety of photoproducts in different surface orientations and is a characteristic of ensemble-averaged measurements of disordered systems. These single-molecule studies indicate a photodecomposition pathway by which the R6G molecule desorbs from the metal surface, an excited-state photoreaction occurs, and the R6G photoproduct(s) readsorbs to the surface. A SERS spectrum is obtained when either the intact R6G or the R6G photoproduct(s) are adsorbed on a SERS-active site. This work further illustrates the power of single-molecule spectroscopy (SMS) to reveal unique behaviors of single molecules that are not discernable with bulk measurements.

Emory, S. R. (Steven R.); Ambrose, W. Patrick; Goodwin, P. M. (Peter M); Keller, Richard A.

2001-01-01T23:59:59.000Z

193

ESS 2012 Peer Review - Architectural Diversity of Metal Oxide Nanostructures - Esther Takeuchi, Stony Brook University  

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

Architectural Diversity of Metal Oxide Nanostructures: Architectural Diversity of Metal Oxide Nanostructures: An Opportunity for the Rational Optimization of Group II Cation Based Batteries. Esther S. Takeuchi, Kenneth J. Takeuchi, Amy C. Marschilok esther.takeuchi@stonybrook.edu, kenneth.takeuchi.1@stonybrook.edu, amy.marschilok@stonybrook.edu Utilize earth abundant, low cost elements with minimal environmental impact as battery materials. Exploit magnesium due to air stability and ~1,000X higher natural abundance than lithium and ~5,000X higher abundance than lead. Cathode materials feature Mn, Fe or V metal centers. Strategy Results Results This project targets some of the unique needs of large scale power storage: 1) reduced cost 2) low environmental impact 3) scalability 4) reversibility

194

Nanostructured europium oxide thin films deposited by pulsed laser ablation of a metallic target in a He buffer atmosphere  

SciTech Connect

Nanostrucured europium oxide and hydroxide films were obtained by pulsed Nd:YAG (532 nm) laser ablation of a europium metallic target, in the presence of a 1 mbar helium buffer atmosphere. Both the produced film and the ambient plasma were characterized. The plasma was monitored by an electrostatic probe, for plume expansion in vacuum or in the presence of the buffer atmosphere. The time evolution of the ion saturation current was obtained for several probe to substrate distances. The results show the splitting of the plume into two velocity groups, being the lower velocity profile associated with metal cluster formation within the plume. The films were obtained in the presence of helium atmosphere, for several target-to-substrate distances. They were analyzed by Rutherford backscattering spectrometry, x-ray diffraction, and atomic force microscopy, for as-deposited and 600 deg. C treated-in-air samples. The results show that the as-deposited samples are amorphous and have chemical composition compatible with europium hydroxide. The thermally treated samples show x-ray diffraction peaks of Eu{sub 2}O{sub 3}, with chemical composition showing excess oxygen. Film nanostructuring was shown to be strongly correlated with cluster formation, as shown by velocity splitting in probe current versus time plots.

Luna, H.; Franceschini, D. F.; Prioli, R.; Guimaraes, R. B.; Sanchez, C. M.; Canal, G. P.; Barbosa, M. D. L.; Galvao, R. M. O. [Instituto de Fisica, Universidade Federal do Rio de Janeiro, Cx. Postal 68528, Rio de Janeiro, RJ 21941-972 (Brazil); Instituto de Fisica, Universidade Federal Fluminense, Niteroi, RJ 24210-346 (Brazil); Departamento de Fisica, Pontificia Universidade Catolica do Rio de Janeiro, Rua Marques de Sao Vicente 225, 22453-970, Rio de Janeiro, RJ (Brazil); Instituto de Fisica, Universidade Federal Fluminense, Niteroi, RJ 24210-346 (Brazil); Centro Brasileiro de Pesquisas Fisicas, Laboratorio de Plasmas Aplicados, Rua Xavier Sigaud 150, 22290-180, Rio de Janeiro, RJ (Brazil); Instituto de Fisica, Departamento de Fisica Nuclear, Universidade de Sao Paulo, Caixa Postal 66328, 05315-970, Sao Paulo, SP (Brazil); Centro Brasileiro de Pesquisas Fisicas, Laboratorio de Plasmas Aplicados, Rua Xavier Sigaud 150, 22290-180, Rio de Janeiro, RJ (Brazil)

2010-09-15T23:59:59.000Z

195

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

E-Print Network (OSTI)

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

Davies, Thomas Edward.

2006-01-01T23:59:59.000Z

196

Abstract No. pan0505 Sorption of Heavy Metal Contaminants onto Hydrated Ferric Oxides: Mechanistic Modeling using X-ray  

E-Print Network (OSTI)

Abstract No. pan0505 Sorption of Heavy Metal Contaminants onto Hydrated Ferric Oxides: Mechanistic. Hence, to understand the mobility and bioavailability of these metal contaminants, these sorption suggesting that sorption of these metal ions onto ferrihydrite can be described by one average type of site

Sparks, Donald L.

197

The Velocity of Oxidation of the Metals and the Structure of Coloured Oxide Films  

Science Journals Connector (OSTI)

... The simplest explanation of these facts would appear to be that the treatment causes a roughening of the surface, whereby the effective area of the metal is increased. If this ...

D. H. BANGHAM; J. STAFFORD

1925-01-17T23:59:59.000Z

198

Photonic crystal membrane reflectors by magnetic field-guided metal-assisted chemical etching  

SciTech Connect

Metal-assisted chemical etching (MacEtch) is a simple etching method that uses metal as the catalyst for anisotropic etching of semiconductors. However, producing nano-structures using MacEtch from discrete metal patterns, in contrast to interconnected ones, has been challenging because of the difficulties in keeping the discrete metal features in close contact with the semiconductor. We report the use of magnetic field-guided MacEtch (h-MacEtch) to fabricate periodic nanohole arrays in silicon-on-insulator (SOI) wafers for high reflectance photonic crystal membrane reflectors. This study demonstrates that h-MacEtch can be used in place of conventional dry etching to produce ordered nanohole arrays for photonic devices.

Balasundaram, Karthik; Mohseni, Parsian K.; Li, Xiuling, E-mail: wzhou@uta.edu, E-mail: xiuling@illinois.edu [Micro and Nanotechnology Laboratory, Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States)] [Micro and Nanotechnology Laboratory, Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States); Shuai, Yi-Chen; Zhao, Deyin; Zhou, Weidong, E-mail: wzhou@uta.edu, E-mail: xiuling@illinois.edu [Department of Electrical Engineering, NanoFAB Center, University of Texas at Arlington, Arlington, Texas 76019 (United States)] [Department of Electrical Engineering, NanoFAB Center, University of Texas at Arlington, Arlington, Texas 76019 (United States)

2013-11-18T23:59:59.000Z

199

Method of making a catalytic metal oxide selective for the conversion of a gas and a coating system for the selective oxidation of hydrocarbons and carbon monoxide  

SciTech Connect

A method is described of making a catalytic metal oxide selective to catalyzing the conversion of given gas species, comprising: intimately supporting a solid film of catalytic metal oxide on an electrically conducting material, said film having an exposed outer surface spaced no greater than 1,000 angstroms from said conducting material and said conducting material being matched to the composition of said oxide to change the electron state of the exposed outer surface to promote a reaction between given gas species and said oxide, said metal oxide being selected from the group consisting of TiO[sub 2], SnO[sub 2], FeO, SrTiO[sub 3], and CoO, and said conducting material being selected from the group consisting of Au, Pt, TiN, Pd, Rh, Ni, and Co.

Logothetis, E.M.; Soltis, R.E.

1993-07-20T23:59:59.000Z

200

Electrical conductivity in oxygen-deficient phases of transition metal oxides from first-principles calculations.  

SciTech Connect

Density-functional theory calculations, ab-initio molecular dynamics, and the Kubo-Greenwood formula are applied to predict electrical conductivity in Ta2Ox (0x5) as a function of composition, phase, and temperature, where additional focus is given to various oxidation states of the O monovacancy (VOn; n=0,1+,2+). Our calculations of DC conductivity at 300K agree well with experimental measurements taken on Ta2Ox thin films and bulk Ta2O5 powder-sintered pellets, although simulation accuracy can be improved for the most insulating, stoichiometric compositions. Our conductivity calculations and further interrogation of the O-deficient Ta2O5 electronic structure provide further theoretical basis to substantiate VO0 as a donor dopant in Ta2O5 and other metal oxides. Furthermore, this dopant-like behavior appears specific to neutral VO cases in both Ta2O5 and TiO2 and was not observed in other oxidation states. This suggests that reduction and oxidation reactions may effectively act as donor activation and deactivation mechanisms, respectively, for VO0 in transition metal oxides.

Bondi, Robert James; Desjarlais, Michael Paul; Thompson, Aidan Patrick; Brennecka, Geoffrey L.; Marinella, Matthew

2013-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "metal oxide chemical" 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

Electrochromic properties of iron oxide thin films prepared by chemical vapor deposition  

SciTech Connect

Iron oxide thin films were prepared by chemical vapor deposition. The source material was iron (III) acetylacetonate. The Fe{sub 2}O{sub 3} films were produced at a substrate temperature above 200 C. The films deposited at a substrate temperature above 300 C were polycrystalline {beta}-Fe{sub 2}O{sub 3}. Reduction and oxidation of the amorphous films in a 0.3 M LiClO{sub 4} propylene carbonate solution caused desirable changes in optical absorption. Coulometry indicated that the coloration efficiency was 6.0 to 6.5 cm{sup 2}/C.

Maruyama, Toshiro; Kanagawa, Tetsuya [Kyoto Univ. (Japan). Dept. of Chemical Engineering

1996-05-01T23:59:59.000Z

202

Secondary cell with orthorhombic alkali metal/manganese oxide phase active cathode material  

DOE Patents (OSTI)

An alkali metal manganese oxide secondary cell is disclosed which can provide a high rate of discharge, good cycling capabilities, good stability of the cathode material, high specific energy (energy per unit of weight) and high energy density (energy per unit volume). The active material in the anode is an alkali metal and the active material in the cathode comprises an orthorhombic alkali metal manganese oxide which undergoes intercalation and deintercalation without a change in phase, resulting in a substantially linear change in voltage with change in the state of charge of the cell. The active material in the cathode is an orthorhombic structure having the formula M.sub.x Z.sub.y Mn.sub.(1-y) O.sub.2, where M is an alkali metal; Z is a metal capable of substituting for manganese in the orthorhombic structure such as iron, cobalt or titanium; x ranges from about 0.2 in the fully charged state to about 0.75 in the fully discharged state, and y ranges from 0 to 60 atomic %. Preferably, the cell is constructed with a solid electrolyte, but a liquid or gelatinous electrolyte may also be used in the cell.

Doeff, Marca M. (Hayward, CA); Peng, Marcus Y. (Cupertino, CA); Ma, Yanping (Albany, CA); Visco, Steven J. (Berkeley, CA); DeJonghe, Lutgard C. (Lafayette, CA)

1996-01-01T23:59:59.000Z

203

Secondary cell with orthorhombic alkali metal/manganese oxide phase active cathode material  

DOE Patents (OSTI)

An alkali metal manganese oxide secondary cell is disclosed which can provide a high rate of discharge, good cycling capabilities, good stability of the cathode material, high specific energy (energy per unit of weight) and high energy density (energy per unit volume). The active material in the anode is an alkali metal and the active material in the cathode comprises an orthorhombic alkali metal manganese oxide which undergoes intercalation and deintercalation without a change in phase, resulting in a substantially linear change in voltage with change in the state of charge of the cell. The active material in the cathode is an orthorhombic structure having the formula M{sub x}Z{sub y}Mn{sub (1{minus}y)}O{sub 2}, where M is an alkali metal; Z is a metal capable of substituting for manganese in the orthorhombic structure such as iron, cobalt or titanium; x ranges from about 0.2 in the fully charged state to about 0.75 in the fully discharged state, and y ranges from 0 to 60 atomic %. Preferably, the cell is constructed with a solid electrolyte, but a liquid or gelatinous electrolyte may also be used in the cell. 11 figs.

Doeff, M.M.; Peng, M.Y.; Ma, Y.; Visco, S.J.; DeJonghe, L.C.

1996-09-24T23:59:59.000Z

204

Natural Ores as Oxygen Carriers in Chemical Looping Combustion  

Science Journals Connector (OSTI)

Natural Ores as Oxygen Carriers in Chemical Looping Combustion ... Chemical looping combustion (CLC) is a combustion technology that utilizes oxygen from oxygen carriers (OC), such as metal oxides, instead of air to combust fuels. ...

Hanjing Tian; Ranjani Siriwardane; Thomas Simonyi; James Poston

2013-01-02T23:59:59.000Z

205

Physicochemical Characterization of Capstone Depleted Uranium Aerosols III: Morphologic and Chemical Oxide Analyses  

SciTech Connect

The impact of depleted uranium (DU) penetrators against an armored target causes erosion and fragmentation of the penetrators, the extent of which is dependent on the thickness and material composition of the target. Vigorous oxidation of the DU particles and fragments creates an aerosol of DU oxide particles and DU particle agglomerations combined with target materials. Aerosols from the Capstone DU aerosol study, in which vehicles were perforated by DU penetrators, were evaluated for their oxidation states using X-ray diffraction (XRD) and particle morphologies using scanning electron microscopy/energy dispersive spectrometry (SEM/EDS). The oxidation state of a DU aerosol is important as it offers a clue to its solubility in lung fluids. The XRD analysis showed that the aerosols evaluated were a combination primarily of U3O8 (insoluble) and UO3 (relatively more soluble) phases, though intermediate phases resembling U4O9 and other oxides were prominent in some samples. Analysis of particle residues in the micrometer-size range by SEM/EDS provided microstructural information such as phase composition and distribution, fracture morphology, size distribution, and material homogeneity. Observations from SEM analysis show a wide variability in the shapes of the DU particles. Some of the larger particles appear to have been fractured (perhaps as a result of abrasion and comminution); others were spherical, occasionally with dendritic or lobed surface structures. Amorphous conglomerates containing metals other than uranium were also common, especially with the smallest particle sizes. A few samples seemed to contain small chunks of nearly pure uranium metal, which were verified by EDS to have a higher uranium content exceeding that expected for uranium oxides. Results of the XRD and SEM/EDS analyses were used in other studies described in this issue of The Journal of Health Physics to interpret the results of lung solubility studies and in selecting input parameters for dose assessments.

Krupka, Kenneth M.; Parkhurst, MaryAnn; Gold, Kenneth; Arey, Bruce W.; Jenson, Evan D.; Guilmette, Raymond A.

2009-03-01T23:59:59.000Z

206

Final Report: Catalytic Hydrocarbon Reactions over Supported Metal Oxides, August 1, 1995 - July 31, 1999  

SciTech Connect

The research program focused on the catalysis of hydrodesulfurization (HDS) over molybdenum-based catalysts and how catalyst composition, redox ability, structure and neighboring sites control the catalytic properties of metal oxides. We sought to understand the catalytic features/sites that control hydrogenation, hydrogenolysis, and isomerization during HDS. Unprompted silica-supported molybdenum oxides and molybdenum sulfides were studied. Model catalyst systems were prepared from organometallic precursors or cluster compounds to generate supported structures that feature Mo(II) and Mo(IV) cations that are isolated or in ensembles and that have either Mo-O or Mo-S bonds. Conventional MOS{sub 2} catalysts, which contain both edge and rim sites, were be studied. Finally, single-layer MOS{sub 2} structures were also prepared from 2H-MoS{sub 2} powder so that the model systems could be compared against a disulfide catalyst that only involves rim sites. Catalytic reactions for thiophene and tetrahydrothione were studied over the various catalysts. Oxidation states were determined using X-ray photoelectron spectroscopy. X-ray crystallography was used to characterize and follow changes in the MOS{sub 2} structures. The program on metal oxides prepared supported oxides that have a specific structure and oxidation state to serve as model templates for the more complex commercial catalysts and then employed these structures in reaction studies. This focus area examined the relationships between structure and cation redox characteristics in oxidation catalysis. Infrared and Raman spectroscopy were used to characterize the cations and reaction intermediates.

Ekerdt, John G.

1999-07-31T23:59:59.000Z

207

Study of metallic materials for solid oxide fuel cell interconnect applications.  

SciTech Connect

Metallic interconnect acts as a gas separator and a gas distributor and therefore, it needs to function adequately in two widely different environments. The interconnect material will be exposed to air on one side and natural gas or coal-derived synthesis gas on the other side. The viable material for the interconnect application must be resistant not only to oxidation but also carburization in hydrocarbon containing low-oxygen environments. In addition, the scales that develop on the exposed surfaces must possess adequate electrical conductivity for them to function as current leads over long service life of the fuel cell. This report addresses five topics of interest for the development of metallic interconnects with adequate performance in fuel cells for long service life. The research conducted over the years and the conclusions reached were used to identify additional areas of research on materials for improved performance of components, especially metallic interconnects, in the complex fuel cell environments. This report details research conducted in the following areas: measurement of area specific electrical resistivity, corrosion performance in dual gas environments by experiments using alloy 446, long term corrosion performance of ferritic and austenitic alloys in hydrogen and methane-reformed synthesis fuel-gas environments, approaches to reduce the area resistance of metallic interconnect, and reduction of electrical resistivity of alumina scales on metallic interconnect. Based on the key requirements for metallic interconnects and the data developed on the corrosion behavior of candidate materials in meeting those requirements, several areas are recommended for further research to develop metallic interconnects with acceptable and reliable long-term performance in solid oxide fuel cells.

Natesan, K.; Zeng, Z.; Nuclear Engineering Division

2009-04-24T23:59:59.000Z

208

Chemical-looping combustion of coal-derived synthesis gas over copper oxide oxygen carriers  

SciTech Connect

CuO/bentonite and CuO-BHA nanocomposites were studied as oxygen carriers in chemical-looping combustion (CLC) of simulated synthesis gas. Global reaction rates of reduction and oxidation, as the function of reaction conversion, were calculated from 10-cycle oxidation/reduction tests utilizing thermogravimetric analysis at atmospheric pressure between 700 and 900 °C. It was found that the reduction reactions are always faster than oxidation reactions; reaction temperature and particle size do not significantly affect the reaction performance of CuO/bentonite. Multicycle CLC tests conducted in a high-pressure flow reactor showed stable reactivity for production of CO2 from fuel gas at 800 and 900 °C and full consumption of hydrogen during the reaction. Results of the tapered element oscillating microbalance showed a negative effect of pressure on the global rates of reduction-oxidation reactions at higher fractional conversions. X-ray diffraction patterns confirmed the presence of CuO in the bulk phase of the oxidized sample. Electron microanalysis showed significant morphology changes of reacted CuO/bentonite samples after the 10 oxidation-reduction cycles above 700 °C in an atmospheric thermogravimetric analyzer. The nanostructured CuO-BHA carrier also showed excellent stability and, in comparison to the CuO/bentonite system, slightly accelerated redox kinetics albeit at the expense of significantly increased complexity of manufacturing. Overall, both types of CuO carriers exhibited excellent reaction performance and thermal stability for the CLC process at 700-900 °C.

Tian, H.; Chaudhari, K.; Simonyi, T.; Poston, J.; Liu, T.; Sanders, T.; Veser, G.; Siriwardane, R.

2008-01-01T23:59:59.000Z

209

Chemical-looping combustion of coal-derived synthesis gas over copper oxide oxygen carriers  

SciTech Connect

CuO/bentonite and CuO?BHA nanocomposites were studied as oxygen carriers in chemical-looping combustion (CLC) of simulated synthesis gas. Global reaction rates of reduction and oxidation, as the function of reaction conversion, were calculated from 10-cycle oxidation/reduction tests utilizing thermogravimetric analysis at atmospheric pressure between 700 and 900 °C. It was found that the reduction reactions are always faster than oxidation reactions; reaction temperature and particle size do not significantly affect the reaction performance of CuO/bentonite. Multicycle CLC tests conducted in a high-pressure flow reactor showed stable reactivity for production of CO2 from fuel gas at 800 and 900 °C and full consumption of hydrogen during the reaction. Results of the tapered element oscillating microbalance showed a negative effect of pressure on the global rates of reduction?oxidation reactions at higher fractional conversions. X-ray diffraction patterns confirmed the presence of CuO in the bulk phase of the oxidized sample. Electron microanalysis showed significant morphology changes of reacted CuO/bentonite samples after the 10 oxidation?reduction cycles above 700 °C in an atmospheric thermogravimetric analyzer. The nanostructured CuO?BHA carrier also showed excellent stability and, in comparison to the CuO/bentonite system, slightly accelerated redox kinetics albeit at the expense of significantly increased complexity of manufacturing. Overall, both types of CuO carriers exhibited excellent reaction performance and thermal stability for the CLC process at 700?900 °C.

Tian, Hanjing; Chaudhari, K.P.; Simonyi, Thomas; Poston, J.A.; Liu, Tengfei; Sanders, Tom; Veser, Goetz; Siriwardane, R.V.

2008-11-01T23:59:59.000Z

210

Inert anode containing oxides of nickel iron and cobalt useful for the electrolytic production of metals  

DOE Patents (OSTI)

An inert anode for the electrolytic production of metals such as aluminum is disclosed. The inert anode includes a ceramic oxide material preferably made from NiO, Fe.sub.2 O.sub.3 and CoO. The inert anode composition may comprise the following mole fractions of NiO, Fe.sub.2 O.sub.3 and CoO: 0.15 to 0.99 NiO; 0.0001 to 0.85 Fe.sub.2 O.sub.3 ; and 0.0001 to 0.45 CoO. The inert anode may optionally include other oxides and/or at least one metal phase, such as Cu, Ag, Pd, Pt, Au, Rh, Ru, Ir and/or Os. The Ni--Fe--Co--O ceramic material exhibits very low solubility in Hall cell baths used to produce aluminum.

Ray, Siba P. (Murrysville, PA); Liu, Xinghua (Monroeville, PA); Weirauch, Jr., Douglas A. (Murrysville, PA)

2002-01-01T23:59:59.000Z

211

Inert anode containing oxides of nickel, iron and zinc useful for the electrolytic production of metals  

DOE Patents (OSTI)

An inert anode for the electrolytic production of metals such as aluminum is disclosed. The inert anode includes a ceramic oxide material preferably made from NiO, Fe.sub.2 O.sub.3 and ZnO. The inert anode composition may comprise the following mole fractions of NiO, Fe.sub.2 O.sub.3 and ZnO: 0.2 to 0.99 NiO; 0.0001 to 0.8 Fe.sub.2 O.sub.3 ; and 0.0001 to 0.3 ZnO. The inert anode may optionally include other oxides and/or at least one metal phase, such as Cu, Ag, Pd, Pt, Au, Rh, Ru, Ir and/or Os. The Ni--Fe--Co--O ceramic material exhibits very low solubility in Hall cell baths used to produce aluminum.

