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Note: This page contains sample records for the topic "ruthenium dimer catalysis" from the National Library of EnergyBeta (NLEBeta).
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1

Structure and Electronic Configurations of the Intermediates of Water Oxidation in Blue Ruthenium Dimer Catalysis  

SciTech Connect (OSTI)

Catalytic O{sub 2} evolution with cis,cis-[(bpy){sub 2}(H{sub 2}O)Ru{sup III}ORu{sup III}(OH{sub 2})(bpy){sub 2}]{sup 4+} (bpy is 2,2-bipyridine), the so-called blue dimer, the first designed water oxidation catalyst, was monitored by UV-vis, EPR, and X-ray absorption spectroscopy (XAS) with ms time resolution. Two processes were identified, one of which occurs on a time scale of 100 ms to a few seconds and results in oxidation of the catalyst with the formation of an intermediate, here termed [3,4]'. A slower process occurring on the time scale of minutes results in the decay of this intermediate and O{sub 2} evolution. Spectroscopic data suggest that within the fast process there is a short-lived transient intermediate, which is a precursor of [3,4]'. When excess oxidant was used, a highly oxidized form of the blue dimer [4,5] was spectroscopically resolved within the time frame of the fast process. Its structure and electronic state were confirmed by EPR and XAS. As reported earlier, the [3,4]' intermediate likely results from reaction of [4,5] with water. While it is generated under strongly oxidizing conditions, it does not display oxidation of the Ru centers past [3,4] according to EPR and XAS. EXAFS analysis demonstrates a considerably modified ligand environment in [3,4]'. Raman measurements confirmed the presence of the O-O fragment by detecting a new vibration band in [3,4]' that undergoes a 46 cm{sup -1} shift to lower energy upon {sup 16}O/{sup 18}O exchange. Under the conditions of the experiment at pH 1, the [3,4]' intermediate is the catalytic steady state form of the blue dimer catalyst, suggesting that its oxidation is the rate-limiting step.

Moonshiram, Dooshaye; Jurss, Jonah W.; Concepcion, Javier J.; Zakharova, Taisiya; Alperovich, Igor; Meyer, Thomas J.; Pushkar, Yulia (Purdue); (UNC)

2013-04-08T23:59:59.000Z

2

Sensitivity of the Properties of Ruthenium Blue Dimer”...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Sensitivity of the Properties of Ruthenium Blue Dimer” to Method, Basis Set, and Continuum Model. Sensitivity of the Properties of Ruthenium Blue Dimer” to Method,...

3

Blue Ruthenium Dimer Catalysis for Hydrogen Generation | Advanced Photon  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth (AOD)ProductssondeadjustsondeadjustAboutScienceCareers Apply forBiosurveillance A LosBloodChronicBlue

4

Sensitivity of the Properties of Ruthenium “Blue Dimer” to Method, Basis Set, and Continuum Model  

SciTech Connect (OSTI)

The ruthenium “blue dimer” [(bpy)2RuIIIOH2]2O4+ is best known as the first well-defined molecular catalyst for water oxidation. It has been subject to numerous computational studies primarily employing density functional theory. However, those studies have been limited in the functionals, basis sets, and continuum models employed. The controversy in the calculated electronic structure and the reaction energetics of this catalyst highlights the necessity of benchmark calculations that explore the role of density functionals, basis sets, and continuum models upon the essential features of blue-dimer reactivity. In this paper, we report Kohn-Sham complete basis set (KS-CBS) limit extrapolations of the electronic structure of “blue dimer” using GGA (BPW91 and BP86), hybrid-GGA (B3LYP), and meta-GGA (M06-L) density functionals. The dependence of solvation free energy corrections on the different cavity types (UFF, UA0, UAHF, UAKS, Bondi, and Pauling) within polarizable and conductor-like polarizable continuum model has also been investigated. The most common basis sets of double-zeta quality are shown to yield results close to the KS-CBS limit; however, large variations are observed in the reaction energetics as a function of density functional and continuum cavity model employed.

Ozkanlar, Abdullah; Clark, Aurora E.

2012-05-23T23:59:59.000Z

5

catalysis | EMSL  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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

6

EMSL - catalysis  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

catalysis en Duets by molecules and plasmons http:www.emsl.pnl.govemslwebnewsduets-molecules-and-plasmons

7

INSTITUTE FOR INTEGRATED CATALYSIS Catalysis Research for  

E-Print Network [OSTI]

. This work includes catalysis for upgrading biomass feedstocks; for chemical energy storage, retrieval

8

Mechanistic Studies at the Interface Between Organometallic Chemistry and Homogeneous Catalysis  

SciTech Connect (OSTI)

Mechanistic Studies at the Interface Between Organometallic Chemistry and Homogeneous Catalysis Charles P. Casey, Principal Investigator Department of Chemistry, University of Wisconsin - Madison, Madison, Wisconsin 53706 Phone 608-262-0584 FAX: 608-262-7144 Email: casey@chem.wisc.edu http://www.chem.wisc.edu/main/people/faculty/casey.html Executive Summary. Our goal was to learn the intimate mechanistic details of reactions involved in homogeneous catalysis and to use the insight we gain to develop new and improved catalysts. Our work centered on the hydrogenation of polar functional groups such as aldehydes and ketones and on hydroformylation. Specifically, we concentrated on catalysts capable of simultaneously transferring hydride from a metal center and a proton from an acidic oxygen or nitrogen center to an aldehyde or ketone. An economical iron based catalyst was developed and patented. Better understanding of fundamental organometallic reactions and catalytic processes enabled design of energy and material efficient chemical processes. Our work contributed to the development of catalysts for the selective and mild hydrogenation of ketones and aldehydes; this will provide a modern green alternative to reductions by LiAlH4 and NaBH4, which require extensive work-up procedures and produce waste streams. (C5R4OH)Ru(CO)2H Hydrogenation Catalysts. Youval Shvo described a remarkable catalytic system in which the key intermediate (C5R4OH)Ru(CO)2H (1) has an electronically coupled acidic OH unit and a hydridic RuH unit. Our efforts centered on understanding and improving upon this important catalyst for reduction of aldehydes and ketones. Our mechanistic studies established that the reduction of aldehydes by 1 to produce alcohols and a diruthenium bridging hydride species occurs much more rapidly than regeneration of the ruthenium hydride from the diruthenium bridging hydride species. Our mechanistic studies require simultaneous transfer of hydride from ruthenium to the aldehyde carbon and of a proton from the CpOH unit to the aldehyde oxygen and support reduction of the aldehyde without its prior coordination to ruthenium. Another important step in the catalysis is the regeneration of 1 from reaction of H2 with the stable diruthenium bridging hydride complex 2. Studies of the microscopic reverse of this process (hydrogen evolution from 1 which occurs at 80 �������°C) in the presence of alcohol (the product of aldehyde hydrogenation) have shown that a dihydrogen complex is formed reversibly at a rate much faster than hydrogen evolution. Kinetic and theoretical studies in collaboration with Professor Qiang Cui of Wisconsin indicated an important role for alcohol in mediating transfer of hydrogen to ruthenium. One key to developing more active catalysts was to destabilize the bridging hydride intermediate 2 to prevent its formation or to speed its conversion to a reactive monohydride 1 by reaction with H2. We found several successful ways to destabilize the bridging hydride and to obtain more active catalysts. Most recently, we discovered related iron catalysts for hydrogenation that do not form dimers; the cost advantage of iron catalysts is spectacular. Iron Catalysts. In an exciting development, we found that a related iron complex is also a very active ketone hydrogenation catalyst. This hydrogenation catalyst shows high chemoselectivity for aldehydes, ketones, and imines and isolated C=C, C���¯�������ºC, C-X, -NO2, epoxides, and ester functions are unaffected by the hydrogenation conditions. Mechanistic studies have established a reversible hydrogen transfer step followed by rapid dihydrogen activation. The same iron complex also catalyzes transfer hydrogenation of ketones.

Charles P. Casey

2012-11-14T23:59:59.000Z

9

2012 Catalysis Lectures  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Bert Weckhuysen, who holds the chair of Inorganic Chemistry and Catalysis at Utrecht University, will give a series of catalysis lectures during his sabbatical period at...

10

Dendrimer-Encapsulated Ruthenium Nanoparticles as Catalysts for Lithium-O2 Batteries  

SciTech Connect (OSTI)

Dendrimer-encapsulated ruthenium nanoparticles (DEN-Ru) have been used as catalysts in lithium-O2 batteries for the first time. Results obtained from UV-vis spectroscopy, electron microscopy and X-ray photoelectron spectroscopy show that the nanoparticles synthesized by the dendrimer template method are ruthenium oxide instead of metallic ruthenium reported earlier by other groups. The DEN-Ru significantly improve the cycling stability of lithium (Li)-O2 batteries with carbon black electrodes and decrease the charging potential even at low catalyst loading. The monodispersity, porosity and large number of surface functionalities of the dendrimer template prevent the aggregation of the ruthenium nanoparticles making their entire surface area available for catalysis. The potential of using DEN-Ru as stand-alone cathode materials for Li-O2 batteries is also explored.

Bhattacharya, Priyanka; Nasybulin, Eduard N.; Engelhard, Mark H.; Kovarik, Libor; Bowden, Mark E.; Li, Shari; Gaspar, Daniel J.; Xu, Wu; Zhang, Jiguang

2014-12-01T23:59:59.000Z

11

Structure of a Loose Dimer: an Intermediate in Nitric Oxide Synthase Assembly  

SciTech Connect (OSTI)

Cooperativity among ligand binding, subunit association, and protein folding has implications for enzyme regulation as well as protein aggregation events associated with disease. The binding of substrate l-arginine or cofactor tetrahydrobiopterin converts nitric oxide synthases (NOSs) from a 'loose dimer', with an exposed active center and higher sensitivity to proteolysis, to a 'tight dimer' competent for catalysis. The crystallographic structure of the Bacillus subtilis NOS loose dimer shows an altered association state with severely destabilized subdomains. Ligand binding or heme reduction converts loose dimers to tight dimers in solution and crystals. Mutations at key positions in the dimer interface that distinguish prokaryotic from eukaryotic NOSs affect the propensity to form loose dimers. The loose dimer structure indicates that non-native interactions can mediate subunit association in NOS.

Pant,K.; Crane, B.

2005-01-01T23:59:59.000Z

12

HETEROGENEOUS CATALYSIS RESEARCH MEETING  

E-Print Network [OSTI]

Williams) Transition~Metal Carbides Heterogeneous CatalysisActivity of Transition-Metal Carbides Wendell S. Williamsand testing of transition-metal carbide electrodes for

Authors, Various

2011-01-01T23:59:59.000Z

13

Moderated ruthenium fischer-tropsch synthesis catalyst  

DOE Patents [OSTI]

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

Abrevaya, Hayim (Wilmette, IL)

1991-01-01T23:59:59.000Z

14

EMSL - In situ catalysis  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

situ-catalysis en Local environment and composition of magnesium gallium layered double hydroxides determined from solid-state 1H and 71Ga NMR http:www.emsl.pnl.govemslweb...

15

Dendrimer-Encapsulated Ruthenium Nanoparticles as Catalysts for...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Dendrimer-Encapsulated Ruthenium Nanoparticles as Catalysts for Lithium-O2 Batteries. Dendrimer-Encapsulated Ruthenium Nanoparticles as Catalysts for Lithium-O2 Batteries....

16

Catalysis Research for Energy Independence  

E-Print Network [OSTI]

production and use, and catalysis lies at the core of efficiently and effectively using our current energy, converting carbon dioxide into fuels, and transforming electrical energy from renewable energy sourcesCatalysis Research for Energy Independence Chemical transformations are at the heart of energy

17

asymmetric catalysis stereoelectronic: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

X Lewis Acid Catalysis Brnsted Acid Catalysis X Johnson, Jeff S. 2 Multidimensional free energy relationships in asymmetric catalysis. Open Access Theses and Dissertations...

18

Cationic Ruthenium Catalysts for Olefin Hydrovinylation  

E-Print Network [OSTI]

CATIONIC RUTHENIUM CATALYSTS FOR OLEFIN HYDROVINYLATION A Thesis by RICHARD P. SANCHEZ, JR. Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER... OF SCIENCE August 2009 Major Subject: Chemistry CATIONIC RUTHENIUM CATALYSTS FOR OLEFIN HYDROVINYLATION A Thesis by RICHARD P. SANCHEZ, JR. Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment...

Sanchez, Richard P., Jr

2010-01-14T23:59:59.000Z

19

Magnetic catalysis and inverse magnetic catalysis in QCD  

E-Print Network [OSTI]

We investigate the effects of strong magnetic fields on the QCD phase structure at vanishing density by solving the gluon and quark gap equations, and by studying the dynamics of the quark scattering with the four-fermi coupling. The chiral crossover temperature as well as the chiral condensate are computed. For asymptotically large magnetic fields we find magnetic catalysis, while we find inverse magnetic catalysis for intermediate magnetic fields. Moreover, for large magnetic fields the chiral phase transition for massless quarks turns into a crossover. The underlying mechanisms are then investigated analytically within a few simplifications of the full numerical analysis. We find that a combination of gluon screening effects and the weakening of the strong coupling is responsible for the phenomenon of inverse catalysis. In turn, the magnetic catalysis at large magnetic field is already indicated by simple arguments based on dimensionality.

Niklas Mueller; Jan M. Pawlowski

2015-02-27T23:59:59.000Z

20

Enhanced Micellar Catalysis LDRD.  

SciTech Connect (OSTI)

The primary goals of the Enhanced Micellar Catalysis project were to gain an understanding of the micellar environment of DF-200, or similar liquid CBW surfactant-based decontaminants, as well as characterize the aerosolized DF-200 droplet distribution and droplet chemistry under baseline ITW rotary atomization conditions. Micellar characterization of limited surfactant solutions was performed externally through the collection and measurement of Small Angle X-Ray Scattering (SAXS) images and Cryo-Transmission Electron Microscopy (cryo-TEM) images. Micellar characterization was performed externally at the University of Minnesota's Characterization Facility Center, and at the Argonne National Laboratory Advanced Photon Source facility. A micellar diffusion study was conducted internally at Sandia to measure diffusion constants of surfactants over a concentration range, to estimate the effective micelle diameter, to determine the impact of individual components to the micellar environment in solution, and the impact of combined components to surfactant phase behavior. Aerosolized DF-200 sprays were characterized for particle size and distribution and limited chemical composition. Evaporation rates of aerosolized DF-200 sprays were estimated under a set of baseline ITW nozzle test system parameters.

Betty, Rita G.; Tucker, Mark David; Taggart, Gretchen; Kinnan, Mark K.; Glen, Crystal Chanea; Rivera, Danielle; Sanchez, Andres; Alam, Todd Michael

2012-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "ruthenium dimer catalysis" 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

Cobalt-ruthenium catalysts for Fischer-Tropsch synthesis  

SciTech Connect (OSTI)

A hydrocarbon synthesis process is described which comprises reacting hydrogen and carbon monoxide in the presence of a catalyst comprised of cobalt and ruthenium on titania, at reaction conditions suitable for the formation of higher hydrocarbons. The catalyst is prepared by impregnating titania with solutions of cobalt and ruthenium salts, drying the impregnated support, reducing the cobalt and ruthenium, treating the reduced metals with an oxygen containing stream at conditions sufficient to form oxides of cobalt and oxides of ruthenium and reducing the cobalt and ruthenium oxides.

Iglesia, E.; Soled, S.L.; Fiato, R.A.

1989-04-18T23:59:59.000Z

22

Fuel Synthesis Catalysis Laboratory (Fact Sheet)  

SciTech Connect (OSTI)

This fact sheet provides information about Fuel Synthesis Catalysis Laboratory capabilities and applications at NREL's National Bioenergy Center.

Not Available

2011-07-01T23:59:59.000Z

23

Fuel Synthesis Catalysis Laboratory (Fact Sheet)  

SciTech Connect (OSTI)

This fact sheet provides information about Fuel Synthesis Catalysis Laboratory capabilities and applications at NREL's National Bioenergy Center.

Not Available

2013-07-01T23:59:59.000Z

24

ALD and Pulsed CVD of Ruthenium and Ruthenium Dioxide Thin Films From an Amidinate Precursor  

E-Print Network [OSTI]

Narrow window of O2 exposure (e.g. 0.02~0.04 Torr·s @ 325ºC) to obtain high quality pure Ru filmALD and Pulsed CVD of Ruthenium and Ruthenium Dioxide Thin Films From an Amidinate Precursor Xinwei, China Introduction Experimental ALD with O2 Ru metal film Pulsed CVD with NH3+H2 Ru metal film Pulsed

25

PHOTOCHEMICAL CO2 REDUCTION BY RHENUIM AND RUTHENIUM COMPLEXES.  

SciTech Connect (OSTI)

Photochemical conversion of CO{sub 2} to fuels or useful chemicals using renewable solar energy is an attractive solution to both the world's need for fuels and the reduction of greenhouse gases. Rhenium(I) and ruthenium(II) diimine complexes have been shown to act as photocatalysts and/or electrocatalysts for CO{sub 2} reduction to CO. We have studied these photochemical systems focusing on the identification of intermediates and the bond formation/cleavage reactions between the metal center and CO{sub 2}. For example, we have produced the one-electron-reduced monomer (i.e. Re(dmb)(CO){sub 3}S where dmb = 4,4'-dimethy-2,2'-bipyridine and S = solvent) either by reductive quenching of the excited states of fac-[Re(dmb)(CO){sub 3}(CH{sub 3}CN)]PF{sub 6} or by photo-induced homolysis of [Re(dmb)(CO){sub 3}]{sub 2}. We previously found that: (1) the remarkably slow dimerization of Re(dmb)(CO){sub 3}S is due to the absence of a vacant coordination site for Re-Re bond formation, and the extra electron is located on the dmb ligand; (2) the reaction of Re(dmb)(CO){sub 3}S with CO{sub 2} forms a CO{sub 2}-bridged binuclear species (CO){sub 3}(dmb)Re-CO(O)-Re(dmb)(CO){sub 3} as an intermediate in CO formation; and (3) the kinetics and mechanism of reactions are consistent with the interaction of the CO{sub 2}-bridged binuclear species with CO{sub 2} to form CO and CO{sub 3}{sup 2-}.

FUJITA,E.; MUCKERMAN, J.T.; TANAKA, K.

2007-11-30T23:59:59.000Z

26

Basic Research Needs: Catalysis for Energy  

SciTech Connect (OSTI)

The report presents results of a workshop held August 6-8, 2007, by DOE SC Basic Energy Sciences to determine the basic research needs for catalysis research.

Bell, Alexis T.; Gates, Bruce C.; Ray, Douglas; Thompson, Michael R.

2008-03-11T23:59:59.000Z

27

SOUTHWEST CATALYSIS SOCIETY 2008 SPRING SYMPOSIUM  

E-Print Network [OSTI]

Design: FCC Feed Hydrotreating Catalysis 11:35 AM Lunch Break/Poster Preview 1:00 PM Zachary T. Ball

Natelson, Douglas

28

Low-Temperature Hydrocarbon/CO Oxidation Catalysis in Support...  

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

& Publications Low-Temperature HydrocarbonCO Oxidation Catalysis in Support of HCCI Emission Control Low-Temperature HydrocarbonCO Oxidation Catalysis in Support of HCCI...

29

Shining Light on Catalysis | Stanford Synchrotron Radiation Lightsourc...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Bokhoven, Professor for Heterogeneous Catalysis Institute for Chemical and Bioengineering ETH Zurich Head of Laboratory for Catalysis and Sustainable Chemistry (LSK) Swiss Light...

30

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

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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

31

Thermochemical Conversion: Using Heat and Catalysis to Make Biofuels...  

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

Conversion: Using Heat and Catalysis to Make Biofuels and Bioproducts Thermochemical Conversion: Using Heat and Catalysis to Make Biofuels and Bioproducts The Bioenergy...

32

Sensitivity of the Properties of Ruthenium Blue Dimer” to Method,  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administrationcontroller systemsBi (2) SrEvaluating theDepartmentSensitivity of Radiative Fluxes

33

Fischer-Tropsch synthesis process employing a moderated ruthenium catalyst  

DOE Patents [OSTI]

A Fischer-Tropsch type process produces hydrocarbons from carbon monoxide and hydrogen using a novel catalyst comprising moderated ruthenium on an inorganic oxide support. The preferred moderator is silicon. Preferably the moderator is effectively positioned in relationship to ruthenium particles through simultaneous placement on the support using reverse micelle impregnation.

Abrevaya, Hayim (Wilmette, IL)

1990-01-01T23:59:59.000Z

34

Fischer-Tropsch synthesis process employing a moderated ruthenium catalyst  

DOE Patents [OSTI]

A Fischer-Tropsch type process produces hydrocarbons from carbon monoxide and hydrogen using a novel catalyst comprising moderated ruthenium on an inorganic oxide support. The preferred moderator is silicon. Preferably the moderator is effectively positioned in relationship to ruthenium particles through simultaneous placement on the support using reverse micelle impregnation. 1 fig.

Abrevaya, H.

1990-07-31T23:59:59.000Z

35

DOE Laboratory Catalysis Research Symposium - Abstracts  

SciTech Connect (OSTI)

The conference consisted of two sessions with the following subtopics: (1) Heterogeneous Session: Novel Catalytic Materials; Photocatalysis; Novel Processing Conditions; Metals and Sulfides; Nuclear Magnetic Resonance; Metal Oxides and Partial Oxidation; Electrocatalysis; and Automotive Catalysis. (2) Homogeneous Catalysis: H-Transfer and Alkane Functionalization; Biocatalysis; Oxidation and Photocatalysis; and Novel Medical, Methods, and Catalyzed Reactions.

Dunham, T.

1999-02-01T23:59:59.000Z

36

"Nanocrystal bilayer for tandem catalysis"  

SciTech Connect (OSTI)

Supported catalysts are widely used in industry and can be optimized by tuning the composition and interface of the metal nanoparticles and oxide supports. Rational design of metal-metal oxide interfaces in nanostructured catalysts is critical to achieve better reaction activities and selectivities. We introduce here a new class of nanocrystal tandem catalysts that have multiple metal-metal oxide interfaces for the catalysis of sequential reactions. We utilized a nanocrystal bilayer structure formed by assembling platinum and cerium oxide nanocube monolayers of less than 10 nm on a silica substrate. The two distinct metal-metal oxide interfaces, CeO2-Pt and Pt-SiO2, can be used to catalyse two distinct sequential reactions. The CeO2-Pt interface catalysed methanol decomposition to produce CO and H2, which were subsequently used for ethylene hydroformylation catalysed by the nearby Pt-SiO2 interface. Consequently, propanal was produced selectively from methanol and ethylene on the nanocrystal bilayer tandem catalyst. This new concept of nanocrystal tandem catalysis represents a powerful approach towards designing high-performance, multifunctional nanostructured catalysts

Yamada, Yusuke; Tsung, Chia Kuang; Huang, Wenyu; Huo, Ziyang; E.Habas, Susan E; Soejima, Tetsuro; Aliaga, Cesar E; Samorjai, Gabor A; Yang, Peidong

2011-01-24T23:59:59.000Z

37

Ruthenium / aerogel nanocomposits via Atomic Layer Deposition  

SciTech Connect (OSTI)

We present a general approach to prepare metal/aerogel nanocomposites via template directed atomic layer deposition (ALD). In particular, we used a Ru ALD process consisting of alternating exposures to bis(cyclopentadienyl)ruthenium (RuCp{sub 2}) and air at 350 C to deposit metallic Ru nanoparticles on the internal surfaces of carbon and silica aerogels. The process does not affect the morphology of the aerogel template and offers excellent control over metal loading by simply adjusting the number of ALD cycles. We also discuss the limitations of our ALD approach, and suggest ways to overcome these.

Biener, J; Baumann, T F; Wang, Y; Nelson, E J; Kucheyev, S O; Hamza, A V; Kemell, M; Ritala, M; Leskela, M

2006-08-28T23:59:59.000Z

38

asymmetric catalysis solvent-free: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

X Lewis Acid Catalysis Brnsted Acid Catalysis X Johnson, Jeff S. 2 Multidimensional free energy relationships in asymmetric catalysis. Open Access Theses and Dissertations...

39

Nanocrystal assembly for tandem catalysis  

DOE Patents [OSTI]

The present invention provides a nanocrystal tandem catalyst comprising at least two metal-metal oxide interfaces for the catalysis of sequential reactions. One embodiment utilizes a nanocrystal bilayer structure formed by assembling sub-10 nm platinum and cerium oxide nanocube monolayers on a silica substrate. The two distinct metal-metal oxide interfaces, CeO.sub.2--Pt and Pt--SiO.sub.2, can be used to catalyze two distinct sequential reactions. The CeO.sub.2--Pt interface catalyzed methanol decomposition to produce CO and H.sub.2, which were then subsequently used for ethylene hydroformylation catalyzed by the nearby Pt--SiO.sub.2 interface. Consequently, propanal was selectively produced on this nanocrystal bilayer tandem catalyst.

Yang, Peidong; Somorjai, Gabor; Yamada, Yusuke; Tsung, Chia-Kuang; Huang, Wenyu

2014-10-14T23:59:59.000Z

40

Magnetic Catalysis vs Magnetic Inhibition  

E-Print Network [OSTI]

We discuss the fate of chiral symmetry in an extremely strong magnetic field B. We investigate not only quark fluctuations but also neutral meson effects. The former would enhance the chiral-symmetry breaking at finite B according to the Magnetic Catalysis, while the latter would suppress the chiral condensate once B exceeds the scale of the hadron structure. Using a chiral model we demonstrate how neutral mesons are subject to the dimensional reduction and the low dimensionality favors the chiral-symmetric phase. We point out that this effect, the Magnetic Inhibition, can be a feasible explanation for recent lattice-QCD data indicating the decreasing behavior of the chiral-restoration temperature with increasing B.

Kenji Fukushima; Yoshimasa Hidaka

2012-09-06T23:59:59.000Z

Note: This page contains sample records for the topic "ruthenium dimer catalysis" 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

Fiber optic D dimer biosensor  

DOE Patents [OSTI]

A fiber optic sensor for D dimer (a fibrinolytic product) can be used in vivo (e.g., in catheter-based procedures) for the diagnosis and treatment of stroke-related conditions in humans. Stroke is the third leading cause of death in the United States. It has been estimated that strokes and stroke-related disorders cost Americans between $15-30 billion annually. Relatively recently, new medical procedures have been developed for the treatment of stroke. These endovascular procedures rely upon the use of microcatheters. These procedures could be facilitated with this sensor for D dimer integrated with a microcatheter for the diagnosis of clot type, and as an indicator of the effectiveness, or end-point of thrombolytic therapy.

Glass, Robert S. (Livermore, CA); Grant, Sheila A. (Pleasanton, CA)

1999-01-01T23:59:59.000Z

42

Fiber optic D dimer biosensor  

DOE Patents [OSTI]

A fiber optic sensor for D dimer (a fibrinolytic product) can be used in vivo (e.g., in catheter-based procedures) for the diagnosis and treatment of stroke-related conditions in humans. Stroke is the third leading cause of death in the United States. It has been estimated that strokes and stroke-related disorders cost Americans between $15-30 billion annually. Relatively recently, new medical procedures have been developed for the treatment of stroke. These endovascular procedures rely upon the use of microcatheters. These procedures could be facilitated with this sensor for D dimer integrated with a microcatheter for the diagnosis of clot type, and as an indicator of the effectiveness, or end-point of thrombolytic therapy. 4 figs.