Ray, Siba P. (Murrysville, PA); Weirauch, Jr., Douglas A. (Murrysville, PA); Liu, Xinghua (Monroeville, PA)

2002-01-01T23:59:59.000Z

212

Oxidative dehydrogenation (ODH) of ethane with O[subscript 2] as oxidant on selected transition metal-loaded zeolites  

SciTech Connect

Ni-, Cu-, and Fe-loaded acidic and basic Y zeolites were synthesized, and their catalytic properties for oxidative dehydrogenation of ethane (ODHE) to ethylene were characterized. Acidic Ni-loaded Y zeolite exhibits an ethylene productivity of up to 108 g{sub C{sub 2}H{sub 4}}g{sub cat}{sup -1} h{sup -1} with a selectivity of {approx}75%. Acidic Cu- and Fe-loaded Y zeolites have an ethylene productivity of up to 0.37 g{sub C{sub 2}H{sub 4}}g{sub cat}{sup -1} h{sup -1} and a selectivity of {approx}50%. For the same metal, the acidity of the zeolite favors both ODHE productivity and ethylene selectivity. Extended X-ray absorption fine structure (EXAFS) studies show that Ni, present in particles on Ni/HY during the ODHE catalytic process, contains both Ni-Ni and Ni-O bonds, and that the ratio of oxidized Ni versus metallic Ni increases with the temperature. The insights these studies provide into the ODHE reaction mechanism are discussed.

Lin, Xufeng; Hoel, Cathleen A.; Sachtler, Wolfgang M.H.; Poeppelmeier, Kenneth R.; Weitz, Eric; (NWU)

2009-09-14T23:59:59.000Z

213

The steady-state thermal-hydraulic performance of 3500 MWth metal and oxide fueled LMRs  

SciTech Connect

The thermal-hydraulic performance of a 3500 MWth metal and oxide fueled LMR is reported. Orifice zones are defined and coolant flowrates are given for use in safety analyses. The flux calculations were carried out in three-dimensional hexagonal-Z geometry using a finite differenced diffusion theory code. The heating calculations included the transport and deposition of gamma energy. The assembly temperature calculations were performed using a subchannel code.

Vilim, R.B.; Hill, R.N.

1989-03-01T23:59:59.000Z

214

Surface Science Letters Bulk-defect dependent adsorption on a metal oxide surface  

E-Print Network (OSTI)

-6028(01)01067-6 #12;Titanium dioxide is a wide-band gap semicon- ductor (Egap 3 eV) that can easily be reducedSurface Science Letters Bulk-defect dependent adsorption on a metal oxide surface: S/TiO2(1 1 0) E Abstract The adsorption of molecular sulfur on TiO2(1 1 0)(1 Ã? 1) has been studied with scanning tunneling

Diebold, Ulrike

215

The interactions between transition metal nanoparticles and their metal-oxide supports are often critical for heterogeneous metal nanoparticle  

E-Print Network (OSTI)

for selective hydrogenations (2, 3), oxidations (3­5), and the water-gas shift (WGS) reaction (3, 6). Several to saturation kinetics, with added water affecting the kinetics of the RDS. We explored potential mechanistic oxygen from the support (21, 27). Perhaps most importantly, as Fig. 1A shows, water dramatically

Napp, Nils

216

Oxidation Resistant, Cr Retaining, Electrically Conductive Coatings on Metallic Alloys for SOFC Interconnects  

SciTech Connect

This report describes significant results from an on-going, collaborative effort to enable the use of inexpensive metallic alloys as interconnects in planar solid oxide fuel cells (SOFCs) through the use of advanced coating technologies. Arcomac Surface Engineering, LLC, under the leadership of Dr. Vladimir Gorokhovsky, is investigating filtered-arc and filtered-arc plasma-assisted hybrid coating deposition technologies to promote oxidation resistance, eliminate Cr volatility, and stabilize the electrical conductivity of both standard and specialty steel alloys of interest for SOFC metallic interconnect (IC) applications. Arcomac has successfully developed technologies and processes to deposit coatings with excellent adhesion, which have demonstrated a substantial increase in high temperature oxidation resistance, stabilization of low Area Specific Resistance values and significantly decrease Cr volatility. An extensive matrix of deposition processes, coating compositions and architectures was evaluated. Technical performance of coated and uncoated sample coupons during exposures to SOFC interconnect-relevant conditions is discussed, and promising future directions are considered. Cost analyses have been prepared based on assessment of plasma processing parameters, which demonstrate the feasibility of the proposed surface engineering process for SOFC metallic IC applications.

Vladimir Gorokhovsky

2008-03-31T23:59:59.000Z

217

Plasmonic transparent conducting metal oxide nanoparticles and nanoparticle films for optical sensing applications  

SciTech Connect

The ability to monitor gas species selectively, sensitively, and reliably in extreme temperatures and harsh conditions is critically important for more efficient energy production using conventional fossil energy based production technologies, enabling advanced technologies for fossil based power plants of the future, and improving efficiency in domestic manufacturing industries. Optical waveguide based sensing platforms have become increasingly important but a need exists for materials that exhibit useful changes in optical properties in response to changing gas atmospheres at high temperatures. In this manuscript, the onset of a near-IR absorption associated with an increase in free carrier density in doped metal oxide nanoparticles to form so-called conducting metal oxides is discussed in the context of results obtained for undoped and Al-doped ZnO nanoparticle based films. Detailed film characterization results are presented along with measured changes in optical absorption resulting from various high temperature treatments in a range of gas atmospheres. Optical property changes are also discussed in the context of a simple model for optical absorption in conducting metal oxide nanoparticles and thin films. The combination of experimental results and theoretical modeling presented here suggests that such materials have potential for high temperature optical gas sensing applications. Simulated sensing experiments were performed at 500 °C and a useful, rapid, and reproducible near-IR optical sensing response to H{sub 2} confirms that this class of materials shows great promise for optical gas sensing.

Ohodnicki, Paul R., Jr.; Wang, Congjun; Andio, Mark

2013-07-31T23:59:59.000Z

218

Catalytic activity of tetravalent metal phosphates and phosphonates on the oxidation of (+)-3-carene  

Science Journals Connector (OSTI)

Tetravalent metal phosphates and phosphonates form highly insoluble inorganic polymers and can act as good catalysts in some oxidative reactions. In the present work, zirconium phosphate amorphous (ZrPA), scandium exchanged zirconium phosphate amorphous (ScZrPA), sodium exchanged zirconium phosphate amorphous (NaZrPA), potassium exchanged zirconium phosphate amorphous (KZrPA), zirconium phenylphosphonate amorphous (ZrPPA) and zirconium phenylphosphonate phosphate amorphous (ZrPA/ZrPPA), were prepared and evaluated as catalysts for the oxidation of 3,7,7-trimethylbicyclo[4.1.0]hept-3-ene [(+)-3-carene)] by hydrogen peroxide, in different solvents. It was found that the oxidation reaction of (+)-3-carene yielded three major products, namely ?-3,4-epoxycarane, carane-3?,4?-diol and 3?-acetoxycaran-4?-ol, depending on the catalyst and solvent conditions. No ?-3,4-epoxycarane was detected in the studied conditions.

Graça M.S.R.O. Rocha; Rui M.A. Domingues; Mário M.Q. Simões; Artur M.S. Silva

2009-01-01T23:59:59.000Z

219

Modelling of thermo-mechanical and irradiation behavior of metallic and oxide fuels for sodium fast reactors  

E-Print Network (OSTI)

A robust and reliable code to model the irradiation behavior of metal and oxide fuels in sodium cooled fast reactors is developed. Modeling capability was enhanced by adopting a non-empirical mechanistic approach to the ...

Karahan, Aydin

2009-01-01T23:59:59.000Z

220

Recent trends in the microwave-assisted synthesis of metal oxide nanoparticles supported on carbon nanotubes and their applications  

Science Journals Connector (OSTI)

The study of coating carbon nanotubes with metal/oxides nanoparticles is now becoming a promising and challenging area of research. To optimize the use of carbon nanotubes in various applications, it is necessary to attach functional groups or other ...

Sarah C. Motshekga; Sreejarani K. Pillai; Suprakas Sinha Ray; Kalala Jalama; Rui. W. M. Krause

2012-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "metal oxide chemical" 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

Using alternative chemicals in the flotation of heavy metals from lead mill tailings  

SciTech Connect

The U.S. Bureau of Mines (USBM) investigated alternative chemicals for the flotation of heavy metal values from southeast Missouri lead mill tailings. The objectives of the study were to lower the Pb remaining in the reprocessed tailings to <500 ppm, concentrate the metal values, and lower the overall toxicity of the flotation reagent scheme. Due to the high toxicity of classic flotation chemicals, collectorless flotation, as well as nontoxic or less-toxic chemicals, was studied for use in the flotation process. The investigation centered on the National tailings pile in Flat River, MO. Advantages to using alternative chemicals for the flotation process are presented. Novel reagent schemes are discussed for the treatment of the tailings. Various nontoxic or less-toxic oils were tested, and a substitute for sodium sulfide was investigated. Using a food additive oil, soda ash, and a frother as the reagent scheme, froth flotation recovered 89% of the Pb values. Further scavenging lowered the Pb remaining in the reprocessed tailings to <500 ppm. A less-toxic substitute for sodium cyanide was also studied for use in the cleaner flotation stages. Preliminary results indicate that the food additive oil, canola oil, to be as effective as classic sulfide flotation reagents.

Benn, F.W. [Bureau of Mines, Rolla, MO (United States)

1995-04-01T23:59:59.000Z

222

Synthesis and structural, magnetic, thermal, and transport properties of several transition metal oxides and aresnides  

SciTech Connect

Oxide compounds containing the transition metal vanadium (V) have attracted a lot of attention in the field of condensed matter physics owing to their exhibition of interesting properties including metal-insulator transitons, structural transitions, ferromagnetic and antiferromagnetic orderings, and heavy fermion behavior. Binary vanadium oxides V{sub n}O{sub 2n-1} where 2 {le} n {le} 9 have triclinic structures and exhibit metal-insulator and antiferromagnetic transitions. The only exception is V{sub 7}O{sub 13} which remains metallic down to 4 K. The ternary vanadium oxide LiV{sub 2}O{sub 4} has the normal spinel structure, is metallic, does not undergo magnetic ordering and exhibits heavy fermion behavior below 10 K. CaV{sub 2}O{sub 4} has an orthorhombic structure with the vanadium spins forming zigzag chains and has been suggested to be a model system to study the gapless chiral phase. These provide great motivation for further investigation of some known vanadium compounds as well as to explore new vanadium compounds in search of new physics. This thesis consists, in part, of experimental studies involving sample preparation and magnetic, transport, thermal, and x-ray measurements on some strongly correlated eletron systems containing the transition metal vanadium. The compounds studied are LiV{sub 2}O{sub 4}, YV{sub 4}O{sub 8}, and YbV{sub 4}O{sub 8}. The recent discovery of superconductivity in RFeAsO{sub 1-x}F{sub x} (R = La, Ce, Pr, Gd, Tb, Dy, Sm, and Nd), and AFe{sub 2}As{sub 2} (A = Ba, Sr, Ca, and Eu) doped with K, Na, or Cs at the A site with relatively high T{sub c} has sparked tremendous activities in the condensed matter physics community and a renewed interest in the area of superconductivity as occurred following the discovery of the layered cuprate high T{sub c} superconductors in 1986. To discover more superconductors with hopefully higher T{sub c}'s, it is extremely important to investigate compounds having crystal structures related to the compounds showing high T{sub c} superconductivity. Along with the vanadium oxide compounds described before, this thesis describes our investigations of magnetic, structural, thermal and transport properties of EuPd{sub 2}Sb{sub 2} single crystals which have a crystal structure closely related to the AFe{sub 2}As{sub 2} compounds and also a study of the reaction kinetics of the formation of LaFeAsO{sub 1-x}F{sub x}.

Das, Supriyo

2010-05-16T23:59:59.000Z

223

Humic Acid Metal Cation Interaction Studied by Spectromicroscopy Techniques in Combination with Quantum Chemical Calculations  

SciTech Connect

Humic acids (HA) have a high binding capacity towards traces of toxic metal cations, thus affecting their transport in aquatic systems. Eu(III)-HA aggregates are studied by synchrotron-based scanning transmission X-ray microscopy (STXM) at the carbon K-edge and laser scanning luminescence microscopy (LSLM) at the {sup 5}D{sub 0} {yields} {sup 7}F{sub 1,2} fluorescence emission lines. Both methods provide the necessary spatial resolution in the sub-micrometre range to resolve characteristic aggregate morphologies: optically dense zones embedded in a matrix of less dense material in STXM images correspond to areas with increased Eu(III) luminescence yield in the LSLM micrographs. In the C 1s-NEXAFS of metal-loaded polyacrylic acid (PAA), used as a HA model compound, a distinct complexation effect is identified. This effect is similar to trends observed in the dense fraction of HA/metal cation aggregates. The strongest complexation effect is observed for the Zr(IV)-HA/PAA system. This effect is confirmed by quantum chemical calculations performed at the ab initio level for model complexes with different metal centres and complex geometries. Without the high spatial resolution of STXM and LSLM and without the combination of molecular modelling with experimental results, the different zones indicating a 'pseudo'-phase separation into strong complexing domains and weaker complexing domains of HA would never have been identified. This type of strategy can be used to study metal interaction with other organic material.

Plaschke, M.; Rothe, J; Armbruster, M; Denecke, M; Naber, A; Geckeis, H

2010-01-01T23:59:59.000Z

224

Novel, band-controlled metal oxide compositions for semiconductor-mediated photocatalytic splitting of water to produce H{sub 2}  

SciTech Connect

Semiconductor-mediated photo-catalytic dissociation of water offers a unique opportunity for the production of H{sub 2}, a sustainable source of energy. More efficient and chemically stable photo-catalysts, however, remain a vital requirement for commercial viability of this process. The recent research in my group has focused on the synthesis of several new metal oxide (MO) photo-catalysts, such as: LaInO{sub 3}, GaFeO{sub 3}, InVO{sub 4}, In{sub 2}TiO{sub 5} and nanotubular TiO{sub 2}. These samples of controlled grain morphology have been synthesized by using different synthesis protocols and with and without coating of a noble metal co-catalyst. The doping of an impurity, either at cationic or at anionic lattice site, has helped in the tailoring of band structure and making these oxides visible-light-sensitive. Our study has revealed that the surface characteristics, grain morphology, band structure, and doping-induced lattice imperfections control the photo-physical properties and overall photo-catalytic water splitting activity of these metal/MO composites [1-6]. We have demonstrated that, besides promoting certain charge-transfer steps, metal-semiconductor interfaces influence the adsorption of water molecules and their subsequent interaction with photo-generated electron-hole pair at the catalyst surface. The role played by the above-mentioned micro-structural properties in photo-catalytic water splitting process will be discussed.

Gupta, Narendra M. [Catalysis Division, National Chemical Laboratory, Dr. Homi Bhabha Road, Pune - 411008 (India)

2013-02-05T23:59:59.000Z

225

IEEE TRANSACTIONS ON NANOTECHNOLOGY, VOL. 10, NO. 3, MAY 2011 499 TiSi2 Nanocrystal Metal Oxide Semiconductor Field  

E-Print Network (OSTI)

IEEE TRANSACTIONS ON NANOTECHNOLOGY, VOL. 10, NO. 3, MAY 2011 499 TiSi2 Nanocrystal Metal Oxide memory window, faster writing and erasing, and longer retention lifetime as a result of the metallic property of the silicide NCs. Due to thermally stable, CMOS compatible properties, TiSi2 NCs are highly

Yang, Zheng

226

High Performance Ceramic Interconnect Material for Solid Oxide Fuel Cells (SOFCs): Ca- and Transition Metal-doped Yttrium Chromite  

SciTech Connect

The effect of transition metal substitution on thermal and electrical properties of Ca-doped yttrium chromite was investigated in relation to use as a ceramic interconnect in high temperature solid oxide fuel cells (SOFCs). 10 at% Co, 4 at% Ni, and 1 at% Cu substitution on B-site of 20 at% Ca-doped yttrium chromite led to a close match of thermal expansion coefficient (TEC) with that of 8 mol% yttria-stabilized zirconia (YSZ), and a single phase Y0.8Ca0.2Cr0.85Co0.1Ni0.04Cu0.01O3 remained stable between 25 and 1100 degree C over a wide oxygen partial pressure range. Doping with Cu significantly facilitated densification of yttrium chromite. Ni dopant improved both electrical conductivity and dimensional stability in reducing environments, likely through diminishing the oxygen vacancy formation. Substitution with Co substantially enhanced electrical conductivity in oxidizing atmosphere, which was attributed to an increase in charge carrier density and hopping mobility. Electrical conductivity of Y0.8Ca0.2Cr0.85Co0.1Ni0.04Cu0.01O3 at 900 degree C is 57 S/cm in air and 11 S/cm in fuel (pO2=5×10^-17 atm) environments. Chemical compatibility of doped yttrium chromite with other cell components was verified at the processing temperatures. Based on the chemical and dimensional stability, sinterability, and thermal and electrical properties, Y0.8Ca0.2Cr0.85Co0.1Ni0.04Cu0.01O3 is suggested as a promising SOFC ceramic interconnect to potentially overcome technical limitations of conventional acceptor-doped lanthanum chromites.

Yoon, Kyung J.; Stevenson, Jeffry W.; Marina, Olga A.

2011-10-15T23:59:59.000Z

227

Origin of deep subgap states in amorphous indium gallium zinc oxide: Chemically disordered coordination of oxygen  

SciTech Connect

The origin of the deep subgap states in amorphous indium gallium zinc oxide (a-IGZO), whether intrinsic to the amorphous structure or not, has serious implications for the development of p-type transparent amorphous oxide semiconductors. We report that the deep subgap feature in a-IGZO originates from local variations in the oxygen coordination and not from oxygen vacancies. This is shown by the positive correlation between oxygen composition and subgap intensity as observed with X-ray photoelectron spectroscopy. We also demonstrate that the subgap feature is not intrinsic to the amorphous phase because the deep subgap feature can be removed by low-temperature annealing in a reducing environment. Atomistic calculations of a-IGZO reveal that the subgap state originates from certain oxygen environments associated with the disorder. Specifically, the subgap states originate from oxygen environments with a lower coordination number and/or a larger metal-oxygen separation.

Sallis, S.; Williams, D. S. [Materials Science and Engineering, Binghamton University, Binghamton, New York 13902 (United States); Butler, K. T.; Walsh, A. [Center for Sustainable Technologies and Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY (United Kingdom); Quackenbush, N. F. [Department of Physics, Applied Physics, and Astronomy, Binghamton University, Binghamton, New York 13902 (United States); Junda, M.; Podraza, N. J. [Department of Physics and Astronomy, University of Toledo, Toledo, Ohio 43606 (United States); Fischer, D. A.; Woicik, J. C. [Materials Science and Engineering Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States); White, B. E.; Piper, L. F. J., E-mail: lpiper@binghamton.edu [Department of Physics, Applied Physics, and Astronomy, Binghamton University, Binghamton, New York 13902 (United States); Materials Science and Engineering, Binghamton University, Binghamton, New York 13902 (United States)

2014-06-09T23:59:59.000Z

228

A quantum chemical study of nitric oxide reduction by ammonia (SCR reaction) on V2O5 catalyst surface  

E-Print Network (OSTI)

A quantum chemical study of nitric oxide reduction by ammonia (SCR reaction) on V2O5 catalyst for the selective catalytic reduction (SCR) of nitric oxide by ammonia on (0 1 0) V2O5 surface represented by a V2O9/6-31G** level. The computations indicated that SCR reaction consisted of three main parts

Senkan, Selim M.

229

On-line coating of glass with tin oxide by atmospheric pressure chemical vapor deposition.  

SciTech Connect

Atmospheric pressure chemical vapor deposition (APCVD) of tin oxide is a very important manufacturing technique used in the production of low-emissivity glass. It is also the primary method used to provide wear-resistant coatings on glass containers. The complexity of these systems, which involve chemical reactions in both the gas phase and on the deposition surface, as well as complex fluid dynamics, makes process optimization and design of new coating reactors a very difficult task. In 2001 the U.S. Dept. of Energy Industrial Technologies Program Glass Industry of the Future Team funded a project to address the need for more accurate data concerning the tin oxide APCVD process. This report presents a case study of on-line APCVD using organometallic precursors, which are the primary reactants used in industrial coating processes. Research staff at Sandia National Laboratories in Livermore, CA, and the PPG Industries Glass Technology Center in Pittsburgh, PA collaborated to produce this work. In this report, we describe a detailed investigation of the factors controlling the growth of tin oxide films. The report begins with a discussion of the basic elements of the deposition chemistry, including gas-phase thermochemistry of tin species and mechanisms of chemical reactions involved in the decomposition of tin precursors. These results provide the basis for experimental investigations in which tin oxide growth rates were measured as a function of all major process variables. The experiments focused on growth from monobutyltintrichloride (MBTC) since this is one of the two primary precursors used industrially. There are almost no reliable growth-rate data available for this precursor. Robust models describing the growth rate as a function of these variables are derived from modeling of these data. Finally, the results are used to conduct computational fluid dynamic simulations of both pilot- and full-scale coating reactors. As a result, general conclusions are reached concerning the factors affecting the growth rate in on-line APCVD reactors. In addition, a substantial body of data was generated that can be used to model many different industrial tin oxide coating processes. These data include the most extensive compilation of thermochemistry for gas-phase tin-containing species as well as kinetic expressions describing tin oxide growth rates over a wide range of temperatures, pressures, and reactant concentrations.