Glass, R.S.; Grant, S.A.

1999-08-17T23:59:59.000Z

43

Ultrafast Electron Transfer Dynamics in Ruthenium Polypyridyl Complexes with a -Conjugated Ligand  

E-Print Network [OSTI]

to the solvent and orders of magnitude more rapidly than in previously studied ruthenium-diquat or ruthenium [(bpy)2RuLDQ]4+ (Chart 1) by broadband femtosecond transient absorption spectroscopy in acetonitrile

Dutta, Prabir K.

44

ISOTOPE METHODS IN HOMOGENEOUS CATALYSIS.  

SciTech Connect (OSTI)

The use of isotope labels has had a fundamentally important role in the determination of mechanisms of homogeneously catalyzed reactions. Mechanistic data is valuable since it can assist in the design and rational improvement of homogeneous catalysts. There are several ways to use isotopes in mechanistic chemistry. Isotopes can be introduced into controlled experiments and followed where they go or don't go; in this way, Libby, Calvin, Taube and others used isotopes to elucidate mechanistic pathways for very different, yet important chemistries. Another important isotope method is the study of kinetic isotope effects (KIEs) and equilibrium isotope effect (EIEs). Here the mere observation of where a label winds up is no longer enough - what matters is how much slower (or faster) a labeled molecule reacts than the unlabeled material. The most careti studies essentially involve the measurement of isotope fractionation between a reference ground state and the transition state. Thus kinetic isotope effects provide unique data unavailable from other methods, since information about the transition state of a reaction is obtained. Because getting an experimental glimpse of transition states is really tantamount to understanding catalysis, kinetic isotope effects are very powerful.

BULLOCK,R.M.; BENDER,B.R.

2000-12-01T23:59:59.000Z

45

aqueous phase catalysis: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

corroborate asymmetry of catalysis in F0F1-ATP synthase. Zarrabi, Nawid; Diez, Manuel; Graeber, Peter; Wrachtrup, Joerg; Boersch, Michael 2007-01-01 292 Magnetic catalysis in hot...

46

Geometrically induced magnetic catalysis and critical dimensions  

E-Print Network [OSTI]

We discuss the combined effect of magnetic fields and geometry in interacting fermionic systems. At leading order in the heat-kernel expansion, the infrared singularity (that in flat space leads to the magnetic catalysis) is regulated by the chiral gap effect and the catalysis is deactivated by effect of the curvature. We discover that an infrared singularity may reappear from higher-order terms in the heat kernel expansion leading to a novel form of geometrically induced magnetic catalysis (absent in flat space). The dynamical mass squared is then modified not only due to the chiral gap effect by an amount proportional to the curvature, but also by a magnetic shift $\\propto (4-D)eB$ where $D$ represents the number of space-time dimensions. We argue that $D=4$ is a critical dimension across which the behaviour of the magnetic shift changes qualitatively.

Antonino Flachi; Kenji Fukushima; Vincenzo Vitagliano

2015-02-21T23:59:59.000Z

47

Geometrically induced magnetic catalysis and critical dimensions  

E-Print Network [OSTI]

We discuss the combined effect of magnetic fields and geometry in interacting fermionic systems. At leading order in the heat-kernel expansion, the infrared singularity (that in flat space leads to the magnetic catalysis) is regulated by the chiral gap effect and the catalysis is deactivated by effect of the curvature. We discover that an infrared singularity may reappear from higher-order terms in the heat kernel expansion leading to a novel form of geometrically induced magnetic catalysis (absent in flat space). The dynamical mass squared is then modified not only due to the chiral gap effect by an amount proportional to the curvature, but also by a magnetic shift $\\propto (4-D)eB$ where $D$ represents the number of space-time dimensions. We argue that $D=4$ is a critical dimension across which the behaviour of the magnetic shift changes qualitatively.

Flachi, Antonino; Vitagliano, Vincenzo

2015-01-01T23:59:59.000Z

48

Carbon dioxide adsorption and methanation on ruthenium  

SciTech Connect (OSTI)

The adsorption and methanation of carbon dioxide on a ruthenium-silica catalyst were studied using temperature-programmed desorption (TPD) and temperature-programmed reaction (TPR). Carbon dioxide adsorption was found to be activated; CO/sub 2/ adsorption increased significantly as the temperature increased from 298 to 435 K. During adsorption, some of the CO/sub 2/ dissociated to carbon monoxide and oxygen; upon hydrogen exposure at room temperature, the oxygen reacted to water. Methanation of adsorbed CO and of adsorbed CO/sub 2/, using TPR in flowing hydrogen, yielded a CH/sub 4/ peak with a peak temperature of 459 K for both adsorbates, indicating that both reactions follow the same mechanism after adsorption. This peak temperature did not change with initial surface coverage of CO, indicating that methanation is first order in CO coverage. The desorption and reaction spectra for Ru/SiO/sub 2/ were similar to those previously obtained for Ni/SiO/sub 2/, but both CO/sub 2/ formation and CH/sub 4/ formation proceeded faster on Ru. Also, the details of CO desorption and the changes in CO/sub 2/ and CO desorptions with initial coverage were different on the two metals. 5 figures, 3 tables.

Zagli, E.; Falconer, J.L.

1981-05-01T23:59:59.000Z

49

Isotopic equilibration of carbon monoxide catalyzed by supported ruthenium  

SciTech Connect (OSTI)

Isotopic equilibration of carbon monoxide catalyzed by supported ruthenium was studied with oxygen-18 and carbon-13 labeled carbon monoxide in the presence and absence of hydrogen. The results showed that carbon monoxide was present on commercial alumina-supported ruthenium in a reactive undissociated form at 373/sup 0/K; that it adsorbed as a single carbonyl and in a geminal dicarbonyl form; and that hydrogen inhibited the exchange reaction by competitive adsorption and by stabilizing the carbonyl bond. The results elucidate the carbon monoxide methanation and Fischer-Tropsch reactions on this catalyst.

Bossi, A. (Cent. Ric. Novara); Zanderighi, L.; Carnisio, G.; Garbassi, F.; Giunchi, G.; Petrini, G.

1980-09-01T23:59:59.000Z

50

Benzene Dimer: Dynamic Structure and Thermodynamics Derived from...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Benzene Dimer: Dynamic Structure and Thermodynamics Derived from On-the-Fly ab initio DFT-D Molecular Dynamic Simulations. Benzene Dimer: Dynamic Structure and Thermodynamics...

51

Cleavage of the Carbon-Sulfur Bonds in Thiophenes by a Binuclear Ruthenium Complex  

E-Print Network [OSTI]

.; Massoth, F. E. Hydrotreating Catalysis; Springer-Verlag: Berlin, 1996. (2) Bianchini, C.; Masi, D.; Meli

Jones, William D.

52

Synthesis and Characterization of Hydrous Ruthenium Oxide-Carbon Supercapacitors  

E-Print Network [OSTI]

of pseudocapacitors are offset by their high cost as compared to carbon. The advantages accrued from carbonSynthesis and Characterization of Hydrous Ruthenium Oxide-Carbon Supercapacitors Manikandan Ramani It is shown that composite Ru oxide-carbon based supercapacitors possess superior energy and power densities

Popov, Branko N.

53

Environment assisted energy transfer in dimer system  

SciTech Connect (OSTI)

The influence of collective and multilocal environments on the energy transfer between the levels of a dimer is studied. The dynamics of energy transfer are investigated by considering coupling of collective environment with the levels of the dimer in the presence of both two individuals and mutually correlated multilocal environments. It is shown that every way of coupling we consider assists, though differently, the probability of transition between the levels of dimer. The probability of transition is strongly enhanced when the two local environments are mutually correlated. -- Highlights: • The dynamics of energy transfer between the levels of a dimer are studied. • Coupling of collective as well as individual environments are considered. • The environments are in spin star configurations. • The environment assists the energy transfer between the levels. • For correlated multilocal environments, the transition probability is almost 100%.

Khan, Salman, E-mail: sksafi@comsats.edu.pk [Department of Physics, COMSATS Institute of Information Technology, Chak Shahzad, Islamabad (Pakistan)] [Department of Physics, COMSATS Institute of Information Technology, Chak Shahzad, Islamabad (Pakistan); Ibrahim, M.; Khan, M.K. [Department of Physics, Quaid-i-Azam University, Islamabad (Pakistan)] [Department of Physics, Quaid-i-Azam University, Islamabad (Pakistan)

2014-02-15T23:59:59.000Z

54

USD Catalysis Group for Alternative Energy  

SciTech Connect (OSTI)

The South Dakota Catalysis Group (SDCG) is a collaborative project with mission to develop advanced catalysts for energy conversion with two primary goals: (1) develop photocatalytic systems in which polyfunctionalized TiO2 are the basis for hydrogen/oxygen synthesis from water and sunlight (solar fuels group), (2) develop new materials for hydrogen utilization in fuel cells (fuel cell group). In tandem, these technologies complete a closed chemical cycle with zero emissions.

James D. Hoefelmeyer, Ranjit Koodali, Grigoriy Sereda, Dan Engebretson, Hao Fong, Jan Puszynski, Rajesh Shende, Phil Ahrenkiel

2012-03-13T23:59:59.000Z

55

Nanoscale Advances in Catalysis and Energy Applications  

SciTech Connect (OSTI)

In this perspective, we present an overview of nanoscience applications in catalysis, energy conversion, and energy conservation technologies. We discuss how novel physical and chemical properties of nanomaterials can be applied and engineered to meet the advanced material requirements in the new generation of chemical and energy conversion devices. We highlight some of the latest advances in these nanotechnologies and provide an outlook at the major challenges for further developments.

Li, Yimin; Somorjai, Gabor A.

2010-05-12T23:59:59.000Z

56

Catalysis by Design: Bridging the Gap Between Theory and Experiments...  

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

Between Theory and Experiments at Nanoscale Level Catalysis by Design: Bridging the Gap Between Theory and Experiments at Nanoscale Level Studies on a simple platinum-alumina...

57

Catalysis by Design: Bridging the Gap between Theory and Experiments...  

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

between Theory and Experiments Catalysis by Design: Bridging the Gap between Theory and Experiments Poster presentation at the 2007 Diesel Engine-Efficiency & Emissions Research...

58

Catalysis by Design - Theoretical and Experimental Studies of...  

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

Design - Theoretical and Experimental Studies of Model Catalysts for Lean NOx Treatment Catalysis by Design - Theoretical and Experimental Studies of Model Catalysts for Lean NOx...

59

Neutrons for Catalysis: A Workshop on Neutron Scattering Techniques for Studies in Catalysis  

SciTech Connect (OSTI)

This report summarizes the Workshop on Neutron Scattering Techniques for Studies in Catalysis, held at the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory (ORNL) on September 16 and 17, 2010. The goal of the Workshop was to bring experts in heterogeneous catalysis and biocatalysis together with neutron scattering experimenters to identify ways to attack new problems, especially Grand Challenge problems in catalysis, using neutron scattering. The Workshop locale was motivated by the neutron capabilities at ORNL, including the High Flux Isotope Reactor (HFIR) and the new and developing instrumentation at the SNS. Approximately 90 researchers met for 1 1/2 days with oral presentations and breakout sessions. Oral presentations were divided into five topical sessions aimed at a discussion of Grand Challenge problems in catalysis, dynamics studies, structure characterization, biocatalysis, and computational methods. Eleven internationally known invited experts spoke in these sessions. The Workshop was intended both to educate catalyst experts about the methods and possibilities of neutron methods and to educate the neutron community about the methods and scientific challenges in catalysis. Above all, it was intended to inspire new research ideas among the attendees. All attendees were asked to participate in one or more of three breakout sessions to share ideas and propose new experiments that could be performed using the ORNL neutron facilities. The Workshop was expected to lead to proposals for beam time at either the HFIR or the SNS; therefore, it was expected that each breakout session would identify a few experiments or proof-of-principle experiments and a leader who would pursue a proposal after the Workshop. Also, a refereed review article will be submitted to a prominent journal to present research and ideas illustrating the benefits and possibilities of neutron methods for catalysis research.

Overbury, Steven {Steve} H [ORNL; Coates, Leighton [ORNL; Herwig, Kenneth W [ORNL; Kidder, Michelle [ORNL

2011-10-01T23:59:59.000Z

60

Thermodynamic data bases for multivalent elements: An example for ruthenium  

SciTech Connect (OSTI)

A careful consideration and understanding of fundamental chemistry, thermodynamics, and kinetics is absolutely essential when modeling predominance regions and solubility behavior of elements that exhibit a wide range of valence states. Examples of this are given using the ruthenium-water system at 298.15 K, for which a critically assessed thermochemical data base is available. Ruthenium exhibits the widest range of known aqueous solution valence states. Known solid anhydrous binary oxides of ruthenium are crystalline RuO/sub 2/, RuO/sub 4/, and possibly RuO/sub 3/ (thin film), and known hydroxides/hydrated oxides (all amorphous) are Ru(OH)/sub 3/ . H/sub 2/O, RuO/sub 2/ . 2H/sub 2/O, RuO/sub 2/ . H/sub 2/O, and a poorly characterized Ru(V) hydrous oxide. Although the other oxides, hydroxides, and hydrous oxides are generally obtained as precipitates from aqueous solutions, they are thermodynamically unstable with regard to RuO/sub 2/(cr) formation. Characterized aqueous species of ruthenium include RuO/sub 4/ (which slowly oxidizes water and which dissociates as a weak acid), RuO/sub 4//sup -/ and RuO/sub 4//sup 2 -/ (which probably contain lesser amounts of RuO/sub 3/(OH)/sub 2//sup -/ and RuO/sub 3/(OH)/sub 2//sup 2 -/, respectively, and other species), Ru(OH)/sub 2//sup 2 +/, Ru/sub 4/(OH)/sub 12//sup 4 +/, Ru(OH)/sub 4/, Ru/sup 3 +/, Ru(OH)/sup 2 +/, Ru(OH)/sub 2//sup +/, Ru/sup 2 +/, and some hydroxytetramers with formal ruthenium valences of 3.75 greater than or equal to Z greater than or equal to 2.0. Potential pH diagrams of the predominance regions change significantly with concentration due to polymerization/depolymerization reactions. Failure to consider the known chemistry of ruthenium can yield large differences in predicted solubilities.

Rard, J.A.

1987-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "ruthenium dimer catalysis" 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

Plasma-Activated Lean NOx Catalysis for Heavy-Duty Diesel Emissions...  

Broader source: Energy.gov (indexed) [DOE]

vs. Plasma-Facilitated Lean NOx Catalysis Selective reduction of NOx in oxygen rich environments with plasma-assisted catalysis: Catalyst development and mechanistic...

62

Hydrogen and oxygen adsorption stoichiometries on silica supported ruthenium nanoparticles  

SciTech Connect (OSTI)

Treatment under H{sub 2} at 300 C of Ru(COD)(COT) dispersed on silica yields 2 nm ruthenium nanoparticles, [Ru{sub p}/SiO{sub 2}], according to EXAFS, HRTEM and XPS. H{sub 2} adsorption measurements on [Ru{sub p}/SiO{sub 2}] in the absence of O{sub 2} show that Ru particles adsorb up to ca. 2 H per surface ruthenium atoms (2H/Ru{sub s}) on various samples; this technique can therefore be used to measure the dispersion of Ru particles. In contrast, O{sub 2} adsorption on [Ru{sub p}/SiO{sub 2}] leads to a partial oxidation of the bulk at 25 C, to RuO{sub 2} at 200 C and to sintering upon further reduction under H{sub 2}, showing that O{sub 2} adsorption cannot be used to measure the dispersion of Ru particles.

Berthoud, Romain; Delichere, Pierre; Gajan, David; Lukens, Wayne; Pelzer, Katrin; Basset, Jean-Marie; Candy, Jean-Pierre; Coperet, Christophe

2008-12-01T23:59:59.000Z

63

A method for activation analysis of ruthenium in sea water  

E-Print Network [OSTI]

grams/year as the amount of material introduced into the oceans (Goldberg, 1963), the residence time of ruthenium is found to be about l. 3 million years. Using the 0. 001 ppm value given by Sidgewick (1950) results in a residence time of about one... earths, for example, have residence times on the order of 500 years (Goldberg, 1963), hence are probably more reactive; and they are found about evenly distributed between soluble and particulate fractions (D. W. Hayes, private communi- cation...

Dixon, Bryan William

2012-06-07T23:59:59.000Z

64

Neutrons for Catalysis: A Workshop on Neutron Scattering Techniques for Studies in Catalysis  

E-Print Network [OSTI]

-EM Fischer Tropsch Catalysis on Fe- or Co-catalysts, ,,CTL" Coal to Liquids ­ ,a rough (?) analogy #12;Peter Albers, AQ-EM Carbonaceous Deposits on Catalysts #12;Peter Albers, AQ-EM IINS on Coked Catalysts from Industrial Plants High-temperature and low-temperature cokes deposited on catalysts during

Pennycook, Steve

65

Lithium Diisopropylamide-Mediated Enolization: Catalysis by Hemilabile Ligands  

E-Print Network [OSTI]

Lithium Diisopropylamide-Mediated Enolization: Catalysis by Hemilabile Ligands Antonio Ramirez of a lithium diisopropylamide (LDA)-mediated ester enolization. Hemilabile amino ether MeOCH2CH2NMe2, binding-based catalysis are thwarted by the occlusion of the catalyst on the lithium salt products and byproducts (eq 1

Collum, David B.

66

Synthesis of Ruthenium Carbonyl Complexes with Phosphine or Substituted Cp Ligands, and Their Activity in the Catalytic Deoxygenation of 1,2-Propanediol  

SciTech Connect (OSTI)

A ruthenium hydride with a bulky tetra-substituted Cp ligand, (Cp{sup iPr{sub 4}})Ru(CO){sub 2}H (Cp{sup iPr{sub 4}} = C{sub 5}(i-C{sub 3}H{sub 7}){sub 4}H) was prepared from the reaction of Ru{sub 3}(CO){sub 12} with 1,2,3,4-tetraisopropylcyclopentadiene. The molecular structure of (Cp{sup iPr{sub 4}})Ru(CO){sub 2}H was determined by X-ray crystallography. The ruthenium hydride complex (C{sub 5}Bz{sub 5})Ru(CO){sub 2}H (Bz = CH{sub 2}Ph) was similarly prepared. The Ru-Ru bonded dimer, [(1,2,3-trimethylindenyl)Ru(CO){sub 2}]{sub 2}, was produced from the reaction of 1,2,3-trimethylindene with Ru{sub 3}(CO){sub 12}, and protonation of this dimer with HOTf gives {l_brace}[(1,2,3-trimethylindenyl)Ru(CO){sub 2}]{sub 2}-({mu}-H){r_brace}{sup +}OTf{sup -}. A series of ruthenium hydride complexes CpRu(CO)(L)H [L = P(OPh){sub 3}, PCy{sub 3}, PMe{sub 3}, P(p-C{sub 6}H{sub 4}F){sub 3}] were prepared by reaction of Cp(CO){sub 2}RuH with added L. Protonation of (Cp{sup iPr{sub 4}})Ru(CO){sub 2}H, Cp*Ru(CO){sub 2}H, or CpRu(CO)[P-(OPh){sub 3}]H by HOTf at -80 C led to equilibria with the cationic dihydrogen complexes, but H{sub 2} was released at higher temperatures. Protonation of CpRu[P(OPh){sub 3}]{sub 2}H with HOTf gave an observable dihydrogen complex, {l_brace}CpRu[P-(OPh){sub 3}]{sub 2}({eta}{sup 2}-H{sub 2}){r_brace}+OTf{sup -} that was converted at -20 C to the dihydride complex {l_brace}CpRu[P(OPh){sub 3}]{sub 2}(H){sub 2}{r_brace}{sup +}OTf{sup -}. These Ru complexes serve as catalyst precursors for the catalytic deoxygenation of 1,2-propanediol to give n-propanol. The catalytic reactions were carried out in sulfolane solvent with added HOTf under H{sub 2} (750 psi) at 110 C.

Bullock, R.M.; Ghosh, P.; Fagan, P.J.; Marshall, W.J.; Hauptman, E.

2009-07-20T23:59:59.000Z

67

Catalysis and Synthesis | Argonne National Laboratory  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation Proposed New Substation Sites ProposedOccupational Health Services >Catalysis and Synthesis

68

Catalysis Working Group | Department of Energy  

Broader source: Energy.gov (indexed) [DOE]

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) "ofEarly Career Scientists' ResearchTheMarketing,Energy-ChevronSeveral salesCarolyn L.in aDataThe CatalysisThe

69

Opportunities in Catalysis Research Using Synchrotron Radiation  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 - September 2006 The 2002 WholesaleEnergy'sRunningOperations Two Argonnein Catalysis

70

Accounting for Scale in Catalysis | EMSL  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth (AOD)ProductssondeadjustsondeadjustAbout the Building Technologies OfficeAccounting for Scale in Catalysis

71

A Literature Review on Ruthenium Behaviour in Nuclear Power Plant Severe Accidents  

E-Print Network [OSTI]

A Literature Review on Ruthenium Behaviour in Nuclear Power Plant Severe Accidents C. MUN , L Literature Review on Ruthenium Behaviour in Nuclear Power Plant Severe Accidents C. MUN a , L. CANTREL a , C Accidents Majeurs (DPAM), CEN Cadarache - France 1 b Commissariat à l'Energie Atomique (CEA), Direction de l'Energie

Boyer, Edmond

72

Vapor Deposition of Ruthenium from an Amidinate Precursor Huazhi Li,a  

E-Print Network [OSTI]

Vapor Deposition of Ruthenium from an Amidinate Precursor Huazhi Li,a Damon B. Farmer,b Roy G School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA October 11, 2007. Thin films of ruthenium have many current and potential appli- cations. They can be used

73

Comparative study of dimer-vacancies and dimer-vacancy lines on Si(001) and Ge(001)  

E-Print Network [OSTI]

Comparative study of dimer-vacancies and dimer-vacancy lines on Si(001) and Ge(001) Cristian V that dimer- vacancy (DV) defects self-organize into vacancy lines (VLs) on Si(0 0 1), but not on Ge(0 0 1 the vacancies on Si(0 0 1) and Ge(0 0 1). We identify three energetic parameters which characterize the DVs

Ciobanu, Cristian

74

Theoretical investigation of solar energy conversion and water oxidation catalysis  

E-Print Network [OSTI]

Solar energy conversion and water oxidation catalysis are two great scientific and engineering challenges that will play pivotal roles in a future sustainable energy economy. In this work, I apply electronic structure ...

Wang, Lee-Ping

2011-01-01T23:59:59.000Z

75

Catalysis Working Group Kick-Off Meeting Agenda | Department...  

Energy Savers [EERE]

Kick-Off Meeting Agenda Agenda for the kick-off meeting of the U.S. Department of Energy Fuel Cell Technologies Program's Catalysis Working Group, held May 14, 2012, in Arlington,...

76

Deposition of ruthenium nanoparticles on carbon aerogels for high energy density supercapacitor electrodes  

SciTech Connect (OSTI)

The preparation and characterization of high surface area ruthenium/carbon aerogel composite electrodes for use in electrochemical capacitors is reported. These new materials have been prepared by the chemical vapor impregnation of ruthenium into carbon aerogels to produce a uniform distribution of adherent {approx}20 {angstrom} nanoparticles on the aerogel surface. The electrochemically oxidized ruthenium particles contribute a pseudocapacitance to the electrode and dramatically improve the energy storage characteristics of the aerogel. These composites have demonstrated specific capacitances in excess of 200 F/g, in comparison to 95 F/g for the untreated aerogel.

Miller, J.M.; Dunn, B. [Univ. of California, Los Angeles, CA (United States). Dept. of Materials Science and Engineering; Tran, T.D.; Pekala, R.W. [Lawrence Livermore National Labs., CA (United States). Chemical Sciences Div.

1997-12-01T23:59:59.000Z

77

The physics doped Quantum Dimer Models  

E-Print Network [OSTI]

-charge separation ­ Topological defects and holon statistics · Approach based on the Quantum Dimer Model ­ A wide ­ Hole doping: exotic properties of holons #12;3 Collaborators · Arnaud Ralko (Toulouse) · Frédéric Mila superconductor under doping Holon (Q=e, S=0) « spin-charge separation » #12;8 Variational approach of RVB #12

Paris-Sud 11, Université de

78

On the Acid-Base Mechanism for Ruthenium Water Oxidation Catalysts  

E-Print Network [OSTI]

We present a detailed theoretical study of the pathway for water oxidation in synthetic ruthenium-based catalysts. As a first step, we consider a recently discovered single center catalyst, where experimental observations ...

Wang, Lee-Ping

79

Ruthenium or osmium complexes and their uses as catalysts for water oxidation  

DOE Patents [OSTI]

The present invention provides ruthenium or osmium complexes and their uses as a catalyst for catalytic water oxidation. Another aspect of the invention provides an electrode and photo-electrochemical cells for electrolysis of water molecules.

Concepcion Corbea, Javier Jesus; Chen, Zuofeng; Jurss, Jonah Wesley; Templeton, Joseph L; Hoertz, Paul; Meyer, Thomas J

2014-10-28T23:59:59.000Z

80

Novel Ruthenium complexes and their application in dye sensitised solar cells   

E-Print Network [OSTI]

This work focuses on the design, synthesis and characterisation of novel ruthenium bipyridyl complexes and their use in dye sensitised solar cells (DSSCs). Four series of dyes have been synthesised with the general formula ...

McCall, Keri Laura

2009-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "ruthenium dimer catalysis" 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

Preparation of olefins from synthesis gas using ruthenium supported on ceric oxide  

DOE Patents [OSTI]

A catalyst comprising a ruthenium carbonyl compound deposited on a cerium oxide-containing support material provides for the selective synthesis of low molecular weight olefinic hydrocarbons from mixtures of hydrogen and carbon monoxide.

Pierantozzi, R.

1985-04-09T23:59:59.000Z

82

Ruthenium carbonyl catalyst supported on ceric oxide for preparation of olefins from synthesis gas  

DOE Patents [OSTI]

A catalyst comprising a ruthenium carbonyl compound deposited on a cerium oxide-containing support material provides for the selective synthesis of low molecular weight olefinic hydrocarbons from mixtures of hydrogen and carbon monoxide.

Pierantozzi, R.

1985-04-02T23:59:59.000Z

83

Ruthenium or osmium complexes and their uses as catalysts for water oxidation  

DOE Patents [OSTI]

The present invention provides ruthenium or osmium complexes and their uses as a catalyst for catalytic water oxidation. Another aspect of the invention provides an electrode and photo-electrochemical cells for electrolysis of water molecules.

Corbea, Javier Jesus Concepcion; Chen, Zuofeng; Jurss, Jonah Wesley; Templeton, Joseph L.; Hoertz, Paul; Meyer, Thomas J.

2013-09-03T23:59:59.000Z

84

Ruthenium carbonyl catalyst supported on ceric oxide for preparation of olefins from synthesis gas  

DOE Patents [OSTI]

A catalyst comprising a ruthenium carbonyl compound deposited on a cerium oxide-containing support material provides for the selective synthesis of low molecular weight olefinic hydrocarbons from mixtures of hydrogen and carbon monoxide.

Pierantozzi, Ronald (Macungie, PA)

1985-01-01T23:59:59.000Z

85

Preparation of olefins from synthesis gas using ruthenium supported on ceric oxide  

DOE Patents [OSTI]

A catalyst comprising a ruthenium carbonyl compound deposited on a cerium oxide-containing support material provides for the selective synthesis of low molecular weight olefinic hydrocarbons from mixtures of hydrogen and carbon monoxide.