Allendorf, Mark D.; Sopko, J.F. (PPF Industries, Pittsburgh, PA); Houf, William G.; Chae, Yong Kee; McDaniel, Anthony H.; Li, M. (PPF Industries, Pittsburgh, PA); McCamy, J.W. (PPF Industries, Pittsburgh, PA)

2006-11-01T23:59:59.000Z

230

Chemical-vapor deposition of complex oxides: materials and process development  

SciTech Connect

This is the final report of a six-month, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL) part of the Advanced Materials Laboratory (AML). The demand for higher performance and lower cost in electronics is driving the need for advanced materials and consequent process integration. Ceramic thin-film technology is becoming more important in the manufacture of microelectronic devices, photovoltaics, optoelectronics, magneto-optics, sensors, microwave, and radio frequency communication devices, and high-Tc superconducting tapes. A flexible processing approach for potential large-scale manufacturing of novel electronic ceramic thin films is desirable. Current thin- film deposition technologies based on physical vapor-deposition techniques are limited in scale potential and have limited control of processing parameters. The lack of control over multiple process parameters inhibits the versatility and reproducibility of the physical vapor deposition processes applied to complex oxides. Chemical vapor deposition is emerging as a viable approach for large- scale manufacturing of electronic materials. Specifically, the ability to control more processing parameters with chemical vapor deposition than with other processing techniques provides the reliability and material property reproducibility required by manufacturing. This project sought to investigate the chemical vapor deposition of complex oxides.

Muenchausen, R.

1996-11-01T23:59:59.000Z

231

Chemical-looping combustion of coal-derived synthesis gas over copper oxide oxygen carriers  

SciTech Connect

CuO/bentonite and CuO-BHA nanocomposites were studied as oxygen carriers in chemical-looping combustion (CLC) of simulated synthesis gas. Global reaction rates of reduction and oxidation, as the function of reaction conversion, were calculated from 10-cycle oxidation/reduction tests utilizing thermogravimetric analysis at atmospheric pressure between 700 and 900{degree}C. It was found that the reduction reactions are always faster than oxidation reactions; reaction temperature and particle size do not significantly affect the reaction performance of CuO/bentonite. Multicycle CLC tests conducted in a high-pressure flow reactor showed stable reactivity for production of CO{sub 2} from fuel gas at 800 and 900{degree}C and full consumption of hydrogen during the reaction. Results of the tapered element oscillating microbalance showed a negative effect of pressure on the global rates of reduction-oxidation reactions at higher fractional conversions. X-ray diffraction patterns confirmed the presence of CuO in the bulk phase of the oxidized sample. Electron microanalysis showed significant morphology changes of reacted CuO/bentonite samples after the 10 oxidation-reduction cycles above 700{degree}C in an atmospheric thermogravimetric analyzer. The nanostructured CuO-BHA carrier also showed excellent stability and, in comparison to the CuO/bentonite system, slightly accelerated redox kinetics albeit at the expense of significantly increased complexity of manufacturing. Overall, both types of CuO carriers exhibited excellent reaction performance and thermal stability for the CLC process at 700-900{degree}C. 48 refs., 12 figs., 8 tabs.

Hanjing Tian; Karuna Chaudhari; Thomas Simonyi; James Poston; Tengfei Liu; Tom Sanders; Goetz Veser; Ranjani Siriwardane [U.S. Department of Energy, Morgantown, WV (United States). National Energy Technology Laboratory

2008-11-15T23:59:59.000Z

232

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

SciTech Connect

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

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

2003-12-31T23:59:59.000Z

233

Chemical analyses of geothermal waters and Strategic Petroleum Reserve brines for metals of economic importance  

SciTech Connect

Waters from seven hydrothermal-geothermal, one geopressured-geothermal, and six Strategic Petroleum Reserve wells have been surveyed for 12 metals of economic importance using trace chemical analysis techniques. The elements sought were Cr, Co, Mn, Ta, Sn, V, Nb, Li, Sr, Pt, Au and Ag. Platinum was found at a concentration of approx. 50 ppb in a brine from the Salton Sea geothermal area. Brine from this region, as has been known from previous studies, is also rich in Li, Sr and Mn. Higher concentrations (approx. 900 ppm) of Sr are found in the high-salinity geopressured brines. None of the fluids contained interesting concentrations of the other metals. Good recovery of precious metals at sub-ppm concentrations from synthetic high salinity brines was achieved using Amborane reductive resin, but similar recovery in the laboratory using real brines could not be demonstrated. Several analytical techniques were compared in sensitivity for the determination of the precious metals; neutron activation analysis with carrier separation is the best for gold and platinum in geothermal brines. 26 references, 7 tables.

Harrar, J.E.; Raber, E.

1984-01-01T23:59:59.000Z

234

Life cycle cost study for coated conductor manufacture by metal organic chemical vapor deposition  

SciTech Connect

The purpose of this report is to calculate the cost of producing high temperature superconducting wire by the Metal Organic Chemical Vapor Deposition (MOCVD) process. The technology status is reviewed from the literature and a plant conceptual design is assumed for the cost calculation. The critical issues discussed are the high cost of the metal organic precursors, the material utilization efficiency and the capability of the final product as measured by the critical current density achieved. Capital, operating and material costs are estimated and summed as the basis for calculating the cost per unit length of wire. Sensitivity analyses of key assumptions are examined to determine their effects on the final wire cost. Additionally, the cost of wire on the basis of cost per kiloampere per meter is calculated for operation at lower temperatures than the liquid nitrogen boiling temperature. It is concluded that this process should not be ruled out on the basis of high cost of precursors alone.

Chapman, J.N.

1999-07-13T23:59:59.000Z

235

Detailed chemical kinetic mechanism for the oxidation of biodiesel fuels blend surrogate.  

SciTech Connect

Detailed chemical kinetic mechanisms were developed and used to study the oxidation of two large unsaturated esters: methyl-5-decenoate and methyl-9-decenoate. These models were built from a previous methyl decanoate mechanism and were compared with rapeseed oil methyl esters oxidation experiments in a jet stirred reactor. A comparative study of the reactivity of these three oxygenated compounds was performed and the differences in the distribution of the products of the reaction were highlighted showing the influence of the presence and the position of a double bond in the chain. Blend surrogates, containing methyl decanoate, methyl-5-decenoate, methyl-9-decenoate and n-alkanes, were tested against rapeseed oil methyl esters and methyl palmitate/n-decane experiments. These surrogate models are realistic kinetic tools allowing the study of the combustion of biodiesel fuels in diesel and homogeneous charge compression ignition engines.

Herbinet, O; Pitz, W J; Westbrook, C K

2009-07-21T23:59:59.000Z

236

The physical and chemical aspects of the leaching behavior of metals from portland cement  

E-Print Network (OSTI)

solvent (such as groundwater) passes through the system. In this work, Cr(NO3)S and Pb(NO3)Z at varying concentrations are mixed with Type I Portland cement to produce simulated waste forms. These samples are then leached by three methods... for the degree of MASTER OF SCIENCE December 1990 Major Subject: Chemistry THE PHYSICAL AND CHEMICAL ASPECTS OF THE LEACHING BEHAVIOR OF METALS FROM PORTLAND CEMENT A Thesis by RICARDO CORYE DAVIS Approved as to style and content by: David L. Cocke (Co...

Davis, Ricardo Corye

1990-01-01T23:59:59.000Z

237

Correlation effects in (111) bilayers of perovskite transition-metal oxides  

SciTech Connect

We investigate the correlation-induced Mott, magnetic, and topological phase transitions in artificial (111) bilayers of perovskite transition-metal oxides LaAuO3 and SrIrO3 for which the previous density-functional theory calculations predicted topological insulating states. Using the dynamical-mean-field theory with realistic band structures and Coulomb interactions, LaAuO3 bilayer is shown to be far away from a Mott insulating regime, and a topological-insulating state is robust. On the other hand, SrIrO3 bilayer is on the verge of an orbital-selective topological Mott transition and turns to a trivial insulator by an antiferromagnetic ordering. Oxide bilayers thus provide a novel class of topological materials for which the interplay between the spin-orbit coupling and electron-electron interactions is a fundamental ingredient.

Okamoto, Satoshi [ORNL] [ORNL; Zhu, Wenguang [University of Science and Technology of China] [University of Science and Technology of China; Nomura, Yusuke [University of Tokyo, Japan] [University of Tokyo, Japan; Arita, R. [University of Tokyo, Japan] [University of Tokyo, Japan; Xiao, Di [Carnegie Mellon University (CMU)] [Carnegie Mellon University (CMU); Nagaosa, Naoto [University of Tokyo, Japan] [University of Tokyo, Japan

2014-01-01T23:59:59.000Z

238

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

239

Strain induced electronic structure changes in magnetic transition metal oxides thin films  

SciTech Connect

We show that the angular dependence of x-ray magnetic circular dichroism (XMCD) is strongly sensitive to strain-induced electronic structure changes in magnetic transition metal oxides. We observe a pronounced dependence of the XMCD spectral shape on the experimental geometry as well as nonvanishing XMCD with distinct spectral features in transverse geometry in compressively strained MnCr{sub 2}O{sub 4} films. The angular dependent XMCD can be described as a sum over an isotropic and anisotropic contribution, the latter linearly proportional to the axial distortion due to strain. The XMCD spectra are well reproduced by atomic multiplet calculations.

van der Laan, G.; Chopdekar, R.V.; Suzuki, Y.; Arenholz, E.

2010-07-08T23:59:59.000Z

240

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

SciTech Connect

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

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

2005-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "metal oxide chemical" 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

Synthesis of transition metal nitride by nitridation of metastable oxide precursor  

SciTech Connect

Metastable transition metal oxides were used as precursors to synthesize transition metal nitrides at low temperature. Amorphous MoO{sub 2} was prepared by reduction of (NH{sub 4}){sub 6}Mo{sub 7}O{sub 24} solution with hydrazine. As-synthesized amorphous MoO{sub 2} was transformed into fcc {gamma}-Mo{sub 2}N at 400 Degree-Sign C and then into hexagonal {delta}-MoN by further increasing the temperature to 600 Degree-Sign C under a NH{sub 3} flow. The nitridation temperature employed here is much lower than that employed in nitridation of crystalline materials, and the amorphous materials underwent a unique nitridation process. Besides this, the bimetallic nitride Ni{sub 2}Mo{sub 3}N was also synthesized by nitridating amorphous bimetallic precursor. These results suggested that the nitridation of amorphous precursor possessed potential to be a general method for synthesizing many interstitial metallic compounds, such as nitrides and carbides at low temperature. - graphical abstract: Amorphous oxide was used as new precursor to prepare nitride at low temperature. Pure {gamma}-Mo{sub 2}N and {delta}-MoN were obtained at 400 Degree-Sign C and at 600 Degree-Sign C, respectively. Highlights: Black-Right-Pointing-Pointer We bring out a new method to synthesize transition metal nitrides at low temperature. Black-Right-Pointing-Pointer Both mono- and bimetallic molybdenum nitrides were synthesized at a mild condition. Black-Right-Pointing-Pointer The formation of two different molybdenum nitrides {gamma}-Mo{sub 2}N and {delta}-MoN can be controlled from the same metastable precursor. Black-Right-Pointing-Pointer The nitridation temperature was much lower than that reported from crystalline precursors. Black-Right-Pointing-Pointer The metastable precursor had different reaction process in comparison with crystalline precursor.

Wang, Huamin; Wu, Zijie; Kong, Jing [Key Laboratory of Advanced Energy Materials Chemistry (MOE), College of Chemistry, Nankai University, Tianjin 300071 (China)] [Key Laboratory of Advanced Energy Materials Chemistry (MOE), College of Chemistry, Nankai University, Tianjin 300071 (China); Wang, Zhiqiang, E-mail: zqwang@mail.nankai.edu.cn [Key Laboratory of Advanced Energy Materials Chemistry (MOE), College of Chemistry, Nankai University, Tianjin 300071 (China) [Key Laboratory of Advanced Energy Materials Chemistry (MOE), College of Chemistry, Nankai University, Tianjin 300071 (China); Tianjin Key Laboratory of Water Environment and Resources, Tianjin Normal University, No. 393 Binshui Road, Xiqing Dist., Tianjin 300387 (China); Zhang, Minghui, E-mail: zhangmh@nankai.edu.cn [Key Laboratory of Advanced Energy Materials Chemistry (MOE), College of Chemistry, Nankai University, Tianjin 300071 (China)] [Key Laboratory of Advanced Energy Materials Chemistry (MOE), College of Chemistry, Nankai University, Tianjin 300071 (China)

2012-10-15T23:59:59.000Z

242

Chemical-looping combustion of simulated synthesis gas using nickel oxide oxygen carrier supported on bentonite  

SciTech Connect

Chemical-looping combustion (CLC) is a combustion technology for clean and efficient utilization of fossil fuels for energy production. This process which produces sequestration ready CO2 systems is a promising technology to be utilized with coal gasification systems. In the present work, chemical-looping combustion has been studied with an oxygen carrier, NiO/bentonite (60 wt % NiO) for the gasification systems utilizing simulated synthesis gas. Global reaction rates of reduction and oxidation as a function of conversion were calculated for oxidation-reduction cycles utilizing the thermogravimetric analysis (TGA) data on multicycle tests conducted with NiO/bentonite at atmospheric pressure between 700 and 900 °C. The rate of reduction increased slightly with an increase in temperature, while the rate of oxidation decreased at 900 °C. The effect of particle size of the oxygen carrier on CLC was studied for the particle size between 20 and 200 mesh. The rates of reactions depended on the particle size of the oxygen carrier. The smaller the particle size, the higher the reaction rates. The multicycle CLC tests conducted in a high-pressure flow reactor showed stable reactivity for the production of CO2 from fuel gas at 800 and 900 °C and full consumption of hydrogen during the reaction. The data from a one cycle test on the effect of the pressure on the performance with NiO/bentonite utilizing the tapered element oscillating microbalance (TEOM) showed a positive effect of the pressure on the global rates of reduction-oxidation reactions at higher fractional conversions. The X-ray diffraction (XRD) analysis confirmed the presence of the NiO phase in NiO/bentonite with the oxidized sample in the highpressure reactor and Ni phase with the reduced sample. The presence of a small amount of NiO in the reduced sample detected by X-ray photoelectron spectroscopy (XPS) may be due to its exposure to air during sample transfer from the reactor to XPS. Scanning electron microscopy (SEM) analysis showed no significant changes in morphology of NiO/bentonite reacted in the temperature range 700-800 °C in an atmospheric TGA for 10 oxidation-reduction cycles, but some loss of surface area and porosity was observed at 900 °C. This effect was found to be greater with increase in the particle size of the oxygen carrier.

Siriwardane, R.V.; Chaudhari, K.; Poston, J.A.; Zinn, A.; Simonyi, T.; Robinson, C.

2007-05-01T23:59:59.000Z

243

Partial oxidation of lower alkanes by active lattice oxygen of metal oxide systems: 2. Synthesis of solid contacts and syngas production in a pilot plant with a riser reactor  

Science Journals Connector (OSTI)

Metal oxide systems with a high lattice-oxygen content, which exhibit reversibility of oxidationreduction transitions, have been synthesized and characterized. Oxidant Solid Contacts have been prepared using t...

I. M. Gerzeliev; N. Ya. Usachev; A. Yu. Popov; S. N. Khadzhiev

2012-09-01T23:59:59.000Z

244

Chemical Engineering Division fuel cycle programs. Quarterly progress report, April-June 1979. [Pyrochemical/dry processing; waste encapsulation in metal; transport in geologic media  

SciTech Connect

For pyrochemical and dry processing materials development included exposure to molten metal and salt of Mo-0.5% Ti-0.07% Ti-0.01% C, Mo-30% W, SiC, Si/sub 2/ON/sub 2/, ZrB/sub 2/-SiC, MgAl/sub 2/O/sub 4/, Al/sub 2/O/sub 3/, AlN, HfB/sub 2/, Y/sub 2/O/sub 3/, BeO, Si/sub 3/N/sub 4/, nickel nitrate-infiltrated W, W-coated Mo, and W-metallized alumina-yttria. Work on Th-U salt transport processing included solubility of Th in liquid Cd, defining the Cd-Th and Cd-Mg-Th phase diagrams, ThO/sub 2/ reduction experiments, and electrolysis of CaO in molten salt. Work on pyrochemical processes and associated hardware for coprocessing U and Pu in spent FBR fuels included a second-generation computer model of the transport process, turntable transport process design, work on the U-Cu-Mg system, and U and Pu distribution coefficients between molten salt and metal. Refractory metal vessels are being service-life tested. The chloride volatility processing of Th-based fuel was evaluated for its proliferation resistance, and a preliminary ternary phase diagram for the Zn-U-Pu system was computed. Material characterization and process analysis were conducted on the Exportable Pyrochemical process (Pyro-Civex process). Literature data on oxidation of fissile metals to oxides were reviewed. Work was done on chemical bases for the reprocessing of actinide oxides in molten salts. Flowsheets are being developed for the processing of fuel in molten tin. Work on encapsulation of solidified radioactive waste in metal matrix included studies of leach rate of crystalline waste materials and of the impact resistance of metal-matrix waste forms. In work on the transport properties of nuclear waste in geologic media, adsorption of Sr on oolitic limestone was studied, as well as the migration of Cs in basalt. Fitting of data on the adsorption of iodate by hematite to a mathematical model was attempted.

Steindler, M.J.; Ader, M.; Barletta, R.E.

1980-09-01T23:59:59.000Z

245

High-energy ultrafine metal powders in the manufacture of ceramic materials  

Science Journals Connector (OSTI)

The addition of metal, powders produced by electric-pulse sputtering is examined as a possible way to activate sintering of conventional and plasma-chemical oxide systems. Since the metal particles have an ext...

T. A. Khabas

1997-12-01T23:59:59.000Z

246

Effect of pre-oxidation and environmental aging on the seal strength of a novel high-temperature solid oxide fuel cell (SOFC) sealing glass with metallic interconnect  

SciTech Connect

A novel high-temperature alkaline-earth silicate sealing glass was developed for solid oxide fuel cell (SOFC) applications. The glass was used to join two ferritic stainless steel coupons for strength evaluation. The steel coupons were pre-oxidized at elevated temperatures to promote thick oxide layers to simulate long-term exposure conditions. In addition, seals to as-received metal coupons were also tested after aging in oxidizing or reducing environments to simulate the actual SOFC environment. Room temperature tensile testing showed strength degradation when using pre-oxidized coupons, and more extensive degradation after aging in air. Fracture surface and microstructural analysis confirmed that the cause of degradation was formation of SrCrO4 at the outer sealing edges exposed to air.

Chou, Y. S.; Stevenson, Jeffry W.; Singh, Prabhakar

2008-09-15T23:59:59.000Z

247

Water growth on metals and oxides: binding, dissociation and role of hydroxyl groups  

SciTech Connect

The authors discuss the role of the presence of dangling H bonds from water or from surface hydroxyl species on the wetting behavior of surfaces. Using Scanning Tunneling and Atomic Force Microscopies, and Photoelectron Spectroscopy, they have examined a variety of surfaces, including mica, oxides, and pure metals. They find that in all cases, the availability of free, dangling H-bonds at the surface is crucial for the subsequent growth of wetting water films. In the case of mica electrostatic forces and H-bonding to surface O atoms determine the water orientation in the first layer and also in subsequent layers with a strong influence in its wetting characteristics. In the case of oxides like TiO{sub 2}, Cu{sub 2}O, SiO{sub 2} and Al{sub 2}O{sub 3}, surface hydroxyls form readily on defects upon exposure to water vapor and help nucleate the subsequent growth of molecular water films. On pure metals, such as Pt, Pd, and Ru, the structure of the first water layer and whether or not it exhibits dangling H bonds is again crucial. Dangling H-bonds are provided by molecules with their plane oriented vertically, or by OH groups formed by the partial dissociation of water. By tying the two II atoms of the water molecules into strong H-bonds with pre-adsorbed O on Ru can also quench the wettability of the surface.

Salmeron, M.; Bluhm, H.; Tatarkhanov, M.; Ketteler, G.; Shimizu, T.K.; Mugarza, A.; Deng, Xingyi; Herranz, T.; Yamamoto, S.; Nilsson, A.

2008-09-01T23:59:59.000Z

248

The one-electron oxidation of a dithiolate molecule: The importance of chemical intuition  

SciTech Connect

A series of nine commonly used density functional methods were assessed to accurately predict the oxidation potential of the (C{sub 2}H{sub 2}S{sub 2}{sup ?2}/C{sub 2}H{sub 2}S{sub 2}{sup •?}) redox couple. It was found that due to their greater tendency for charge delocalization the GGA functionals predict a structure where the radical electron is delocalized within the alkene backbone of C{sub 2}H{sub 2}S{sub 2}{sup •?}, whereas the hybrid functionals and the reference QCISD/cc-pVTZ predict that the radical electron remains localized on the sulfurs. However, chemical intuition suggests that the results obtained with the GGA functionals should be correct. Indeed, with the use of the geometries obtained at the HCTH/6-311++G(3df,3pd) level of theory both the QCISD and hybrid DFT methods yield a molecule with a delocalized electron. Notably, this new molecule lies at least 53 kJ mol{sup ?1} lower in energy than the previously optimized one that had a localized radical. Using these new structures the calculated oxidation potential was found to be 2.71–2.97 V for the nine DFT functionals tested. The M06-L functional provided the best agreement with the QCISD/cc-pVTZ reference oxidation potential of 3.28 V.

Bushnell, Eric A. C.; Burns, Thomas D.; Boyd, Russell J., E-mail: russell.boyd@dal.ca [Department of Chemistry, Dalhousie University, Halifax, Nova Scotia B3H 4R2 (Canada)

2014-05-14T23:59:59.000Z

249

Unusual Physical and Chemical Properties of Cu in Ce1-xCuxO2 Oxides  

SciTech Connect

The structural and electronic properties of Ce{sub 1-x}Cu{sub x}O{sub 2} nano systems prepared by a reverse microemulsion method were characterized with synchrotron-based X-ray diffraction, X-ray absorption spectroscopy, Raman spectroscopy, and density functional calculations. The Cu atoms embedded in ceria had an oxidation state higher than those of the cations in Cu{sub 2}O or CuO. The lattice of the Ce{sub 1-x}Cu{sub x}O{sub 2} systems still adopted a fluorite-type structure, but it was highly distorted with multiple cation-oxygen distances with respect to the single cation-oxygen bond distance seen in pure ceria. The doping of CeO{sub 2} with copper introduced a large strain into the oxide lattice and favored the formation of O vacancies, leading to a Ce{sub 1-x}Cu{sub x}O{sub 2-y} stoichiometry for our materials. Cu approached the planar geometry characteristic of Cu(II) oxides, but with a strongly perturbed local order. The chemical activities of the Ce{sub 1-x}Cu{sub x}O{sub 2} nanoparticles were tested using the reactions with H2 and O2 as probes. During the reduction in hydrogen, an induction time was observed and became shorter after raising the reaction temperature. The fraction of copper that could be reduced in the Ce{sub 1-x}Cu{sub x}O{sub 2} oxides also depended strongly on the reaction temperature. A comparison with data for the reduction of pure copper oxides indicated that the copper embedded in ceria was much more difficult to reduce. The reduction of the Ce{sub 1-x}Cu{sub x}O{sub 2} nanoparticles was rather reversible, without the generation of a significant amount of CuO or Cu{sub 2}O phases during reoxidation. This reversible process demonstrates the unusual structural and chemical properties of the Cu-doped ceria materials.