Pierantozzi, Ronald (Macungie, PA)

1985-01-01T23:59:59.000Z

86

Some General Themes in Catalysis at LANL  

SciTech Connect (OSTI)

Some general themes in catalysis at LANL are: (1) Storage and release of energy within chemical bonds (e.g. H{sub 2} storage in and release from covalent bonds, N{sub 2} functionalization, CO{sub 2} functionalization, H{sub 2} oxidation/evolution, O{sub 2} reduction/evolution); (2) Can we control the chemistry of reactive substrates to effect energy relevant transformations in non-traditional media (e.g. can we promote C-C couplings, dehydrations, or hydrogenations in water under relatively mild conditions)? (3) Can we supplant precious metal or rare earth catalysts to effect these transformations, by using earth abundant metals/elements instead? Can we use organocatalysis and circumvent the use of metals completely? (4) Can we improve upon existing rare earth catalyst systems (e.g. in rare earth oxides pertinent to fluid cracking or polymerization) and reduce amounts required for catalytic efficacy? Carbohydrates can be accessed from non-food based biomass sources such as woody residues and switchgrass. After extracted from the plant source, our goal is to upgrade these classes of molecules into useful fuels.

Gordon, John C. [Los Alamos National Laboratory

2012-07-19T23:59:59.000Z

87

E-Print Network 3.0 - alkane oxidation catalysis Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

hydrogen... Reforming of Methane 10 Gas Phase Incorporation of Pd onto Iron-Ceria Aerogels for Water Gas Shift Catalysis... at the 20 North American Meeting of the Catalysis...

88

acid-base catalysis ii: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

corroborate asymmetry of catalysis in F0F1-ATP synthase. Zarrabi, Nawid; Diez, Manuel; Graeber, Peter; Wrachtrup, Joerg; Boersch, Michael 2007-01-01 232 Magnetic catalysis in hot...

89

Final technical report, Symposium on New Theoretical Concepts and Directions in Catalysis  

SciTech Connect (OSTI)

We organized in August 2013 a “Symposium on New Theoretical Concepts and Directions in Catalysis” with the participation of 20 invited distinguished quantum chemists and other researchers who use computations to study catalysis. Symposium website; http://catalysis.cnsi.ucsb.edu/

Metiu, Horia [University of California, Santa Barbara

2014-08-22T23:59:59.000Z

90

Seventh BES (Basic Energy Sciences) catalysis and surface chemistry research conference  

SciTech Connect (OSTI)

Research programs on catalysis and surface chemistry are presented. A total of fifty-seven topics are included. Areas of research include heterogeneous catalysis; catalysis in hydrogenation, desulfurization, gasification, and redox reactions; studies of surface properties and surface active sites; catalyst supports; chemical activation, deactivation; selectivity, chemical preparation; molecular structure studies; sorption and dissociation. Individual projects are processed separately for the data bases. (CBS)

Not Available

1990-03-01T23:59:59.000Z

91

Center for Catalysis at Iowa State University  

SciTech Connect (OSTI)

The overall objective of this proposal is to enable Iowa State University to establish a Center that enjoys world-class stature and eventually enhances the economy through the transfer of innovation from the laboratory to the marketplace. The funds have been used to support experimental proposals from interdisciplinary research teams in areas related to catalysis and green chemistry. Specific focus areas included: • Catalytic conversion of renewable natural resources to industrial materials • Development of new catalysts for the oxidation or reduction of commodity chemicals • Use of enzymes and microorganisms in biocatalysis • Development of new, environmentally friendly reactions of industrial importance These focus areas intersect with barriers from the MYTP draft document. Specifically, section 2.4.3.1 Processing and Conversion has a list of bulleted items under Improved Chemical Conversions that includes new hydrogenation catalysts, milder oxidation catalysts, new catalysts for dehydration and selective bond cleavage catalysts. Specifically, the four sections are: 1. Catalyst development (7.4.12.A) 2. Conversion of glycerol (7.4.12.B) 3. Conversion of biodiesel (7.4.12.C) 4. Glucose from starch (7.4.12.D) All funded projects are part of a soybean or corn biorefinery. Two funded projects that have made significant progress toward goals of the MYTP draft document are: Catalysts to convert feedstocks with high fatty acid content to biodiesel (Kraus, Lin, Verkade) and Conversion of Glycerol into 1,3-Propanediol (Lin, Kraus). Currently, biodiesel is prepared using homogeneous base catalysis. However, as producers look for feedstocks other than soybean oil, such as waste restaurant oils and rendered animal fats, they have observed a large amount of free fatty acids contained in the feedstocks. Free fatty acids cannot be converted into biodiesel using homogeneous base-mediated processes. The CCAT catalyst system offers an integrated and cooperative catalytic system that performs both esterification (of free fatty acids) and transesterification (of soybean oil) in a one-pot fashion. This will allow the biodiesel producers to use the aforementioned cheap feedstocks without any pretreatment. In addition, the catalyst system is heterogeneous and is highly recyclable and reusable. Although markets currently exist for glycerin, concern is mounting that the price of glycerin may plummet to $.05 - $.10 per pound if future production exceeds demand. Developing a system to make high value chemicals such as 1,3-propanediol from the glycerin stream will add value for biodiesel producers who implement the new technology. Given the fact that both DuPont and Shell chemicals have announced the commercialization of two new PDO-based polymers, a rapid increase of market demand for a cheaper PDO source is very likely. 4. Comparison of actual accomplishments with goals and objectives From our progress reports, the four areas are: 1. Catalyst development (7.4.12.A) 2. Conversion of glycerol (7.4.12.B) 3. Conversion of biodiesel (7.4.12.C) 4. Glucose from starch (7.4.12.D)

Kraus, George A.

2006-10-17T23:59:59.000Z

92

Catalysis-by-design impacts assessment  

SciTech Connect (OSTI)

Catalyst researchers have always recognized the need to develop a detailed understanding of the mechanisms of catalytic processes, and have hoped that it would lead to developing a theoretical predictive base to guide the search for new catalysts. This understanding allows one to develop a set of hierarchical models, from fundamental atomic-level ab-initio models to detailed engineering simulations of reactor systems, to direct the search for optimized, efficient catalyst systems. During the last two decades, the explosions of advanced surface analysis techniques have helped considerably to develop the building blocks for understanding various catalytic reactions. An effort to couple these theoretical and experimental advances to develop a set of hierarchical models to predict the nature of catalytic materials is a program entitled Catalysis-by-Design (CRD).'' In assessing the potential impacts of CBD on US industry, the key point to remember is that the value of the program lies in developing a novel methodology to search for new catalyst systems. Industrial researchers can then use this methodology to develop proprietary catalysts. Most companies involved in catalyst R D have two types of ongoing projects. The first type, what we call market-driven R D,'' are projects that support and improve upon a company's existing product lines. Project of the second type, technology-driven R D,'' are longer term, involve the development of totally new catalysts, and are initiated through scientists' research ideas. The CBD approach will impact both types of projects. However, this analysis indicates that the near-term impacts will be on market-driven'' projects. The conclusions and recommendations presented in this report were obtained by the authors through personal interviews with individuals involved in a variety of industrial catalyst development programs and through the three CBD workshops held in the summer of 1989. 34 refs., 7 figs., 7 tabs.

Fassbender, L L; Young, J K [Pacific Northwest Lab., Richland, WA (USA); Sen, R K [Sen (R.K.) and Associates, Washington, DC (USA)

1991-05-01T23:59:59.000Z

93

High-Spin Cobalt Hydrides for Catalysis  

SciTech Connect (OSTI)

Organometallic chemists have traditionally used catalysts with strong-field ligands that give low-spin complexes. However, complexes with a weak ligand field have weaker bonds and lower barriers to geometric changes, suggesting that they may lead to more rapid catalytic reactions. Developing our understanding of high-spin complexes requires the use of a broader range of spectroscopic techniques, but has the promise of changing the mechanism and/or selectivity of known catalytic reactions. These changes may enable the more efficient utilization of chemical resources. A special advantage of cobalt and iron catalysts is that the metals are more abundant and cheaper than those currently used for major industrial processes that convert unsaturated organic molecules and biofeedstocks into useful chemicals. This project specifically evaluated the potential of high-spin cobalt complexes for small-molecule reactions for bond rearrangement and cleavage reactions relevant to hydrocarbon transformations. We have learned that many of these reactions proceed through crossing to different spin states: for example, high-spin complexes can flip one electron spin to access a lower-energy reaction pathway for beta-hydride elimination. This reaction enables new, selective olefin isomerization catalysis. The high-spin cobalt complexes also cleave the C-O bond of CO2 and the C-F bonds of fluoroarenes. In each case, the detailed mechanism of the reaction has been determined. Importantly, we have discovered that the cobalt catalysts described here give distinctive selectivities that are better than known catalysts. These selectivities come from a synergy between supporting ligand design and electronic control of the spin-state crossing in the reactions.

Holland, Patrick L. [Yale University] [Yale University

2013-08-29T23:59:59.000Z

94

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

SciTech Connect (OSTI)

The reverse micelle catalyst preparation method has been used to prepare catalysts on four supports: magnesium oxide, carbon, alumina- titania and steamed Y zeolite. These catalysts were not as active as a reference catalyst prepared during previous contracts to Union Carbide Corp. This catalyst was supported on steamed Y zerolite support and was impregnated by a pore-filling method using a nonaqueous solvent. Additional catalysts were prepared via pore- filling impregnation of steamed Y zeolites. These catalysts had levels of cobalt two to three and a half times as high as the original Union Carbide catalyst. On a catalyst volume basis they were much more active than the previous catalyst; on an atom by atom basis the cobalt was about of the same activity, i.e., the high cobalt catalysts` cobalt atoms were not extensively covered over and deactivated by other cobalt atoms. The new, high activity, Y zerolite catalysts were not as stable as the earlier Union Carbide catalyst. However, stability enhancement of these catalysts should be possible, for instance, through adjustment of the quantity and/or type of trace metals present. A primary objective of this work was determination whether small amounts of ruthenium could enhance the activity of the cobalt F-T catalyst. The reverse micelle catalysts were not activated by ruthenium, indeed scanning transmission electronic microscopy (STEM) analysis provided some evidence that ruthenium was not present in the cobalt crystallites. Ruthenium did not seem to activate the high cobalt Y zeolite catalyst either, but additional experiments with Y zeolite-supported catalysts are required. Should ruthenium prove not to be an effective promoter under the simple catalyst activation procedure used in this work, more complex activation procedures have been reported which are claimed to enhance the cobalt/ruthenium interaction and result in activity promotion by ruthenium.

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

1995-02-01T23:59:59.000Z

95

Allylation of acetanilides with allyl acetate under conditions of metal-complex catalysis combined with phase-transfer catalysis  

SciTech Connect (OSTI)

Acetanilides are alkylated at the nitrogen atom under the conditions of phase-transfer catalysis. For the case of the reaction of acetanilides with allyl acetate the authors showed that 2-alkenyl esters can be used for the alkylation of acetanilides under the conditions of phase-transfer catalysis in the presence of the complexes of zero valent palladium. N-Acetylskatole was obtained with a yield of 50% from N-allyl-2-bromoacetanilide by intramolecular cyclization in the presence of Od(OAc)/sub 2/ as catalyst.

Lebedev, S.A.; Leonova, Yu.P.; Berestova, S.S.; Petrov, E.S.

1988-10-20T23:59:59.000Z

96

High contrast solid state electrochromic devices based on Ruthenium Purple nanocomposites fabricated by layer-by-layer assemblyw  

E-Print Network [OSTI]

High contrast solid state electrochromic devices based on Ruthenium Purple nanocomposites: 10.1039/b803915a Electrochromic Ruthenium Purple­polymer nanocomposite films, fabricated by multilayer assembly, were found to exhibit sub-second switching speed and the highest electrochromic con

Heflin, Randy

97

PHYSICAL REVIEW B 84, 214110 (2011) Ordered phases in ruthenium binary alloys from high-throughput first-principles calculations  

E-Print Network [OSTI]

of developing solar energy technologies. Alloys of ruthenium with platinum and palladium make extremely durable panels. The addition of ruthenium improves the mechanical properties and corrosion resistance of titanium agent has led to studies of its bulk properties4­6 and its behavior in various chemical reactions

Hart, Gus

98

Development of carbon-metal oxide supercapacitors from sol-gel derived carbon-ruthenium xerogels  

SciTech Connect (OSTI)

There has been increasing interest in electrochemical capacitors as energy storage systems because of their high power density and long cycle life, compared to battery devices. According to the mechanism of energy storage, there are two types of electrochemical capacitors. One type is based on double layer (dl) formation due to charge separation, and the other type is based on a faradaic process due to redox reactions. Sol-gel derived high surface area carbon-ruthenium xerogels were prepared from carbonized resorcinol-formaldehyde resins containing an electrochemically active form of ruthenium oxide. The electrochemical capacitance of these materials increased with an increase in the ruthenium content indicating the presence of pseudocapacitance associated with the ruthenium oxide undergoing reversible faradaic redox reactions. A specific capacitance of 256 F/g (single electrode) was obtained from a carbon xerogel containing 14 wt% Ru, which corresponded to more than 50% utilization of the ruthenium. The double layer accounted for 40% of this capacitance. This material was also electrochemically stable, showing no change in a cyclic voltammogram for over 2,000 cycles.

Lin, C.; Ritter, J.A.; Popov, B.N.

1999-09-01T23:59:59.000Z

99

Frontiers in Catalysis Science and Engineering Seminar Series  

E-Print Network [OSTI]

THE CATALYTIC UPGRADE OF PYROLYSIS OIL IN VAPOR AND LIQUID PHASES Presented by... Daniel E. Resasco ·Douglas Engineering ·University of Oklahoma Abstract An effective approach to stabilize pyrolysis oil is conducting for Interfacial Reaction Engineering (CIRE) http://www.ou.edu/catalysis/ Center for Biomass Befining (CBR) http

100

Lithium Diisopropylamide-Mediated Ortholithiations: Lithium Chloride Catalysis  

E-Print Network [OSTI]

Lithium Diisopropylamide-Mediated Ortholithiations: Lithium Chloride Catalysis Lekha Gupta, 2008 Ortholithiations of a range of arenes mediated by lithium diisopropylamide (LDA) in THF at -78 °C protocols with unpurified commercial samples of n-butyl- lithium to prepare LDA or commercially available

Collum, David B.

Note: This page contains sample records for the topic "ruthenium dimer catalysis" 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

Frontiers in Catalysis Science and Engineering Seminar Series  

E-Print Network [OSTI]

Frontiers in Catalysis Science and Engineering Seminar Series On the role of hydrogen of Chemical & Biological Engineering ·University of Wisconsin - Madison Abstract Hydrogen is a frequent principles governing the role of hydrogen in a wide range of catalytic transformations begin to emerge

102

Overview of surface science and catalysis by Qifei Wu  

E-Print Network [OSTI]

surfaces: single crystal transition metals, metal nanoparticles (Au), metal oxides, sulfides, carbides: · Metcars are the better catalysts for HDS than the other metal carbide materials. · Metcars have better: Sulfides (RuS2), carbides (MoC, TiC) #12;Density Functional Theory in Catalysis Employ DFT to understand

103

Isomerization of methyl linoleate on ruthenium(III) alkoxide complex; Mathematical modeling  

SciTech Connect (OSTI)

The isomerization of methyl linoleate using ruthenium alkoxide complexes is described. With alcohols, such as isopropyl alcohol (IPA), 1-butanol, 1-hexanol, and 1-octanol, isomerization of double bonds to produce a conjugated system is the main reaction, with hydrogenation being the side reaction. The latter is formed via the conjugated product. Based on kinetic and infrared spectroscopic data, it is concluded that the active catalytic species is a ruthenium hydride complex formed by the decomposition of the unstable alkoxide. The reaction is mathematically modeled, and the rate parameters are obtained by fitting the simulation to experimental data. These values are compared with data obtained from reactions carried out with supported ruthenium-nickel heterogeneous catalyst.

Mukesh, D.; Narasimhan, C.S.; Ramnarayan, K.; Deshpande, V.M

1989-08-01T23:59:59.000Z

104

Adsorption of silver dimer on graphene - A DFT study  

SciTech Connect (OSTI)

We performed a systematic density functional theory (DFT) study of the adsorption of silver dimer (Ag{sub 2}) on graphene using SIESTA (Spanish Initiative for Electronic Simulations with Thousands of Atoms) package, in the generalized gradient approximation (GGA). The adsorption energy, geometry, and charge transfer of Ag2-graphene system are calculated. The minimum energy configuration for a silver dimer is parallel to the graphene sheet with its two atoms directly above the centre of carbon-carbon bond. The negligible charge transfer between the dimer and the surface is also indicative of a weak bond. The methodology demonstrated in this paper may be applied to larger silver clusters on graphene sheet.

Kaur, Gagandeep, E-mail: gaganj1981@yahoo.com [Department of Physics and Centre of Advanced Studies in Physics, Panjab University, Chandigarh-160014, India and Chandigarh Engineering College, Landran, Mohali-140307, Punjab (India); Gupta, Shuchi [Department of Physics and Centre of Advanced Studies in Physics, Panjab University, Chandigarh-160014, India and University Institute of Engineering and Technology, Panjab University, Chandigarh -160014 (India); Rani, Pooja; Dharamvir, Keya [Department of Physics and Centre of Advanced Studies in Physics, Panjab University, Chandigarh-160014 (India)

2014-04-24T23:59:59.000Z

105

Coordination of dibensothiophenes and corannulenes to organometallic ruthenium (II) fragments  

SciTech Connect (OSTI)

This dissertation contains five papers in the format required for journal publication which describe (in part) my research accomplishments as a graduate student at Iowa State University. This work can be broadly categorized as the binding of weakly-coordinating ligands to cationic organometallic ruthenium fragments, and consists of two main areas of study. Chapters 2-4 are investigations into factors that influence the binding of dibenzothiophenes to {l_brace}Cp'Ru(CO){sub 2}{r_brace}{sup +} fragments, where Cp' = {eta}{sup 5}-C{sub 5}H{sub 5} (Cp) and {eta}{sup 5}-C{sub 5}Me{sub 5} (Cp*). Chapters 5 and 6 present the synthesis and structural characterization of complexes containing corannulene buckybowls that are {eta}{sup 6}-coordinated to {l_brace}Cp*Ru{r_brace}{sup +} fragments. The first chapter contains a brief description of the difficulty in lowering sulfur levels in diesel fuel along with a review of corannulene derivatives and their metal complexes. After the final paper is a short summary of the work herein (Chapter 7). Each chapter is independent, and all equations, schemes, figures, tables, references, and appendices in this dissertation pertain only to the chapter in which they appear.

Vecchi, Paul Anthony

2005-05-01T23:59:59.000Z

106

Molecular-Level Design of Heterogeneous Chiral Catalysis  

SciTech Connect (OSTI)

The following is a proposal to continue our multi-institutional research on heterogeneous chiral catalysis. Our team combines the use of surface-sensitive analytical techniques for the characterization of model systems with quantum and statistical mechanical calculations to interpret experimental data and guide the design of future research. Our investigation focuses on the interrelation among the three main mechanisms by which enantioselectivity can be bestowed to heterogeneous catalysts, namely: (1) by templating chirality via the adsorption of chiral supramolecular assemblies, (2) by using chiral modifiers capable of forming chiral complexes with the reactant and force enantioselective surface reactions, and (3) by forming naturally chiral surfaces using imprinting chiral agents. Individually, the members of our team are leaders in these various aspects of chiral catalysis, but the present program provides the vehicle to generate and exploit the synergies necessary to address the problem in a comprehensive manner. Our initial work has advanced the methodology needed for these studies, including an enantioselective titration procedure to identify surface chiral sites, infrared spectroscopy in situ at the interface between gases or liquids and solids to mimic realistic catalytic conditions, and DFT and Monte Carlo algorithms to simulate and understand chirality on surfaces. The next step, to be funded by the monies requested in this proposal, is to apply those methods to specific problems in chiral catalysis, including the identification of the requirements for the formation of supramolecular surface structures with enantioselective behavior, the search for better molecules to probe the chiral nature of the modified surfaces, the exploration of the transition from supramolecular to one-to-one chiral modification, the correlation of the adsorption characteristics of one-to-one chiral modifiers with their physical properties, in particular with their configuration, and the development of ways to imprint chiral centers on achiral solid surfaces. Chiral catalysis is not only a problem of great importance in its own right, but also the ultimate test of how to control selectivity in catalysis. The time is ripe for fundamental work in heterogeneous chiral catalysis to provide the U.S. with a leadership role in developing the next generation of catalytic processes for medicinal and agrochemical manufacturing. Our team provides the required expertise for a synergistic and comprehensive integration of physical and chemical experimentation with solid state and molecular reactivity theories to solve this problem.

Francisco Zaera

2012-03-21T23:59:59.000Z

107

Corrosion behavior of a high-chromium duplex stainless steel with minor additions of ruthenium in sulfuric acid  

SciTech Connect (OSTI)

The influence of small ruthenium additions on the corrosion behavior of high-chromium duplex stainless steels (DSS) was studied. Ruthenium additions ({le} 0.28%) increased the corrosion resistance of the base alloy by simultaneously improving hydrogen evolution efficiency and inhibiting anodic dissolution. The corrosion behavior of the high-chromium DSS with small ruthenium additions differed somewhat from behavior of similar duplex alloys of the 22%-Cr type. The lowering of hydrogen overpotential, which promotes an elevated corrosion potential leading to passivity, was much more significant in the 29%-Cr duplex alloys than in the 22%-Cr types.

Potgieter, J.H. [Pretoria Portland Cement, Johannesburg (South Africa). Technical Services Dept.; Brookes, H.C. [Univ. of Natal, Durban (South Africa). Dept. of Chemistry

1995-04-01T23:59:59.000Z

108

Characterization of hydrous ruthenium oxide/carbon nanocomposite supercapacitors prepared by a colloidal method  

E-Print Network [OSTI]

, the recent research has focused on devel- oping structures of RuO2/carbon composite materials. Miller 20 July 2001 Abstract Amorphous nanostructured composite materials with different RuO2 loadings converted to ruthenium oxide after annealing at 100 8C. The speci®c capacitance of RuO2/carbon composite

Popov, Branko N.

109

Electrodeposited ruthenium oxide thin films for supercapacitor: Effect of surface treatments  

E-Print Network [OSTI]

Electrodeposited ruthenium oxide thin films for supercapacitor: Effect of surface treatments V Supercapacitor is similar to a regular capacitor in operation; however, it offers a very high capacitance for supercapacitor should be able to get oxidized and reduce reversibility between various oxidation states [1

Chow, Lee

110

Near-Infrared Electrochromic and Electroluminescent Polymers Containing Pendant Ruthenium Complex Groups  

E-Print Network [OSTI]

Near-Infrared Electrochromic and Electroluminescent Polymers Containing Pendant Ruthenium ComplexVised Manuscript ReceiVed August 30, 2006 ABSTRACT: A series of near-infrared (NIR) electrochromic. All the polymers are near-infrared (NIR) electrochromic, displaying an intense absorption centered

Wan, Xin-hua

111

Vapor Deposition of Ruthenium from an Amidinate Precursor Huazhi Li,a  

E-Print Network [OSTI]

Vapor Deposition of Ruthenium from an Amidinate Precursor Huazhi Li,a Damon B. Farmer,b Roy G. Gordon* ,a Youbo Lin,b Joost Vlassakb a Department of Chemistry and Chemical Biology and b School and potential applications. They can be used as electrodes for capacitors, in which their high work function

112

Method for producing electricity using a platinum-ruthenium-palladium catalyst in a fuel cell  

DOE Patents [OSTI]

A method for producing electricity using a fuel cell that utilizes a ternary alloy composition as a fuel cell catalyst, the ternary alloy composition containing platinum, ruthenium and palladium. The alloy shows increased activity as compared to well-known catalysts.

Gorer, Alexander

2004-01-27T23:59:59.000Z

113

Pacific Northwest National Laboratory Catalysis Highlights for FY2007  

SciTech Connect (OSTI)

To reduce the nation’s dependence on imported oil, the U.S. Department of Energy (DOE) and other federal and private agencies are investing in understanding catalysis. This report focuses on catalysis research conducted by Pacific Northwest National Laboratory (PNNL) and its collaborators. Using sophisticated instruments in DOE’s Environmental Molecular Sciences Laboratory, a national scientific user facility, research was conducted to answer key questions related to the nation’s use of automotive fuels. Research teams investigated how hydrogen can be safely stored and efficiently released, critical questions to use this alternative fuel. Further, they are answering key questions to design molecular catalysts to control the transfer of hydrogen atoms, hydrides, and protons important to hydrogen production. In dealing with today’s fuels, researchers examined adsorption of noxious nitrous oxides in automotive exhaust. Beyond automotive fuel, researchers worked on catalysts to harness solar power. These catalysts include the rutile and anatase forms of titanium dioxide. Basic research was conducted on designing catalysts for these and other applications. Our scientists examined how to build catalysts with the desired properties atom by atom and molecule by molecule. In addition, this report contains brief descriptions of the outstanding accomplishments of catalysis experts at PNNL.

Garrett, Bruce C.

2007-11-15T23:59:59.000Z

114

Support for U.S. Participants at the 15th International Congress on Catalysis  

SciTech Connect (OSTI)

The grant was used to partially assist the travel expenses of U.S. academic scientists to attend the 15th International Congress on Catalysis. The conference was held in Munich, Germany from July 1-6, 2012. The importance of the International Congress was to bring together the international community of faculty members who participate in catalysis research, and to share information that would lead to further developments and directions in the field of study. Graduate students and Post Docs were invited to apply for travel assistance based on criteria established by the North American Catalysis Society (NACS) and the local Catalysis Clubs.

Wachs, Israel E.

2013-08-05T23:59:59.000Z

115

Plasma-Activated Lean NOx Catalysis for Heavy-Duty Diesel Emissions...  

Broader source: Energy.gov (indexed) [DOE]

Lean NOx Catalysis l Chemistry l Reducing Agent Effects l Collaboration with LEP CRADA l Aging Studies Plasma Initiation - + Electron Avalanche e - e - e - e - e - e - e -...

116

Synthesis and reactivity of compounds containing ruthenium-carbon, -nitrogen, and -oxygen bonds  

SciTech Connect (OSTI)

The products and mechanisms of the thermal reactions of several complexes of the general structure (PMe{sub 3}){sub 4}Ru(X)(Y) and (DMPM){sub 2}Ru(X)(Y) where X and Y are hydride, aryl, and benzyl groups, have been investigated. The mechanism of decomposition depends critically on the structure of the complex and the medium in which the thermolysis is carried out. The alkyl hydride complexes are do not react with alkane solvent, but undergo C-H activation processes with aromatic solvents by several different mechanisms. Thermolysis of (PMe{sub 3}){sub 4}Ru(Ph)(Me) or (PMe{sub 3}){sub 4}Ru(Ph){sub 2} leads to the ruthenium benzyne complex (PMe{sub 3}){sub 4}Ru({eta}{sup 2}-C{sub 6}H{sub 4}) (1) by a mechanism which involves reversible dissociation of phosphine. In many ways its chemistry is analogous to that of early rather than late organo transition metal complexes. The synthesis, structure, variable temperature NMR spectroscopy and reactivity of ruthenium complexes containing aryloxide or arylamide ligands are reported. These complexes undergo cleavage of a P-C bond in coordinated trimethylphosphine, insertion of CO and CO{sub 2} and hydrogenolysis. Mechanistic studies on these reactions are described. The generation of a series of reactive ruthenium complexes of the general formula (PMe{sub 3}){sub 4}Ru(R)(enolate) is reported. Most of these enolates have been shown to bind to the ruthenium center through the oxygen atom. Two of the enolate complexes 8 and 9 exist in equilibrium between the O- and C-bound forms. The reactions of these compounds are reported, including reactions to form oxygen-containing metallacycles. The structure and reactivity of these ruthenium metallacycles is reported, including their thermal chemistry and reactivity toward protic acids, electrophiles, carbon monoxide, hydrogen and trimethylsilane. 243 refs., 10 tabs.