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

2005-01-01T23:59:59.000Z

250

Ab initio study of lithium intercalation in metal oxides and metal dichalcogenides M. K. Aydinol, A. F. Kohan, and G. Ceder  

E-Print Network (OSTI)

-metal-oxides due to their application potential as rechargeable battery electrodes1 and electrochromic displays.2. In electrochromic applications, band filling is used to adjust the electronic and optical properties.3 Figure 1-potential difference between cathode and anode is desirable as this leads to a high OCV. For electrochromic

Ceder, Gerbrand

251

Disposition of Uranium -233 (sup 233U) in Plutonium Metal and Oxide at the Rocky Flats Environmental Technology Site  

SciTech Connect

This report documents the position that the concentration of Uranium-233 ({sup 233}U) in plutonium metal and oxide currently stored at the DOE Rocky Flats Environmental Technology Site (RFETS) is well below the maximum permissible stabilization, packaging, shipping and storage limits. The {sup 233}U stabilization, packaging and storage limit is 0.5 weight percent (wt%), which is also the shipping limit maximum. These two plutonium products (metal and oxide) are scheduled for processing through the Building 371 Plutonium Stabilization and Packaging System (PuSPS). This justification is supported by written technical reports, personnel interviews, and nuclear material inventories, as compiled in the ''History of Uranium-233 ({sup 233}U) Processing at the Rocky Flats Plant In Support of the RFETS Acceptable Knowledge Program'' RS-090-056, April 1, 1999. Relevant data from this report is summarized for application to the PuSPS metal and oxide processing campaigns.

Freiboth, Cameron J.; Gibbs, Frank E.

2000-03-01T23:59:59.000Z

252

Formation and distribution of neutral vanadium, niobium, and tantalum oxide clusters: Single photon ionization at 26.5 eV  

E-Print Network (OSTI)

. INTRODUCTION Transition metals, as well as their oxides, carbides, ni- trides, and sulfides, are unique bonds at a surface.1 Transition metal oxides are employed extensively as catalysts in the chemical. During the ionization process the metal oxide clusters are almost free of fragmentation. The most stable

Rocca, Jorge J.

253

In-situ X-ray photoelectron spectroscopy studies of water on metals and oxides at ambient conditions  

SciTech Connect

X-ray photoelectron spectroscopy (XPS) is a powerful tool for surface and interface analysis, providing the elemental composition of surfaces and the local chemical environment of adsorbed species. Conventional XPS experiments have been limited to ultrahigh vacuum (UHV) conditions due to a short mean free path of electrons in a gas phase. The recent advances in instrumentation coupled with third-generation synchrotron radiation sources enables in-situ XPS measurements at pressures above 5 Torr. In this review, we describe the basic design of the ambient pressure XPS setup that combines differential pumping with an electrostatic focusing. We present examples of the application of in-situ XPS to studies of water adsorption on the surface of metals and oxides including Cu(110), Cu(111), TiO2(110) under environmental conditions of water vapor pressure. On all these surfaces we observe a general trend where hydroxyl groups form first, followed by molecular water adsorption. The importance of surface OH groups and their hydrogen bonding to water molecules in water adsorption on surfaces is discussed in detail.

Salmeron, Miquel; Yamamoto, S.; Bluhm, H.; Andersson, K.; Ketteler, G.; Ogasawara, H.; Salmeron, M.; Nilsson, A.

2007-10-29T23:59:59.000Z

254

Method and apparatus for preparation of spherical metal carbonates and lithium metal oxides for lithium rechargeable batteries  

DOE Patents (OSTI)

A number of materials with the composition Li.sub.1+xNi.sub..alpha.Mn.sub..beta.Co.sub..gamma.M'.sub..delta.O.sub.2-- zF.sub.z (M'=Mg,Zn,Al,Ga,B,Zr,Ti) for use with rechargeable batteries, wherein x is between about 0 and 0.3, .alpha. is between about 0.2 and 0.6, .beta. is between about 0.2 and 0.6, .gamma. is between about 0 and 0.3, .delta. is between about 0 and 0.15, and z is between about 0 and 0.2. Adding the above metal and fluorine dopants affects capacity, impedance, and stability of the layered oxide structure during electrochemical cycling. Another aspect of the invention includes materials with the composition Li.sub.1+xNi.sub..alpha.Co.sub..beta.Mn.sub..gamma.M'.sub..delta.O.sub.yF- .sub.z (M'=Mg,Zn,Al,Ga,B,Zr,Ti), where the x is between 0 and 0.2, the .alpha. between 0 and 1, the .beta. between 0 and 1, the .gamma. between 0 and 2, the .delta. between about 0 and about 0.2, the y is between 2 and 4, and the z is between 0 and 0.5.

Kang, Sun-Ho (Naperville, IL); Amine, Khalil (Downers Grove, IL)

2008-10-14T23:59:59.000Z

255

Standard test methods for chemical and mass spectrometric analysis of nuclear-grade gadolinium oxide (Gd2O3) powder  

E-Print Network (OSTI)

1.1 These test methods cover procedures for the chemical and mass spectrometric analysis of nuclear-grade gadolinium oxide powders to determine compliance with specifications. 1.2 The analytical procedures appear in the following order: Sections Carbon by Direct CombustionThermal Conductivity C1408 Test Method for Carbon (Total) in Uranium Oxide Powders and Pellets By Direct Combustion-Infrared Detection Method Total Chlorine and Fluorine by Pyrohydrolysis Ion Selective Electrode C1502 Test Method for Determination of Total Chlorine and Fluorine in Uranium Dioxide and Gadolinium Oxide Loss of Weight on Ignition 7-13 Sulfur by CombustionIodometric Titration Impurity Elements by a Spark-Source Mass Spectrographic C761 Test Methods for Chemical, Mass Spectrometric, Spectrochemical,Nuclear, and Radiochemical Analysis of Uranium Hexafluoride C1287 Test Method for Determination of Impurities In Uranium Dioxide By Inductively Coupled Plasma Mass Spectrometry Gadolinium Content in Gadolinium Oxid...

American Society for Testing and Materials. Philadelphia

2006-01-01T23:59:59.000Z

256

Use of high-temperature gas-tight electrochemical cells to measure electronic transport and thermodynamics in metal oxides  

SciTech Connect

By using a gas-tight electrochemical cell, the authors can perform high-temperature coulometric titration and measure electronic transport properties to determine the electronic defect structure of metal oxides. This technique reduces the time and expense required for conventional thermogravimetric measurements. The components of the gas-tight coulometric titration cell are an oxygen sensor, Pt/yttria stabilized zirconia (YSZ)/Pt, and an encapsulated metal oxide sample. Based on cell design, both transport and thermodynamic measurements can be performed over a wide range of oxygen partial pressures (pO{sub 2} = 10{sup {minus}35} to 1 atm). This paper describes the high-temperature gas-tight electrochemical cells used to determine electronic defect structures and transport properties for pure and doped-oxide systems, such as YSZ, doped and pure ceria (Ca-CeO{sub 2} and CeO{sub 2}), copper oxides, and copper-oxide-based ceramic superconductors, transition metal oxides, SrFeCo{sub 0.5}O{sub x}, and BaTiO{sub 3}.

Park, J.H.; Ma, B.; Park, E.T. [Argonne National Lab., IL (United States). Energy Technology Div.

1997-10-01T23:59:59.000Z

257

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

SciTech Connect

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

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

2011-12-31T23:59:59.000Z

258

Hydrodynamic Analysis of a Three-Fluidized Bed Reactor Cold Flow Model for Chemical Looping Hydrogen Generation: Pressure Characteristics  

Science Journals Connector (OSTI)

Chemical looping hydrogen generation (CLHG) can produce pure hydrogen with inherent separation of CO2 from fossils fuel. The process involves a metal oxide, as an oxygen carrier, such as iron oxide. The CLHG syst...

Zhipeng Xue; Wenguo Xiang; Shiyi Chen…

2013-01-01T23:59:59.000Z

259

Studies on the chemical synthesis and characterization of lead oxide nanoparticles with different organic capping agents  

SciTech Connect

Lead oxide (PbO) nanoparticles were chemically synthesized using Lead (II) acetate as precursor. The effects of organic capping agents such as Oleic acid, Ethylene Diamine Tetra Acetic acid (EDTA) and Cetryl Tri Methyl Butoxide (CTAB) on the size and morphology of the nanoparticles were studied. Characterization techniques such as X-ray diffraction (XRD), Fourier Transform-Infrared spectroscopy (FT-IR), Photoluminescence (PL) Field Emission Scanning Electron Microscopy (FE-SEM), Energy Dispersive Spectroscopy (EDS) and Transmission Electron Microscopy (TEM) were used to analyse the prepared nanoparticles for their physical, structural and optical properties. The characterization studies reveal that the synthesized PbO nanoparticles had well defined crystalline structure and sizes in the range of 25 nm to 36 nm for capping agents used and 40 nm for pure PbO nanoparticles.

Arulmozhi, K. T., E-mail: arulsheelphy@gmail.com [Physics Wing (DDE), Annamalai University, Tamil Nadu, India - 608 002 (India); Mythili, N. [Department of Physics, Annamalai University, Tamil Nadu, India - 608 002 (India)] [Department of Physics, Annamalai University, Tamil Nadu, India - 608 002 (India)

2013-12-15T23:59:59.000Z

260

HEU to LEU conversion and blending facility: Metal blending alternative to produce LEU oxide for disposal  

SciTech Connect

US DOE is examining options for disposing of surplus weapons-usable fissile materials and storage of all weapons-usable fissile materials. The nuclear material is converted to a form more proliferation- resistant than the original form. Blending HEU (highly enriched uranium) with less-enriched uranium to form LEU has been proposed as a disposition option. Five technologies are being assessed for blending HEU. This document provides data to be used in environmental impact analysis for the HEU-LEU disposition option that uses metal blending with an oxide waste product. It is divided into: mission and assumptions, conversion and blending facility descriptions, process descriptions and requirements, resource needs, employment needs, waste and emissions from plant, hazards discussion, and intersite transportation.

NONE

1995-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "metal oxide chemical" 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

Performance and degradation of metal-supported solid oxide fuel cells with impregnated electrodes  

Science Journals Connector (OSTI)

Abstract Metal-supported solid oxide fuel cells (MS-SOFCs) containing porous 430L stainless steel supports, YSZ electrolytes and porous YSZ cathode backbones are fabricated by tape casting, laminating and co-firing in a reducing atmosphere. Nano-scale Ni and La0.6Sr0.4Fe0.9Sc0.1O3?? (LSFSc) coatings are impregnated onto the internal surfaces of porous 430L and YSZ, acting as the anode and the cathode catalysts, respectively. The resulting MS-SOFCs exhibit maximum power densities of 193, 418, 636 and 907 mW cm?2 at 650, 700, 750 and 800 °C, respectively. Nevertheless, a continuous degradation in the fuel cell performance is observed at 650 °C and 0.7 V during a 200-h durability measurement. Possible degradation mechanisms were discussed in detail.

Yucun Zhou; Xianshuang Xin; Junliang Li; Xiaofeng Ye; Changrong Xia; Shaorong Wang; Zhongliang Zhan

2014-01-01T23:59:59.000Z

262

Corrosion and Protection of Metallic Interconnects in Solid Oxide Fuel Cells  

SciTech Connect

Energy security and increased concern over environmental protection have spurred a dramatic world-wide growth in research and development of fuel cells, which electrochemically convert incoming fuel into electricity with no or low pollution. Fuel cell technology has become increasingly attractive to a number of sectors, including utility, automotive, and defense industries. Among the various types of fuel cells, solid oxide fuel cells (SOFCs) operate at high temperature (typically 650-1,000 C) and have advantages in terms of high conversion efficiency and the flexibility of using hydrocarbon fuels, in addition to hydrogen. The high temperature operation, however, can lead to increased mass transport and interactions between the surrounding environment and components that are required to be stable during a lifetime of thousands of hours and up to hundreds of thermal cycles. For stacks with relatively low operating temperatures (<800 C), the interconnects that are used to electrically connect a number of cells in series are typically made from cost-effective metals or alloys. The metallic interconnects must demonstrate excellent stability in a very challenging environment during SOFC operation, as they are simultaneously exposed to both an oxidizing (air) environment on the cathode side and a reducing environment (hydrogen or a reformed hydrocarbon fuel) on the anode side. Other challenges include the fact that water vapor is likely to be present in both of these environments, and the fuel is likely to contain impurities, such as sulfides. Since the fuel is usually a reformed hydrocarbon fuel, such as natural gas, coal gas, biogas, gasoline, etc., the interconnect is exposed to a wet carbonaceous environment at the anode side. Finally, the interconnect must be stable towards any adjacent components, such as electrodes, seals and electrical contact materials, with which it is in physical contact.

Yang, Z Gary; Stevenson, Jeffry W.; Singh, Prabhakar

2007-12-09T23:59:59.000Z

263

Gas-phase chemical reactions of transition metal clusters with simple molecules  

SciTech Connect

Chemical reactions of isolated transition metal clusters are studied in a laser-vaporization cluster source coupled to a continuous-flow reactor. Detection of reaction products is via laser ionization and time-of-flight mass spectrometry. Experimental probes that have been developed include: (1) kinetics measurements, in which the disappearance of bare cluster signal with increasing reagent gas flow is used to determine absolute reaction rate constants for the addition of the first adsorbate molecule; (2) product composition measurements, in which inferences as to cluster structure and the nature of surface binding sites are derived by determining the total number of adsorbates the clusters can accommodate; (3) laser-induced desorption experiments, from which adsorbate binding energies can be derived; and (4) the observation of actual chemical reactions on cluster surfaces, such as hydrogen/deuterium exchange or adsorbate photochemistry. In addition, a new experimental procedure has been developed that, in a single series of measurements, provides measures of the first three parameters listed above. A review is given of earlier studies of the reaction of iron clusters with hydrogen. More recent results on the reaction of iron clusters with ammonia, and the reaction of ammoniated iron clusters with hydrogen, are also presented.

Riley, S.J.; Parks, E.K.

1986-01-01T23:59:59.000Z

264

Chemical Bonding, Interfaces and Defects in Hafnium Oxide/Germanium Oxynitride Gate Stacks on Ge (100)  

SciTech Connect

Correlations among interface properties and chemical bonding characteristics in HfO{sub 2}/GeO{sub x}N{sub y}/Ge MIS stacks were investigated using in-situ remote nitridation of the Ge (100) surface prior to HfO{sub 2} atomic layer deposition (ALD). Ultra thin ({approx}1.1 nm), thermally stable and aqueous etch-resistant GeO{sub x}N{sub y} interfaces layers that exhibited Ge core level photoelectron spectra (PES) similar to stoichiometric Ge{sub 3}N{sub 4} were synthesized. To evaluate GeO{sub x}N{sub y}/Ge interface defects, the density of interface states (D{sub it}) was extracted by the conductance method across the band gap. Forming gas annealed (FGA) samples exhibited substantially lower D{sub it} ({approx} 1 x 10{sup 12} cm{sup -2} eV{sup -1}) than did high vacuum annealed (HVA) and inert gas anneal (IGA) samples ({approx} 1x 10{sup 13} cm{sup -2} eV{sup -1}). Germanium core level photoelectron spectra from similar FGA-treated samples detected out-diffusion of germanium oxide to the HfO{sub 2} film surface and apparent modification of chemical bonding at the GeO{sub x}N{sub y}/Ge interface, which is related to the reduced D{sub it}.

Oshima, Yasuhiro; /Stanford U., Materials Sci. Dept.; Sun, Yun; /SLAC, SSRL; Kuzum, Duygu; /Stanford U.; Sugawara, Takuya; Saraswat, Krishna C.; Pianetta, Piero; /SLAC, SSRL; McIntyre, Paul C.; /Stanford U., Materials Sci. Dept.

2008-10-31T23:59:59.000Z

265

AlGaN/GaN metal-oxide-semiconductor heterostructure field-effect transistors using barium strontium titanate  

E-Print Network (OSTI)

AlGaN/GaN metal-oxide-semiconductor heterostructure field-effect transistors using barium strontium-effect transistors have been formed by incorporating barium strontium titanate (BST) deposited by rf magnetron in increased leakage. Due to its large dielectric constant, barium strontium ti- tanate [Ba1-xSrxTiO3, (BST

York, Robert A.

266

High-temperature corrosion of metallic alloys in an oxidizing atmosphere containing NaCl  

SciTech Connect

A particular heat-exchanger application involved metallic alloys exposed to flue gases of an aluminum remelt furnace. Because the flue gases might contain NaCl and other halides, the corrosion behavior of the alloys was to be investigated. Planned direct exposure of candidate alloys to the flue gases, however, was not conducted because of premature termination of the project. Complementary laboratory testing was conducted on seven commercially available alloys and two nickel aluminides. These materials were exposed to an oxidizing atmosphere containing 0.06 wt % NaCl for 1100 h at 1000/degree/C. Most of the alloy exhibited grain-boundary attack, which resulted in complete oxidation of enveloped grains. The alloys Incoloy MA-956, Incoloy 800, Inconel 625, Inconel 601, Hastelloy X, Haynes 188, and nickel aluminide IC-50 were substantially more corroded than Alloy 214 and nickel aluminide IC-221. The latter two alloys, therefore, would probably be superior to the others in application involving flue gases containing NaCl. Strength fabricability, and weldability, which are briefly discussed, would also affect selection of materials. 8 refs., 12 figs., 5 tabs.

Federer, J.I.

1989-02-01T23:59:59.000Z

267

Metal-gate-induced reduction of the interfacial layer in Hf oxide gate stacks  

SciTech Connect

The properties of high-{kappa} metal oxide gate stacks are often determined in the final processing steps following dielectric deposition. We report here results from medium energy ion scattering and x-ray photoelectron spectroscopy studies of oxygen and silicon diffusion and interfacial layer reactions in multilayer gate stacks. Our results show that Ti metallization of HfO{sub 2}/SiO{sub 2}/Si stacks reduces the SiO{sub 2} interlayer and (to a more limited extent) the HfO{sub 2} layer. We find that Si atoms initially present in the interfacial SiO{sub 2} layer incorporate into the bottom of the high-{kappa} layer. Some evidence for Ti-Si interdiffusion through the high-{kappa} film in the presence of a Ti gate in the crystalline HfO{sub 2} films is also reported. This diffusion is likely to be related to defects in crystalline HfO{sub 2} films, such as grain boundaries. High-resolution transmission electron microscopy and corresponding electron energy loss spectroscopy scans show aggressive Ti-Si intermixing and oxygen diffusion to the outermost Ti layer, given high enough annealing temperature. Thermodynamic calculations show that the driving forces exist for some of the observed diffusion processes.

Goncharova, L. V.; Dalponte, M.; Gustafsson, T.; Celik, O.; Garfunkel, E.; Lysaght, P. S.; Bersuker, G. [Department of Physics and Astronomy, and Laboratory for Surface Modification, Rutgers University, 136 Frelinghuysen Rd., Piscataway, New Jersey 08854 (United States); Department of Chemistry and Chemical Biology, and Laboratory for Surface Modification, Rutgers University, 610 Taylor Rd., Piscataway, New Jersey 08854 (United States); SEMATECH, 2705 Montopolis Dr., Austin, Texas 78741 (United States)

2007-03-15T23:59:59.000Z

268

INFLUENCE OF OXIDE GROWTH AND METAL CREEP ON STRAIN DEVELOPMENT IN THE STEAM-SIDE OXIDE IN BOILER TUBES  

SciTech Connect

This effort is concerned with developing a quantitative description of the exfoliation behavior of oxide scales grown inside steam tubes in a pressure boiler. Consideration of the development of stress/strain in growing oxides has included expansion mismatch-induced strains during thermal cycling as well as inelastic mechanical effects from oxide/alloy creep phenomena and volume change from oxide growth. The magnitude of the parameters used has been closely matched to actual boiler operating practice. The creep model used was validated against published data. Representation of oxide growth-induced strain was found to be a difficult challenge because the processes involved are not fully understood. In addition to the traditional uniaxial (radial) and dilatational models, lateral growth models are discussed in the context of experimentally-derived criteria, such as the level of elastic strains involved in oxide exfoliation. It was found that strain variation in the oxide cannot be neglected.

Sabau, Adrian S [ORNL; Wright, Ian G [ORNL

2010-01-01T23:59:59.000Z

269

Confronting Workplace Exposure to Chemicals with LCA:? Examples of Trichloroethylene and Perchloroethylene in Metal Degreasing and Dry Cleaning  

Science Journals Connector (OSTI)

Confronting Workplace Exposure to Chemicals with LCA:? Examples of Trichloroethylene and Perchloroethylene in Metal Degreasing and Dry Cleaning ... Life-Cycle Assessment (LCA) aims to assess all environmental impacts “from cradle to grave”. ... We therefore conclude that occupational health effects need to be considered in LCA to prevent overlooking key environmental-health impacts in LCA. ...

Stefanie Hellweg; Evangelia Demou; Martin Scheringer; Thomas E. McKone; Konrad Hungerbühler

2005-08-30T23:59:59.000Z

270

Fully Integrated Complementary Metal Oxide Semiconductor (CMOS) Bio-Assay Platform  

E-Print Network (OSTI)

PON IVD platform, namely high bio- chemical sensitivity andthat this platform had the bio- chemical selectivityThe bio-chemical sensitivity of this platform was evaluated

Florescu, Octavian

2010-01-01T23:59:59.000Z

271

Selective CO{sub 2} reduction conjugated with H{sub 2}O oxidation utilizing semiconductor/metal-complex hybrid photocatalysts  

SciTech Connect

We developed a new hybrid photocatalyst for CO{sub 2} reduction, which is composed of a semiconductor and a metal complex. In the hybrid photocatalyst, ?G between the position of conduction band minimum (E{sub CBM}) of the semiconductor and the CO{sub 2} reduction potential of the complex is an essential factor for realizing fast electron transfer from the conduction band of semiconductor to metal complex leading to high photocatalytic activity. On the basis of this concept, the hybrid photocatalyst InP/Ru-complex, which functions in aqueous media, was developed. The photoreduction of CO{sub 2} to formate using water as an electron donor and a proton source was successfully achieved as a Z-scheme system by functionally conjugating the InP/Ru-complex photocatalyst for CO{sub 2} reduction with a TiO{sub 2} photocatalyst for water oxidation. The conversion efficiency from solar energy to chemical energy was ca. 0.04%, which approaches that for photosynthesis in a plant. Because this system can be applied to many other inorganic semiconductors and metal-complex catalysts, the efficiency and reaction selectivity can be enhanced by optimization of the electron transfer process including the energy-band configurations, conjugation conformations, and catalyst structures. This electrical-bias-free reaction is a huge leap forward for future practical applications of artificial photosynthesis under solar irradiation to produce organic species.

Morikawa, T., E-mail: morikawa@mosk.tytlabs.co.jp; Sato, S., E-mail: morikawa@mosk.tytlabs.co.jp; Arai, T., E-mail: morikawa@mosk.tytlabs.co.jp; Uemura, K., E-mail: morikawa@mosk.tytlabs.co.jp; Yamanaka, K. I., E-mail: morikawa@mosk.tytlabs.co.jp; Suzuki, T. M., E-mail: morikawa@mosk.tytlabs.co.jp; Kajino, T., E-mail: morikawa@mosk.tytlabs.co.jp; Motohiro, T., E-mail: morikawa@mosk.tytlabs.co.jp [Toyota Central R and D Labs, Inc., Nagakute, Aichi 480-1192 (Japan)

2013-12-10T23:59:59.000Z

272

Promises and problems with metallic interconnects for reduced temperature solid oxide fuel cells  

E-Print Network (OSTI)

Symposium on Solid Oxide Fuel Cells (SOFC-VI) ed. S. C.FOR REDUCED TEMPERATURE SOLID OXIDE FUEL CELLS Peggy Y. Hou,for low temperature solid oxide fuel cell is discussed in

Hou, Peggy Y.; Huang, Keqin; Bakker, Wate T.

1999-01-01T23:59:59.000Z

273

Rapid thermal cycling of metal-supported solid oxide fuel cell membranes  

E-Print Network (OSTI)

effect of pressure on solid oxide fuel cell performance," inand flat plate solid oxide fuel cells," in Proceedings ofSymposium on Solid Oxide Fuel Cells. Electrochem. Soc. 1993,

Matus, Yuriy B.; De Jonghe, Lutgard C.; Jacobson, Craig P.; Visco, Steven J.

2004-01-01T23:59:59.000Z

274

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

E-Print Network (OSTI)

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

Henkes, Amanda Erin

2009-05-15T23:59:59.000Z

275

Oxidation of Metals, Vol. 61, Nos. 3/4, April 2004 ( 2004) Thermal Conductivity, Phase Stability, and Oxidation  

E-Print Network (OSTI)

, and Oxidation Resistance of Y3Al5O12 (YAG)/Y2O3­ZrO2 (YSZ) Thermal-Barrier Coatings Y. J. Su, R. W. Trice,# K oxidation resistance while maintaining low thermal conductivity and good phase stability. Padture) is proposed. The objective of this work is to quantify the effect of YAG on thermal resistance, long

Trice, Rodney W.

276

Ultra-high vacuum fabrication and electrical characterization of environmentally sensitive metal oxide semiconductor capacitors  

SciTech Connect

We describe an integrated, ultra-high vacuum system for metal oxide semiconductor (MOS) device fabrication and characterization. Such a system is advantageous for electrical property measurements of electronic devices consisting of environmentally sensitive materials especially as device dimensions approach the nanoscale. Without exposure to atomosphere, MOS capacitors were fabricated by evaporating gate metal on molecular-beam-epitaxy (MBE) grown dielectrics on 3 inch-diameter substrates through a shadow mask in a UHV electrode-patterning chamber. The finished device is transferred in vacuum to an in-situ, UHV electrical characterization probe station that was designed with standard UHV coaxial feedthroughs and UHV-compatible, Kapton-insulated coaxial cable. The probe station also includes a heated sample stage that allows for annealing and measurements in a controlled ambient. We obtained excellent agreement between air-ambient ex-situ and in-situ probe station measurements utilizing a capacitor standard compatible with UHV based on single crystal sapphire as the dielectric. The measurements show less than 0.3 % dispersion for frequencies from 20 Hz to 1 MHz. We have successfully measured MOS capacitors and are sensitive to a density of interface states of 1x1010 states cm-2 eV-1. These measurements also show 0.5 % dispersion for measurement frequencies from 20 Hz to 1 kHz and less than 0.1 % from 1 kHz to 1 MHz. The integrated system presented here is one where complex, MBE-grown MOS heterostructures can be synthesized and tested rapidly to elucidate new field-effect-device physics and functionality.

Billman, Curt [Oak Ridge National Laboratory (ORNL); Walker, Frederick Joseph [ORNL

2007-01-01T23:59:59.000Z

277

Chemical Looping Combustion Kinetics  

SciTech Connect

One of the most promising methods of capturing CO{sub 2} emitted by coal-fired power plants for subsequent sequestration is chemical looping combustion (CLC). A powdered metal oxide such as NiO transfers oxygen directly to a fuel in a fuel reactor at high temperatures with no air present. Heat, water, and CO{sub 2} are released, and after H{sub 2}O condensation the CO{sub 2} (undiluted by N{sub 2}) is ready for sequestration, whereas the nickel metal is ready for reoxidation in the air reactor. In principle, these processes can be repeated endlessly with the original nickel metal/nickel oxide participating in a loop that admits fuel and rejects ash, heat, and water. Our project accumulated kinetic rate data at high temperatures and elevated pressures for the metal oxide reduction step and for the metal reoxidation step. These data will be used in computational modeling of CLC on the laboratory scale and presumably later on the plant scale. The oxygen carrier on which the research at Utah is focused is CuO/Cu{sub 2}O rather than nickel oxide because the copper system lends itself to use with solid fuels in an alternative to CLC called 'chemical looping with oxygen uncoupling' (CLOU).

Edward Eyring; Gabor Konya

2009-03-31T23:59:59.000Z

278

Safety and core design of large liquid-metal cooled fast breeder reactors  

E-Print Network (OSTI)

Absorption Metal (Zr) Metal (Mo) Carbide Nitride Oxidef /? a k ? Metal (Zr) Metal (Mo) Carbide Nitride Oxide Table? a k ? Metal (Zr) Metal (Mo) Carbide Nitride Oxide CHAPTER

Qvist, Staffan Alexander

2013-01-01T23:59:59.000Z

279

High-Temperature Zirconia Oxygen Sensor with Sealed Metal/Metal...  

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

High-Temperature Zirconia Oxygen Sensor with Sealed MetalMetal Oxide Internal Reference High-Temperature Zirconia Oxygen Sensor with Sealed MetalMetal Oxide Internal Reference...

280

Improved layered mixed transition metal oxides for Li-ion batteries  

SciTech Connect

Recent work in our laboratory has been directed towards development of mixed layered transition metal oxides with general composition Li[Ni, Co, M, Mn]O2 (M=Al, Ti) for Li ion battery cathodes. Compounds such as Li[Ni1/3Co1/3Mn1/3]O2 (often called NMCs) are currently being commercialized for use in consumer electronic batteries, but the high cobalt content makes them too expensive for vehicular applications such as electric vehicles (EV), plug-in hybrid electric vehicles (PHEVs), or hybrid electric vehicles (HEVs). To reduce materials costs, we have explored partial or full substitution of Co with Al, Ti, and Fe. Fe substitution generally decreases capacity and results in poorer rate and cycling behavior. Interestingly, low levels of substitution with Al or Ti improve aspects of performance with minimal impact on energy densities, for some formulations. High levels of Al substitution compromise specific capacity, however, so further improvements require that the Ni and Mn content be increased and Co correspondingly decreased. Low levels of Al or Ti substitution can then be used offset negative effects induced by the higher Ni content. The structural and electrochemical characterization of substituted NMCs is presented in this paper.

Doeff, Marca M.; Conry, Thomas; Wilcox, James

2010-03-05T23:59:59.000Z

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

Degradation of solid oxide fuel cell metallic interconnects in fuels containing sulfur  

SciTech Connect

Hydrogen is the main fuel for all types of fuel cells except direct methanol fuel cells. Hydrogen can be generated from all manner of fossil fuels, including coal, natural gas, diesel, gasoline, other hydrocarbons, and oxygenates (e.g., methanol, ethanol, butanol, etc.). Impurities in the fuel can cause significant performance problems and sulfur, in particular, can decrease the cell performance of fuel cells, including solid oxide fuel cells (SOFC). In the SOFC, the high (800-1000°C) operating temperature yields advantages (e.g., internal fuel reforming) and disadvantages (e.g., material selection and degradation problems). Significant progress in reducing the operating temperature of the SOFC from ~1000 ºC to ~750 ºC may allow less expensive metallic materials to be used for interconnects and as balance of plant (BOP) materials. This paper provides insight on the material performance of nickel, ferritic steels, and nickel-based alloys in fuels containing sulfur, primarily in the form of H2S, and seeks to quantify the extent of possible degradation due to sulfur in the gas stream.

Ziomek-Moroz, M.; Hawk, Jeffrey A.

2005-01-01T23:59:59.000Z

282

Growth of monodisperse mesoscopic metal-oxide colloids under constant monomer supply  

Science Journals Connector (OSTI)

In closed systems, control over the size of monodisperse metal-oxide colloids is generally limited to submicrometric dimensions. To overcome this difficulty, we explore the formation and growth of silica particles under constant monomer supply. The monomer source is externally driven by the progressive addition into the system of one of the precursors. Monodisperse spherical particles are produced up to a mesoscopic size. We analyze their growth versus the monomer addition rate at different temperatures. Our results show that in the presence of a continuous monomer addition, growth is limited by diffusion over the investigated temporal window. Using the temperature variation of the growth rate, we prove that rescaling leads to a data reduction onto a single master curve. Contrary to the growth process, the final particle’s size reached after the end of the reagent supply strongly depends on the addition rate. The variation of the final particle size versus addition rate can be deduced from an analogy with crystal formation in jet precipitation. Within this framework, and using the temperature dependences of both the particle growth law and the final size, we determine the value of the molecular heat of dissolution associated to the silica solubility. These observations support the fact that classical theories of phase-ordering dynamics can be extended to the synthesis of inorganic particles. The emergence of a master behavior in the presence of continuous monomer addition also suggests the extension of these theories to open systems.

Koh Nozawa; Marie-Hélène Delville; Hideharu Ushiki; Pascal Panizza; Jean-Pierre Delville

2005-07-11T23:59:59.000Z

283

An electrochemical investigation of the chemical diffusivity in liquid metal alloys  

E-Print Network (OSTI)

The liquid metal battery has been shown to be a viable candidate for grid-scale energy storage, due to its fast kinetics and ability to be constructed from economically feasible materials. Various of the liquid metal couples ...

Barriga, Salvador A. (Salvador Aguilar)

2013-01-01T23:59:59.000Z

284

Doped palladium containing oxidation catalysts  

DOE Patents (OSTI)

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

Mohajeri, Nahid

2014-02-18T23:59:59.000Z

285

Metallic Interconnects for Solid Oxide Fuel Cell: Performance of Reactive Element Oxide Coating During 10, 20 and 30 Months Exposure  

Science Journals Connector (OSTI)

One of challenges in improving the performance and cost-effectiveness of SOFCs (Solid Oxide Fuel Cells) is the development of suitable interconnect materials. Chromia-forming alloys and especially ferritic sta...

S. Fontana; S. Chevalier; G. Caboche

2012-12-01T23:59:59.000Z

286

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

SciTech Connect

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

Bitterwolf, Thomas E. [University of Idaho

2014-12-09T23:59:59.000Z

287

Multilayered thermal insulation formed of zirconia bonded layers of zirconia fibers and metal oxide fibers and method for making same  

DOE Patents (OSTI)

A multilayered thermal insulating composite is formed of a first layer of zirconia-bonded zirconia fibers for utilization near the hot phase or surface of a furnace or the like. A second layer of zirconia-bonded metal oxide fibers is attached to the zirconia fiber layer by a transition layer formed of intermingled zirconia fibers and metal oxide fibers. The thermal insulation is fabricated by vacuum molding with the layers being sequentially applied from aqueous solutions containing the fibers to a configured mandrel. A portion of the solution containing the fibers forming the first layer is intermixed with the solution containing the fibers of the second layer for forming the layer of mixed fibers. The two layers of fibers joined together by the transition layer are saturated with a solution of zirconium oxynitrate which provides a zirconia matrix for the composite when the fibers are sintered together at their nexi.

Wrenn, Jr., George E. (Clinton, TN); Holcombe, Jr., Cressie E. (Farragut, TN)

1988-01-01T23:59:59.000Z

288

Electric pulse induced resistance change effect in manganites due to polaron localization at the metal-oxide interfacial region  

Science Journals Connector (OSTI)

Combining pulse-probe measurements as well as local transport measurements in an electron microscope system by a simultaneous monitoring of the structural changes, we show that the nonvolatile electric pulse induced resistance change in Ca-doped praseodymium manganite is related to a polaron order-disorder transition, modified by electronic band bending in the vicinity of an interface to a metallic electrode. A pronounced resistance change requires a critical distance between the two electrode and/or oxide interfaces to form an insulating incommensurate polaron-ordered phase during the initialization of the device. Based on these observations, a qualitative model for the electronic structure of the metal-oxide interface is developed.

Ch. Jooss, J. Hoffmann, J. Fladerer, M. Ehrhardt, T. Beetz, L. Wu, and Y. Zhu

2008-04-23T23:59:59.000Z

289

Comparative electron paramagnetic resonance investigation of reduced graphene oxide and carbon nanotubes with different chemical functionalities for quantum dot attachment  

SciTech Connect

Electron paramagnetic resonance (EPR) spectroscopy has been applied to different chemically treated reduced graphene oxide (rGO) and multiwalled carbon nanotubes (CNTs). A narrow EPR signal is visible at g?=?2.0029 in both GO and CNT-Oxide from carbon-related dangling bonds. EPR signals became broader and of lower intensity after oxygen-containing functionalities were reduced and partially transformed into thiol groups to obtain thiol-functionalized reduced GO (TrGO) and thiol-functionalized CNT (CNT-SH), respectively. Additionally, EPR investigation of CdSe quantum dot-TrGO hybrid material reveals complete quenching of the TrGO EPR signal due to direct chemical attachment and electronic coupling. Our work confirms that EPR is a suitable tool to detect spin density changes in different functionalized nanocarbon materials and can contribute to improved understanding of electronic coupling effects in nanocarbon-nanoparticle hybrid nano-composites promising for various electronic and optoelectronic applications.

Pham, Chuyen V.; Krueger, Michael, E-mail: michael.krueger@fmf.uni-freiburg.de, E-mail: emre.erdem@physchem.uni-freiburg.de; Eck, Michael [Freiburg Materials Research Center (FMF), University of Freiburg, Stefan-Meier-Str. 21, 79104 Freiburg (Germany); Department of Microsystems Engineering (IMTEK), University of Freiburg, Georges-Köhler-Allee 103, 79110 Freiburg (Germany); Weber, Stefan; Erdem, Emre, E-mail: michael.krueger@fmf.uni-freiburg.de, E-mail: emre.erdem@physchem.uni-freiburg.de [Institute of Physical Chemistry, University of Freiburg, Albertstr. 21, 79104 Freiburg (Germany)

2014-03-31T23:59:59.000Z

290

Scaling properties in the adsorption of ionic polymeric surfactants on generic nanoparticles of metallic oxides by mesoscopic simulation  

E-Print Network (OSTI)

We study the scaling of adsorption isotherms of polyacrylic dispersants on generic surfaces of metallic oxides $XnOm$ as a function of the number of monomeric units, using Electrostatic Dissipative Particle Dynamics simulations. The simulations show how the scaling properties in these systems emerge and how the isotherms rescale to a universal curve, reproducing reported experimental results. The critical exponent for these systems is also obtained, in perfect agreement with the scaling theory of deGennes. Some important applications are mentioned.

E. Mayoral; E. Nahmad-Achar

2014-02-11T23:59:59.000Z

291

Roles of Glutamates and Metal ions in a Rationally Designed Nitric Oxide Reductase Based on Myoglobin  

SciTech Connect

A structural and functional model of bacterial nitric oxide reductase (NOR) has been designed by introducing two glutamates (Glu) and three histidines (His) in sperm whale myoglobin. X-ray structural data indicate that the three His and one Glu (V68E) residues bind iron, mimicking the putative FeB site in NOR, while the second Glu (I107E) interacts with a water molecule and forms a hydrogen bonding network in the designed protein. Unlike the first Glu (V68E), which lowered the heme reduction potential by {approx}110 mV, the second Glu has little effect on the heme potential, suggesting that the negatively charged Glu has a different role in redox tuning. More importantly, introducing the second Glu resulted in a {approx}100% increase in NOR activity, suggesting the importance of a hydrogen bonding network in facilitating proton delivery during NOR reactivity. In addition, EPR and X-ray structural studies indicate that the designed protein binds iron, copper, or zinc in the FeB site, each with different effects on the structures and NOR activities, suggesting that both redox activity and an intermediate five-coordinate heme-NO species are important for high NOR activity. The designed protein offers an excellent model for NOR and demonstrates the power of using designed proteins as a simpler and more well-defined system to address important chemical and biological issues.

Y Lin; N Yeung; Y Gao; K Miner; S Tian; H Robinson; Y Lu

2011-12-31T23:59:59.000Z

292

Chemical interactions at polymer interfaces: poly(p-xylylene-?-tetrahydrothiophene-bromide, chloride) on indium–tin-oxide  

Science Journals Connector (OSTI)

Chemical interactions, at the interface between a precursor polymer for poly(p-phenylenevinylene), namely poly(p-xylylene-?-tetrahydrothiophene-chloride), and an indium–tin-oxide transparent electrode, are identified using X-ray photoelectron spectroscopy. The \\{HCl\\} eliminated in the conversion process interacts with the surface of the indium–tin-oxide substrate leading to the formation of indium chloride which then diffuses into the polymer. It appears that indium–tin-oxide, or possibly the indium chloride generated at the interface, acts as a catalyst for the thermal elimination reaction. The results show unequivocally that interfacial interactions are of major importance in understanding, and ultimately improving, the performance of polymer-based electro-luminescent devices.

A Andersson; Th Kugler; M Lögdlund; A.B Holmes; X Li; W.R Salaneck

1999-01-01T23:59:59.000Z

293

Stress-induced chemical detection using flexible metal-organic frameworks.  

SciTech Connect

In this work we demonstrate the concept of stress-induced chemical detection using metal-organic frameworks (MOFs) by integrating a thin film of the MOF HKUST-1 with a microcantilever surface. The results show that the energy of molecular adsorption, which causes slight distortions in the MOF crystal structure, can be efficiently converted to mechanical energy to create a highly responsive, reversible, and selective sensor. This sensor responds to water, methanol, and ethanol vapors, but yields no response to either N{sub 2} or O{sub 2}. The magnitude of the signal, which is measured by a built-in piezoresistor, is correlated with the concentration and can be fitted to a Langmuir isotherm. Furthermore, we show that the hydration state of the MOF layer can be used to impart selectivity to CO{sub 2}. We also report the first use of surface-enhanced Raman spectroscopy to characterize the structure of a MOF film. We conclude that the synthetic versatility of these nanoporous materials holds great promise for creating recognition chemistries to enable selective detection of a wide range of analytes. A force field model is described that successfully predicts changes in MOF properties and the uptake of gases. This model is used to predict adsorption isotherms for a number of representative compounds, including explosives, nerve agents, volatile organic compounds, and polyaromatic hydrocarbons. The results show that, as a result of relatively large heats of adsorption (> 20 kcal mol{sup -1}) in most cases, we expect an onset of adsorption by MOF as low as 10{sup -6} kPa, suggesting the potential to detect compounds such as RDX at levels as low as 10 ppb at atmospheric pressure.

Allendorf, Mark D.; Hesketh, Peter J. (Georgia Institute of Technology, Atlanta, GA); Gall, Kenneth A. (Georgia Institute of Technology, Atlanta, GA); Choudhury, A. (Georgia Institute of Technology, Atlanta, GA); Pikarsky, J. (Georgia Institute of Technology, Atlanta, GA); Andruszkiewicz, Leanne (Georgia Institute of Technology, Atlanta, GA); Houk, Ronald J. T.; Talin, Albert Alec (National Institute of Standards & Technology, Gaithersburg, MD)

2009-09-01T23:59:59.000Z

294

Product/metal ratio (PMR): A novel criterion for the evaluation of electrolytes on micro-arc oxidation (MAO) of Mg and its alloys  

Science Journals Connector (OSTI)

Product/metal ratio (PMR...) was introduced as a novel criterion for the evaluation of electrolytes on micro-arc oxidation (MAO) of Mg and its alloys....PBR), focused on the roles of electrolytes for the compactn...

LaiWen Song; YingWei Song; DaYong Shan; GuoYi Zhu…

2011-10-01T23:59:59.000Z

295

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

Science Journals Connector (OSTI)

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

C. Kuhrs; M. Swoboda; W. Weiss

2001-01-01T23:59:59.000Z

296

CHEMICAL ANALYSIS OF THE NINTH MAGNITUDE CARBON-ENHANCED METAL-POOR STAR BD+44 Degree-Sign 493  

SciTech Connect

We present detailed chemical abundances for the bright carbon-enhanced metal-poor (CEMP) star BD+44 Degree-Sign 493, previously reported on by Ito et al. Our measurements confirm that BD+44 Degree-Sign 493 is an extremely metal-poor ([Fe/H] =-3.8) subgiant star with excesses of carbon and oxygen. No significant excesses are found for nitrogen and neutron-capture elements (the latter of which place it in the CEMP-no class of stars). Other elements that we measure exhibit abundance patterns that are typical for non-CEMP extremely metal-poor stars. No evidence for variations of radial velocity has been found for this star. These results strongly suggest that the carbon enhancement in BD+44 Degree-Sign 493 is unlikely to have been produced by a companion asymptotic giant-branch star and transferred to the presently observed star, nor by pollution of its natal molecular cloud by rapidly-rotating, massive, mega metal-poor ([Fe/H] < - 6.0) stars. A more likely possibility is that this star formed from gas polluted by the elements produced in a ''faint'' supernova, which underwent mixing and fallback, and only ejected small amounts of elements of metals beyond the lighter elements. The Li abundance of BD+44 Degree-Sign 493 (A(Li) = log (Li/H)+12 =1.0) is lower than the Spite plateau value, as found in other metal-poor subgiants. The upper limit on Be abundance (A(Be) = log (Be/H)+12 < - 1.8) is as low as those found for stars with similarly extremely-low metallicity, indicating that the progenitors of carbon- (and oxygen-) enhanced stars are not significant sources of Be, or that Be is depleted in metal-poor subgiants with effective temperatures of {approx}5400 K.