Hartwig, J.F.

1990-12-01T23:59:59.000Z

117

Selective catalytic reduction system and process for treating NOx emissions using a palladium and rhodium or ruthenium catalyst  

SciTech Connect (OSTI)

A process for the catalytic reduction of nitrogen oxides (NOx) in a gas stream (29) in the presence of H.sub.2 is provided. The process comprises contacting the gas stream with a catalyst system (38) comprising zirconia-silica washcoat particles (41), a pre-sulfated zirconia binder (44), and a catalyst combination (40) comprising palladium and at least one of rhodium, ruthenium, or a mixture of ruthenium and rhodium.

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

2011-07-12T23:59:59.000Z

118

Optofluidic taming of a colloidal dimer with a silicon nanocavity  

SciTech Connect (OSTI)

We report here the optical trapping of a heterogeneous colloidal dimer above a photonic crystal nanocavity used as an on-chip optical tweezer. The trapped dimer consists of a cluster of two dielectric microbeads of different sizes linked by van der Waals forces. The smallest bead, 1??m in diameter, is observed to be preferentially trapped by the nanotweezer, leaving the second bead untrapped. The rotational nature of the trapped dimer Brownian motion is first evidenced. Then, in the presence of a fluid flow, control of its orientation and rotation is achieved. The whole system is found to show high rotational degrees of freedom, thereby acting as an effective flow-sensitive microscopic optical ball joint.

Pin, C.; Renaut, C. [Groupe d'Optique de Champ Proche - LRC CEA n°DSM-08-36, Laboratoire Interdisciplinaire Carnot de Bourgogne, UMR CNRS n°6303- Université de Bourgogne, Dijon (France); University Grenoble Alpes, INAC-SP2M-SINAPS, F-38000 Grenoble, France and CEA, INAC-SP2M-SINAPS, F-38000 Grenoble (France); University Grenoble Alpes, CNRS, CEA-Leti Minatec, LTM, F-38054 Grenoble Cedex (France); Cluzel, B., E-mail: benoit.cluzel@u-bourgogne.fr; Fornel, F. de [Groupe d'Optique de Champ Proche - LRC CEA n°DSM-08-36, Laboratoire Interdisciplinaire Carnot de Bourgogne, UMR CNRS n°6303- Université de Bourgogne, Dijon (France); Peyrade, D. [University Grenoble Alpes, CNRS, CEA-Leti Minatec, LTM, F-38054 Grenoble Cedex (France); Picard, E.; Hadji, E. [University Grenoble Alpes, INAC-SP2M-SINAPS, F-38000 Grenoble, France and CEA, INAC-SP2M-SINAPS, F-38000 Grenoble (France)

2014-10-27T23:59:59.000Z

119

Tandem Catalysis A Highly Efficient and Rapid Approach to Synthetic Elaboration  

E-Print Network [OSTI]

diiodide catalyzed Mukaiyama Michael-aldol reactions C.) Zirconium catalyzed synthesis of !-cyanohydrins D and rhodium catalyzed annulation. B.) Cobalt catalyzed annulation and cycloaddition C.) Rapid synthesis of pyrroles and furans D.) Organocatalytic / Lewis acid tandem catalysis 5.) Conclusions Tandem catalysis

Stoltz, Brian M.

120

Inorganic Chemistry in Hydrogen Storage and Biomass Catalysis  

SciTech Connect (OSTI)

Making or breaking C-H, B-H, C-C bonds has been at the core of catalysis for many years. Making or breaking these bonds to store or recover energy presents us with fresh challenges, including how to catalyze these transformations in molecular systems that are 'tuned' to minimize energy loss and in molecular and material systems present in biomass. This talk will discuss some challenging transformations in chemical hydrogen storage, and some aspects of the inorganic chemistry we are studying in the development of catalysts for biomass utilization.

Thorn, David [Los Alamos National Laboratory

2012-06-13T23:59:59.000Z

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


121

Microwaves and Chemistry: The Catalysis of an Exciting Marriage  

E-Print Network [OSTI]

. Product distrihution of microwave catalysis of carbon dioxide and water. Product Relative % yield Methane 55.1 Methanol 5.5 Acetone 4.7 C J alcohols 5.8 C 4 alcohols 28.4 o.5,------------------ 0.4 'C v >= 0.3 !i ;:I '" 0.2 &1... our first major success in cracking methane to ethylene and hydrogen [1,2], lhe destruction of chlorinated hydrocarbons [3,4], the hydrodesulfurization of hydrocracked pitch [5], and the microwave treatment of some Alberta oil sands and bitumens...

Wan, J.

122

Catalysis Working Group Meeting: June 2014 | Department of Energy  

Broader source: Energy.gov (indexed) [DOE]

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) "ofEarly Career Scientists' ResearchTheMarketing,Energy-ChevronSeveral salesCarolyn L.in aDataThe Catalysis

123

E-Print Network 3.0 - active dimeric form Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

myosin VI is capable of form- ing stable, processive dimers when... to form a coiled coil with high probability (Rock et al., 2005), so far dimerization has only been... that...

124

Complex of transferrin with ruthenium for medical applications. [Ru 97, Ru 103  

DOE Patents [OSTI]

A novel Ruthenium-transferrin complex, prepared by reacting iron-free human transferrin dissolved in a sodium acetate solution at pH 7 with ruthenium by heating at about 40/sup 0/C for about 2 hours, and purifying said complex by means of gel chromatography with pH 7 sodium acetate as eluent. The mono- or di-metal complex produced can be used in nuclear medicine in the diagnosis and/or treatment of tumors and abscesses. Comparitive results with Ga-67-citrate, which is the most widely used tumor-localizing agent in nuclear medicine, indicate increased sensitivity of detection and greater tumor uptake with the Ru-transferrin complex.

Richards, P.; Srivastava, S.C.; Meinken, G.E.

1980-11-03T23:59:59.000Z

125

Experimental Investigation of the Kinetics of a Ruthenium-Catalyzed Deconstruction of Lignin Model Compounds  

SciTech Connect (OSTI)

Lignin is a major component of plant cell walls that is typically underutilized in selective conversion strategies for renewable fuels and chemicals. The mechanisms by which thermal and catalytic treatments deconstruct lignin remain elusive. In this work, we have investigated the kinetics of the catalytic deconstruction of lignin model compounds using a ruthenium catalyst reported by Bergman et al. in 2010. A series of investigations using NMR spectroscopy and GC/MS will be presented. In addition, we propose detailed mechanisms for lignin depolymerization with ruthenium catalysts. We have also used DFT to compute transition state geometries of catalytic cycle intermediates and compare the values determined computationally with those observed experimentally. Ultimately, our objective is to apply our methods to the design of new homogeneous and heterogeneous catalysts for the effective deconstruction and valorization of lignin.

Bu, L.; Nimlos, M. R.; Shirts, M. R.; Himmel, M. E.; Crowley, M. F.; Beckham, G. T.

2012-01-01T23:59:59.000Z

126

Precise ruthenium fission product isotopic analysis using dynamic reaction cell inductively coupled plasma mass spectrometry (DRC-ICP-MS)  

SciTech Connect (OSTI)

99Tc is a subsurface contaminant of interest at numerous federal, industrial, and international facilities. However, as a mono-isotopic fission product, 99Tc lacks the ability to be used as a signature to differentiate between the different waste disposal pathways that could have contributed to subsurface contamination at these facilities. Ruthenium fission-product isotopes are attractive analogues for the characterization of 99Tc sources because of their direct similarity to technetium with regard to subsurface mobility, and their large fission yields and low natural background concentrations. We developed an inductively coupled plasma mass spectrometry (ICP-MS) method capable of measuring ruthenium isotopes in groundwater samples and extracts of vadose zone sediments. Samples were analyzed directly on a Perkin Elmer ELAN DRC II ICP-MS after a single pass through a 1-ml bed volume of Dowex AG 50W-X8 100-200 mesh cation exchange resin. Precise ruthenium isotopic ratio measurements were achieved using a low-flow Meinhard-type nebulizer and long sample acquisition times (150,000 ms). Relative standard deviations of triplicate replicates were maintained at less than 0.5% when the total ruthenium solution concentration was 0.1 ng/ml or higher. Further work was performed to minimize the impact caused by mass interferences using the dynamic reaction cell (DRC) with O2 as the reaction gas. The aqueous concentrations of 96Mo and 96Zr were reduced by more than 99.7% in the reaction cell prior to injection of the sample into the mass analyzer quadrupole. The DRC was used in combination with stable-mass correction to quantitatively analyze samples containing up to 2-orders of magnitude more zirconium and molybdenum than ruthenium. The analytical approach documented herein provides an efficient and cost-effective way to precisely measure ruthenium isotopes and quantitate total ruthenium (natural vs. fission-product) in aqueous matrixes.

Brown, Christopher F.; Dresel, P. Evan; Geiszler, Keith N.; Farmer, Orville T.

2006-05-09T23:59:59.000Z

127

Metal Carbonyl-Hydrosilane Reactions and Hydrosilation Catalysis  

SciTech Connect (OSTI)

Manganese carbonyl complexes serve as hydrosilation precatalysts for selectively transforming a carbonyl group into a siloxy methylene or a fully reduced methylene group. Substrates of interest include (1) aldehydes, ketones, carboxylic acids, silyl esters, and esters, and (2) their organometallic acyl counterparts. Three relevant catalytic reactions are shown. Two types of manganese precatalysts have been reported: (a) alkyl and acyl complexes (L)(C0){sub 4}MnR [L = CO, PPh{sub 3}; R = COCH{sub 3}, COPh, CH{sub 3}] and (b) halides (CO){sub 5}MnX and [(CO){sub 4}MnX]{sub 2} (X = Br, I). The former promote hydrosilation and deoxygenation catalysis; the latter promote dehydrogenative silation of alcohols and carboxylic acids as well as hydrosilation and deoxygenation of some metallocarboxylic acid derivatives. In every case studied, these Mn precatalysts are far more reactive or selective than traditional Rh(I) precatalysts.

Cutler, A. R.

2001-04-14T23:59:59.000Z

128

Spontaneous generation of local CP violation and inverse magnetic catalysis  

E-Print Network [OSTI]

In the chiral symmetric phase, the polarized instanton--anti-instanton molecule pairing induces a nontrivial repulsive interaction in the iso-scalar axial-vector channel. As a consequence, one unusual property is observed that in the chiral restoration phase, there is a first order phase transition for the spontaneous generation of local CP violation and chiral imbalance. Furthermore, it is found that external magnetic fields will lower the critical temperature for the local CP-odd phase transition and catalyze the chiral imbalance, which destroys the chiral condensate with pairing quarks between different chiralities. A reasonable strength of the repulsive interaction in the iso-scalar axial-vector channel can naturally explain the inverse magnetic catalysis around the critical temperature under external magnetic fields.

Lang Yu; Hao Liu; Mei Huang

2014-09-14T23:59:59.000Z

129

On the origin of the selectivity of oxygen reduction of ruthenium-containing electrocatalysts in methanol-containing electrolyte  

SciTech Connect (OSTI)

The reactivity with water and methanol of oxygen-reducing (Ru{sub 1{minus}x}Mo{sub x}SeO{sub z}) and oxygen (from water)-evolving electrocatalysts (RuS{sub 2}, RuO{sub 2}), which permit electron transfer via ruthenium d-states, was studied using electrochemical techniques and differential electrochemical mass spectroscopy (DEMS). In contrast to platinum, which is depolarized by methanol, ruthenium compounds show a high reactivity with water species and an extremely low reactivity with methanol. The authors conclude that the ruthenium-centered coordination chemical reactivity with water channels electrochemical currents, thus producing kinetic selectivity. The reason for the higher reactivity with water of Ru d-states as compared to platinum is seen in the higher density of d-states near the Fermi level as shown by this comparative study.

Alonso-Vante, N.; Bogdanoff, P.; Tributsch, H.

2000-03-10T23:59:59.000Z

130

Dimerization-assisted energy transport in light-harvesting complexes  

E-Print Network [OSTI]

We study the role of the dimer structure of light-harvesting complex II (LH2) in excitation transfer from the LH2 (without a reaction center (RC)) to the LH1 (surrounding the RC), or from the LH2 to another LH2. The excited and un-excited states of a bacteriochlorophyll (BChl) are modeled by a quasi-spin. In the framework of quantum open system theory, we represent the excitation transfer as the total leakage of the LH2 system and then calculate the transfer efficiency and average transfer time. For different initial states with various quantum superposition properties, we study how the dimerization of the B850 BChl ring can enhance the transfer efficiency and shorten the average transfer time.

S. Yang; D. Z. Xu; Z. Song; C. P. Sun

2010-06-24T23:59:59.000Z

131

UV resonance Raman analysis of trishomocubane and diamondoid dimers  

SciTech Connect (OSTI)

We present resonance Raman measurements of crystalline trishomocubane and diamantane dimers containing a C=C double bond. Raman spectra were recorded with excitation energies between 2.33 eV and 5.42 eV. The strongest enhancement is observed for the C=C stretch vibration and a bending mode involving the two carbon atoms of the C=C bond, corresponding to the B{sub 2g} wagging mode of ethylene. This is associated with the localization of the ?-HOMO and LUMO and the elongation of the C=C bond length and a pyramidalization of the two sp{sup 2}-hybridized carbon atoms at the optical excitation. The observed Raman resonance energies of the trishomocubane and diamantane dimers are significantly lower than the HOMO-LUMO gaps of the corresponding unmodified diamondoids.

Meinke, Reinhard, E-mail: rene@physik.tu-berlin.de; Thomsen, Christian; Maultzsch, Janina [Institut für Festkörperphysik, Technische Universität Berlin, Hardenbergstr. 36, D-10623 Berlin (Germany)] [Institut für Festkörperphysik, Technische Universität Berlin, Hardenbergstr. 36, D-10623 Berlin (Germany); Richter, Robert; Merli, Andrea [Institut für Optik und Atomare Physik, Technische Universität Berlin, Hardenbergstr. 36, D-10623 Berlin (Germany)] [Institut für Optik und Atomare Physik, Technische Universität Berlin, Hardenbergstr. 36, D-10623 Berlin (Germany); Fokin, Andrey A. [Institute of Organic Chemistry, Justus-Liebig University, Heinrich-Buff-Ring 58, D-35392 Giessen (Germany) [Institute of Organic Chemistry, Justus-Liebig University, Heinrich-Buff-Ring 58, D-35392 Giessen (Germany); Department of Organic Chemistry, Kiev Polytechnic Institute, pr. Pobedy 37, 03056 Kiev (Ukraine); Koso, Tetyana V.; Schreiner, Peter R. [Institute of Organic Chemistry, Justus-Liebig University, Heinrich-Buff-Ring 58, D-35392 Giessen (Germany)] [Institute of Organic Chemistry, Justus-Liebig University, Heinrich-Buff-Ring 58, D-35392 Giessen (Germany); Rodionov, Vladimir N. [Department of Organic Chemistry, Kiev Polytechnic Institute, pr. Pobedy 37, 03056 Kiev (Ukraine)] [Department of Organic Chemistry, Kiev Polytechnic Institute, pr. Pobedy 37, 03056 Kiev (Ukraine)

2014-01-21T23:59:59.000Z

132

Studies toward biomimetic claisen condensation using nucleic acid templates and ribozyme catalysis  

E-Print Network [OSTI]

Many different experimental approaches were attempted to achieve carbon-carbon bond formation by nucleic acid template-directed reactions and ribozyme catalysis as potential lipid synthesizing machineries in the RNA world. A novel biomimetic...

Ryu, Youngha

2005-08-29T23:59:59.000Z

133

Transformation of Sorbitol to Biofuels by Heterogeneous Catalysis: Chemical and Industrial  

E-Print Network [OSTI]

Transformation of Sorbitol to Biofuels by Heterogeneous Catalysis: Chemical and Industrial ainsi que des exemples d'applications industrielles. Abstract -- Transformation of Sorbitol to Biofuels and biodiesel production led to first generation biofuels. Nowadays, research is focused on lignocellulosic

Boyer, Edmond

134

Combined Catalysis and Optical Screening for High Throughput Discovery of Solar Fuels Catalysts  

E-Print Network [OSTI]

Combined Catalysis and Optical Screening for High Throughput Discovery of Solar Fuels Catalysts J,b a Joint Center for Artificial Photosynthesis, California Institute of Technology, Pasadena, California 91125, USA b Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720

Faraon, Andrei

135

Molecular computations for reactions and phase transitions: applications to protein stabilization, hydrates and catalysis  

E-Print Network [OSTI]

In this work we have made significant contributions in three different areas of interest: therapeutic protein stabilization, thermodynamics of natural gas clathrate-hydrates, and zeolite catalysis. In all three fields, ...

Anderson, Brian J.

136

On the structure of the Nx phase of symmetric dimers  

E-Print Network [OSTI]

NMR measurements on a selectively deuteriated liquid crystal dimer CB-C9-CB exhibiting two nematic phases show that the molecules in the lower temperature nematic phase, Nx, experience a chiral environment and are ordered about a unique direction. The results are contrasted with previous reports that proposed a twist-bend spatial variation of the director. A structural model is proposed wherein the molecules show organization into highly correlated assemblies of opposite chirality.

Anke Hoffmann; Alexandros G. Vanakaras; Alexandra Kohlmeier; Georg H. Mehl; Demetri J. Photinos

2014-07-07T23:59:59.000Z

137

Benchmark calculations for elastic fermion-dimer scattering  

E-Print Network [OSTI]

We present continuum and lattice calculations for elastic scattering between a fermion and a bound dimer in the shallow binding limit. For the continuum calculation we use the Skorniakov-Ter-Martirosian (STM) integral equation to determine the scattering length and effective range parameter to high precision. For the lattice calculation we use the finite-volume method of L\\"uscher. We take into account topological finite-volume corrections to the dimer binding energy which depend on the momentum of the dimer. After subtracting these effects, we find from the lattice calculation kappa a_fd = 1.174(9) and kappa r_fd = -0.029(13). These results agree well with the continuum values kappa a_fd = 1.17907(1) and kappa r_fd = -0.0383(3) obtained from the STM equation. We discuss applications to cold atomic Fermi gases, deuteron-neutron scattering in the spin-quartet channel, and lattice calculations of scattering for nuclei and hadronic molecules at finite volume.

Shahin Bour; H. -W. Hammer; Dean Lee; Ulf-G. Meißner

2012-06-08T23:59:59.000Z

138

Journal of Catalysis 260 (2008) 342350 Contents lists available at ScienceDirect  

E-Print Network [OSTI]

strong electrostatic adsorption: II. Mesoporous silica SBA-15 L. Jiao, J.R. Regalbuto Department electrostatic adsorption Platinum Palladium Ruthenium Copper Cobalt Ammine SBA-15 Point of zero charge PZC The catalyst synthesis method of strong electrostatic adsorption (SEA) was applied to mesoporous silica SBA-15

Regalbuto, John R.

139

Final Report on Kokes Awards for the 20th North American Catalysis Society Meeting  

SciTech Connect (OSTI)

This Final Report describes how the Kokes Awards program was carried out for the 2007 meeting with regard to selection of students and disbursement of funds received from DOE and other sources. The objective of the Richard J. Kokes Travel Award program of the American Catalysis Society is to encourage graduate students to attend and participate meaningfully in the biennial North American Catalysis Society Meeting.

Wong, Michael S.

2008-01-01T23:59:59.000Z

140

Structure-based redesign of the dimerization interface reduces the toxicity of zinc-finger nucleases  

E-Print Network [OSTI]

energy with respect to the combination of two wild-typewild-type configuration (top) and for the variants (bottom). (i) In silico computation of dimerization energy.

Szczepek, Michal; Brondani, Vincent; Büchel, Janine; Serrano, Luis; Segal, David J; Cathomen, Toni

2007-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "ruthenium dimer catalysis" 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

Exploring ruthenium dye synthesis and TiO2-dye-I-/I3- electron transfer reactions in a dye-sensitised solar cell.   

E-Print Network [OSTI]

Octahedral, six co-ordinate ruthenium complexes containing acid substituted polypyridyl ligands have proved particularly successful as dyes for Dye-Sensitised Solar Cells (DSSCs); thus there have been hundreds, if not ...

Chadwick, Nina

2013-11-28T23:59:59.000Z

142

New Directions for Cancer Drug Research of Ruthenium and Rhodium Compounds: Investigation of Cytotoxicities, Mechanisms of Cancer Cell Death, and Cellular Targets  

E-Print Network [OSTI]

(Ru) compounds are a promising class of anticancer compounds that display improved therapeutic activities, different mechanisms of action, and reduced side-effects as compared to cisplatin. Two ruthenium compounds are being tested in clinical trials...

Pena Maceda, Bruno

2014-07-02T23:59:59.000Z

143

Lean NOx Trap Catalysis for Lean Natural Gas Engine Applications  

SciTech Connect (OSTI)

Distributed energy is an approach for meeting energy needs that has several advantages. Distributed energy improves energy security during natural disasters or terrorist actions, improves transmission grid reliability by reducing grid load, and enhances power quality through voltage support and reactive power. In addition, distributed energy can be efficient since transmission losses are minimized. One prime mover for distributed energy is the natural gas reciprocating engine generator set. Natural gas reciprocating engines are flexible and scalable solutions for many distributed energy needs. The engines can be run continuously or occasionally as peak demand requires, and their operation and maintenance is straightforward. Furthermore, system efficiencies can be maximized when natural gas reciprocating engines are combined with thermal energy recovery for cooling, heating, and power applications. Expansion of natural gas reciprocating engines for distributed energy is dependent on several factors, but two prominent factors are efficiency and emissions. Efficiencies must be high enough to enable low operating costs, and emissions must be low enough to permit significant operation hours, especially in non-attainment areas where emissions are stringently regulated. To address these issues the U.S. Department of Energy and the California Energy Commission launched research and development programs called Advanced Reciprocating Engine Systems (ARES) and Advanced Reciprocating Internal Combustion Engines (ARICE), respectively. Fuel efficiency and low emissions are two primary goals of these programs. The work presented here was funded by the ARES program and, thus, addresses the ARES 2010 goals of 50% thermal efficiency (fuel efficiency) and <0.1 g/bhp-hr emissions of oxides of nitrogen (NOx). A summary of the goals for the ARES program is given in Table 1-1. ARICE 2007 goals are 45% thermal efficiency and <0.015 g/bhp-hr NOx. Several approaches for improving the efficiency and emissions of natural gas reciprocating engines are being pursued. Approaches include: stoichiometric engine operation with exhaust gas recirculation and three-way catalysis, advanced combustion modes such as homogeneous charge compression ignition, and extension of the lean combustion limit with advanced ignition concepts and/or hydrogen mixing. The research presented here addresses the technical approach of combining efficient lean spark-ignited natural gas combustion with low emissions obtained from a lean NOx trap catalyst aftertreatment system. This approach can be applied to current lean engine technology or advanced lean engines that may result from related efforts in lean limit extension. Furthermore, the lean NOx trap technology has synergy with hydrogen-assisted lean limit extension since hydrogen is produced from natural gas during the lean NOx trap catalyst system process. The approach is also applicable to other lean engines such as diesel engines, natural gas turbines, and lean gasoline engines; other research activities have focused on those applications. Some commercialization of the technology has occurred for automotive applications (both diesel and lean gasoline engine vehicles) and natural gas turbines for stationary power. The research here specifically addresses barriers to commercialization of the technology for large lean natural gas reciprocating engines for stationary power. The report presented here is a comprehensive collection of research conducted by Oak Ridge National Laboratory (ORNL) on lean NOx trap catalysis for lean natural gas reciprocating engines. The research was performed in the Department of Energy's ARES program from 2003 to 2007 and covers several aspects of the technology. All studies were conducted at ORNL on a Cummins C8.3G+ natural gas engine chosen based on industry input to simulate large lean natural gas engines. Specific technical areas addressed by the research include: NOx reduction efficiency, partial oxidation and reforming chemistry, and the effects of sulfur poisons on the partial oxidation

Parks, II, James E [ORNL; Storey, John Morse [ORNL; Theiss, Timothy J [ORNL; Ponnusamy, Senthil [ORNL; Ferguson, Harley Douglas [ORNL; Williams, Aaron M [ORNL; Tassitano, James B [ORNL

2007-09-01T23:59:59.000Z

144

Converting Homogeneous to Heterogeneous in Electrophilic Catalysis using Monodisperse Metal Nanoparticles  

SciTech Connect (OSTI)

A continuing goal in catalysis is the transformation of processes from homogeneous to heterogeneous. To this end, nanoparticles represent a new frontier in heterogeneous catalysis, where this conversion is supplemented by the ability to obtain new or divergent reactivity and selectivity. We report a novel method for applying heterogeneous catalysts to known homogeneous catalytic reactions through the design and synthesis of electrophilic platinum nanoparticles. These nanoparticles are selectively oxidized by the hypervalent iodine species PhICl{sub 2}, and catalyze a range of {pi}-bond activation reactions previously only homogeneously catalyzed. Multiple experimental methods are utilized to unambiguously verify the heterogeneity of the catalytic process. The discovery of treatments for nanoparticles that induce the desired homogeneous catalytic activity should lead to the further development of reactions previously inaccessible in heterogeneous catalysis. Furthermore, our size and capping agent study revealed that Pt PAMAM dendrimer-capped nanoparticles demonstrate superior activity and recyclability compared to larger, polymer-capped analogues.

Witham, Cole A.; Huang, Wenyu; Tsung, Chia-Kuang; Kuhn, John N.; Somorjai, Gabor A.; Toste, F. Dean

2009-10-15T23:59:59.000Z

145

Higher Energy States in the CO Dimer: Millimeter-Wave Spectra and Rovibrational Calculations  

E-Print Network [OSTI]

Higher Energy States in the CO Dimer: Millimeter-Wave Spectra and Rovibrational Calculations Leonid millimeter-wave data yielded the precise location of 33 new energy levels of A+ symmetry and 20 levels of A extensive millimeter-wave measurements of the 12C16O dimer have been made, and more than 300 new spectral

146

Disulfide bond-mediated dimerization of HLA-G on the cell surface  

E-Print Network [OSTI]

. Here, we demonstrate that HLA-G forms disulfide-linked dimers that are present on the cell surface. Immunoprecipitation of HLA-G from surface biotinylated transfec- tants using the anti- 2-microglobulin mAb BBM.1 linkage formed exclusively through this residue. A possible interaction between the HLA-G monomer or dimer

Strominger, Jack L.

147

Electron-nuclear correlations for photo-induced dynamics in molecular dimers  

E-Print Network [OSTI]

January 2004; accepted 11 March 2004 Ultrafast photoinduced dynamics of electronic excitation in molecularElectron-nuclear correlations for photo-induced dynamics in molecular dimers Dmitri S. Kilin, Yuri dimers is drastically affected by the dynamic reorganization of inter- and intra- molecular nuclear

148

Nonlinear friction of a damped dimer sliding on a periodic substrate S. Gonalves,1,2,  

E-Print Network [OSTI]

Nonlinear friction of a damped dimer sliding on a periodic substrate S. Gonçalves,1,2, * V. M, USA (Received 23 July 2004; published 12 November 2004) The nonlinear sliding friction of a dimer over that the friction force has an approximate v-3 depen- dence if the velocity is sufficiently large

Kenkre, V.M.

149

2010 CATALYSIS GORDON RESEARCH CONFERENCE, JUNE 27 - JULY 2, 2010, NEW LONDON, NEW HAMPSHIRE  

SciTech Connect (OSTI)

Catalysis is a key technology for improving the quality of life while simultaneously reducing the adverse impact of human activities on the environment. The discovery of new catalytic processes and the improvement of existing ones are also critically important for securing the nation's energy supply. The GRC on Catalysis is considered one the most prestigious conference for catalysis research, bringing together leading researchers from both academia, industry and national labs to discuss the latest, most exciting research in catalysis and the future directions for the field. The 2010 GRC on Catalysis will follow time-honored traditions and feature invited talks from the world's leading experts in the fundamentals and applications of catalytic science and technology. We plan to have increased participation from industry. The extended discussions in the company of outstanding thinkers will stimulate and foster new science. The conference will include talks in the following areas: Alternative feedstocks for chemicals and fuels, Imaging and spectroscopy, Design of novel catalysts, Catalyst preparation fundamentals, Molecular insights through theory, Surface Science, Catalyst stability and dynamics. In 2010, the Catalysis conference will move to a larger conference room with a new poster session area that will allow 40 posters per session. The dorm rooms provide single and double accommodations, free WiFi and the registration fee includes all meals and the famous lobster dinner on Thursday night. Afternoons are open to enjoy the New England ambiance with opportunities for hiking, sailing, golf and tennis to create an outstanding conference that will help you network with colleagues, and make long lasting connections.

Abhaya Datye

2010-07-02T23:59:59.000Z

150

Growth mechanism of graphene on platinum: Surface catalysis and carbon segregation  

SciTech Connect (OSTI)

A model of the graphene growth mechanism of chemical vapor deposition on platinum is proposed and verified by experiments. Surface catalysis and carbon segregation occur, respectively, at high and low temperatures in the process, representing the so-called balance and segregation regimes. Catalysis leads to self-limiting formation of large area monolayer graphene, whereas segregation results in multilayers, which evidently “grow from below.” By controlling kinetic factors, dominantly monolayer graphene whose high quality has been confirmed by quantum Hall measurement can be deposited on platinum with hydrogen-rich environment, quench cooling, tiny but continuous methane flow and about 1000?°C growth temperature.

Sun, Jie, E-mail: jie.sun@chalmers.se; Lindvall, Niclas; Yurgens, August [Quantum Device Physics Laboratory, Department of Microtechnology and Nanoscience, Chalmers University of Technology, SE-41296 Gothenburg (Sweden); Nam, Youngwoo [Quantum Device Physics Laboratory, Department of Microtechnology and Nanoscience, Chalmers University of Technology, SE-41296 Gothenburg (Sweden); Department of Physics and Astronomy, Seoul National University, Seoul 151-747 (Korea, Republic of); Cole, Matthew T. [Electrical Engineering Division, Department of Engineering, University of Cambridge, 9 JJ Thomson Avenue, CB3 0FA Cambridge (United Kingdom); Teo, Kenneth B. K. [AIXTRON Nanoinstruments Ltd., Swavesey, CB24 4FQ Cambridge (United Kingdom); Woo Park, Yung [Department of Physics and Astronomy, Seoul National University, Seoul 151-747 (Korea, Republic of)

2014-04-14T23:59:59.000Z

151

Synthesis, structures and properties of new hybrid solids containing ruthenium complexes and polyoxometalates  

SciTech Connect (OSTI)

Two new organic-inorganic hybrid solids containing Keggin ions and ruthenium complexes have been synthesized and characterized by FT-IR, UV-vis, luminescence, X-ray, and TG analysis. In KNa[Ru(bpy){sub 3}]{sub 2}[H{sub 2}W{sub 12}O{sub 40}]{center_dot}8H{sub 2}O (1), the [Ru(bpy){sub 3}]{sup 2+} (bpy=2,2 Prime -bipyridine) complex ions are located in between the infinite one-dimensional double-chains formed by adjacent Keggin anions [H{sub 2}W{sub 12}O{sub 40}]{sup 6-} linked through {l_brace}KO{sub 7}{r_brace} and {l_brace}NaO{sub 6}{r_brace} polyhedra, while in K{sub 6}[Ru(pzc){sub 3}]{sub 2}[SiW{sub 12}O{sub 40}] Bullet 12H{sub 2}O (2), the [Ru(pzc){sub 3}]{sup -} (pzc=pyrazine-2-carboxylate) complex anions are confined by layered networks of the [SiW{sub 12}O{sub 40}]{sup 4-} clusters connected by potassium ions. Both compounds exhibit three-dimensional frameworks through noncovalent interactions such as hydrogen bonds and anion Midline-Horizontal-Ellipsis {pi} interactions. Additionally, compound 1 shows strong luminescence at 604 nm in solid state at room temperature. - Graphical abstract: Two three-dimensional framework solids are constructed from polyoxoanions and ruthenium-organic complexes through noncovalent interactions. Highlights: Black-Right-Pointing-Triangle Ru complexes form hybrid solids with polyoxometalates. Black-Right-Pointing-Triangle Anion Midline-Horizontal-Ellipsis {pi} interaction between polyoxometalates and metal complexes was observed. Black-Right-Pointing-Triangle Noncovalent interactions play an important role in the assembly of solids. Black-Right-Pointing-Triangle The hybrid solid shows luminescence properties.

Yan Bangbo, E-mail: bangbo.yan@wku.edu [Department of Chemistry, Western Kentucky University, Bowling Green, KY 42101 (United States); Hodsdon, Samantha A.; Li Yanfen; Carmichael, Christopher N.; Cao Yan; Pan Weiping [Department of Chemistry, Western Kentucky University, Bowling Green, KY 42101 (United States)

2011-12-15T23:59:59.000Z

152

Calculation of the Dimer Equilibrium Constant of Heavy Water Saturated Vapor  

E-Print Network [OSTI]

Water is the most common substance on Earth.The discovery of heavy water and its further study have shown that the change of hydrogen for deuterium leads to the significant differences in their properties.The triple point temperature of heavy water is higher,at the same time the critical temperature is lower.Experimental values of the second virial coefficient of the EOS for the vapor of normal and heavy water differ at all temperatures.This fact can influence the values of the dimerization constant for the heavy water vapor.The equilibrium properties of the dimerization process are described with the methods of chemical thermodynamics.The chemical potentials for monomers (m) and dimers (d)are the functions of their concentrations.The interactions of monomer-dimer and dimer-dimer types are taken into account within the solution of equation for chemical potentials.The obtained expression for the dimerization constant contains the contributions of these types.The averaged potentials are modeled by the Sutherlan...

Bulavin, L A; Makhlaichuk, V N

2015-01-01T23:59:59.000Z

153

KINETICS, CATALYSIS, AND REACTION ENGINEERING Nonthermal Plasma Reactions of Dilute Nitrogen Oxide Mixtures  

E-Print Network [OSTI]

for the conversion of nitrogen oxides,1,2,4-10 sulfur dioxide,11 and volatile organic car- bons.12 Despite itsKINETICS, CATALYSIS, AND REACTION ENGINEERING Nonthermal Plasma Reactions of Dilute Nitrogen Oxide Mixtures: NOx in Nitrogen Gui-Bing Zhao, Xudong Hu, Man-Chung Yeung, Ovid A. Plumb,§ and Maciej Radosz

Yeung, Man-Chung

154

Enantioselective Organocatalytic Indole Alkylations. Design of a New and Highly Effective Chiral Amine for Iminium Catalysis  

E-Print Network [OSTI]

structural motifs of established value in medicinal chemistry or complex target synthesis. In this regard the capacity of iminium catalysis to mediate the enantioselective coupling of pyrroles and R, -unsaturated alde nucleophiles. Despite struc- tural similarities, it has long been established7 that the pyrrole -system

MacMillan, David W. C.

155

Argonne National Laboratory Chemical Engineering Division Water-gas shift catalysis  

E-Print Network [OSTI]

Argonne National Laboratory Chemical Engineering Division Water-gas shift catalysis Sara Yu Choung Engineering Division Argonne National Laboratory Hydrogen, Fuel Cells, and Infrastructure Technologies 2003 Merit Review Berkeley, CA May 19-22, 2003 #12;Argonne National Laboratory Chemical Engineering Division

156

Applied Catalysis A: General 254 (2003) 97106 Photoionization detection (PID) as a high throughput  

E-Print Network [OSTI]

Applied Catalysis A: General 254 (2003) 97­106 Photoionization detection (PID) as a high throughput 2002 Abstract A versatile photoionization detection (PID) system has been developed to rapidly screen libraries of catalytic materials. The PID approach involves the use of an appropriately selected dc

Senkan, Selim M.

157

Enzyme-Like Catalysis of the Nazarov Cyclization by Supramolecular Encapsulation  

SciTech Connect (OSTI)

A primary goal in the design and synthesis of molecular hosts has been the selective recognition and binding of a variety of guests using non-covalent interactions. Supramolecular catalysis, which is the application of such hosts towards catalysis, has much in common with many enzymatic reactions, chiefly the use of both spatially appropriate binding pockets and precisely oriented functional groups to recognize and activate specific substrate molecules. Although there are now many examples which demonstrate how selective encapsulation in a host cavity can enhance the reactivity of a bound guest, all have failed to reach the degree of increased reactivity typical of enzymes. We now report the catalysis of the Nazarov cyclization by a self-assembled coordination cage, a carbon-carbon bond-forming reaction which proceeds under mild, aqueous conditions. The acceleration in this system is over a million-fold, and represents the first example of supramolecular catalysis that achieves the level of rate enhancement comparable to that observed in several enzymes. We explain the unprecedented degree of rate increase as due to the combination of (a) preorganization of the encapsulated substrate molecule, (b) stabilization of the transition state of the cyclization by constrictive binding, and (c) increase in the basicity of the complexed alcohol functionality.

Hastings, Courtney; Pluth, Michael; Bergman, Robert; Raymond, Kenneth

2010-03-29T23:59:59.000Z

158

High-throughput metal nanoparticle catalysis by pulsed laser ablation Selim Senkan a,*, Michael Kahn a  

E-Print Network [OSTI]

High-throughput metal nanoparticle catalysis by pulsed laser ablation Selim Senkan a,*, Michael online 18 July 2006 Abstract A high-throughput pulsed laser ablation (HT-PLA) system was developed-TEM) and energy dispersive X-ray (EDX) spectroscopy, respectively. The supported nanoparticles created by HT

Senkan, Selim M.

159

Journal of Catalysis 225 (2004) 300306 www.elsevier.com/locate/jcat  

E-Print Network [OSTI]

shown that methanol can be produced by using N2O as the oxidant, rather than O2 [1­3]. More recently framework positions and ex- traframework Fe) can be used to produce methanol from CH4 and N2O. Above 523 KJournal of Catalysis 225 (2004) 300­306 www.elsevier.com/locate/jcat Methanol formation on Fe

Bell, Alexis T.

160

Catalysis Today 53 (1999) 433441 New insights into methanol synthesis catalysts from X-ray absorption  

E-Print Network [OSTI]

O and Cr2O3 mixtures and produced methanol in low yields from CO­H2 mixtures at high temperatures (593Catalysis Today 53 (1999) 433­441 New insights into methanol synthesis catalysts from X a consistent structural picture of methanol synthesis catalysts. Copper metal is the principal Cu species

Iglesia, Enrique

Note: This page contains sample records for the topic "ruthenium dimer catalysis" 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

ISHHC XIII International Symposium on the Relations betweenHomogeneous and Heterogeneous Catalysis  

SciTech Connect (OSTI)

The International Symposium on Relations between Homogeneous and Heterogeneous Catalysis (ISHHC) has a long and distinguished history. Since 1974, in Brussels, this event has been held in Lyon, France (1977), Groeningen, The Netherlands (1981); Asilomar, California (1983); Novosibirsk, Russia (1986); Pisa, Italy (1989); Tokyo, Japan (1992); Balatonfuered, Hungary (1995); Southampton, United Kingdom (1999); Lyon, France (2001); Evanston, Illinois (2001) and Florence, Italy (2005). The aim of this international conference in Berkeley is to bring together practitioners in the three fields of catalysis, heterogeneous, homogeneous and enzyme, which utilize mostly nanosize particles. Recent advances in instrumentation, synthesis and reaction studies permit the nanoscale characterization of the catalyst systems, often for the same reaction, under similar experimental conditions. It is hoped that this circumstance will permit the development of correlations of these three different fields of catalysis on the molecular level. To further this goal we aim to uncover and focus on common concepts that emerge from nanoscale studies of structures and dynamics of the three types of catalysts. Another area of focus that will be addressed is the impact on and correlation of nanosciences with catalysis. There is information on the electronic and atomic structures of nanoparticles and their dynamics that should have importance in catalyst design and catalytic activity and selectivity.

Somorjai (Ed.), G.A.

2007-06-11T23:59:59.000Z

162

Electrochemistry and photocurrents of the tris(bipyridine)ruthenium(II) and methyl viologen cations immobilized in carrageenan hydrogel. [tris(2,2'-bipyridine)ruthenium(II)  

SciTech Connect (OSTI)

A procedure for immobilization of both a photochromophore, tris(2,2{prime}-bipyridine)ruthenium(II) (Ru(bpy){sub 3}{sup 2+}), and a quencher, methyl viologen (MV{sup 2+}), within a carrageenan hydrogel matrix at an electrode surface is described. Ru(bpy){sub 3}{sup 2+} and MV{sup 2+} exhibited diffusion coefficients that ranged from 10{sup {minus} 7} to 10{sup {minus} 6} cm{sup 2}/s in the hydrogel, which represents an improvement over other immobilization matrices. Photolysis of the resulting hydrogel surface modified electrodes gave rise to a significant photocurrent which depended on the concentrations of Ru(bpy){sub 3}{sup 2+}, MV{sup 2+}, and triethanolamine and resulted in a maximum value of 12 {mu}A/cm{sup 2} after the hydrogel was cured with a solution containing 5 mM Ru(bpy){sub 3}{sup 2+} and 50 mM MV{sup 2+}. The photocurrent was the result of reoxidation of MV{sup +} at the electrode surface following reduction of MV{sup 2+} by photoexcited Ru(bpy){sub 3}{sup 2+}. The quenching rate constant of Ru(bpy){sub 3}{sup 2+} by MV{sup 2+} in the hydrogel was 4.2 {times} 10{sup 8} M{sup {minus}1} s{sup {minus}1}. The photocurrent action spectrum was consistent with Ru(bpy){sub 3}{sup 2+} acting as the photochromophore. Offsetting the potential of the hydrogel electrode verified the role of the MV{sup 2+}/{sup +} redox couple as the source of the current.

Rillema, D.P.; Edwards, A.K. (Univ., of North Carolina, Charlotte (United States)); Perine, S.C.; Crumbliss, A.L. (Duke Univ., Durham, NC (United States))

1991-11-13T23:59:59.000Z

163

Matching measure, Benjamini-Schramm convergence and the monomer-dimer free energy  

E-Print Network [OSTI]

We define the matching measure of a lattice L as the spectral measure of the tree of self-avoiding walks in L. We connect this invariant to the monomer-dimer partition function of a sequence of finite graphs converging to L. This allows us to express the monomer-dimer free energy of L in terms of the measure. Exploiting an analytic advantage of the matching measure over the Mayer series then leads to new, rigorous bounds on the monomer-dimer free energies of various Euclidean lattices. While our estimates use only the computational data given in previous papers, they improve the known bounds significantly.

Miklós Abért; Péter Csikvári; Tamás Hubai

2014-05-26T23:59:59.000Z

164

On the ro-vibrational energies for the lithium dimer; maximum-possible rotational levels  

E-Print Network [OSTI]

The Deng-Fan potential is used to discuss the reliability of the improved Greene-Aldrich approximation and the factorization recipe of Badawi et al.'s [17] for the central attractive/repulsive core. The factorization recipe is shown to be a more reliable approximation and is used to obtain the ro-vibrational energies for the lithium dimer. For each vibrational state only a limited number of the rotational levels are found to be supported by the lithium dimer.

Omar Mustafa

2015-03-02T23:59:59.000Z

165

On the ro-vibrational energies for the lithium dimer; maximum-possible rotational levels  

E-Print Network [OSTI]

The Deng-Fan potential is used to discuss the reliability of the improved Greene-Aldrich approximation and the factorization recipe of Badawi et al.'s [17] for the central attractive/repulsive core. The factorization recipe is shown to be a more reliable approximation and is used to obtain the ro-vibrational energies for the lithium dimer. For each vibrational state only a limited number of the rotational levels are found to be supported by the lithium dimer.

Omar Mustafa

2015-01-27T23:59:59.000Z

166

The oxidative dimerization of methane over promoted and unpromoted magnesium oxide monoliths  

E-Print Network [OSTI]

for the degree of MASTER OF SCIENCE May 1989 Major Subject: Chemistry THE OXIDATIVE DIMERIZATION OF METHANE OVER PROMOTED AND UNPROMOTED MAGNESIUM OxiDE MONOLITHS A Thesis by JANE MARIE AIGLER Approved as to style and content by: uns or (Chair of Commi... ee) os e (Member) nt ony (Member) a (Head of Department) May 1989 ABSTRACT The Oxidative Dimerization of Methane over Promoted and Unpromoted Magnesium Oxide Monoliths. (May 1989) Jane Marie Aigier, B. S. , Pennsylvania State University...

Aigler, Jane Marie

1989-01-01T23:59:59.000Z

167

The roles of redox active cofactors in catalysis : structural studies of iron sulfur cluster and flavin dependent enzymes  

E-Print Network [OSTI]

Cofactors are highly prevalent in biological systems and have evolved to take on many functions in enzyme catalysis. Two cofactors, flavin adenine dinucleotide (FAD) and [4Fe-4S] clusters, were originally determined to aid ...

Goldman, Peter John

2013-01-01T23:59:59.000Z

168

Role of Human DNA Polymerase kappa in Extension Opposite from a cis-syn Thymine Dimer  

SciTech Connect (OSTI)

Exposure of DNA to UV radiation causes covalent linkages between adjacent pyrimidines. The most common lesion found in DNA from these UV-induced linkages is the cis-syn cyclobutane pyrimidine dimer. Human DNA polymerase {Kappa} (Pol{Kappa}), a member of the Y-family of DNA polymerases, is unable to insert nucleotides opposite the 3'T of a cis-syn T-T dimer, but it can efficiently extend from a nucleotide inserted opposite the 3'T of the dimer by another DNA polymerase. We present here the structure of human Pol{Kappa} in the act of inserting a nucleotide opposite the 5'T of the cis-syn T-T dimer. The structure reveals a constrained active-site cleft that is unable to accommodate the 3'T of a cis-syn T-T dimer but is remarkably well adapted to accommodate the 5'T via Watson-Crick base pairing, in accord with a proposed role for Pol{Kappa} in the extension reaction opposite from cyclobutane pyrimidine dimers in vivo.

R Vasquez-Del Carpio; T Silverstein; S Lone; R Johnson; L Prakash; S Prakash; A Aggarwal

2011-12-31T23:59:59.000Z

169

Rhodium mediated bond activation: from synthesis to catalysis  

SciTech Connect (OSTI)

Recently, our lab has developed monoanionic tridentate ligand, To{sup R}, showing the corresponding coordination chemistry and catalyst reactivity of magnesium, zirconium, zinc and iridium complexes. This thesis details synthetic chemistry, structural study and catalytic reactivity of the To{sup R}-supported rhodium compounds. Tl[To{sup R}] has been proved to be a superior ligand transfer agent for synthesizing rhodium complexes. The salt metathesis route of Tl[To{sup M}] with [Rh({mu}-Cl)(CO)]{sub 2} and [Rh({mu}- Cl)(COE)]{sub 2} gives To{sup M}Rh(CO){sub 2} (2.2) and To{sup M}RhH({eta}{sup 3}-C{sub 8}H{sub 13}) (3.1) respectively while Tl[To{sup P}] with [Rh({mu}-Cl)(CO)]{sub 2} affords To{sup P}Rh(CO){sub 2} (2.3). 2.2 reacts with both strong and weak electrophiles, resulting in the oxazoline N-attacked and the metal center-attacked compounds correspondingly. Using one of the metal center-attacked electrophiles, 2.3 was demonstrated to give high diastereoselectivity. Parallel to COE allylic C-H activation complex 3.1, the propene and allylbenzene allylic C-H activation products have also been synthesized. The subsequent functionalization attempts have been examined by treating with Brønsted acids, Lewis acids, electrophiles, nucleophiles, 1,3-dipolar reagents and reagents containing multiple bonds able to be inserted. Various related complexes have been obtained under these conditions, in which one of the azide insertion compounds reductively eliminates to give an allylic functionalization product stoichiometrically. 3.1 reacts with various primary alcohols to give the decarbonylation dihydride complex To{sup M}Rh(H){sub 2}CO (4.1). 4.1 shows catalytic reactivity for primary alcohol decarbonylation under a photolytic condition. Meanwhile, 2.2 has been found to be more reactive than 4.1 for catalytic alcohol decarbonylation under the same condition. Various complexes and primary alcohols have been investigated as well. The proposed mechanism is based on the stochiometric reactions of the possible metal and organic intermediates. Primary amines, hypothesized to undergo a similar reaction pathway, have been verified to give dehydrogenative coupling product, imines. In the end, the well-developed neutral tridentate Tpm coordinates to the rhodium bis(ethylene) dimer in the presence of TlPF{sub 6} to give the cationic complex, [TpmRh(C{sub 2}H{sub 4}){sub 2}][PF{sub 6}] (5.1). 5.1 serves as the first example of explicit determination of the solid state hapticity, evidenced by X-ray structure, among all the cationic Tpm{sup R}M(C{sub 2}H{sub 4}){sub 2}{sup +} (Tpm{sup R} = Tpm, Tpm*, M = Rh, Ir) derivatives. The substitution chemistry of this compound has been studied by treating with soft and hard donors. The trimethylphosphine-sbustituted complex activates molecular hydrogen to give the dihydride compound.

Ho, Hung-An

2012-03-06T23:59:59.000Z

170

Charge Transfer and Support Effects in Heterogeneous Catalysis  

SciTech Connect (OSTI)

The kinetic, electronic and spectroscopic properties of two?dimensional oxide?supported catalysts were investigated in order to understand the role of charge transfer in catalysis. Pt/TiO{sub 2} nanodiodes were fabricated and used as catalysts for hydrogen oxidation. During the reaction, the current through the diode, as well as its I?V curve, were monitored, while gas chromatography was used to measure the reaction rate. The current and the turnover rate were found to have the same temperature dependence, indicating that hydrogen oxidation leads to the non?adiabatic excitation of electrons in Pt. A fraction of these electrons have enough energy to ballistically transport through Pt and overcome the Schottky barrier at the interface with TiO{sub 2}. The yield for this phenomenon is on the order of 10{sup ?4} electrons per product molecule formed, similar to what has been observed for CO oxidation and for the adsorption of many different molecules. The same Pt/TiO{sub 2} system was used to compare currents in hydrogen oxidation and deuterium oxidation. The current through the diode under deuterium oxidation was found to be greater than under hydrogen oxidation by a factor of three. Weighted by the difference in turnover frequencies for the two isotopes, this would imply a chemicurrent yield 5 times greater for D{sub 2} compared to H{sub 2}, contrary to what is expected given the higher mass of D{sub 2}. Reversible changes in the rectification factor of the diode are observed when switching between D{sub 2} and H{sub 2}. These changes are a likely cause for the differences in current between the two isotopes. In the nanodiode experiments, surface chemistry leads to charge flow, suggesting the possibility of creating charge flow to tune surface chemistry. This was done first by exposing a Pt/Si diode to visible light while using it as a catalyst for H{sub 2} oxidation. Absorption of the light in the Si, combined with the band bending at the interface, gives rise to a steady?state flow of hot holes to the surface. This leads to a decrease in turnover on the surface, an effect which is enhanced when a reverse bias is applied to the diode. Similar experiments were carried out for CO oxidation. On Pt/Si diodes, the reaction rate was found to increase when a forward bias was applied. When the diode was exposed to visible light and a reverse bias was applied, the rate was instead decreased. This implies that a flow of negative charges to the surface increases turnover, while positive charges decrease it. Charge flow in an oxide supported metal catalyst can be modified even without designing the catalyst as a solid state electronic device. This was done by doping stoichiometric and nonstoichiometric TiO{sub 2} films with F, and using the resulting oxides as supports for Pt films. In the case of stoichiometric TiO{sub 2}, F was found to act as an n?type dopant, creating a population of filled electronic states just below the conduction band, and dramatically increasing the conductivity of the oxide film. The electrons in those states can transfer to surface O, activating it for reaction with CO, and leading to increased turnover for CO oxidation. This reinforces the hypothesis that CO oxidation is activated by a flow of negative charges to the surface. The same set of catalysts was used for methanol oxidation. The electronic properties of the TiO{sub 2} films again correlated with the turnover rates, but also with selectivity. With stoichiometric TiO{sub 2} as the support, F?doping caused an increase in selectivity toward the formation of partial oxidation products, formaldehyde and methyl formate, versus the total oxidation product, CO{sub 2}. With non?stoichiometric TiO{sub 2}, F?doping had the reverse effect. Ambient Pressure X?Ray Photoelectron Spectroscopy was used to investigate this F?doping effect in reaction conditions. In O2 alone, and in CO oxidation conditions, the O1s spectrum showed a high binding energy peak that correlated in intensity with the activity of the different films: for stoichiomet

Hervier, Antoine

2011-12-21T23:59:59.000Z

171

An infrared study of the influence of CO adsorption on the topology of supported ruthenium  

SciTech Connect (OSTI)

The interaction of CO with alumina-supported ruthenium, reduced at different temperatures, was investigated by following the development of infrared bands due to adsorbed CO. It was concluded that the adsorption of Co on Ru at 170-350 K leads to the oxidative disruption of Ru clusters as indicated by the slow transformation of the band at 2020-2040 cm{sup {minus}1} due to Ru{sub x}-CO to bands at 2140 and 2075 cm{sup {minus}1} attributed to Ru{sup n+}(CO){sub 2} species (n = 1-3). This process occurred more slowly under dry conditions, and in the presence of hydrogen, whereas it was accelerated by H{sub 2}O addition. Analysis of spectral features suggested the involvement of the isolated OH groups on the alumina support in the oxidative disruption process. It was demonstrated that at higher temperatures, namely at around 500 K, the presence of CO causes the reductive agglomeration of Ru{sup n+} sites, i.e., the reformation of Ru{sub x} clusters.