Ito, Hiroko; Aoki, Wako [Department of Astronomical Science, School of Physical Sciences, Graduate University for Advanced Studies (SOKENDAI), 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Beers, Timothy C. [National Optical Astronomy Observatory, Tucson, AZ 85719 (United States); Tominaga, Nozomu [Department of Physics, Faculty of Science and Engineering, Konan University, 8-9-1 Okamoto, Kobe, Hyogo 658-8501 (Japan); Honda, Satoshi [Kwasan Observatory, School of Science, Kyoto University, Kyoto 377-0702 (Japan); Carollo, Daniela, E-mail: aoki.wako@nao.ac.jp, E-mail: beers@noao.edu, E-mail: tominaga@konan-u.ac.jp, E-mail: honda@kwasan.kyoto-u.ac.jp, E-mail: daniela.carollo@mq.edu.au [Department of Physics and Astronomy, Astronomy, Astrophysics and Astrophotonic Research Center, Macquarie University, North Ryde, NSW 2109 (Australia)

2013-08-10T23:59:59.000Z

297

Investigation on edge fringing effect and oxide thickness dependence of inversion current in metal-oxide-semiconductor tunneling diodes with comb-shaped electrodes  

SciTech Connect

A particular edge-dependent inversion current behavior of metal-oxide-semiconductor (MOS) tunneling diodes was investigated utilizing square and comb-shaped electrodes. The inversion tunneling current exhibits the strong dependence on the tooth size of comb-shaped electrodes and oxide thickness. Detailed illustrations of current conduction mechanism are developed by simulation and experimental measurement results. It is found that the electron diffusion current and Schottky barrier height lowering for hole tunneling current both contribute on inversion current conduction. In MOS tunneling photodiode applications, the photoresponse can be improved by decreasing SiO{sub 2} thickness and using comb-shaped electrodes with smaller tooth spacing. Meantime, the high and steady photosensitivity can also be approached by introducing HfO{sub 2} into dielectric stacks.

Lin, Chien-Chih; Hsu, Pei-Lun; Lin, Li; Hwu, Jenn-Gwo, E-mail: jghwu@ntu.edu.tw [Graduate Institute of Electronics Engineering, Department of Electrical Engineering, National Taiwan University, Taipei 10617, Taiwan (China)

2014-03-28T23:59:59.000Z

298

High Activity of Ce1-xNixO2-y for H2 Production through Ethanol Steam Reforming: Tuning Catalytic Performance through Metal-Oxide Interactions  

SciTech Connect

The importance of the oxide: Ce{sub 0.8}Ni{sub 0.2}O{sub 2-y} is an excellent catalyst for ethanol steam reforming. Metal-oxide interactions perturb the electronic properties of the small particles of metallic nickel present in the catalyst under the reaction conditions and thus suppress any methanation activity. The nickel embedded in ceria induces the formation of O vacancies, which facilitate cleavage of the OH bonds in ethanol and water.

G Zhou; L Barrio; S Agnoli; S Senanayake; J Evans; A Kubacka; M Estrella; J Hanson; A Martinez-Arias; et al.

2011-12-31T23:59:59.000Z

299

Fabrication of Metal/Oxide Nanostructures by Anodization Processes for Biosensor, Drug Delivery and Supercapacitor Applications  

E-Print Network (OSTI)

applications of micro/nano structures; (2) novel processes to innovate anodic aluminum oxide nanotube template; (3) the supercapacitor applications of anodic titanium oxide. First, the extremely high surface area AAO coated microneedle and microneedle array...

Chen, Po-Chun

2014-01-13T23:59:59.000Z

300

Operation of mixed conducting metal oxide membrane systems under transient conditions  

DOE Patents (OSTI)

Method of operating an oxygen-permeable mixed conducting membrane having an oxidant feed side, an oxidant feed surface, a permeate side, and a permeate surface, which method comprises controlling the differential strain between the permeate surface and the oxidant feed surface at a value below a selected maximum value by varying the oxygen partial pressure on either or both of the oxidant feed side and the permeate side of the membrane.

Carolan, Michael Francis (Allentown, PA)

2008-12-23T23:59:59.000Z

Note: This page contains sample records for the topic "metal oxide chemical" 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

E-Print Network 3.0 - alkali metal oxides Sample Search Results  

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

, sodium carbide, turpentine, finely divided metals Calcium water, carbon dioxide, carbon tetrachloride... , and chlorinated hydrocarbons Carbon, activated calcium...

302

Low Temperature Deposition of Metal Oxide Thin Films in Supercritical Carbon Dioxide using Metal-organic Precursors  

E-Print Network (OSTI)

and are driven by the energy provided by a heated substrate. Both these vacuum-based techniques require in the precursor adsorption, oxidation and by-product desorption. [5] Use of solvation energy may provide a viable. Pressurized CO2 was delivered using an ISCO 260D syringe pump through a high- pressure manifold. Resistive

Gougousi, Theodosia

303

Synthesis and characterization of novel group VI metal (Mo, W) nitride and oxide compounds  

SciTech Connect

Investigations into the preparation of tungsten nitrides have involved the synthesis of molecular precursors, and their conversion to tungsten nitrides at relatively low temperatures. Two interesting molecular precursors, [WNCl{sub 3}{center_dot}NCCH{sub 3}]{sub 4} and WN(N{sub 3}){sub 3}{center_dot}xNCCH{sub 3}, have been prepared and characterized. The molecular structure of the first consists of a W{sub 4}N{sub 4} tetrameric core with multiple and single W-N bonds arranged in an alternating fashion. Three new solid state phases, amorphous W{sub 3}N{sub 5}, cubic WN, and W{sub 2}N{sub 2}(C{sub 2}N{sub 2}), have been discovered by solid state and chemical vapor transport reactions. The structures have been investigated. A systematic study in the Ln{sub 2}O{sub 3}-MoO{sub 3}-Mo (Ln = La, Ce, Pr, Nd, Sm) system has been explored to better understand LnMo{sub 8}O{sub 14}. The study has shown that the sizes of the rare-earth cations affect the formation of these phases. Larger cations (La, Ce, and Pr) aid in the formation of trans-Mo{sub 8} bicapped octahedra, and the smaller cations (Nd, Sm) only stabilize the cis-Mo{sub 8} bicapped octahedra. Magnetic susceptibility measurements have indicated that no effective moment contribution arises from the Mo{sub 8} metal clusters, even though the cis-Mo{sub 8} cluster in LnMo{sub 8}O{sub 14}, containing all cis-Mo{sub 8} octahedra, apparently contains an odd number of electrons (23). Electrical resistivity measurements and electronic structure calculations have shown that the LnMo{sub 8}O{sub 14} compounds containing cis-Mo{sub 8} clusters are metallic, and the LnMo{sub 8}O{sub 14} compounds containing a 1:1 ratio of cis- to trans-Mo{sub 8} clusters are semiconducting.

Zhang, Z.

1998-02-23T23:59:59.000Z

304

Hydrolysis of Naptalam and Structurally Related Amides: Inhibition by Dissolved Metal Ions and Metal (Hydr)Oxide Surfaces  

E-Print Network (OSTI)

. INTRODUCTION Several important classes of agrochemicals possess amide and anilide functional groups. Naptalam). Agrochemicals often possess functional groups in the vicinity of amide and anilide linkages; participation and anilide agrochemicals. Granados et al. (1995) reported no significant effects of dissolved divalent metal

Huang, Ching-Hua

305

Metal enrichment in bauxites by deposition of chemically mature aeolian dust  

Science Journals Connector (OSTI)

... is determined by X-ray fluorescence and other metals investigated were determined by flame or flameless atomic absorption spec-troscopy.

George H Brimhall; Christopher J. Lewis; Jay J. Ague; William E. Dietrich; Joachim Hampel; Tim Teague; Peter Rix

1988-06-30T23:59:59.000Z

306

Consistent LDA' + DMFT approach to the electronic structure of transition metal oxides: Charge transfer insulators and correlated metals  

SciTech Connect

We discuss the recently proposed LDA' + DMFT approach providing a consistent parameter-free treatment of the so-called double counting problem arising within the LDA + DMFT hybrid computational method for realistic strongly correlated materials. In this approach, the local exchange-correlation portion of the electron-electron interaction is excluded from self-consistent LDA calculations for strongly correlated electronic shells, e.g., d-states of transition metal compounds. Then, the corresponding double-counting term in the LDA' + DMFT Hamiltonian is consistently set in the local Hartree (fully localized limit, FLL) form of the Hubbard model interaction term. We present the results of extensive LDA' + DMFT calculations of densities of states, spectral densities, and optical conductivity for most typical representatives of two wide classes of strongly correlated systems in the paramagnetic phase: charge transfer insulators (MnO, CoO, and NiO) and strongly correlated metals (SrVO{sub 3} and Sr{sub 2}RuO{sub 4}). It is shown that for NiO and CoO systems, the LDA' + DMFT approach qualitatively improves the conventional LDA + DMFT results with the FLL type of double counting, where CoO and NiO were obtained to be metals. Our calculations also include transition-metal 4s-states located near the Fermi level, missed in previous LDA + DMFT studies of these monoxides. General agreement with optical and the X-ray experiments is obtained. For strongly correlated metals, the LDA' + DMFT results agree well with the earlier LDA + DMFT calculations and existing experiments. However, in general, LDA' + DMFT results give better quantitative agreement with experimental data for band gap sizes and oxygen-state positions compared to the conventional LDA + DMFT method.

Nekrasov, I. A., E-mail: nekrasov@iep.uran.ru; Pavlov, N. S.; Sadovskii, M. V. [Russian Academy of Sciences, Institute for Electrophysics, Ural Branch (Russian Federation)

2013-04-15T23:59:59.000Z

307

Selective Alcohol Dehydrogenation and Hydrogenolysis with Semiconductor-Metal Photocatalysts: Toward Solar-to-Chemical Energy Conversion of Biomass-Relevant Substrates  

Science Journals Connector (OSTI)

Selective Alcohol Dehydrogenation and Hydrogenolysis with Semiconductor-Metal Photocatalysts: Toward Solar-to-Chemical Energy Conversion of Biomass-Relevant Substrates ... Coupled semiconductors of well-matched band energies are convenient to improve charge sepn. ...

T. Purnima A. Ruberu; Nicholas C. Nelson; Igor I. Slowing; Javier Vela

2012-09-13T23:59:59.000Z

308

Synthesis of Mixed Metal Oxides for Hydrodeoxygenation of Pyrolysis Oil for Alternative Fuels Sarah McNew, Tiorra Ross and Carsten Sievers  

E-Print Network (OSTI)

· Flash pyrolysis on biomass [1] · Short residence times and flexible feed · Bio-oils produced are close to dissociate hydrogen Goal: synthesize metal free, sulfur free, catalysts for HDO Biomass Pyrolysis OilSynthesis of Mixed Metal Oxides for Hydrodeoxygenation of Pyrolysis Oil for Alternative Fuels Sarah

Das, Suman

309

ROLE OF C AND P SITES ON THE CHEMICAL ACTIVITY OF METAL CARBIDE AND PHOSPHIDES: FROM CLUSTERS TO SINGLE-CRYSTAL SURFACES  

SciTech Connect

Transition metal carbides and phosphides have shown tremendous potential as highly active catalysts. At a microscopic level, it is not well understood how these new catalysts work. Their high activity is usually attributed to ligand or/and ensemble effects. Here, we review recent studies that examine the chemical activity of metal carbide and phosphides as a function of size, from clusters to extended surfaces, and metal/carbon or metal/phosphorous ratio. These studies reveal that the C and P sites in these compounds cannot be considered as simple spectators. They moderate the reactivity of the metal centers and provide bonding sites for adsorbates.

RODRIGUEZ,J.A.; VINES, F.; LIU, P.; ILLAS, F.

2007-07-01T23:59:59.000Z

310

Photocatalytic and chemical oxidation of organic compounds in supercritical carbon dioxide. Progress report for FY97  

SciTech Connect

'The background for the project is briefly reviewed and the work done during the nine months since funding was received is documented. Work began in January, 1997. A post doctoral fellow joined the team in April. The major activities completed this fiscal year were: staffing the project, design of the experimental system, procurement of components, assembly of the system. preparation of the Safe Operating Procedure and ES and H compliance, pressure testing, establishing data collection and storage methodology, and catalyst preparation. Objective The objective of the project is to develop new chemistry for the removal of organic contaminants from supercritical carbon dioxide. This has application in processes used for continuous cleaning and extraction of parts and waste materials. A secondary objective is to increase the fundamental understanding of photocatalytic chemistry. Cleaning and extraction using supercritical carbon dioxide (scCO{sub 2}) can be applied to the solution of a wide range of environmental and pollution prevention problems in the DOE complex. Work is being done that explores scCO{sub 2} in applications ranging from cleaning contaminated soil to cleaning components constructed from plutonium. The rationale for use of scCO{sub 2} are based on the benign nature, availability and low cost, attractive solvent properties, and energy efficient separation of the extracted solute from the solvent by moderate temperature or pressure changes. To date, R and D has focussed on the methods and applications of the extraction steps of the process. Little has been done that addresses methods to polish the scCO{sub 2} for recycle in the cleaning or extraction operations. In many applications it will be desirable to reduce the level of contamination from that which would occur at steady state operation of a process. This proposal addresses chemistry to achieve that. This would be an alternative to removing a fraction of the contaminated scCO{sub 2} for disposal and using makeup scCO{sub 2}. A chemical polishing operation can reduce the release of CO{sub 2} from the process. It can also reduce the consumption of reagents that may be used in the process to enhance extraction and cleaning. A polishing operation will also reduce or avoid formation of an additional waste stream. Photocatalytic and other photochemical oxidation chemistry have not been investigated in scCO{sub 2}. The large base of information for these reactions in water, organic solvents, or air suggest that the chemistry will work in carbon dioxide. There are compelling reasons to believe that the properties of scCO{sub 2} should increase the performance of photocatalytic chemistry over that found in more conventional fluid phases.'

Blake, D.M.; Bryant, D.L.; Reinsch, V.

1997-09-30T23:59:59.000Z

311

Cu–Zn–Al mixed metal oxides derived from hydroxycarbonate precursors for H2S removal at low temperature  

Science Journals Connector (OSTI)

One series of Cu–Zn and two series of Cu–Zn–Al hydroxycarbonate precursors with varying metal molar ratios were prepared via co-precipitation or multi-precipitation method, and the mixed metal oxides obtained by calcination of the precursor materials were used as adsorbents for H2S removal in the range of 25–100 °C. The results of H2S adsorption tests showed that these mixed oxides, especially two series of Cu–Zn–Al mixed metal oxides exhibited markedly high breakthrough sulfur capacities (ranging from 4.4 to 25.7 g S/100 g-sorbent with increase of Cu/Zn molar ratio) at 40 °C. Incorporation Cu and/or Al decreased the mean crystalline sizes of ZnO and CuO species in the Cu–Zn and Cu–Zn–Al mixed metal oxide adsorbents by decreasing of mean crystalline sizes of hydroxycarbanate phases mainly including hydrozincite, aurichalcite and malachite, segregation of Al phase, etc. Higher breakthrough sulfur capacity of each adsorbent in two ternary series than that of the corresponding adsorbent in binary series should be ascribed to the enhancement of the dispersion of ZnO and/or CuO species with incorporation of aluminum, thereby increasing the overall rate of reaction between the adsorbent and H2S by reducing the thickness of potential sulfide shell on the outer layer of the oxide crystalline grains and increasing the area of the interface for the exchange of HS?/S2? and O2?. For each series of adsorbents, the breakthrough sulfur capacity increased with the increase of Cu/Zn molar ratio regardless of changes of the dispersion of CuO and/or ZnO. This phenomenon might be mainly attributed to faster rate of the lattice diffusion of HS?, S2? and O2? or exchange of HS?/S2? and O2? during the sulfidation of CuO than that during the sulfidation of ZnO due to less rearrangement of the anion lattice.

Dahao Jiang; Lianghu Su; Lei Ma; Nan Yao; Xiaoliang Xu; Haodong Tang; Xiaonian Li

2010-01-01T23:59:59.000Z

312

Implications of the toxicity of tetramethyltin, dimethyl tin dichloride, and tin tetrachloride in selecting a suitable tin precursor in the chemical vapor deposition of tin oxide  

Science Journals Connector (OSTI)

Potential health hazards in the chemical vapor deposition of tin oxide films from tetramethylin dimethylin dichloride and tin tetrachloride have to be balanced against the benefits to solar cell fabrication. Concerns regarding the toxicity costs and physical properties of and the quality of the tin oxide films produced with these tin precursors are outlined. (AIP)

Roy G. Gordon; James W. Prescia

1988-01-01T23:59:59.000Z

313

Control of differential strain during heating and cooling of mixed conducting metal oxide membranes  

DOE Patents (OSTI)

Method of operating an oxygen-permeable mixed conducting membrane having an oxidant feed side and a permeate side, which method comprises controlling the differential strain between the oxidant feed side and the permeate side by varying either or both of the oxygen partial pressure and the total gas pressure on either or both of the oxidant feed side and the permeate side of the membrane while changing the temperature of the membrane from a first temperature to a second temperature.

Carolan, Michael Francis (Allentown, PA)

2007-12-25T23:59:59.000Z

314

Molten Metal Anodes for Direct Carbon-Solid Oxide Fuel Cells.  

E-Print Network (OSTI)

??The aim of this thesis was to enable the direct utilization of solid carbonaceous fuels like coal and biomass, in solid oxide fuel cells (SOFC).… (more)

Jayakumar, Abhimanyu

2012-01-01T23:59:59.000Z

315

Chemical Leaching of Antimony and Other Metals from Small Arms Shooting Range Soil  

E-Print Network (OSTI)

the development of new technologies for the treatment of contaminated soils (Blais et al. 2010). Few innovative technologies have been developed and applied at commercial scales for the remediation of metals contaminated

Short, Daniel

316

Experimental Study of Electron Transport through Nanometer-Scale Metal-Oxide Junctions  

E-Print Network (OSTI)

-annealing. The resistive bistability effect has been observed for all these materials, with particularly high switching, crested barrier, rapid thermal annealing, endurance, resistive bistability, reproducibility. #12;v List properties of Nb/Al/Nb junctions fabricated using thermal oxidation or rf-plasma oxidation at various

317

Metal-free mild oxidation of 5-hydroxymethylfurfural to 2,5-diformylfuran  

Science Journals Connector (OSTI)

The potential of 4-hydroxy-2,2,6,6-tetramethyl-piperidine-1-oxyl (4-hydroxy-TEMPO radical) as an oxidant with [bis(acetoxy)-iodo]benzene (BAIB) and acetic acid (CH3COOH) as co-oxidants to convert 5-hydroxymethylfurfural

Neha Mittal; Grace M. Nisola; Lenny B. Malihan…

2014-08-01T23:59:59.000Z

318

Pressure dependence of phonons and excitons in InSe films prepared by metal-organic chemical vapor deposition  

Science Journals Connector (OSTI)

The pressure dependence of the Raman spectra of phase-pure InSe thin films prepared by the low-pressure metal-organic chemical vapor deposition technique has been studied using a diamond-anvil high-pressure cell. Enhancement in the intensities of the Raman modes has been observed as a result of pressure-induced “tuning” of the energy of the M1-type hyperbolic exciton in InSe at ?2.54 eV through discrete incident laser photon energies. The pressure coefficients of the phonon modes and of the hyperbolic exciton in InSe have been determined.

In-Hwan Choi and Peter Y. Yu

2003-10-27T23:59:59.000Z

319

Multichannel, time-resolved picosecond laser ultrasound imaging and spectroscopy with custom complementary metal-oxide-semiconductor detector  

SciTech Connect

This paper presents a multichannel, time-resolved picosecond laser ultrasound system that uses a custom complementary metal-oxide-semiconductor linear array detector. This novel sensor allows parallel phase-sensitive detection of very low contrast modulated signals with performance in each channel comparable to that of a discrete photodiode and a lock-in amplifier. Application of the instrument is demonstrated by parallelizing spatial measurements to produce two-dimensional thickness maps on a layered sample, and spectroscopic parallelization is demonstrated by presenting the measured Brillouin oscillations from a gallium arsenide wafer. This paper demonstrates the significant advantages of our approach to pump probe systems, especially picosecond ultrasonics.

Smith, Richard J.; Light, Roger A.; Johnston, Nicholas S.; Pitter, Mark C.; Somekh, Mike G. [Institute of Biophysics, Imaging and Optical Science, University of Nottingham, Nottinghamshire NG7 2RD (United Kingdom); Sharples, Steve D. [Applied Optics Group, Electrical Systems and Optics Research Division, University of Nottingham, Nottinghamshire NG7 2RD (United Kingdom)

2010-02-15T23:59:59.000Z

320

Gasification and Chemical-Looping Combustion of a Lignite Char in a Fluidized Bed of Iron Oxide  

Science Journals Connector (OSTI)

Gasification and Chemical-Looping Combustion of a Lignite Char in a Fluidized Bed of Iron Oxide ... Taking reactions R1 and R2 together, the fuel has been combusted but resulting CO2 has been separated from N2 in the air, while the total heat evolved is the same as for the direct combustion of the fuel in air. ... The amount of carbon in the bed at the end of each feeding period could then be determined by combusting the char in air and measuring the total amount of CO2 and CO produced. ...

T. A. Brown; J. S. Dennis; S. A. Scott; J. F. Davidson; A. N. Hayhurst

2010-05-06T23:59:59.000Z

Note: This page contains sample records for the topic "metal oxide chemical" 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

Life Prediction of Coated and Uncoated Metallic Interconnect for Solid Oxide Fuel Cell Applications  

SciTech Connect

Oxidation reaction of the ferritic stainless interconnects in a typical SOFC working environment is unavoidable and the thickness of the oxide scale will continue to grow with operating time, even with protective coatings. The interfacial strength of the various interfaces for the uncoated and coated ferritic interconnects is crucial to long term performance of SOFCs. In this paper, we employ an integrated experimental/modeling approach to quantify the interfacial strength and to further predict the life of Crofer 22 APU as SOFC interconnect under isothermal cooling condition. The life of Crofer 22 APU was predicted by comparing the predicted interfacial strength, interfacial stresses induced by the cooling process from the operating temperature to room temperature, together with the growth kinetics of oxide scale with and without spinel coating. It was found that the interfacial strength between the oxide scale and Crofer 22 APU substrate decreases with the growth of the oxide scale. The interfacial strength of the oxide scale and spinel coating is much higher than that of the oxide scale and Crofer 22 APU substrate. With the spinel coating, the predicted life of the Crofer 22 APU is significantly longer than that of the uncoated Crofer 22 APU.

Liu, Wenning N.; Sun, Xin; Stephens, Elizabeth V.; Khaleel, Mohammad A.

2009-04-15T23:59:59.000Z

322

Aromatic hydroxylation. 8. A radiation chemical study of the oxidation of hydroxycyclohexadienyl radicals  

SciTech Connect

Substituted hydroxycyclohexadienyl radicals have been generated by pulse radiolysis of N/sub 2/O-saturated aqueous solutions of monosubstituted benzene derivatives. Their rates of disproportionation/dimerization and of oxidation by Fe(CN)/sub 6//sup 3 -/ and by IrCl/sub 6//sup 2 -/ have been measured by optical and conductimetric methods. For the fluoro- and chlorohydroxycyclohexadienyl radicals disproportionation is shown to involve hydrogen atom abstraction rather than electron transfer. However, the Fe(CN)/sub 6//sup 3 -/ oxidation of the substituted hydroxycyclohexadienyl radicals occurs by a rate-determining electron transfer followed by a fast proton loss rather than by hydrogen atom abstraction or synchronous removal of an electron and a proton. A plot of the log of the rate constants for oxidation against Hammett sigma/sup +/ constants gives a good linear relationship with a rho value of -3.0 +/- 0.1. With the more powerful oxidant IrCl/sub 6//sup -/, the electron-transfer oxidation of all but the least reactive hydroxycyclohexadienyl radicals is diffusion controlled.

Buxton, G.V.; Langan, J.R.; Smith, J.R.L.

1986-11-06T23:59:59.000Z

323

Mechanism of oxygen reduction reaction on transition metal oxide catalysts for high temperature fuel cells  

E-Print Network (OSTI)

The solid oxide fuel cell (SOFC) with its high energy conversion efficiency, low emissions, silent operation and its ability to utilize commercial fuels has the potential to create a large impact on the energy landscape. ...

La O', Gerardo Jose Cordova

2008-01-01T23:59:59.000Z

324

Suitability of Metallic Materials for Interconnects in Solid Oxide Fuel Cells  

Science Journals Connector (OSTI)

FeCr model alloys with variation of chromium content, reactive element addition and spinel forming elements were studied in respect to oxidation resistance at 800°C. Additionally, in-situ studies were carried ...

W. J. Quadakkers; J. Piron-Abellan…

2002-01-01T23:59:59.000Z

325

Autothermal oxidative pyrolysis of biomass feedstocks over noble metal catalysts to liquid products.  

E-Print Network (OSTI)

??Two thermal processing technologies have emerged for processing biomass into renewable liquid products: pyrolysis and gasification/Fischer-Tropsch processing. The work presented here will demonstrate oxidative pyrolysis… (more)

Balonek, Christine Marie

2011-01-01T23:59:59.000Z

326

Nonlinear response of the surface electrostatic potential formed at metal oxide/electrolyte interfaces. A Monte Carlo simulation study  

SciTech Connect

An analysis of surface potential nonlinearity at metal oxide/electrolyte interfaces is presented. By using Grand Canonical Monte Carlo simulations of a simple lattice model of an interface, we show a correlation exists between ionic strength as well as surface site densities and the non-Nernstian response of a metal oxide electrode. We propose two approaches to deal with the 0-nonlinearity: one based on perturbative expansion of the Gibbs free energy and another based on assumption of the pH-dependence of surface potential slope. The theoretical anal ysis based on our new potential form gives excellent performance at extreme pH regions, where classical formulae based on the Poisson-Boltzmann equation fail. The new formula is general and independent of any underlying assumptions. For this reason, it can be directly applied to experimental surface potential measurements, including those for individual surfaces of single crystals, as we present for data reported by Kallay and Preocanin [Kallay, Preocanin J. Colloid and Interface20 Sci. 318 (2008) 290].

Zarzycki, Piotr P.; Rosso, Kevin M.

2010-01-01T23:59:59.000Z

327

High-temperature desulfurization of gasifier effluents with rare earth and rare earth/transition metal oxides  

SciTech Connect

We have improved the application of mixed rare-earth oxides (REOs) as hot gas desulfurization adsorbents by impregnating them on stable high surface area supports and by the inclusion of certain transition metal oxides. We report comparative desulfurization experiments at high temperature (900 K) using a synthetic biomass gasifier effluent containing 0.1 vol % H{sub 2}S, along with H{sub 2}, CO{sub 2}, and water. More complex REO sorbents outperform the simpler CeO{sub 2}/La{sub 2}O{sub 3} mixtures, in some cases significantly. Supporting REOs on Al{sub 2}O{sub 3} (?20 wt % REO) or ZrO{sub 2} actually increased the sulfur capacities found after several cycles on a total weight basis. Another major increase in sulfur capacity took place when MnO{sub x} or FeO{sub x} is incorporated. Apparently most of the Mn or Fe is dispersed on or near the surface of the mixed REOs because the capacities with REOs greatly exceeded those of Al{sub 2}O{sub 3}-supported MnO{sub x} or FeO{sub x} alone at these conditions. In contrast, incorporating Cu has little effect on sulfur adsorption capacities. Both the REO and transition metal/REO adsorbents could be regenerated completely using air for at least five repetitive cycles.

Dooley, Kerry M.; Kalakota, Vikram; Adusumilli, Sumana

2011-01-01T23:59:59.000Z

328

Standard test methods for chemical, mass spectrometric, and spectrochemical analysis of nuclear-grade aluminum oxide and aluminum oxide-boron carbide composite pellets  

E-Print Network (OSTI)

1.1 These test methods cover procedures for the chemical, mass spectrometric, and spectrochemical analysis of nuclear-grade aluminum oxide and aluminum oxide-boron carbide composite pellets to determine compliance with specifications. 1.2 The analytical procedures appear in the following order: Sections Boron by Titrimetry 7 to 13 Separation of Boron for Mass Spectrometry 14 to 19 Isotopic Composition by Mass Spectrometry 20 to 23 Separation of Halides by Pyrohydrolysis 24 to 27 Fluoride by Ion-Selective Electrode 28 to 30 Chloride, Bromide, and Iodide by Amperometric Microtitrimetry 31 to 33 Trace Elements by Emission Spectroscopy 34 to 46 1.3 The values stated in SI units are to be regarded as the standard. 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. (F...

American Society for Testing and Materials. Philadelphia

1994-01-01T23:59:59.000Z

329

Interplay between electronic structure and catalytic activity in transition metal oxide model system  

E-Print Network (OSTI)

The efficiency of many energy storage and conversion technologies, such as hydrogen fuel cells, rechargeable metal-air batteries, and hydrogen production from water splitting, is limited by the slow kinetics of the oxygen ...

Suntivich, Jin

2012-01-01T23:59:59.000Z

330

Biomonitoring on Carcinogenic Metals and Oxidative DNA Damage in a Cross-Sectional Study  

Science Journals Connector (OSTI)

...result of human activities such as mining, smelting, fossil fuel combustion, and industrial application of metals. The highest...production of stainless steel, high-nickel alloys, Ni-Cd batteries, and electronic components. A major fraction of nickel absorbed...

Hiltrud Merzenich; Andrea Hartwig; Wolfgang Ahrens; Detmar Beyersmann; Regina Schlepegrell; Martin Scholze; Jürgen Timm; and Karl-Heinz Jöckel

2001-05-01T23:59:59.000Z

331

Simple Chemical Routes for Changing Composition or Morphology in Metal Chalcogenide Nanomaterials  

E-Print Network (OSTI)

InSe2 nanoparticles could be tuned from small 10 nm spheres to micron length nanowires by varying the relative amount of strong and weak surfactants passivating the surface. Oleylamine and trioctylphosphine oxide were chosen as the strong and weak...

Wark, Stacey Elaine

2012-07-16T23:59:59.000Z

332

Effect of Fly Ash on Solidification and Heavy Metals Chemical Speciation of Sludge  

Science Journals Connector (OSTI)

In order to explore new municipal sewage sludge treatment method and reduce its harm for environment, fly ash discarded from power plant was used as conditioner in sludge treatment in the paper. The properties of sewage sludge were changed after adding ... Keywords: fly ash, sludge, compressive strength, heavy metal, speciation

Yongjian Piao; Mingsong Wu; Xun Xu; Qingliang Zhao; Fugui Zhang; Nanqi Ren

2011-01-01T23:59:59.000Z

333

THE METALLICITY DISTRIBUTION FUNCTIONS OF SEGUE G AND K DWARFS: CONSTRAINTS FOR DISK CHEMICAL EVOLUTION AND FORMATION  

SciTech Connect

We present the metallicity distribution function (MDF) for 24,270 G and 16,847 K dwarfs at distances from 0.2 to 2.3 kpc from the Galactic plane, based on spectroscopy from the Sloan Extension for Galactic Understanding and Exploration (SEGUE) survey. This stellar sample is significantly larger in both number and volume than previous spectroscopic analyses, which were limited to the solar vicinity, making it ideal for comparison with local volume-limited samples and Galactic models. For the first time, we have corrected the MDF for the various observational biases introduced by the SEGUE target-selection strategy. SEGUE is particularly notable for its sample of K dwarfs, which are too faint to examine spectroscopically far from the solar neighborhood. The MDF of both spectral types becomes more metal-poor with increasing |Z|, which reflects the transition from a sample with small [{alpha}/Fe] values at small heights to one with enhanced [{alpha}/Fe] above 1 kpc. Comparison of our SEGUE distributions to those of two different Milky Way models reveals that both are more metal-rich than our observed distributions at all heights above the plane. Our unbiased observations of G and K dwarfs provide valuable constraints over the |Z|-height range of the Milky Way disk for chemical and dynamical Galaxy evolution models, previously only calibrated to the solar neighborhood, with particular utility for thin- and thick-disk formation models.

Schlesinger, Katharine J. [Research School of Astronomy and Astrophysics, Australian National University, Weston, ACT 2611 (Australia); Johnson, Jennifer A.; Schoenrich, Ralph [Department of Astronomy, The Ohio State University, 140 W 18th Avenue, Columbus, OH 43210 (United States); Rockosi, Constance M. [UCO/Lick Observatory, University of California, Santa Cruz, CA 95064 (United States); Lee, Young Sun [Tombaugh Fellow, Department of Astronomy, New Mexico State University, Las Cruces, NM 88003 (United States); Morrison, Heather L.; Harding, Paul [Department of Astronomy, Case Western Reserve University, Cleveland, OH 44106 (United States); Allende Prieto, Carlos [Instituto de Astrofisica de Canarias, E-38205 La Laguna, Tenerife (Spain); Beers, Timothy C. [Department of Physics and Astronomy and JINA (Joint Institute for Nuclear Astrophysics), Michigan State University, East Lansing, MI 48824 (United States); Yanny, Brian [Fermi National Accelerator Laboratory, P.O. Box 500, Batavia, IL 60510 (United States); Schneider, Donald P. [Department of Astronomy and Astrophysics, Penn State University, 408A Davey Laboratory, University Park, PA 16802 (United States); Chiappini, Cristina; Da Costa, Luiz N.; Maia, Marcio A. G.; Rocha-Pinto, Helio; Santiago, Basilio X. [Laboratorio Interinstitucional de e-Astronomia (LIneA), Rua Gal. Jose Cristino 77, 20921-400 Rio de Janeiro (Brazil); Minchev, Ivan [Leibniz-Institut fuer Astrophysik Potsdam, An der Sternwarte 16, D-14482 Potsdam (Germany)

2012-12-20T23:59:59.000Z

334

Ultrathin aluminum oxide films: Al-sublattice structure and the effect of substrate on ad-metal adhesion  

SciTech Connect

First principles density-functional slab calculations are used to study 5 {angstrom} (two O-layer) Al{sub 2}O{sub 3} films on Ru(0001) and Al(111). Using larger unit cells than in a recent study, it is found that the lowest energy stable film has an even mix of tetrahedral (t) and octahedral (o) site Al ions, and thus most closely resembles the {kappa}-phase of bulk alumina. Here, alternating zig-zag rows of t and o occur within the surface plane, resulting in a greater average lateral separation of the Al-ions than with pure t or o. A second structure with an even mix of t and o has also been found, consisting of alternating stripes. These patterns mix easily, can exist in three equivalent directions on basal substrates, and can also be displaced laterally, suggesting a mechanism for a loss of long-range order in the Al-sublattice. While the latter would cause the film to appear amorphous in diffraction experiments, local coordination and film density are little affected. On a film supported by rigid Ru(0001), overlayers of Cu, Pd, and Pt bind similarly as on bulk truncated {alpha}-Al{sub 2}O{sub 3}(0001). However, when the film is supported by soft Al(111), the adhesion of Cu, Pd, and Pt metal overlayers is significantly increased: Oxide-surface Al atoms rise so only they contact the overlayer, while substrate Al metal atoms migrate into the oxide film. Thus the binding energy of metal overlayers is strongly substrate dependent, and these numbers for the above Pd-overlayer systems bracket a recent experimentally derived value for a film on NiAl(110).

JENNISON,DWIGHT R.; BOGICEVIC,ALEXANDER

2000-03-06T23:59:59.000Z

335

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

SciTech Connect

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

Ates Akyurtlu; Jale F. Akyurtlu

2000-04-10T23:59:59.000Z

336

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

SciTech Connect

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

Ates Akyurtlu; Jale F. Akyurtlu

1999-11-30T23:59:59.000Z

337

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

SciTech Connect

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

Akyurtlu, A.; Akyurtlu, J.F.

1999-03-31T23:59:59.000Z

338

Enhancement in Ethanol Electrooxidation by SnO(x) Nanoislands Grown on Pt(111): Effect of Oxide-Metal Interface Sites  

SciTech Connect

An integrated surface science and electrochemistry approach has been used to prepare and characterize SnO{sub x}/Pt(111) model catalysts and evaluate their electrochemical activity for the ethanol oxidation reaction (EOR). Nanoislands of SnO{sub x} are deposited onto the Pt(111) by reactive layer assisted deposition in which Sn metal is vapor deposited onto a Pt(111) surface precovered by NO{sub 2}. X-ray photoelectron spectroscopy (XPS) shows that the SnO{sub x} islands are highly reduced with Sn{sup 2+} being the dominant chemical species. After exposing the SnO{sub x}/Pt(111) surface to H{sub 2}O or an electrolyte solution, XPS provides evidence for a significant amount of H{sub 2}O/OH adsorbed on the reduced SnO{sub x} surfaces. Electrochemical testing reveals that the catalytic performance of Pt(111) toward ethanol electrooxidation is significantly enhanced with SnO{sub x} islands added onto the surface. The enhanced EOR activity is tentatively attributed to the efficient removal of CO{sub ads}-like poisoning species at Pt sites by oxygen-containing species that are readily formed on the SnO{sub x} nanoislands. Moreover, the strong dependence of the EOR activity on SnO{sub x} coverage provides experimental evidence for the importance of SnO{sub x}-Pt interface sites in the EOR.

Zhou, W.P.; Axnanda, S.; White, M.G.; Adzic, R.R.; Hrbek, J.

2011-08-25T23:59:59.000Z

339

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

SciTech Connect

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

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

2010-01-01T23:59:59.000Z

340

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

SciTech Connect

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

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

2010-01-13T23:59:59.000Z

Note: This page contains sample records for the topic "metal oxide chemical" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
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341

Inhibition of Cellulase-Catalyzed Lignocellulosic Hydrolysis by Iron and Oxidative Metal Ions and Complexes  

Science Journals Connector (OSTI)

...promise for bio-based energy and chemical industries...as the prevention and mitigation of this effect in industrial...for carbon cycling, energy conversion, microbiota...the U.S. National Renewable Energy Laboratory, was first...

Ani Tejirian; Feng Xu

2010-10-01T23:59:59.000Z

342

High temperature water electrolysis using metal supported solid oxide electrolyser cells (SOEC)  

Science Journals Connector (OSTI)

The use of renewable energy has attained increasing interest over the past years. For a wider utilisation of renewable energy sources such as wind, photovoltaic, solar thermal power and others chemical energy car...

G. Schiller; A. Ansar; M. Lang; O. Patz

2009-02-01T23:59:59.000Z

343

Synthesis of graphene nanosheets via oxalic acid-induced chemical reduction of exfoliated graphite oxide  

SciTech Connect

Preparing high-quality graphene through reduction of graphene oxide (GO) by oxalic acid is demonstrated in this paper. Transmission electron microscopy, scanning electron microscopy, Fourier transform infrared spectrometry, X-ray diffraction and Raman spectrometry were taken to confirm the reduction of GO and the formation of graphene under these mild conditions. Thermogravimetric analysis and conductivity measurements further testify the excellent thermal stability and conductivity of the obtained graphene. A possible mechanism for the reduction process was also proposed. Furthermore, a Pt-graphene composite was fabricated on a glassy carbon electrode and excellent electrocatalytic activity towards methanol oxidation was observed. With advantages of low toxicity, simple purification process and high quality of the product, oxalic acid provides a feasible route to prepare graphene from GO under mild conditions, thus facilitating the use of graphene-based materials for large-scale applications.

Song, Peng; Zhang, Xiao-Yan; Sun, Mingxun; Cui, Xiao-Li; Lin, Yuehe

2012-02-01T23:59:59.000Z

344

Laser Desorption/Ionization of Transition Metal Atoms and Oxides from Solid Argon Lester Andrews,*, Andreas Rohrbacher, Christopher M. Laperle, and Robert E. Continetti  

E-Print Network (OSTI)

, approximately 10% of the gas sample condensed on the 10K copper plate. For ablation a focused (10 cm f of the laser-ablated metal atoms and O2 in excess argon during condensation at 10 K, have been laser desorbed spectrometry. Adding the C6H5Br chromophore to the Ar/O2 gas mixture also enhanced the metal and oxide ion

Continetti, Robert E.

345

Interaction of iron-copper mixed metal oxide oxygen carriers with simulated synthesis gas derived from steam gasification of coal  

SciTech Connect

The objective of this work was to prepare supported bimetallic Fe–Cu oxygen carriers and to evaluate their performance for the chemical-looping combustion (CLC) process with simulated synthesis gas derived from steam gasification of coal/air. Ten-cycle CLC tests were conducted with Fe–Cu oxygen carriers in an atmospheric thermogravimetric analyzer utilizing simulated synthesis gas derived from the steam gasification of Polish Janina coal and Illinois #6 coal as fuel. The effect of temperature on reaction rates, chemical stability, and oxygen transport capacity were determined. Fractional reduction, fractional oxidation, and global rates of reactions were calculated from the thermogravimetric analysis (TGA) data. The supports greatly affected reaction performance. Data showed that reaction rates and oxygen capacities were stable during the 10-cycle TGA tests for most Fe–Cu/support oxygen carriers. Bimetallic Fe–Cu/support oxygen carriers showed higher reduction rates than Fe-support oxygen carriers. The carriers containing higher Cu content showed better stabilities and better reduction rates. An increase in temperature from 800 °C to 900 °C did not have a significant effect on either the oxygen capacity or the reduction rates with synthesis gas derived from Janina coal. Oxidation reaction was significantly faster than reduction reaction for all supported Fe–Cu oxygen carriers. Carriers with higher Cu content had lower oxidation rates. Ten-cycle TGA data indicated that these oxygen carriers had stable performances at 800–900 °C and might be successfully used up to 900 °C for coal CLC reaction in the presence of steam.

Siriwardane, Ranjani V. [U.S. DOE; Ksepko, Ewelina; Tian, Hanging [URS

2013-01-01T23:59:59.000Z

346

Investigation of zinc oxide doped with metal impurities for use as thin film conductive phosphors  

E-Print Network (OSTI)

of a viable flat panel display, low voltage, conductive phosphors which emit blue, red, and green light will be required for the field emission technology. This thesis examines zinc oxide (ZnO) based thin ( ) phosphors for such an application. ZnO is a...

Evatt, Steven R.

1994-01-01T23:59:59.000Z

347

Method of producing highly oxidized superconductors containing barium, copper, and a third metal  

DOE Patents (OSTI)

Novel superconducting materials in the form of compounds, structures or phases are formed by performing otherwise known syntheses in a highly oxidizing atmosphere rather than that created by molecular oxygen at atmospheric pressure or below. This leads to the successful synthesis of novel superconducting compounds which are thermodynamically stable at the conditions under which they are formed. 16 figs.

Morris, D.E.

1996-02-20T23:59:59.000Z

348

Decoupled catalytic hydrogen evolution from a molecular metal oxide redox mediator in water splitting  

Science Journals Connector (OSTI)

...system that uses a carbon cathode to reduce protons and a...SiW 12 O 40 ] at a carbon cathode. Alternatively, starting from the fully oxidized...Nanostructured nickel phosphide as an electrocatalyst for the hydrogen evolution reaction . J...electrocatalysis to stack development . Int. J. Hydrogen Energy...

Benjamin Rausch; Mark D. Symes; Greig Chisholm; Leroy Cronin

2014-09-12T23:59:59.000Z

349

Chemical looping combustion of high-sulfur coal with NiFe2O4-combined oxygen carrier  

Science Journals Connector (OSTI)

Chemical looping combustion (CLC) of coal has gained increasing attention as a novel combustion technology for its attractive advantage in the...2. In relative to the single metal oxide-based oxygen carrier (OC),...