Solymosi, F.; Rasko, J. (Univ. of Szeged (Hungary))

1989-01-01T23:59:59.000Z

172

The pure rotational spectrum of ruthenium monocarbide, RuC, and relativistic ab initio predictions  

SciTech Connect (OSTI)

The J = 1 ? J = 0 and J = 2 ? J = 1 rotational transitions of ruthenium monocarbide, RuC, have been recorded using the separated field pump/probe microwave optical double resonance technique and analyzed to determine the fine and hyperfine parameters for the X{sup 1}?{sup +} state. The {sup 101}Ru(I = 5/2) electric quadrupole parameter, eq{sub 0}Q, and nuclear spin-rotation interaction parameter, C{sub I}{sup eff}, were determined to be 433.19(8) MHz and ?0.049(6) MHz, respectively. The equilibrium bond distance, r{sub e}, was determined to be 1.605485(2) Å. Hartree-Fock and coupled-cluster calculations were carried out for the properties of the X{sup 1}?{sup +} state. Electron-correlation effects are pronounced for all properties studied. It is shown that (a) the moderate scalar-relativistic contribution to eq{sub 0}Q is entirely due to the coupling between scalar-relativistic and electron-correlation effects, (b) the spin-free exact two-component theory in its one-electron variant offers a reliable and efficient treatment of scalar-relativistic effects, and (c) non-relativistic theory performs quite well for the prediction of C{sub I}{sup elec}, provided that electron correlation is treated accurately.

Wang, Fang; Steimle, Timothy C.; Adam, Allan G. [Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287-1604 (United States)] [Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287-1604 (United States); Cheng, Lan; Stanton, John F. [Department of Chemistry and Biochemistry, The University of Texas at Austin, Austin, Texas 78712 (United States)] [Department of Chemistry and Biochemistry, The University of Texas at Austin, Austin, Texas 78712 (United States)

2013-11-07T23:59:59.000Z

173

Behavior of molybdenum nitrides as materials for electrochemical capacitors: Comparison with ruthenium oxide  

SciTech Connect (OSTI)

Ruthenium oxide (RuO{sub 2}), formed as a thin film on a Ru or Ti metal substrate, exhibits a large specific (cm{sup {minus}2}) and almost constant, electrochemical capacitance over a 1.35 V range in aqueous H{sub 2}SO{sub 4}. This behavior has led to its investigation and use as a material for fabrication of supercapacitor devices. However, its cost has encouraged search for other materials exhibiting similar behavior. Work reported in the present paper evaluates two nitrides of Mo, Mo{sub 2}N and MoN, as substitutes for RuO{sub 2}. It is shown that very similar capacitance behavior to that of RuO{sub 2} films arises, e.g., in cyclic voltammetry and dc charging curves; in the former, almost mirror-image anodic and cathodic current-response profiles, characteristic of a capacitor, arise. However, the nitride materials have a substantially smaller voltage operating range of only some 0.7 V due to electrochemical decomposition above ca. 0.7 V vs. RHE. This limits their usefulness as a substitute for RuO{sub 2}. Of interest is that the nitride films exhibit potential-decay and potential-recovery on open circuit after respective charge and forced discharge. The decay and recovery processes are logarithmic in time, indicating the role of internal faradaic charge redistribution processes.

Liu, T.C.; Pell, W.G.; Conway, B.E. [Univ. of Ottawa, Ontario (Canada). Dept. of Chemistry; Roberson, S.L. [North Carolina State Univ., Raleigh, NC (United States). Dept. of Materials Science and Engineering

1998-06-01T23:59:59.000Z

174

On the role of interfacial hydrogen bonds in "on-water" catalysis  

E-Print Network [OSTI]

Numerous experiments have demonstrated that many classes of organic reactions exhibit increased reaction rates when performed in heterogeneous water emulsions. Despite enormous practical importance of the observed "on-water" catalytic effect and several mechanistic studies, its microscopic origins remains unclear. In this work, the second generation Car-Parrinello molecular dynamics method is extended to self-consistent charge density-functional based tight-binding in order to study "on-water" catalysis of the Diels-Alder reaction between dimethyl azodicarboxylate and quadricyclane. We find that the stabilization of the transition state by dangling hydrogen bonds exposed at the aqueous interfaces plays a significantly smaller role in "on-water" catalysis than has been suggested previously.

Kristof Karhan; Rustam Z. Khaliullin; Thomas D. Kühne

2014-08-21T23:59:59.000Z

175

Major Successes of Theory-and-Experiment-Combined Studies in Surface Chemistry and Heterogeneous Catalysis.  

SciTech Connect (OSTI)

Experimental discoveries followed by theoretical interpretations that pave the way of further advances by experimentalists is a developing pattern in modern surface chemistry and catalysis. The revolution of modern surface science started with the development of surface-sensitive techniques such as LEED, XPS, AES, ISS and SIMS, in which the close collaboration between experimentalists and theorists led to the quantitative determination of surface structure and composition. The experimental discovery of the chemical activity of surface defects and the trends in the reactivity of transitional metals followed by the explanations from the theoretical studies led to the molecular level understanding of active sites in catalysis. The molecular level knowledge, in turn, provided a guide for experiments to search for new generation of catalysts. These and many other examples of successes in experiment-and-theory-combined studies demonstrate the importance of the collaboration between experimentalists and theorists in the development of modern surface science.

Somorjai, Gabor A.; Li, Yimin

2009-11-21T23:59:59.000Z

176

Collective dark states controlled transmission in plasmonic slot waveguide with a stub coupled to a cavity dimer  

E-Print Network [OSTI]

We report collective dark states controlled transmission in metal-dielectric-metal waveguides with a stub coupled to two twin cavities, namely, plasmonic waveguide-stub-dimer systems. In absence of one individual cavity in the dimer, plasmon induced transparency (PIT) is possible when the cavity and the stub have the same resonance frequency. However, it is shown that the hybridized modes in the dimer collectively generate two dark states which make the stub-dimer "invisible" to the straight waveguide, splitting the original PIT peak into two in the transmission spectrum. Simultaneously, the original PIT peak becomes a dip due to dark state interaction, yielding anti-PIT-like modulation of the transmission. With full-wave electromagnetic simulation, we demonstrate that this transition is controlled by the dimer-stub separation and the dimer-stub relative position. All results are analytically described by the temporal coupled mode theory. Our results may be useful in designing densely integrated optical circu...

Liu, Zhenzhen; Zhang, Qiang; Zhang, Xiaoming; Tao, Keyu

2015-01-01T23:59:59.000Z

177

NMR Computational Studies of Solid Acidity/Fundamental Studies of Catalysis by Solid Acids  

SciTech Connect (OSTI)

This project focused on catalysis by zeolites and the synergy of spectroscopic characterization and theoretical modeling. In collaboration with the Waroquier group in Belgium we used state-of-the-art quantum chemical simulations on a supramolecular model of both the HZSM-5 zeolite and the co-catalytic hydrocarbon pool species and calculated a full catalytic cycle (including all rate constants) for methanol-to-olefin (MTO) catalysis involving a hydrocarbon pool species. This work not only represents the most robust computational analysis of a successful MTO route to date, but it also succeeds in tying together the many experimental clues. That work was featured on the cover of Angewandte Chemie. More recently we elucidated several unsuspected roles for formaldehyde in methanol to olefin catalysis. Formaldehyde proves to be a key species responsible for both the growth of the catalytically active hydrocarbon pool and its inevitable aging into deactivated polycyclic aromatic species. The apparent inevitability of formaldehyde formation at high temperatures, in particular in contact with active metal or metal oxide surfaces, may put some fundamental limitations on the economic potential of conversion of methanol to olefins.

James F. Haw

2008-06-28T23:59:59.000Z

178

Transformation of carbon monoxide dimer surface structures on yttrium oxide modified by silver  

SciTech Connect (OSTI)

It has been established that introducing ions of silver(II) in yttrium(III) oxide leads to the formation of a significant concentration of a paramagnetic dimer species (CO)/sub 2/-in the course of the adsorption of carbon monoxide, and that these dimers exhibit high thermal stability and reactivity. Reactions are proposed for the formation of the dimer species (CO)/sub 2//sup 2 -/ and (CO)/sub 2//sup -/ on the surface of the Ag/Y/sub 2/O/sub 3/ catalyst that involve the reduction of the anion vacancies and a change in the oxidation state of the silver ions. Modifying the yttrium oxide with ionic silver leads to a marked decrease in the strength of the oxidative ability of the surface of the catalyst for CO, while the nature of the active sites of the yttrium oxide, which adsorbs CO in three forms, remains unchanged.

Vydrin, S.N.; Bobolev, A.V.; Loginov, A.Yu.

1987-09-10T23:59:59.000Z

179

Dimerization Induced Deprotonation of Water on RuO2(110)  

SciTech Connect (OSTI)

RuO2 has proven to be indispensable as a co-catalyst in numerous systems designed for photocatalytic water splitting. In this study we have carried out a detailed mechanistic study of water behavior on the most stable RuO2 face, RuO2(110), by employing variable temperature scanning tunneling microscopy and density functional theory calculations. We show that water monomers adsorb molecularly on Ru sites, become mobile above 238 K, diffuse along the Ru rows and form water dimers. The onset for dimer diffusion is observed at ~277 K indicating significantly higher diffusion barrier than that for monomers. More importantly, we find that water dimers deprotonate readily to form Ru-bound H3O2 and bridging OH species. The observed behavior is compared and contrasted with that observed for water on isostructural rutile TiO2(110).

Mu, Rentao; Cantu Cantu, David; Lin, Xiao; Glezakou, Vassiliki Alexandra; Wang, Zhitao; Lyubinetsky, Igor; Rousseau, Roger J.; Dohnalek, Zdenek

2014-10-02T23:59:59.000Z

180

Electrochemical DNA biosensor for detection of porcine oligonucleotides using ruthenium(II) complex as intercalator label redox  

SciTech Connect (OSTI)

A DNA biosensor detection of oligonucleotides via the interactions of porcine DNA with redox active complex based on the electrochemical transduction is described. A ruthenium(II) complex, [Ru(bpy){sub 2}(PIP)]{sup 2+}, (bpy = 2,2?bipyridine, PIP = 2-phenylimidazo[4,5-f[[1,10-phenanthroline]) as DNA label has been synthesized and characterized by 1H NMR and mass spectra. The study was carried out by covalent bonding immobilization of porcine aminated DNA probes sequences on screen printed electrode (SPE) modified with succinimide-acrylic microspheres and [Ru(bpy){sub 2}(PIP)]{sup 2+} was used as electrochemical redox intercalator label to detect DNA hybridization event. Electrochemical detection was performed by cyclic voltammetry (CV) and differential pulse voltammetry (DPV) over the potential range where the ruthenium (II) complex was active. The results indicate that the interaction of [Ru(bpy){sub 2}(PIP)]{sup 2+} with hybridization complementary DNA has higher response compared to single-stranded and mismatch complementary DNA.

Halid, Nurul Izni Abdullah; Hasbullah, Siti Aishah; Heng, Lee Yook; Karim, Nurul Huda Abd [School of Chemical Sciences and Food Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor Darul Ehsan (Malaysia); Ahmad, Haslina; Harun, Siti Norain [Chemistry Department, Faculty of Science, Universiti Putra Malaysia, 43400, Serdang, Selangor (Malaysia)

2014-09-03T23:59:59.000Z

Note: This page contains sample records for the topic "ruthenium dimer catalysis" 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

Complete characterization of the water dimer vibrational ground state and testing the VRT(ASP-W)III,  

E-Print Network [OSTI]

Complete characterization of the water dimer vibrational ground state and testing the VRT(ASP-W)III, SAPT-5st, and VRT(MCY-5f) surfaces FRANK N. KEUTSCH1 , NIR GOLDMAN2 , HEATHER A. HARKER3 , CLAUDE of the water dimer very well. The VRT(MCY-5f) and especially the VRT(ASP-W)III potentials show larger

Cohen, Ronald C.

182

Proton transfer in adsorbed water dimers Xiao Liang Hu, Jir i Klimes and Angelos Michaelides*  

E-Print Network [OSTI]

of intact and dissociated states of water are similar. Proton transfer between water moleculesProton transfer in adsorbed water dimers Xiao Liang Hu, Jir i´ Klimes and Angelos Michaelides 25th February 2010 DOI: 10.1039/b924422k Density functional theory simulations of water on MgO(001

Alavi, Ali

183

Analyzing human epidermal growth factor receptor family dimerization and activation using Duolink  

E-Print Network [OSTI]

dimerization and activation. Two different cell lines, SKBR3 (known to express EGFR and high levels of HER2 using an anti- EGFR antibody (Y-1068). However, only the SKBR3 cell line gave a detectable signal after. Both cell lines responded to EGF stimulation by phosphorylation of EGFR (Fig. 2), which was measured

Cai, Long

184

Isotope effects and Born-Oppenheimer breakdown in excited singlet states of the lithium dimer  

E-Print Network [OSTI]

Isotope effects and Born-Oppenheimer breakdown in excited singlet states of the lithium dimer A of infrared electronic transitions involving the 1 1 g state of 7 Li2 has instigated an investigation of Born-Oppenheimer and the leading vibrational and/or rotational Born-Oppenheimer breakdown terms for the X 1 g , A 1 u , B 1 u

Le Roy, Robert J.

185

Synthesis of a 7-Azaindole by Chichibabin Cyclization: Reversible Base-Mediated Dimerization of 3-Picolines  

E-Print Network [OSTI]

Synthesis of a 7-Azaindole by Chichibabin Cyclization: Reversible Base-Mediated Dimerization of 3 of heteroannulation- appending a pyrrole to a pyridine or vice versa.1,2 In connection with a program at Sanofi-Aventis to synthesize polycyclic pyrrole derivatives to be tested for the treatment of asthma,2c the conversion of 2

Collum, David B.

186

Molecular Dynamics Simulation of Amyloid b Dimer Formation B. Urbanc,* L. Cruz,* F. Ding,*y  

E-Print Network [OSTI]

of amyloid plaques. Hence, finding the conformation of these oligo- meric forms of Ab may be important; Thompson, 2003). The most common view is that Ab(1­40) and Ab(1­ 42) in fibrils form parallel bMolecular Dynamics Simulation of Amyloid b Dimer Formation B. Urbanc,* L. Cruz,* F. Ding,*y D

Stanley, H. Eugene

187

Rows of ATP Synthase Dimers in Native Mitochondrial Inner Membranes Nikolay Buzhynskyy,* Pierre Sens,y  

E-Print Network [OSTI]

Rows of ATP Synthase Dimers in Native Mitochondrial Inner Membranes Nikolay Buzhynskyy,* Pierre Marseille, France ABSTRACT The ATP synthase is a nanometric rotary machine that uses a transmembrane electrochemical gradient to form ATP. The structures of most components of the ATP synthase are known, andtheir

Sens, Pierre

188

2010 Macmillan Publishers Limited. All rights reserved. Highly stable tetrathiafulvalene radical dimers in  

E-Print Network [OSTI]

Stoddart1 * Two [3]catenane `molecular flasks' have been designed to create stabilized, redox observation of p­p radical-cation dimers on the redox stimulation of electron rich or poor heterocycles, rather than the fundamental cornerstone of functional devices7 . Specifically, methyl viologen (MV2þ

Goddard III, William A.

189

A Novel Dimerization Interface of Cyclic Nucleotide Binding Domain, which is  

E-Print Network [OSTI]

1 A Novel Dimerization Interface of Cyclic Nucleotide Binding Domain, which is Disrupted Modeling 18, 9 (2012) 4053-4060" DOI : 10.1007/s00894-012-1404-5 #12;2 ABSTRACT Cyclic nucleotide binding and eukaryota. CNBD activation by cyclic nucleotide monophosphate (cNMP) is studied well in case of several

Paris-Sud XI, Université de

190

Alignment of molecules in gaseous transport: Alkali dimers in supersonic nozzle beams  

E-Print Network [OSTI]

Alignment of molecules in gaseous transport: Alkali dimers in supersonic nozzle beams M. P. SinhaO) + a.P lcosO), where 0 is the angle between the angular momentum vector J of the molecule and the beam direction. This method is applied to determine the alignment of Na2 molecules in a supersonic nozzle beam

Zare, Richard N.

191

Functional Characterization of Rhodopsin Monomers and Dimers in Detergents*S  

E-Print Network [OSTI]

International Institute of Molecular and Cell Biology, Warsaw PL-02109, Poland Rhodopsin (Rho) is a G protein-coupled from atomic force microscopy, transmission electron microscopy, and chemical cross-linking experiments resistant to heat denaturation. Both Rho* mono- mers and dimers are capable of activating Gt, and both

Palczewski, Krzysztof

192

Water dimer hydrogen bond stretch, donor torsion overtone, and ``in-plane bend'' vibrations  

E-Print Network [OSTI]

Water dimer hydrogen bond stretch, donor torsion overtone, and ``in-plane bend'' vibrations Frank N. Brown Los Alamos National Laboratory, Los Alamos, New Mexico 87545 Heather A. Harker and Poul B. © 2003 American Institute of Physics. DOI: 10.1063/1.1614774 I. INTRODUCTION Water clusters have been

Cohen, Ronald C.

193

The Mechanical Fingerprint of a Parallel Polyprotein Dimer Atom Sarkar, Sofia Caamano, and Julio M. Fernandez  

E-Print Network [OSTI]

The Mechanical Fingerprint of a Parallel Polyprotein Dimer Atom Sarkar, Sofia Caamano, and Julio M and in final form 22 November 2006. Address reprint requests and inquiries to Atom Sarkar, E-mail: atom.sarkar@osumc.edu; or Julio M. Fernandez, E-mail: jfernandez@columbia.edu. Atom Sarkar's present address is Dept

Fernandez, Julio M.

194

Proton Mediated Chemistry and Catalysis in a Self-Assembled Supramolecular Host  

SciTech Connect (OSTI)

Synthetic supramolecular host assemblies can impart unique reactivity to encapsulated guest molecules. Synthetic host molecules have been developed to carry out complex reactions within their cavities, despite the fact that they lack the type of specifically tailored functional groups normally located in the analogous active sites of enzymes. Over the past decade, the Raymond group has developed a series of self-assembled supramolecules and the Bergman group has developed and studied a number of catalytic transformations. In this Account, we detail recent collaborative work between these two groups, focusing on chemical catalysis stemming from the encapsulation of protonated guests and expanding to acid catalysis in basic solution. We initially investigated the ability of a water-soluble, self-assembled supramolecular host molecule to encapsulate protonated guests in its hydrophobic core. Our study of encapsulated protonated amines revealed rich host-guest chemistry. We established that self-exchange (that is, in-out guest movement) rates of protonated amines were dependent on the steric bulk of the amine rather than its basicity. The host molecule has purely rotational tetrahedral (T) symmetry, so guests with geminal N-methyl groups (and their attendant mirror plane) were effectively desymmetrized; this allowed for the observation and quantification of the barriers for nitrogen inversion followed by bond rotation. Furthermore, small nitrogen heterocycles, such as N-alkylaziridines, N-alkylazetidines, and N-alkylpyrrolidines, were found to be encapsulated as proton-bound homodimers or homotrimers. We further investigated the thermodynamic stabilization of protonated amines, showing that encapsulation makes the amines more basic in the cavity. Encapsulation raises the effective basicity of protonated amines by up to 4.5 pK{sub a} units, a difference almost as large as that between the moderate and strong bases carbonate and hydroxide. The thermodynamic stabilization of protonated guests was translated into chemical catalysis by taking advantage of the potential for accelerating reactions that take place via positively charged transition states, which could be potentially stabilized by encapsulation. Orthoformates, generally stable in neutral or basic solution, were found to be suitable substrates for catalytic hydrolysis by the assembly. Orthoformates small enough to undergo encapsulation were readily hydrolyzed by the assembly in basic solution, with rate acceleration factors up to 3900 compared with those of the corresponding uncatalyzed reactions. Furthering the analogy to enzymes that obey Michaelis-Menten kinetics, we observed competitive inhibition with the inhibitor NPr{sub 4}{sup +}, thereby confirming that the interior cavity of the assembly was the active site for catalysis. Mechanistic studies revealed that the assembly is required for catalysis and that the rate-limiting step of the reaction involves proton transfer from hydronium to the encapsulated substrate. Encapsulation in the assembly changes the orthoformate hydrolysis from an A-1 mechanism (in which decomposition of the protonated substrate is the rate-limiting step) to an A-S{sub E}2 mechanism (in which proton transfer is the rate-limiting step). The study of hydrolysis in the assembly was next extended to acetals, which were also catalytically hydrolyzed by the assembly in basic solution. Acetal hydrolysis changed from the A-1 mechanism in solution to an A-2 mechanism inside the assembly, where attack of water on the protonated substrate is rate limiting. This work provides rare examples of assembly-catalyzed reactions that proceed with substantial rate accelerations despite the absence of functional groups in the cavity and with mechanisms fully elucidated by quantitative kinetic studies.

Pluth, Michael; Bergman, Robert; Raymond, Kenneth

2009-04-10T23:59:59.000Z

195

Journal of Molecular Catalysis A: Chemical 251 (2006) 823 Design and study of homogeneous catalysts for the selective,  

E-Print Network [OSTI]

material for materials and energy. Its abundance has garnered much interest in the scientific communityJournal of Molecular Catalysis A: Chemical 251 (2006) 8­23 Design and study of homogeneous the landscape of the current materials and energy industries. Natural gas continues to represent a vast source

Goddard III, William A.

196

Decarboxylative Arylation of Amino Acids via Photoredox Catalysis: A One-Step Conversion of Biomass to Drug  

E-Print Network [OSTI]

Decarboxylative Arylation of Amino Acids via Photoredox Catalysis: A One-Step Conversion of Biomass. This method offers rapid entry to prevalent benzylic amine architectures from an abundant biomass the worldwide abundance of biomass6 that incorporates carboxylate functionality (e.g., amino acids, -hydroxy

MacMillan, David W. C.

197

Conformationally controlled pK-switching in membrane proteins: One more mechanism specic to the enzyme catalysis?  

E-Print Network [OSTI]

-active tyrosine YZ in the oxygen- evolving photosystem II. It is conceivable that YZ switches its pK from VV4 to general mechanisms of enzymatic catalysis. In the bacterial photosyn- thetic reaction center (RC transfer; Photosynthetic reaction center; Bacteriorhodopsin; Photosystem II 1. Introduction The nature

Steinhoff, Heinz-Jürgen

198

Channeling of Fusion Alpha-Particle Power Using Minority Ion Catalysis A. I. Zhmoginov and N. J. Fisch  

E-Print Network [OSTI]

, with electrons kept cold, so that the effective fusion reactivity can be increased [9­11]. The meansChanneling of Fusion Alpha-Particle Power Using Minority Ion Catalysis A. I. Zhmoginov and N. J greatly facilitate controlled nuclear fusion. The parameter range for achieving this temperature disparity

199

Effects of catalysis on particle motion in plane-parallel and cylindrical channels in a catalytic reactor  

SciTech Connect (OSTI)

A theoretical study is made on aerosol behavior in a catalysis zone for a plane-parallel or cylindrical channel in a catalytic reactor. It is found that the thermophoretic trapping coefficient may attain 10-15% in a laminar flow having longitudinal Pe and Re >> 1 even for small relative temperature differences.

Kabanov, A.N.; Murashkevich, F.I.; Shulimanova, Z.L.; Shukin, E.R.

1987-09-01T23:59:59.000Z

200

General basic and coordination catalysis in reactions of haloaromatic compounds with ammonia in the presence of copper(I) compounds  

SciTech Connect (OSTI)

This paper presents a study made to detect general basic catalysis by ammonia (reagent) in reactions of ammonolysis of haloaromatic compounds in the presence of Cu/sup +/ ions, as well as to determine the generality of the mechanisms of the catalytic replacement of a halogen atom by an amino group in the anthraquinone and benzene series.

Chumak, V.T.; Shein, S.M.

1985-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "ruthenium dimer catalysis" 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.
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to obtain the most current and comprehensive results.


201

Zeolite catalysis  

SciTech Connect (OSTI)

This patent describes a process for preparing hydrocarbons boiling in the gasoline and/or distillate range by contacting a feedstock comprising lower molecular weight olefins in a reaction zone under conditions of elevated temperature and pressure with a shape selective crystalline aluminosilicate catalyst, comprising: reducing the non-shape selective surface-cracking and/or surface isomerization activity of the aluminosilicate catalyst by a process comprising: preparing an aqueous solution comprising colloidal silica, optionally an organic directing agent, and a source of hydroxide ions; mixing the aqueous solution with an aqueous dispersion of shape-selective crystalline aluminosilicate to form a homogeneous mixture which is subsequently heated; adding an aqueous solution comprising a source of fluoride ions to the homogeneous mixture to form a reactive composition; heating the reactive composition at a temperature to effectively form a surface-deactivated catalyst comprising a crystalline fluoride-containing silica outer shell on an aluminosilicate; withdrawing the surface-deactivated catalyst from the reactive composition for washing, drying, and calcining of the catalyst; and removing the catalyst to the reaction zone for contact with the olefin feedstock.

Chu, P.; Garwood, W.E.; Schwartz, A.B.

1988-11-29T23:59:59.000Z

202

Catalysis Workshop  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation Proposed New Substation Sites ProposedOccupational Health Services >

203

Lab Safety: RuO4Lab Safety: RuO4 Ruthenium tetroxide is a strong oxidizing agent and must be stored in the  

E-Print Network [OSTI]

Lab Safety: RuO4Lab Safety: RuO4 RuO4 Note: Ruthenium tetroxide is a strong oxidizing agent with sodium bisulfite solution to decompose RuO4 and then flush with plenty of water. #12;Lab Safety:Lab Safety: Reaction used to create RuO4 for staining: RuCl3 #12;Sodium hypochlorite: HARMFUL IF SWALLOWED

Cohen, Robert E.

204

Elastic properties of the degenerate f.c.c. crystal of polydisperse soft dimers at zero temperature  

E-Print Network [OSTI]

Elastic properties of soft, three-dimensional dimers, interacting through site-site n-inverse-power potential, are determined by computer simulations at zero temperature. The degenerate crystal of dimers exhibiting (Gaussian) size distribution of atomic diameters - i.e. size polydispersity - is studied at the molecular number density $1/\\sqrt{2}$; the distance between centers of atoms forming dimers is considered as a length unit. It is shown that, at the fixed number density of the dimers, increasing polydispersity causes, typically, an increase of pressure, elastic constants and Poisson's ratio; the latter is positive in most direction. A direction is found, however, in which the size polydispersity causes substantial decrease of Poisson's ratio, down to negative values for large $n$. Thus, the system is partially auxetic for large polydispersity and large n.

J. W. Narojczyk; K. W. Wojciechowski

2015-04-12T23:59:59.000Z

205

The 13th International Symposium on Relations between Homogeneous and Heterogeneous Catalysis -- AnIntroduction  

SciTech Connect (OSTI)

Over forty years, there have been major efforts to aim at understanding the properties of surfaces, structure, composition, dynamics on the molecular level and at developing the surface science of heterogeneous and homogeneous catalysis. Since most catalysts (heterogeneous, enzyme and homogeneous) are nanoparticles, colloid synthesis methods were developed to produce monodispersed metal nanoparticles in the 1-10 nm range and controlled shapes to use them as new model catalyst systems in two-dimensional thin film form or deposited in mezoporous three-dimensional oxides. Studies of reaction selectivity in multipath reactions (hydrogenation of benzene, cyclohexene and crotonaldehyde) showed that reaction selectivity depends on both nanoparticle size and shape. The oxide-metal nanoparticle interface was found to be an important catalytic site because of the hot electron flow induced by exothermic reactions like carbon monoxide oxidation.

Somorjai, Gabor A.

2008-02-06T23:59:59.000Z

206

Asymmetry of rotational catalysis of single membrane-bound F0F1-ATP synthase  

E-Print Network [OSTI]

Synthesis of the cellular 'energy currency' ATP is catalyzed by membrane-bound F0F1-ATP synthases. The chemical reaction at three binding sites in the F1 part is coupled to proton translocation through the membrane-integrated F0 part by an internal rotation of subunits. We examined the rotary movements of the epsilon-subunit of the 'rotor' with respect to the b-subunits of the 'stator' by single-molecule fluorescence resonance energy transfer (FRET). Rotation of epsilon during ATP hydrolysis is divided into three major steps with constant FRET level corresponding to three binding sites. Different catalytic activities of the individual binding sites were observed depending on the relative orientation of the 'rotor'. Computer simulations of the FRET signals and non-equally distributed orientations of epsilon strongly corroborate asymmetry of catalysis in F0F1-ATP synthase.

Zarrabi, Nawid; Diez, Manuel; Graeber, Peter; Wrachtrup, Joerg; Boersch, Michael

2007-01-01T23:59:59.000Z

207

Protein conformational dynamics in the mechanism of HIV-1 protease catalysis  

SciTech Connect (OSTI)

We have used chemical protein synthesis and advanced physical methods to probe dynamics-function correlations for the HIV-1 protease, an enzyme that has received considerable attention as a target for the treatment of AIDS. Chemical synthesis was used to prepare a series of unique analogues of the HIV-1 protease in which the flexibility of the 'flap' structures (residues 37-61 in each monomer of the homodimeric protein molecule) was systematically varied. These analogue enzymes were further studied by X-ray crystallography, NMR relaxation, and pulse-EPR methods, in conjunction with molecular dynamics simulations. We show that conformational isomerization in the flaps is correlated with structural reorganization of residues in the active site, and that it is preorganization of the active site that is a rate-limiting factor in catalysis.

Torbeev, Vladimir Yu.; Raghuraman, H.; Hamelberg, Donald; Tonelli, Marco; Westler, William M.; Perozo, Eduardo; Kent, Stephen B.H. (GSU); (UW); (UC)

2013-09-17T23:59:59.000Z

208

Methane Oxidation to Methanol without CO2 Emission: Catalysis by Atomic Negative Ions  

E-Print Network [OSTI]

The catalytic activities of the atomic Y-, Ru-, At-, In-, Pd-, Ag-, Pt-, and Os- ions have been investigated theoretically using the atomic Au- ion as the benchmark for the selective partial oxidation of methane to methanol without CO2 emission. Dispersion-corrected density-functional theory has been used for the investigation. From the energy barrier calculations and the thermodynamics of the reactions, we conclude that the catalytic effect of the atomic Ag-, At-, Ru-, and Os- ions is higher than that of the atomic Au- ion catalysis of CH4 conversion to methanol. By controlling the temperature around 290K (Os-), 300K (Ag-), 310K (At-), 320K (Ru-) and 325K (Au-) methane can be completely oxidized to methanol without the emission of CO2. We conclude by recommending the investigation of the catalytic activities of combinations of the above negative ions for significant enhancement of the selective partial oxidation of methane to methanol.

Tesfamichael, Aron; Felfli, Zineb; Msezane, Alfred Z

2014-01-01T23:59:59.000Z

209

Molecular Beam Scattering of Aligned Oxygen Molecules. The Nature of the Bond in the O2-O2 Dimer  

E-Print Network [OSTI]

. These results indicate that most of the bonding in the dimer comes from van der Waals forces, but chemical (spin that it is not paramagnetic." He also gave a value of 5.60 meV for the heat of dissociation of the O2-O2 dimer. Actually from different spin coupling of the monomers in the ground electronic state. Spin coupling leads

Pirani, Fernando

210

The reaction dynamics of alkali dimer molecules and electronically excited alkali atoms with simple molecules  

SciTech Connect (OSTI)

This dissertation presents the results from the crossed molecular beam studies on the dynamics of bimolecular collisions in the gas phase. The primary subjects include the interactions of alkali dimer molecules with simple molecules, and the inelastic scattering of electronically excited alkali atoms with O{sub 2}. The reaction of the sodium dimers with oxygen molecules is described in Chapter 2. Two reaction pathways were observed for this four-center molecule-molecule reaction, i.e. the formations of NaO{sub 2} + Na and NaO + NaO. NaO{sub 2} products exhibit a very anisotropic angular distribution, indicating a direct spectator stripping mechanism for this reaction channel. The NaO formation follows the bond breaking of O{sub 2}, which is likely a result of a charge transfer from Na{sub 2} to the excited state orbital of O{sub 2}{sup {minus}}. The scattering of sodium dimers from ammonium and methanol produced novel molecules, NaNH{sub 3} and Na(CH{sub 3}OH), respectively. These experimental observations, as well as the discussions on the reaction dynamics and the chemical bonding within these molecules, will be presented in Chapter 3. The lower limits for the bond dissociation energies of these molecules are also obtained. Finally, Chapter 4 describes the energy transfer between oxygen molecules and electronically excited sodium atoms.

Hou, H. [Univ. of California, Berkeley, CA (United States). Dept. of Chemistry]|[Lawrence Berkeley National Lab., CA (United States). Chemical Sciences Div.

1995-12-01T23:59:59.000Z

211

The HPr Proteins from the Thermophile Bacillus stearothermophilus Can Form Domain-swapped Dimers  

SciTech Connect (OSTI)

The study of proteins from extremophilic organisms continues to generate interest in the field of protein folding because paradigms explaining the enhanced stability of these proteins still elude us and such studies have the potential to further our knowledge of the forces stabilizing proteins. We have undertaken such a study with our model protein HPr from a mesophile, Bacillus subtilis, and a thermophile, Bacillus stearothermophilus. We report here the high-resolution structures of the wild-type HPr protein from the thermophile and a variant, F29W. The variant proved to crystallize in two forms: a monomeric form with a structure very similar to the wild-type protein as well as a domain-swapped dimer. Interestingly, the structure of the domain-swapped dimer for HPr is very different from that observed for a homologous protein, Crh, from B. subtilis. The existence of a domain-swapped dimer has implications for amyloid formation and is consistent with recent results showing that the HPr proteins can form amyloid fibrils. We also characterized the conformational stability of the thermophilic HPr proteins using thermal and solvent denaturation methods and have used the high-resolution structures in an attempt to explain the differences in stability between the different HPr proteins. Finally, we present a detailed analysis of the solution properties of the HPr proteins using a variety of biochemical and biophysical methods.

Sridharan, Sudharsan; Razvi, Abbas; Scholtz, J. Martin; Sacchettini, James C. (TAM)

2010-07-20T23:59:59.000Z

212

The Structure of the Poxvirus A33 Protein Reveals a Dimer of Unique C-Type Lectin-Like Domains  

SciTech Connect (OSTI)

The current vaccine against smallpox is an infectious form of vaccinia virus that has significant side effects. Alternative vaccine approaches using recombinant viral proteins are being developed. A target of subunit vaccine strategies is the poxvirus protein A33, a conserved protein in the Chordopoxvirinae subfamily of Poxviridae that is expressed on the outer viral envelope. Here we have determined the structure of the A33 ectodomain of vaccinia virus. The structure revealed C-type lectin-like domains (CTLDs) that occur as dimers in A33 crystals with five different crystal lattices. Comparison of the A33 dimer models shows that the A33 monomers have a degree of flexibility in position within the dimer. Structural comparisons show that the A33 monomer is a close match to the Link module class of CTLDs but that the A33 dimer is most similar to the natural killer (NK)-cell receptor class of CTLDs. Structural data on Link modules and NK-cell receptor-ligand complexes suggest a surface of A33 that could interact with viral or host ligands. The dimer interface is well conserved in all known A33 sequences, indicating an important role for the A33 dimer. The structure indicates how previously described A33 mutations disrupt protein folding and locates the positions of N-linked glycosylations and the epitope of a protective antibody.

Su, Hua-Poo; Singh, Kavita; Gittis, Apostolos G.; Garboczi, David N. (NIH)

2010-11-03T23:59:59.000Z

213

Adsorption of Ruthenium, Rhodium and Palladium from Simulated High-Level Liquid Waste by Highly Functional Xerogel - 13286  

SciTech Connect (OSTI)

Fission products are generated by fission reactions in nuclear fuel. Platinum group (Pt-G) elements, such as palladium (Pd), rhodium (Rh) and ruthenium (Ru), are also produced. Generally, Pt-G elements play important roles in chemical and electrical industries. Highly functional xerogels have been developed for recovery of these useful Pt-G elements from high - level radioactive liquid waste (HLLW). An adsorption experiment from simulated HLLW was done by the column method to study the selective adsorption of Pt-G elements, and it was found that not only Pd, Rh and Ru, but also nickel, zirconium and tellurium were adsorbed. All other elements were not adsorbed. Adsorbed Pd was recovered by washing the xerogel-packed column with thiourea solution and thiourea - nitric acid mixed solution in an elution experiment. Thiourea can be a poison for automotive exhaust emission system catalysts, so it is necessary to consider its removal. Thermal decomposition and an acid digestion treatment were conducted to remove sulfur in the recovered Pd fraction. The relative content of sulfur to Pd was decreased from 858 to 0.02 after the treatment. These results will contribute to design of the Pt-G element separation system. (authors)

Onishi, Takashi [Fukushima Fuels and Materials Department O-arai Research and Development Center Japan Atomic Energy Agency, Narita-cho 4002, O-arai-machi, Ibaraki, 311-1393 (Japan)] [Fukushima Fuels and Materials Department O-arai Research and Development Center Japan Atomic Energy Agency, Narita-cho 4002, O-arai-machi, Ibaraki, 311-1393 (Japan); Koyama, Shin-ichi [Fukushima Fuels and Materials Department O-arai Research and Development Center Japan Atomic Energy Agency, Narita-cho 4002, O-arai-machi, Ibaraki, 311-1393 (Japan)] [Fukushima Fuels and Materials Department O-arai Research and Development Center Japan Atomic Energy Agency, Narita-cho 4002, O-arai-machi, Ibaraki, 311-1393 (Japan); Mimura, Hitoshi [Dept. of Quantum Science and Energy Engineering, Graduate School of Engineering, Tohoku University Aramaki-Aza-Aoba 6-6-01-2,Aoba-ku, Sendai-shi, Miyagi-ken, 980-8579 (Japan)] [Dept. of Quantum Science and Energy Engineering, Graduate School of Engineering, Tohoku University Aramaki-Aza-Aoba 6-6-01-2,Aoba-ku, Sendai-shi, Miyagi-ken, 980-8579 (Japan)

2013-07-01T23:59:59.000Z

214

Mesoporous Silica Nanomaterials for Applications in Catalysis, Sensing, Drug Delivery and Gene Transfection  

SciTech Connect (OSTI)

The central theme of this dissertation is represented by the versatility of mesoporous silica nanomaterials in various applications such as catalysis and bio-applications, with main focus on biological applications of Mesoporous Silica Nanospheres (MSN). The metamorphosis that we impose to these materials from catalysis to sensing and to drug and gene delivery is detailed in this dissertation. First, we developed a synthetic method that can fine tune the amount of chemically accessible organic functional groups on the pores surface of MSN by exploiting electrostatic and size matching between the cationic alkylammonium head group of the cetyltrimethylammonium bromide (CTAB) surfactant and various anionic organoalkoxysilane precursors at the micelle-water interface in a base-catalyzed condensation reaction of silicate. Aiming nature imitation, we demonstrated the catalytic abilities of the MSNs, We utilized an ethylenediamine functional group for chelating Cu{sup 2+} as a catalytic functional group anchored inside the mesopores. Thus, a polyalkynylene-based conducting polymer (molecular wire) was synthesized within the Cu-functionalized MSNs silica catalyst. For sensing applications, we have synthesized a poly(lactic acid) coated mesoporous silica nanosphere (PLA-MSN) material that serves as a fluorescence sensor system for detection of amino-containing neurotransmitters in neutral aqueous buffer. We exploited the mesoporosity of MSNs for encapsulating pharmaceutical drugs. We examined bio-friendly capping molecules such as polyamidoamine dendrimers of generations G2 to G4, to prevent the drug leaching. Next, the drug delivery system employed MSNs loaded with Doxorubicin, an anticancer drug. The results demonstrated that these nano-Trojan horses have ability to deliver Doxorubicin to cancer cells and induce their death. Finally, to demonstrate the potential of MSN as an universal cellular transmembrane nanovehicle, we anchored positively charged dendrimers on the surface of MSN and utilize them to complex cationic DNA. The p-EGFP-CI gene-coated MSN nanocomposite was able to transfect cancer cell lines, such as human HeLa and CHO cancer cell lines. The gene carrier ability of MSNs was further proved by transfecting primary cells and cotransfecting of two different genes in cancer cell lines. In sum, MSN are versatile partners in several types of applications.

Daniela Rodica Radu

2005-12-19T23:59:59.000Z

215

The retroviral RNA dimer linkage: different structures may reflect different roles  

E-Print Network [OSTI]

's Hospital, Hills Road, Cambridge, CB2 2QQ, UK Email: Jane Greatorex* - jg10018@mole.bio.cam.ac.uk * Corresponding author Abstract Retroviruses are unique among virus families in having dimeric genomes. The RNA sequences and structures that link the two... stem-loop H1 (278–303) and new roles for stem-loops H2 (310–352) and H3 (355–374). Biochem-Page 8 of 10 (page number not for citation purposes) istry 1998, 37:6077-6085. 23. Rasmussen SV, Mikkelsen JG, Pedersen FS: Modulation of homo...

Greatorex, Jane S

2004-08-18T23:59:59.000Z

216

Hydrogen atom trapping in a self-organized one-dimensional dimer  

SciTech Connect (OSTI)

Metal–organic frameworks (MOFs) have attracted widespread attention owing to their unusual structure and properties produced by their nanospaces. However, many MOFs possess the similar three-dimensional frameworks, limiting their structural variety and operating capacity for hydrogen storage under ambient conditions. Here we report the synthesis and structural characterization of a single-crystal one-dimensional dimer whose structure, operating capacity, and physical mechanism contrast with those of existing MOFs. The hydrogen storage capacity of 2.6 wt.% is comparable to the highest capacity achieved by existing MOFs at room temperature. This exceptional storage capacity is realized by self-organization during crystal growth using a weak base.

Takami, Tsuyoshi, E-mail: takami@phys.sci.osaka-u.ac.jp [Department of Physics, Graduate School of Science, Osaka University, 1-1 Machikaneyama-cho, Toyonaka, Osaka 560-0043 (Japan); Kawamura, Kazushi [Analytical Measurement Room, Graduate School of Science, Osaka University, 1-1 Machikaneyama-cho, Toyonaka, Osaka 560-0043 (Japan)

2014-09-01T23:59:59.000Z

217

Catalysis and clean environment: What do these two have in common?  

SciTech Connect (OSTI)

The theme of the 1990s, ``Continual Expansion through Sustainable Development,`` is the outcome of interdisciplinary studies undertaken in the preceding two decades to arrest ongoing global environmental deterioration. A critical component of various international efforts to formulate and implement environmentally-sound technologies is the planned involvement of developing countries and countries with economies in-transition which are poised for explosive growth well into the twenty-first century but do not have policies or financial resources to simultaneously manage their environment. Though CO{sub 2}-producing, technologies utilizing relatively abundant and inexpensive carbon-based feedstocks will still play a major role on the scene. Related to this, the aim of the ongoing effort at Brookhaven National Laboratory is to develop technologies for enhancing natural gas and coal usage through liquid phase catalysis. A successful application of this concept in the synthesis of oxygenates is described. The potential impact of this activity on methanol-energy, non-petroleum feedstocks development, H{sub 2}-energy, CO{sub 2}-recycle, and several other areas in relation to CO{sub 2}-mitigation, is also discussed.

Mahajan, D.; Gupta, N.; Kobayashi, A.

1993-07-01T23:59:59.000Z

218

DFT calculations of EPR parameters of transition metal complexes: Implications for catalysis  

SciTech Connect (OSTI)

Transition metal and ligand hyperfine coupling constants for paramagnetic vanadium and copper model complexes have been calculated using DFT methods that are available in commercial software packages. Variations in EPR parameters with ligand identity and ligand orientation are two of the trends that have been investigated with DFT calculations. For example, the systematic variation of the vanadium hyperfine coupling constant with orientation for an imidazole ligand in a VO2+ complex has been observed experimentally and has also been reproduced by DFT calculations. Similarly, changes in the vanadium hyperfine coupling constant with ligand binding have been calculated using model complexes and DFT methods. DFT methods were also used to calculate ligand hyperfine coupling constants in transition metal systems. The variation of the proton hyperfine coupling constant with water ligand orientation was investigated for [VO(H2O)5]2+ and the results were used to interpret high resolution EPR data of VO2+-exchanged zeolites. Nitrogen hyperfine and quadrupole coupling constants for VO2+ model complexes were calculated and compared with experimental data. The computational results were used to enhance the interpretation of the EPR data for vanadium-exchanged zeolites which are promising catalytic materials. The implications of the DFT calculations of EPR parameters with respect to catalysis will be discussed

Saladino, Alexander C.; Larsen, Sarah C.

2005-07-15T23:59:59.000Z

219

Steam catalysis in CaO carbonation under low steam partial pressure  

SciTech Connect (OSTI)

CaO was widely used to capture CO{sub 2} in direct hydrogen production process, where steam always existed simultaneously. The effect of steam on CaO carbonation performance under low steam partial pressure was investigated using a pressurized thermogravimetric apparatus. The experimental results revealed that steam improved CaO carbonation performance significantly no matter whether Ca(OH){sub 2} was produced or not. At 823 K and 0.5 MPa of steam partial pressure, effect of steam on CaO carbonation performance could not be attributed mainly to production of Ca(OH){sub 2} because the hydration rate of CaO was very slow. The main reason was steam catalysis in CaO carbonation. Enhancement of steam on CaO carbonation performance without Ca(OH){sub 2} production could not be attributed to improvement of steam on the physical property, but to catalytic effect of steam. Effects of CaO precursors, CO{sub 2} partial pressure, steam partial pressure, and temperature with steam addition on CaO carbonation performance were also investigated.

Yang, S.J.; Xiao, Y.H. [Chinese Academy of Science, Beijing (China)

2008-06-15T23:59:59.000Z

220

Relativistic calculations of $C_6$ and $C_8$ coefficients for strontium dimers  

E-Print Network [OSTI]

The electric dipole and quadrupole polarizabilities of the $5s5p~^3\\!P_1^o$ state and the $C_6$ and $C_8$ coefficients for the $^1\\!S_0 +\\, ^1\\!S_0$ and $^1\\!S_0 +\\, ^3\\!P_1^o$ dimers of strontium are calculated using a high-precision relativistic approach that combines configuration interaction and linearized coupled-cluster methods. Our recommended values of the long range dispersion coefficients for the $0_u$ and $1_u$ energy levels are $C_6(0_u)=3771(32)$ a.u. and $C_6(1_u)= 4001(33)$ a.u., respectively. They are in good agreement with recent results from experimental photoassociation data. We also calculate $C_8$ coefficients for Sr dimers, which are needed for precise determination of long-range interaction potential. We confirm the experimental value for the magic wavelength, where the Stark shift on the $^1\\!S_0$-$^3\\!P_1^o$ transition vanishes. The accuracy of calculations is analyzed and uncertainties are assigned to all quantities reported in this work.

S. G. Porsev; M. S. Safronova; Charles W. Clark

2014-09-21T23:59:59.000Z

Note: This page contains sample records for the topic "ruthenium dimer catalysis" 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

Computational Mechanistic Studies of Acid-Catalyzed Lignin Model Dimers for Lignin Depolymerization  

SciTech Connect (OSTI)

Lignin is a heterogeneous alkyl-aromatic polymer that constitutes up to 30% of plant cell walls, and is used for water transport, structure, and defense. The highly irregular and heterogeneous structure of lignin presents a major obstacle in the development of strategies for its deconstruction and upgrading. Here we present mechanistic studies of the acid-catalyzed cleavage of lignin aryl-ether linkages, combining both experimental studies and quantum chemical calculations. Quantum mechanical calculations provide a detailed interpretation of reaction mechanisms including possible intermediates and transition states. Solvent effects on the hydrolysis reactions were incorporated through the use of a conductor-like polarizable continuum model (CPCM) and with cluster models including explicit water molecules in the first solvation shell. Reaction pathways were computed for four lignin model dimers including 2-phenoxy-phenylethanol (PPE), 1-(para-hydroxyphenyl)-2-phenoxy-ethanol (HPPE), 2-phenoxy-phenyl-1,3-propanediol (PPPD), and 1-(para-hydroxyphenyl)-2-phenoxy-1,3-propanediol (HPPPD). Lignin model dimers with a para-hydroxyphenyl ether (HPPE and HPPPD) show substantial differences in reactivity relative to the phenyl ether compound (PPE and PPPD) which have been clarified theoretically and experimentally. The significance of these results for acid deconstruction of lignin in plant cell walls will be discussed.

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

2013-01-01T23:59:59.000Z

222

Vibrations, Tunneling, and Transition Dipole Moments in the Water Dimer Michael J. Smit, Gerrit C. Groenenboom, Paul E. S. Wormer, and Ad van der Avoird*  

E-Print Network [OSTI]

shows that only the states of E( symmetry of the water dimer have a permanent dipole moment. A model dipole moment of the E( states. 1. Introduction Liquid water is the most important biological substanceVibrations, Tunneling, and Transition Dipole Moments in the Water Dimer Michael J. Smit, Gerrit C

223

MOLYBDENUM, RUTHENIUM, AND THE HEAVY r-PROCESS ELEMENTS IN MODERATELY METAL-POOR MAIN-SEQUENCE TURNOFF STARS  

SciTech Connect (OSTI)

The ratios of elemental abundances observed in metal-poor stars of the Galactic halo provide a unique present-day record of the nucleosynthesis products of its earliest stars. While the heaviest elements were synthesized by the r- and s-processes, dominant production mechanisms of light trans-ironic elements were obscure until recently. This work investigates further our 2011 conclusion that the low-entropy regime of a high-entropy wind (HEW) produced molybdenum and ruthenium in two moderately metal-poor turnoff stars that showed extreme overabundances of those elements with respect to iron. Only a few, rare nucleosynthesis events may have been involved. Here we determine abundances for Mo, Ru, and other trans-Fe elements for 28 similar stars by matching spectral calculations to well-exposed near-UV Keck HIRES spectra obtained for beryllium abundances. In each of the 26 turnoff stars with Mo or Ru line detections and no evidence for s-process production (therefore old), we find Mo and Ru to be three to six times overabundant. In contrast, the maximum overabundance is reduced to factors of three and two for the neighboring elements zirconium and palladium. Since the overproduction peaks sharply at Mo and Ru, a low-entropy HEW is confirmed as its origin. The overabundance level of the heavy r-process elements varies significantly, from none to a factor of four, but is uncorrelated with Mo and Ru overabundances. Despite their moderate metallicity, stars in this group trace the products of different nucleosynthetic events: possibly very few events, possibly events whose output depended on environment, metallicity, or time.

Peterson, Ruth C. [Astrophysical Advances, 607 Marion Place, Palo Alto, CA 94301 (United States)

2013-05-01T23:59:59.000Z

224

Opportunities for Catalysis in The 21st Century. A report from the Basic Energy Sciences Advisory Committee  

SciTech Connect (OSTI)

Chemical catalysis affects our lives in myriad ways. Catalysis provides a means of changing the rates at which chemical bonds are formed and broken and of controlling the yields of chemical reactions to increase the amounts of desirable products from these reactions and reduce the amounts of undesirable ones. Thus, it lies at the heart of our quality of life: The reduced emissions of modern cars, the abundance of fresh food at our stores, and the new pharmaceuticals that improve our health are made possible by chemical reactions controlled by catalysts. Catalysis is also essential to a healthy economy: The petroleum, chemical, and pharmaceutical industries, contributors of $500 billion to the gross national product of the United States, rely on catalysts to produce everything from fuels to ''wonder drugs'' to paints to cosmetics. Today, our Nation faces a variety of challenges in creating alternative fuels, reducing harmful by-products in manufacturing, cleaning up the environment and preventing future pollution, dealing with the causes of global warming, protecting citizens from the release of toxic substances and infectious agents, and creating safe pharmaceuticals. Catalysts are needed to meet these challenges, but their complexity and diversity demand a revolution in the way catalysts are designed and used. This revolution can become reality through the application of new methods for synthesizing and characterizing molecular and material systems. Opportunities to understand and predict how catalysts work at the atomic scale and the nanoscale are now appearing, made possible by breakthroughs in the last decade in computation, measurement techniques, and imaging and by new developments in catalyst design, synthesis, and evaluation.

White, J. M.; Bercaw, J.

2002-05-16T23:59:59.000Z

225

Structural, Spectroscopic, And Theoretical Elucidation of a Redox-Active Pincer-Type Ancillary Applied in Catalysis  

SciTech Connect (OSTI)

Pincer-type ligands are believed to be very robust scaffolds that can support multifarious functionalities as well as highly reactive metal motifs applied in organometallic chemistry, especially in the realm of catalysis. In this paper, we describe the redox and, therefore, noninnocent behavior of a PNP (PNP{sup -} = N[2-P(CHMe{sub 2}){sub 2}-4-methylphenyl]{sub 2}) pincer ancillary bound to nickel. A combination of structural, spectroscopic, and theoretical techniques suggests that this type of framework can house an electron hole when coordinated to Ni(II).

Adhikari, D.; Mossin, S.; Basuli, F.; Huffman, J.C.; Szilagyi, R.K.; Meyer, K.; Mindiola, D.J.

2009-05-11T23:59:59.000Z

226

Copyright 01990 by the Genetics Society of America Synapsis-MediatedFusion of Free DNA Ends Forms Inverted Dimer  

E-Print Network [OSTI]

Inverted Dimer Plasmids in Yeast Sam Kunes, David Botstein' and Maurice S. Fox Department of Biology plasmid DNA and the endsof the plasmid do not share homology with the yeast genome, circular inverted of genetically marked plasmids, we show that two plasmid molecules are required to form an inverted dimerplasmid

Botstein, David

227

Phase transition between quantum and classical regimes for the escape rate of dimeric molecular nanomagnets in a staggered magnetic field  

E-Print Network [OSTI]

We study the phase transition of the escape rate of exchange-coupled dimer of single-molecule magnets which are coupled either ferromagnetic ally or antiferromagnetically in a staggered magnetic field and an easy $z$-axis anisotropy. The Hamiltonian for this system has been used to study molecular dimer nanomagnets [Mn$_4$]$_2$. We generalize the method of mapping a single-molecule magnetic spin problem onto a quantum-mechanical particle to dimeric molecular nanomagnets. The problem is mapped to a single particle quantum-mechanical Hamiltonian in terms of the relative coordinate and a coordinate dependent reduced mass. It is shown that the presence of the external staggered magnetic field creates a phase boundary separating the first- from the second-order transition. With the set of parameters used by R. Tiron, $\\textit{et al}$, \\prl {\\bf 91}, 227203 (2003), and S. Hill, $\\textit{et al}$ science {\\bf 302}, 1015 (2003) to fit experimental data for [Mn$_{4}$]$_2$ dimer we find that the critical temperature at the phase boundary is $T^{(c)}_0 =0.29K$. Therefore, thermally activated transitions should occur for temperatures greater than $T^{(c)}_0$.