Baowen Wang; Gan Xiao; Xiaoyong Song…

2014-12-01T23:59:59.000Z

350

Metal organic chemical vapor deposition of 111-v compounds on silicon  

DOE Patents (OSTI)

Expitaxial composite comprising thin films of a Group III-V compound semiconductor such as gallium arsenide (GaAs) or gallium aluminum arsenide (GaAlAs) on single crystal silicon substrates are disclosed. Also disclosed is a process for manufacturing, by chemical deposition from the vapor phase, epitaxial composites as above described, and to semiconductor devices based on such epitaxial composites. The composites have particular utility for use in making light sensitive solid state solar cells.

Vernon, Stanley M. (Wellesley, MA)

1986-01-01T23:59:59.000Z

351

Giant and switchable surface activity of liquid metal via surface oxidation  

Science Journals Connector (OSTI)

...recent developments . Adv Colloid Interface Sci 159 ( 2 ): 198 – 212 . 27 Ladd C So J-H Muth J Dickey MD ( 2013 ) 3D printing of free standing liquid metal microstructures . Adv Mater 25 ( 36 ): 5081 – 5085 . 28 Regan MJ ( 1997 ) X-ray reflectivity...

Mohammad Rashed Khan; Collin B. Eaker; Edmond F. Bowden; Michael D. Dickey

2014-01-01T23:59:59.000Z

352

Selective Separation of Thiols from a Model Fuel by Metal Oxides  

Science Journals Connector (OSTI)

These fossil fuels typically contain sulfur compounds on the order of a few percent. ... The authors have found that sulfur-loaded coals adsorb heavy metals in aqueous solutions. ... methods for fuel oils in relation to demand of low-sulfur fuel oils for air pollution control. ...

Yuuki Mochizuki; Katsuyasu Sugawara

2008-10-14T23:59:59.000Z

353

Integrated chemical/biological treatment of paint stripper mixed waste: Metals toxicity and separation  

SciTech Connect

The DOE complex has generated vast quantities of complex heterogeneous mixed wastes. Paint stripper waste (PSW) is a complex waste that arose from decontamination and decommissioning activities. It contains paint stripper, cheesecloth, cellulose-based paints with Pb and Cr, and suspect Pu. Los Alamos National Laboratory has 150--200 barrels of PSW and other national laboratories such as Rocky Flats Plant have many more barrels of heterogeneous waste. Few technologies exist that can treat this complex waste. Our approach to solving this problem is the integration of two established technologies: biodegradation and metals chelation.

Vanderberg-Twary, L.; Grumbine, R.K.; Foreman, T.; Hanners, J.L.; Brainard, J.R.; Sauer, N.N.; Unkefer, P.J.

1995-05-01T23:59:59.000Z

354

The growth of CdTe/GaAs heteroepitaxial films by metal–organic chemical vapor deposition  

Science Journals Connector (OSTI)

A process for the growth of CdTe/GaAs heteroepitaxialfilms using metal–organic chemical vapor deposition(MOCVD) has been developed. The initial results of the determination of the deposition mechanism are reported. A pilot production demonstration using experimentally determined operating conditions has been completed. This is the first reported pilot production of CdTe/GaAs using 2 in. diam GaAs substrates in a multiple slice commercially manufactured MOCVD system. The results reported therein demonstrate that MOCVD is a reliable reproducible production worthy process for preparation of CdTe/GaAs heterostructures. These results are applicable to a wide variety of CdTe based device technologies including IR detection fiber optics solar cells and others.

Philip L. Anderson

1986-01-01T23:59:59.000Z

355

Realistic multisite lattice-gas modeling and KMC simulation of catalytic surface reactions: Kinetics and multiscale spatial behavior for CO-oxidation on metal (100) surfaces  

SciTech Connect

A realistic molecular-level description of catalytic reactions on single-crystal metal surfaces can be provided by stochastic multisite lattice-gas (msLG) models. This approach has general applicability, although in this report, we will focus on the example of CO-oxidation on the unreconstructed fcc metal (100) or M(100) surfaces of common catalyst metals M = Pd, Rh, Pt and Ir (i.e., avoiding regimes where Pt and Ir reconstruct). These models can capture the thermodynamics and kinetics of adsorbed layers for the individual reactants species, such as CO/M(100) and O/M(100), as well as the interaction and reaction between different reactant species in mixed adlayers, such as (CO + O)/M(100). The msLG models allow population of any of hollow, bridge, and top sites. This enables a more flexible and realistic description of adsorption and adlayer ordering, as well as of reaction configurations and configuration-dependent barriers. Adspecies adsorption and interaction energies, as well as barriers for various processes, constitute key model input. The choice of these energies is guided by experimental observations, as well as by extensive Density Functional Theory analysis. Model behavior is assessed via Kinetic Monte Carlo (KMC) simulation. We also address the simulation challenges and theoretical ramifications associated with very rapid diffusion and local equilibration of reactant adspecies such as CO. These msLG models are applied to describe adsorption, ordering, and temperature programmed desorption (TPD) for individual CO/M(100) and O/M(100) reactant adlayers. In addition, they are also applied to predict mixed (CO + O)/M(100) adlayer structure on the nanoscale, the complete bifurcation diagram for reactive steady-states under continuous flow conditions, temperature programmed reaction (TPR) spectra, and titration reactions for the CO-oxidation reaction. Extensive and reasonably successful comparison of model predictions is made with experimental data. Furthermore, we discuss the possible transition from traditional mean-field-type bistability and reaction kinetics for lower-pressure to multistability and enhanced fluctuation effects for moderate- or higher-pressure. Behavior in the latter regime reflects a stronger influence of adspecies interactions and also lower diffusivity in the higher-coverage mixed adlayer. We also analyze mesoscale spatiotemporal behavior including the propagation of reaction diffusion fronts between bistable reactive and inactive states, and associated nucleation-mediated transitions between these states. This behavior is controlled by complex surface mass transport processes, specifically chemical diffusion in mixed reactant adlayers for which we provide a precise theoretical formulation. The msLG models together with an appropriate treatment of chemical diffusivity enable equation-free heterogeneous coupled lattice-gas (HCLG) simulations of spatiotemporal behavior. In addition, msLG + HCLG modeling can describe coverage variations across polycrystalline catalysts surfaces, pressure variations across catalyst surfaces in microreactors, and could be incorporated into a multiphysics framework to describe mass and heat transfer limitations for high-pressure catalysis. (C) 2013 Elsevier Ltd. All rights reserved.

Liu, Dajiang [Ames Laboratory; Evans, James W. [Ames Laboratory

2013-12-01T23:59:59.000Z

356

Speciation of Heavy Metals in Floodplain and Flood Sediments: a Reconnaissance Survey of the Aire Valley, West Yorkshire, Great Britain  

Science Journals Connector (OSTI)

A five-step sequential extraction technique was used to determine the chemical association of heavy metals (Pb, Zn, Cu and Cd), with major sedimentary phases (exchangeable, surface oxide and carbonate, Fe and ...

E.J. Dawson; M.G. Macklin

1998-06-01T23:59:59.000Z

357

Functionalized Graphene Sheets as Molecular Templates for Controlled Nucleation and Self-Assembly of Metal Oxide-Graphene Nanocomposites  

SciTech Connect

Graphene sheets have been extensively studied as a key functional component of graphene-based nanocomposites for electronics, energy, catalysis,and sensing applications. However, fundamental understanding of the interfacial binding and nucleation processes at graphene surfaces remains lacking, and the range of controlled structures that can be produced are limited. Here, by using a combination of theoretical and experimental approaches, we demonstrate that functionalized graphene sheets (FGS) can function as a new class of molecular templates to direct nucleation and self-assembly and produce novel, three-dimensional nanocomposite materials. Two key aspects are demonstrated: First, the functional groups on FGS surface determine the nucleation energy, and thus control the nucleation sites and nucleation density, as well as the preferred crystalline phases. Second, FGS can function as a template to direct the self-assembly of surfactant micelles and produce ordered, mesoporous arrays of crystalline metal oxides and composites.

Li, Xiaolin; Qi, Wen N.; Mei, Donghai; Sushko, Maria L.; Aksay, Ilhan A.; Liu, Jun

2012-09-25T23:59:59.000Z

358

Use of impure inert gases in the controlled heating and cooling of mixed conducting metal oxide materials  

DOE Patents (OSTI)

Method for processing an article comprising mixed conducting metal oxide material. The method comprises contacting the article with an oxygen-containing gas and either reducing the temperature of the oxygen-containing gas during a cooling period or increasing the temperature of the oxygen-containing gas during a heating period; during the cooling period, reducing the oxygen activity in the oxygen-containing gas during at least a portion of the cooling period and increasing the rate at which the temperature of the oxygen-containing gas is reduced during at least a portion of the cooling period; and during the heating period, increasing the oxygen activity in the oxygen-containing gas during at least a portion of the heating period and decreasing the rate at which the temperature of the oxygen-containing gas is increased during at least a portion of the heating period.

Carolan, Michael Francis (Allentown, PA); Bernhart, John Charles (Fleetwood, PA)

2012-08-21T23:59:59.000Z

359

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

SciTech Connect

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

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

2007-01-01T23:59:59.000Z

360

Computational screening of perovskite metal oxides for optimal solar light Ivano E. Castelli,a  

E-Print Network (OSTI)

increasing energy demands, together with the CO2 related climate problems, make the development of sustainable energy technology one of the most important problems of today.1 Direct harvesting and conversion of solar light to electrical energy in photovoltaic (PV) cells or to chemical energy

Thygesen, Kristian

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361

Performance Optimization of Metallic Iron and Iron Oxide Nanomaterials for Treatment of Impaired Water Supplies  

E-Print Network (OSTI)

S.J. ; Livi, K.J.T. ; Fairbrother, D.H. ; Roberts, A.L. ,Ball, W.P. ; O'Melia, C. ; Fairbrother, D.H. , ColloidalB.A. ; Bitter, J.L. ; Fairbrother, D.H. , Chemical and

Xie, Yang

2011-01-01T23:59:59.000Z

362

Mercury-control technology-assessment study: D. F. Goldsmith Chemical and Metal Corporation, Evanston, Illinois. In-depth survey report for the site visit of May 4-6, 1982. Final report  

SciTech Connect

An in-depth survey was conducted at the D. F. Goldsmith Chemical and Metal Corporation in Evanston, Illinois; emphasis was placed on the recirculating air unit for control of mercury vapor. Major products were prime virgin mercury, precious metals, and rare inorganic chemicals. Mercury was poured into an open vessel which was subsequently covered, and the mercury treated by agitation with an acidic or caustic solution. Mercury was then transferred to the still where it was batch-distilled. After distillation, mercury was bottled in 1 or 5 pound quantities and packed and shipped. The ventilation system included local exhaust, dilution, and recirculation steps. Local exhaust ventilation was particularly important at the bottle-filling station. Personal protective equipment included respirators, disposable lab coats, vinyl coated cloth gloves, plastic shoe coverings, and barrier creams. Work practices were controlled, and biological and air monitoring were in place. The recirculating unit removed 76% of the mercury vapor in the air stream. The authors recommend that a study be made of the advisability of using a charcoal filter in addition to the manganese oxide precoat bag filter with post filtration.

Telesca, D.R.

1982-09-01T23:59:59.000Z

363

Design and construction of a radiation resistant quadrupole using metal oxide insulated CICC  

SciTech Connect

The construction of a engineering test model of a radiation resistant quadrupole is described. The cold-iron quadrupole uses coils fabricated from metal-oixide (synthetic spinel) insulated Cable-In-Conduit-Conductor (CICC). The superconductor is NbTi in a copper matrix. The quadrupole is designed to produce a pole-tip field of 2 T with an operating current of 7,000 A.

Albert F. Zeller

2012-12-28T23:59:59.000Z

364

Method for improving the oxidation-resistance of metal substrates coated with thermal barrier coatings  

DOE Patents (OSTI)

A method for providing a protective coating on a metal-based substrate is disclosed. The method involves the application of an aluminum-rich mixture to the substrate to form a discontinuous layer of aluminum-rich particles, followed by the application of a second coating over the discontinuous layer of aluminum-rich particles. Aluminum diffuses from the aluminum-rich layer into the substrate, and into any bond coat layer which is subsequently applied. Related articles are also described.

Thompson, Anthony Mark (Niskayuna, NY); Gray, Dennis Michael (Delanson, NY); Jackson, Melvin Robert (Niskayuna, NY)

2002-01-01T23:59:59.000Z

365

Sorption Capacity of Mesoporous Metal Oxides for the Removal of MCPA from Polluted Waters  

Science Journals Connector (OSTI)

where qe and q are the amount of herbicide sorbed (?mol kg?1) at equilibrium and at time t, respectively, Ka is the rate constant of sorption (min?1) and t is the time (min). ... The sorbing capacity for Zn and Cu was strongly influenced by Cr(III), whereas the sorbing capacity of for(III) was not affected by the presence of the other two metals. ...

Veria Addorisio; Serena Esposito; Filomena Sannino

2010-03-24T23:59:59.000Z

366

Molybdenum-based additives to mixed-metal oxides for use in hot gas cleanup sorbents for the catalytic decomposition of ammonia in coal gases  

DOE Patents (OSTI)

This invention relates to additives to mixed-metal oxides that act simultaneously as sorbents and catalysts in cleanup systems for hot coal gases. Such additives of this type, generally, act as a sorbent to remove sulfur from the coal gases while substantially simultaneously, catalytically decomposing appreciable amounts of ammonia from the coal gases.

Ayala, Raul E. (Clifton Park, NY)

1993-01-01T23:59:59.000Z

367

PVP-functionalized nanometre scale metal oxide coatings for cathode materials: successful application to LiMn2O4 spinel nanoparticlesw  

E-Print Network (OSTI)

PVP-functionalized nanometre scale metal oxide coatings for cathode materials: successful-MnO2, may react with the electrolyte, leading to passivating structural changes of the active material retention compared to the bare counterpart. Spinel LiMn2O4 cathodes have been studied for possible use in Li

Cho, Jaephil

368

Noble Metal-Free Reduced Graphene Oxide-ZnxCd1-xS Nanocomposite with Enhanced Solar Photocatalytic H2Production  

E-Print Network (OSTI)

solar energy by production of hydrogen from water splitting is of great importance from both theoretical strategy for solving simultaneously the incoming energy and environmental problems.2 So far, numerousNoble Metal-Free Reduced Graphene Oxide-ZnxCd1-xS Nanocomposite with Enhanced Solar Photocatalytic

Gong, Jian Ru

369

Preparation of iron oxide thin film by metal organic deposition from Fe(III)-acetylacetonate: a study of photocatalytic properties  

Science Journals Connector (OSTI)

Iron oxide thin films have been deposited over fused quartz substrate by simple metal organic deposition from Fe-(III) acetylacetonate as the organic precursor. The decomposition of Fe-acetylacetonate is characterised by its distinct transition temperatures and thermogravimetric loss rates, which have been measured by thermal gravimetric analysis. As-deposited films were sintered in the temperature range 365–800°C and the structural changes of the iron oxide thin films as they transform into different crystalline phases have been studied by X-ray diffraction, Fourier transform infrared spectroscopy, ultraviolet-visible absorption spectroscopy and scanning electron microscopy techniques. Mainly amorphous ?-Fe2O3 is formed at an annealing temperature of approximately 365–400°C, which transforms to ?-Fe2O3 phase with a further increase (600–800°C) in sintering temperature. The film sintered at 800°C consists of mainly crystalline ?-Fe2O3 phase, which shows photocatalytic degradation of an oxygenated aqueous solution of phenol upon visible light illumination.

Bonamali Pal; Maheshwar Sharon

2000-01-01T23:59:59.000Z

370

Compliant alkali silicate sealing glass for solid oxide fuel cell applications: thermal cycle stability and chemical compatibility  

SciTech Connect

An alkali silicate glass (SCN-1) is currently being evaluated as a candidate sealing glass for solid oxide fuel (SOFC) applications. The glass containing ~17 mole% alkalis (K2O and Na2O) remains vitreous and compliant during SOFC operation, unlike conventional SOFC sealing glasses, which experience substantial devitrification after the sealing process. The non-crystallizing compliant sealing glass has lower glass transition and softening temperatures since the microstructure remains glassy without significant crystallite formation, and hence can relieve or reduce residual stresses and also has the potential for crack healing. Sealing approaches based on compliant glass will also need to satisfy all the mechanical, thermal, chemical, physical, and electrical requirements for SOFC applications, not only in bulk properties but also at sealing interfaces. In this first of a series of papers we will report the thermal cycle stability of the glass when sealed between two SOFC components, i.e., a NiO/YSZ anode supported YSZ bilayer and a coated ferritic stainless steel interconnect material. High temperature leak rates were monitored versus thermal cycles between 700-850oC using back pressures ranging from 0.2 psi to 1.0 psi. Isothermal stability was also evaluated in a dual environment consisting of flowing dilute H2 fuel versus ambient air. In addition, chemical compatibility at the alumina and YSZ interfaces was examined with scanning electron microscopy and energy dispersive spectroscopy. The results shed new light on the topic of SOFC glass seal development.

Chou, Y. S.; Thomsen, Edwin C.; Williams, Riley T.; Choi, Jung-Pyung; Canfield, Nathan L.; Bonnett, Jeff F.; Stevenson, Jeffry W.; Shyam, Amit; Lara-Curzio, E.

2011-03-01T23:59:59.000Z

371

Understanding Atom Probe Tomography of Oxide-Supported Metal Nanoparticles by Correlation with Atomic Resolution Electron Microscopy and Field Evaporation Simulation  

SciTech Connect

Metal-dielectric composite materials, specifically metal nanoparticles supported on or embedded in metal oxides, are widely used in catalysis. The accurate optimization of such nanostructures warrants the need for detailed three-dimensional characterization. Atom probe tomography is uniquely capable of generating sub-nanometer structural and compositional data with part-per-million mass sensitivity, but there are reconstruction artifacts for composites containing materials with strongly differing fields of evaporation, as for oxide-supported metal nanoparticles. By correlating atom probe tomography with scanning transmission electron microscopy for Au nanoparticles embedded in an MgO support, deviations from an ideal topography during evaporation are demonstrated directly, and correlated with compositional errors in the reconstructed data. Finite element simulations of the field evaporation process confirm that protruding Au nanoparticles will evolve on the tip surface, and that evaporation field variations lead to an inaccurate assessment of the local composition, effectively lowering the spatial resolution of the final reconstructed dataset. Cross-correlating the experimental data with simulations results in a more detailed understanding of local evaporation aberrations during APT analysis of metal-oxide composites, paving the way towards a more accurate three-dimensional characterization of this technologically important class of materials.

Devaraj, Arun; Colby, Robert J.; Vurpillot, F.; Thevuthasan, Suntharampillai

2014-03-26T23:59:59.000Z

372

IN-SITU CHEMICAL STABILIZATION OF METALS AND RADIONUCLIDES THROUGH ENHANCED ANAEROBIC REDUCTIVE PRECIPITATION  

SciTech Connect

The objective of this NETL sponsored bench-scale study was to demonstrate the efficacy of enhanced anaerobic reductive precipitation (EARP) technology for precipitating uranium using samples from contaminated groundwater at the Fernald Closure Project (FCP) in Cincinnati, Ohio. EARP enhances the natural biological reactions in the groundwater through addition of food grade substrates (typically molasses) to drive the oxidative-reductive potential of the groundwater to a lower, more reduced state, thereby precipitating uranium from solution. In order for this in-situ technology to be successful in the long term, the precipitated uranium must not be re-dissolved at an unacceptable rate once groundwater geochemical conditions return to their pretreatment, aerobic state. The approach for this study is based on the premise that redissolution of precipitated uranium will be slowed by several mechanisms including the presence of iron sulfide precipitates and coatings, and sorption onto fresh iron oxides. A bench-scale study of the technology was performed using columns packed with site soil and subjected to a continuous flow of uranium-contaminated site groundwater (476 {micro}g/L). The ''treated'' column received a steady stream of dilute food grade molasses injected into the contaminated influent. Upon attainment of a consistently reducing environment and demonstrated removal of uranium, an iron sulfate amendment was added along with the molasses in the influent solution. After a month long period of iron addition, the treatments were halted, and uncontaminated, aerobic, unamended water was introduced to the treated column to assess rebound of uranium concentrations. In the first two months of treatment, the uranium concentration in the treated column decreased to the clean-up level (30 {micro}g/L) or below, and remained there for the remainder of the treatment period. A brief period of resolubilization of uranium was observed as the treated column returned to aerobic conditions, but the concentration later returned to below the clean-up level. Speciation analysis was conducted on soil collected from the treated column after rebound testing. The experimental results show that: (a) The mass of uranium resolubilized in more than four months of column testing was much lower than the amount precipitated. (b) The majority of the uranium was precipitated in the first few inches of the treated column. The majority of the uranium precipitated was associated with iron oxides or in other immobile/sequestered phases. It is important to contrast this result with the results reported by Bryan (2003) who shows that most of the uranium associated with contaminated aquifer solids at Fernald under the existing natural attenuation/pump and treat with reinjection conditions is carbonate bound. Carbonate bound forms are traditionally seen as fairly mobile, but may not be under a calcite/dolomite saturated condition. Fernald is currently conducting further studies to investigate the mobility of the carbonate bound forms. (c) Though reoxidation concentrations from the bench-scale column exceeded 30 {micro}g/L for a time, they later returned to below this value. Effluent concentrations from the treated column are expected to over predict full-scale concentrations for reasons discussed in depth in the text. Finally, these results must be viewed in light of the site's ongoing pump-and-treat with reinjection system. There is reason to believe that although the pump-and-treat technology is currently effectively controlling the uranium plume and reducing the groundwater concentration, it may not be able to reach the treatment standard of 30 {micro}g/L within an economical operating lifetime and then maintain that concentration without rebound. This study suggests that Enhanced Anaerobic Reductive Precipitation can change the speciation and thus reduce the mobility of uranium at the site and expedite closure.

Christopher C. Lutes; Angela Frizzell, PG; Todd A. Thornton; James M. Harrington

2003-08-01T23:59:59.000Z

373

Determining the Behavior of RuO(x) Nanoparticles in Mixed-Metal Oxides:  

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Mechanism of Ethanol Synthesis from Syngas on Rh(111) Understanding of Mechanism of Ethanol Synthesis from Syngas on Rh(111) Understanding of ethanol decomposition on Rh(1 1 1) from density functional theory and kinetic Monte Carlo simulations Theoretical perspective of alcohol decomposition and synthesis from CO2 hydrogenation