Solomon Akaraka Owerre; M. B Paranjape

2014-07-02T23:59:59.000Z

228

A Two-site Kinetic Mechanism for ATP Binding and Hydrolysis by E. coli Rep Helicase Dimer Bound to a  

E-Print Network [OSTI]

A Two-site Kinetic Mechanism for ATP Binding and Hydrolysis by E. coli Rep Helicase Dimer Bound that are coupled to ATP binding and hydrolysis. We have investi- gated the kinetic mechanism of ATP binding 17(Ã?2) sÃ?1 ; KM 3 mM), pre-steady-state studies provide evidence for a two-ATP site mechanism

Lohman, Timothy M.

229

Fermion-dimer scattering using an impurity lattice Monte Carlo approach and the adiabatic projection method  

E-Print Network [OSTI]

We present lattice Monte Carlo calculations of fermion-dimer scattering in the limit of zero-range interactions using the adiabatic projection method. The adiabatic projection method uses a set of initial cluster states and Euclidean time projection to give a systematically improvable description of the low-lying scattering cluster states in a finite volume. We use L\\"uscher's finite-volume relations to determine the s-wave, p-wave, and d-wave phase shifts. For comparison, we also compute exact lattice results using Lanczos iteration and continuum results using the Skorniakov-Ter-Martirosian equation. For our Monte Carlo calculations we use a new lattice algorithm called impurity lattice Monte Carlo. This algorithm can be viewed as a hybrid technique which incorporates elements of both worldline and auxiliary-field Monte Carlo simulations.

Serdar Elhatisari; Dean Lee

2014-12-01T23:59:59.000Z

230

Structure, Vol. 10, 673686, May, 2002, 2002 Elsevier Science Ltd. All rights reserved. PII S0969-2126(02)00758-X The Domain-Swapped Dimer of Cyanovirin-N Is  

E-Print Network [OSTI]

Institute NCI-Frederick Here we report on studies concerning the domain- swapped dimer formed by the potent-2126(02)00758-X The Domain-Swapped Dimer of Cyanovirin-N Is in a Metastable Folded State: Reconciliation of X-Ray and NMR Structures classical example for a domain-swapped dimer is bo- vine pancreatic ribonuclease

231

Dimer Structure of an Interfacially Impaired Phosphatidylinositol-Specific Pholpholipase C  

SciTech Connect (OSTI)

The crystal structure of the W47A/W242A mutant of phosphatidylinositol-specific phospholipase C (PI-PLC) from Bacillus thuringiensis has been solved to 1.8{angstrom} resolution. The W47A/W242A mutant is an interfacially challenged enzyme, and it has been proposed that one or both tryptophan side chains serve as membrane interfacial anchors (Feng, J., Wehbi, H., and Roberts, M. F. (2002) J. Biol. Chem. 277, 19867-19875). The crystal structure supports this hypothesis. Relative to the crystal structure of the closely related (97% identity) wild-type PI-PLC from Bacillus cereus, significant conformational differences occur at the membrane-binding interfacial region rather than the active site. The Trp {yields} Ala mutations not only remove the membrane-partitioning aromatic side chains but also perturb the conformations of the so-called helix B and rim loop regions, both of which are implicated in interfacial binding. The crystal structure also reveals a homodimer, the first such observation for a bacterial PI-PLC, with pseudo-2-fold symmetry. The symmetric dimer interface is stabilized by hydrophobic and hydrogen-bonding interactions, contributed primarily by a central swath of aromatic residues arranged in a quasiherringbone pattern. Evidence that interfacially active wild-type PI-PLC enzymes may dimerize in the presence of phosphatidylcholine vesicles is provided by fluorescence quenching of PI-PLC mutants with pyrene-labeled cysteine residues. The combined data suggest that wild-type PI-PLC can form similar homodimers, anchored to the interface by the tryptophan and neighboring membrane-partitioning residues.

Shao,C.; Shi, X.; Wehbi, H.; Zambonelli, C.; Head, J.; Seaton, B.; Roberts, M,.

2007-01-01T23:59:59.000Z

232

Electrochemical investigations of polymer films and monolayers on electrode surfaces: Determination of the reaction entropy for Os(bpy)[sub 3][sup 3+/2+] in nafion, and the influence of supporting electrolyte activity on the formal potential of a monolayer containing a ruthenium redox center, and, Synthesis and characterization of monometallic and bimetallic complexes of ruthenium(II) and iron(II) with 4,4[prime]bipyrimidine (4,4[prime]BPM) and pyridyl viologen (PV[sup 2+])  

SciTech Connect (OSTI)

This thesis is comprised of two major projects: An analytical project and an inorganic synthesis project. The first project dealt with the investigation of the electrochemistry of thin polymer films and monolayers on electrode surfaces. The second project dealt with the synthesis of novel monometallic and bimetallic complexes of ruthenium and iron in which the metals were bridged by either 4, 4[prime] bipyrimidine or pyridyl viologen. The first project involved the investigation of the reaction entropy for a redox couple which had been exchanged into an ion-exchange polymer on an electrode surface. The measured values for the reaction entropy were shown to be dominated by the entropy change for partitioning the redox couple into the film and by supporting electrolyte cation transfer between the film and the polymer. Electrochemical studies were also carried out on an alkanethiol monolayer which contained a ruthenium redox center at the monolayer/solution interface. The electrochemistry supported the fact that the monolayer was displaying permselective behavior with the exclusion of supporting electrolyte cations from the monolayer. Equations were presented that described the electrochemical nature of the monolayer and the dependence of the formal potential for the monolayer on the supporting electrolyte cation transfer at the monolayer/solution interface. The second section of the thesis dealt with the synthesis and characterization of a number of novel ruthenium and iron complexes utilizing 4,4[prime] bipyrimidine and pyridyl viologen. The complexes show shifts in the energy of the MLCT bands and reduction potentials which can be correlated to either the reduction potential of the ligand involved in the complex or the relationship between iron and ruthenium in the group VIII family. Comparisons are made between the complexes studied and a number of ruthenium and iron complexes of nitrogen heterocycles from the literature.

Tunison, H.M.

1992-01-01T23:59:59.000Z

233

Water addition for increased CO/H[sub 2] hydrocarbon synthesis activity over catalysts comprising cobalt, ruthenium and mixtures thereof which may include a promoter metal  

SciTech Connect (OSTI)

A once-through, fixed or slurry bed Fischer Tropsch process is described with enhanced CO conversion activity and C[sub 5] + liquid hydrocarbon selectivity comprising contacting a feed mixture of carbon monoxide and hydrogen in a reaction zone with about 1 Vol % to about 70 Vol % water based on the total volume of feed mixture, at a pressure above one atmosphere and a temperature ranging from about 150 C to about 300 C, with a catalyst selected from the group consisting of cobalt, ruthenium, and mixtures thereof on a titania support, wherein said titania support is less than 40 m[sup 2]/g, converting at least 90 Vol % of the carbon monoxide to liquid hydrocarbons, and in the substantial absence of CO[sub 2] formation.

Kim, C.J.

1993-07-13T23:59:59.000Z

234

Investigation of the release of Si from SiO{sub 2} during the formation of manganese/ruthenium barrier layers  

SciTech Connect (OSTI)

The thermodynamic and structural stability of ruthenium-manganese diffusion barriers on SiO{sub 2} is assessed. A {approx}2 nm film composed of partially oxidized manganese (MnO{sub x} where x < 1) was deposited on a 3 nm thick Ru film and the Mn-MnO{sub x}/Ru/SiO{sub 2} structure was subsequently thermally annealed. X-ray photoelectron spectroscopy and secondary ion mass spectroscopy studies suggest the release and upward diffusion of Si from the dielectric substrate as a result of manganese-silicate formation at the Ru/SiO{sub 2} interface. The migration of Si up through the Ru film results in further manganese-silicate formation upon its interaction with the Mn-MnO{sub x} deposited layer.

McCoy, A. P.; Casey, P.; Bogan, J.; Byrne, C.; Hughes, G. [School of Physical Sciences, Dublin City University, Dublin 9 (Ireland)] [School of Physical Sciences, Dublin City University, Dublin 9 (Ireland)

2013-05-20T23:59:59.000Z

235

Heat capacity of the site-diluted spin dimer system Ba?(Mn1-xVx)?O?  

DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

Heat-capacity and susceptibility measurements have been performed on the diluted spin dimer compound Ba?(Mn1-xVx)?O?. The parent compound Ba?Mn?O? is a spin dimer system based on pairs of antiferromagnetically coupled S=1, 3d² Mn?? ions such that the zero-field ground state is a product of singlets. Substitution of nonmagnetic S=0, 3d? V?? ions leads to an interacting network of unpaired Mn moments, the low-temperature properties of which are explored in the limit of small concentrations 0?x?0.05. The zero-field heat capacity of this diluted system reveals a progressive removal of magnetic entropy over an extended range of temperatures, with no evidence for a phase transition. The concentration dependence does not conform to expectations for a spin-glass state. Rather, the data suggest a low-temperature random singlet phase, reflecting the hierarchy of exchange energies found in this system.

Samulon, E. C.; Shapiro, M. C.; Fisher, I. R.

2011-08-01T23:59:59.000Z

236

Communication: Towards the binding energy and vibrational red shift of the simplest organic hydrogen bond: Harmonic constraints for methanol dimer  

SciTech Connect (OSTI)

The discrepancy between experimental and harmonically predicted shifts of the OH stretching fundamental of methanol upon hydrogen bonding to a second methanol unit is too large to be blamed mostly on diagonal and off-diagonal anharmonicity corrections. It is shown that a decisive contribution comes from post-MP2 electron correlation effects, which appear not to be captured by any of the popular density functionals. We also identify that the major deficiency is in the description of the donor OH bond. Together with estimates for the electronic and harmonically zero-point corrected dimer binding energies, this work provides essential constraints for a quantitative description of this simple hydrogen bond. The spectroscopic dissociation energy is predicted to be larger than 18 kJ/mol and the harmonic OH-stretching fundamental shifts by about ?121 cm{sup ?1} upon dimerization, somewhat more than in the anharmonic experiment (?111 cm{sup ?1})

Heger, Matthias; Suhm, Martin A.; Mata, Ricardo A., E-mail: rmata@gwdg.de [Georg-August-Universität Göttingen, Institut für Physikalische Chemie, Tammannstr. 6, 37077 Göttingen (Germany)

2014-09-14T23:59:59.000Z

237

SELECTIVE REDUCTION OF NOX IN OXYGEN RICH ENVIRONMENTS WITH PLASMA-ASSISTED CATALYSIS: CATALYST DEVELOPMENT AND MECHANISTIC STUDIES  

SciTech Connect (OSTI)

The control of NOx (NO and NO2) emissions from so-called ''lean-burn'' vehicle engines remains a challenge. In recent years, there have been a number of reports that show that a plasma device combined with a catalyst can reduce as high as 90% or more of NOx in simulated diesel and other ''lean-burn'' exhaust. In the case of propylene containing simulated diesel exhaust, the beneficial role of a plasma treatment is now thought to be due to oxidation of NO to NO2, and the formation of partially oxidized hydrocarbons that are more active for the catalytic reduction of NO2 than propylene. Thus, the overall system can be most usefully described as hydrocarbon selective catalytic reduction (SCR) enhanced by 'reforming' the exhaust with a non-thermal plasma (NTP) device. For plasma-enhanced catalysis, both zeolite- and alumina-based materials have shown high activity, albeit in somewhat different temperature ranges, when preceded by an NTP reactor. This paper will briefly describe our research efforts aimed at optimizing the catalyst materials for NTP-catalysis devices based, in part, on our continuing studies of the NTP- and catalytic-reaction mechanisms. Various alkali- and alkaline earth-cation-exchanged Y zeolites have been prepared, their material properties characterized, and they have been tested as catalytic materials for NOx reduction in laboratory NTP-catalysis reactors. Interestingly, NO2 formed in the plasma and not subsequently removed over these catalysts, will back-convert to NO, albeit to varying extents depending upon the nature of the cation. Besides this comparative reactivity, we will also discuss selected synthesis strategies for enhancing the performance of these zeolite-based catalyst materials. A particularly important result from our mechanistic studies is the observation that aldehydes, formed during the plasma treatment of simulated diesel exhaust, are the important species for the reduction of NOx to N2. Indeed, acetaldehyde has been found to be especially effective in the thermal reduction of both NO and NO2 over Ba- and Na-Y zeolite catalysts.

Peden, C; Barlow, S; Hoard, J; Kwak, J; *Balmer-Millar, M; *Panov, A; Schmieg, S; Szanyi, J; Tonkyn, R

2003-08-24T23:59:59.000Z

238

Modulation of Bacillus thuringiensis Phosphatidylinositol-Specific Phospholipase C Activity by Mutations in the Putative Dimerization Interface  

SciTech Connect (OSTI)

Cleavage of phosphatidylinositol (PI) to inositol 1,2-(cyclic)-phosphate (cIP) and cIP hydrolysis to inositol 1-phosphate by Bacillus thuringiensis phosphatidylinositol-specific phospholipase C are activated by the enzyme binding to phosphatidylcholine (PC) surfaces. Part of this reflects improved binding of the protein to interfaces. However, crystallographic analysis of an interfacially impaired phosphatidylinositol-specific phospholipase (W47A/W242A) suggested protein dimerization might occur on the membrane. In the W47A/W242A dimer, four tyrosine residues from one monomer interact with the same tyrosine cluster of the other, forming a tight dimer interface close to the membrane binding regions. We have constructed mutant proteins in which two or more of these tyrosine residues have been replaced with serine. Phospholipid binding and enzymatic activity of these mutants have been examined to assess the importance of these residues to enzyme function. Replacing two tyrosines had small effects on enzyme activity. However, removal of three or four tyrosine residues weakened PC binding and reduced PI cleavage by the enzyme as well as PC activation of cIP hydrolysis. Crystal structures of Y247S/Y251S in the absence and presence of myo-inositol as well as Y246S/Y247S/Y248S/Y251S indicate that both mutant proteins crystallized as monomers, were very similar to one another, and had no change in the active site region. Kinetic assays, lipid binding, and structural results indicate that either (i) a specific PC binding site, critical for vesicle activities and cIP activation, has been impaired, or (ii) the reduced dimerization potential for Y246S/Y247S/Y248S and Y246S/Y247S/Y248S/Y251S is responsible for their reduced catalytic activity in all assay systems.

Shi, X.; Shao, C; Zhang, X; Zambonelli, C; Redfield, A; Head, J; Seaton, B; Roberts, M

2009-01-01T23:59:59.000Z

239

Spectroscopic signatures of proton transfer dynamics in the water dimer cation  

SciTech Connect (OSTI)

Using full dimensional EOM-IP-CCSD/aug-cc-pVTZ potential energy surfaces, the photoelectron spectrum, vibrational structure, and ionization dynamics of the water dimer radical cation, (H2O)+2, were computed. We also report an experimental photoelectron spectrum which is derived from photoionization efficiency measurements and compares favorably with the theoretical spectrum. The vibrational structure is also compared with the recent experimental work of Gardenier et al. [J. Phys. Chem. A 113, 4772 (2009)] and the recent theoretical calculations by Cheng et al. [J. Phys. Chem. A 113 13779 (2009)]. A reduced dimensionality nuclear Hamiltonian was used to compute the ionization dynamics for both the ground state and first excited state of the cation. The dynamics show markedly different behavior and spectroscopic signatures depending on which state of the cation is accessed by the ionization. Ionization to the ground-state cation surface induces a hydrogen transfer which is complete within 50 femtoseconds, whereas ionization to the first excited state results in a much slower process.

Kamarchik, Eugene; Kostko, Oleg; Bowman, Joel M.; Ahmed, Musahid; Krylov, Anna I.

2009-12-21T23:59:59.000Z

240

Universality of weakly bound dimers and Efimov trimers close to Li-Cs Feshbach resonances  

E-Print Network [OSTI]

We study the interspecies scattering properties of ultracold Li-Cs mixtures in their two energetically lowest spin channels in the magnetic field range between 800 G and 1000 G. Close to two broad Feshbach resonances we create weakly bound LiCs dimers by radio-frequency association and measure the dependence of the binding energy on the external magnetic field strength. Based on the binding energies and complementary atom loss spectroscopy of three other Li-Cs s-wave Feshbach resonances we construct precise molecular singlet and triplet electronic ground state potentials using a coupled-channels calculation. We extract the Li-Cs interspecies scattering length as a function of the external field and obtain almost a ten-fold improvement in the precision of the values for the pole positions and widths of the s-wave Li-Cs Feshbach resonances as compared to our previous work [Pires \\textit{et al.}, Phys. Rev. Lett. \\textbf{112}, 250404 (2014)]. We discuss implications on the Efimov scenario and the universal geome...

Ulmanis, J; Pires, R; Kuhnle, E D; Weidemüller, M; Tiemann, E

2015-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "ruthenium dimer catalysis" 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

Boron-nitrogen-hydrogen (BNH) compounds: recent developments in hydrogen storage, applications in hydrogenation and catalysis, and new syntheses  

SciTech Connect (OSTI)

The strong efforts devoted to the exploration of BNH compounds for hydrogen storage have led to impressive advances in the field of boron chemistry. This review summarizes progress in this field from three aspects. It starts with the most recent developments in using BNH compounds for hydrogen storage, covering NH3BH3, B3H8¯ containing compounds, and CBN compounds. The following section then highlights interesting applications of BNH compounds in hydrogenation and catalysis. The last part is focused on breakthroughs in the syntheses and discovery of new BNH organic analogues. The role of N?H?+•••H?-?B dihydrogen interactions in molecule packing, thermal hydrogen evolution, and syntheses is also discussed within the review. Part of this research is supported by the U.S. Department of Energy’s Basic Energy Sciences, Division of Chemical Sciences, Biosciences and Geosciences. Pacific Northwest National Laboratory is operated by Battelle.

Huang, Zhenguo; Autrey, Thomas

2012-11-15T23:59:59.000Z

242

Methanol Synthesis over Cu/ZnO/Al2O3: The Active Site in Industrial Catalysis  

SciTech Connect (OSTI)

Unlike homogeneous catalysts, heterogeneous catalysts that have been optimized through decades are typically so complex and hard to characterize that the nature of the catalytically active site is not known. This is one of the main stumbling blocks in developing rational catalyst design strategies in heterogeneous catalysis. We show here how to identify the crucial atomic structure motif for the industrial Cu/ZnO/Al{sub 2}O{sub 3} methanol synthesis catalyst. Using a combination of experimental evidence from bulk-, surface-sensitive and imaging methods collected on real high-performance catalytic systems in combination with DFT calculations. We show that the active site consists of Cu steps peppered with Zn atoms, all stabilized by a series of well defined bulk defects and surface species that need jointly to be present for the system to work.

Behrens, Malte

2012-03-28T23:59:59.000Z

243

Crystal Structure of 12-Lipoxygenase Catalytic-Domain-Inhibitor Complex Identifies a Substrate-Binding Channel for Catalysis  

SciTech Connect (OSTI)

Lipoxygenases are critical enzymes in the biosynthesis of families of bioactive lipids including compounds with important roles in the initiation and resolution of inflammation and in associated diseases such as diabetes, cardiovascular disease, and cancer. Crystals diffracting to high resolution (1.9 {angstrom}) were obtained for a complex between the catalytic domain of leukocyte 12-lipoxygenase and the isoform-specific inhibitor, 4-(2-oxapentadeca-4-yne)phenylpropanoic acid (OPP). In the three-dimensional structure of the complex, the inhibitor occupied a new U-shaped channel open at one end to the surface of the protein and extending past the redox-active iron site that is essential for catalysis. In models, the channel accommodated arachidonic acid, defining the binding site for the substrate of the catalyzed reaction. There was a void adjacent to the OPP binding site connecting to the surface of the enzyme and providing a plausible access channel for the other substrate, oxygen.

Xu, Shu; Mueser, Timothy C.; Marnett, Lawrence J.; Funk, Jr., Max O. (Toledo); (Vanderbilt)

2014-10-02T23:59:59.000Z

244

Metal carbonyl-hydrosilane reactions and hydrosilation catalysis. Final report for period May 1, 1995 - August 14, 1999  

SciTech Connect (OSTI)

Manganese carbonyl complexes serve as hydrosilation precatalysts for selectively transforming a carbonyl group into a doxy methylene or a fully reduced methylene group. Substrates of interest include (1) aldehydes, ketones, carboxylic acids, silyl esters, and esters, and (2) their organometallic acyl counterparts. Two types of manganese precatalysts have been reported: (a) alkyl and acyl complexes (L)(CO){sub 4}MnR [L = CO, PPh{sub 3}; R = COCH{sub 3}, COPh, CH{sub 3}] and (b) halides (CO){sub 5}MnX and [(CO){sub 4}MnX]{sub 2} (X = Br, I). The former promote hydrosilation and deoxygenation catalysis; the latter promote dehydrogenative silation of alcohols and carboxylic acids as well as hydrosilation and deoxygenation of some metallocarboxylic acid derivatives. In every case studied, these Mn precatalysts are far more reactive or selective than traditional Rh(l) precatalysts. The reaction chemistry of the above and other Mn alkyl complexes with hydrosilanes was studied in order to probe catalysis mechanism(s). Thus, Mn(CO){sub 5} methyl, benzyl, acetyl, and benzoyl (4 p-substituents) complexes reacted with hydrosilines by four different mechanisms, which were established. A noteworthy development was that the methyl and benzoyl complexes gave moderate yields of a new ({eta}{sup 2}-Si-H) silane adduct (CO){sub 4}Mn(SiMe{sub 2}Ph)(H-SiMe{sub 2}Ph), which is stable in the presence of excess silane. This silane adduct promotes all three catalytic reactions; its extraordinary activity and potential selectivity are under study.

Cutler, Alan R.

2001-04-14T23:59:59.000Z

245

Water dimer equilibrium constant calculation: A quantum formulation including metastable states  

SciTech Connect (OSTI)

We present a full quantum evaluation of the water second virial coefficient B(T) based on the Takahashi-Imada second order approximation. As the associated trace Tr[e{sup ??H{sub A}{sub B}}?e{sup ??H{sub A}{sub B}{sup o}}] is performed in the coordinate representation, it does also include contribution from the whole continuum, i.e., resonances and collision pairs of monomers. This approach is compared to a Path Integral Monte Carlo evaluation of this coefficient by Schenter [J. Chem. Phys. 117, 6573 (2002)] for the TIP4P potential and shown to give extremely close results in the low temperature range (250–450 K) reported. Using a recent ab initio flexible potential for the water dimer, this new formulation leads to very good agreement with experimental values over the whole range of temperatures available. The virial coefficient is then used in the well known relation K{sub p}(T) = ?(B(T) ? b{sub M})/RT where the excluded volume b{sub M} is assimilated to the second virial coefficient of pure water monomer vapor and approximated from the inner repulsive part of the interaction potential. This definition, which renders b{sub M} temperature dependent, allows us to retrieve the 38?cm{sup 3}?mol{sup ?1} value commonly used, at room temperature. The resulting values for K{sub p}(T) are in agreement with available experimental data obtained from infrared absorption spectra of water vapor.

Leforestier, Claude, E-mail: claude.leforestier@univ-montp2.fr [Institut Charles Gerhardt, CNRS 5253, CC 15.01, Université Montpellier II-CNRS, 34095 Montpellier Cedex 05 (France)] [Institut Charles Gerhardt, CNRS 5253, CC 15.01, Université Montpellier II-CNRS, 34095 Montpellier Cedex 05 (France)

2014-02-21T23:59:59.000Z

246

A Novel Dimeric Inhibitor Targeting Beta2GPI in Beta2GPI/Antibody Complexes Implicated in Antiphospholipid Syndrome  

SciTech Connect (OSTI)

{beta}2GPI is a major antigen for autoantibodies associated with antiphospholipid syndrome (APS), an autoimmune disease characterized by thrombosis and recurrent pregnancy loss. Only the dimeric form of {beta}2GPI generated by anti-{beta}2GPI antibodies is pathologically important, in contrast to monomeric {beta}2GPI which is abundant in plasma. We created a dimeric inhibitor, A1-A1, to selectively target {beta}2GPI in {beta}2GPI/antibody complexes. To make this inhibitor, we isolated the first ligand-binding module from ApoER2 (A1) and connected two A1 modules with a flexible linker. A1-A1 interferes with two pathologically important interactions in APS, the binding of {beta}2GPI/antibody complexes with anionic phospholipids and ApoER2. We compared the efficiency of A1-A1 to monomeric A1 for inhibition of the binding of {beta}2GPI/antibody complexes to anionic phospholipids. We tested the inhibition of {beta}2GPI present in human serum, {beta}2GPI purified from human plasma and the individual domain V of {beta}2GPI. We demonstrated that when {beta}2GPI/antibody complexes are formed, A1-A1 is much more effective than A1 in inhibition of the binding of {beta}2GPI to cardiolipin, regardless of the source of {beta}2GPI. Similarly, A1-A1 strongly inhibits the binding of dimerized domain V of {beta}2GPI to cardiolipin compared to the monomeric A1 inhibitor. In the absence of anti-{beta}2GPI antibodies, both A1-A1 and A1 only weakly inhibit the binding of pathologically inactive monomeric {beta}2GPI to cardiolipin. Our results suggest that the approach of using a dimeric inhibitor to block {beta}2GPI in the pathological multivalent {beta}2GPI/antibody complexes holds significant promise. The novel inhibitor A1-A1 may be a starting point in the development of an effective therapeutic for antiphospholipid syndrome.

A Kolyada; C Lee; A De Biasio; N Beglova

2011-12-31T23:59:59.000Z

247

Crystal Structure of (+)-[delta]-Cadinene Synthase from Gossypium arboreum and Evolutionary Divergence of Metal Binding Motifs for Catalysis  

SciTech Connect (OSTI)

(+)-{delta}-Cadinene synthase (DCS) from Gossypium arboreum (tree cotton) is a sesquiterpene cyclase that catalyzes the cyclization of farnesyl diphosphate in the first committed step of the biosynthesis of gossypol, a phytoalexin that defends the plant from bacterial and fungal pathogens. Here, we report the X-ray crystal structure of unliganded DCS at 2.4 {angstrom} resolution and the structure of its complex with three putative Mg{sup 2+} ions and the substrate analogue inhibitor 2-fluorofarnesyl diphosphate (2F-FPP) at 2.75 {angstrom} resolution. These structures illuminate unusual features that accommodate the trinuclear metal cluster required for substrate binding and catalysis. Like other terpenoid cyclases, DCS contains a characteristic aspartate-rich D{sup 307}DTYD{sup 311} motif on helix D that interacts with Mg{sub A}{sup 2+} and Mg{sub C}{sup 2+}. However, DCS appears to be unique among terpenoid cyclases in that it does not contain the 'NSE/DTE' motif on helix H that specifically chelates Mg{sub B}{sup 2+}, which is usually found as the signature sequence (N,D)D(L,I,V)X(S,T)XXXE (boldface indicates Mg{sub B}{sup 2+} ligands). Instead, DCS contains a second aspartate-rich motif, D{sup 451}DVAE{sup 455}, that interacts with Mg{sub B}{sup 2+}. In this regard, DCS is more similar to the isoprenoid chain elongation enzyme farnesyl diphosphate synthase, which also contains two aspartate-rich motifs, rather than the greater family of terpenoid cyclases. Nevertheless, the structure of the DCS-2F-FPP complex shows that the structure of the trinuclear magnesium cluster is generally similar to that of other terpenoid cyclases despite the alternative Mg{sub B}{sup 2+} binding motif. Analyses of DCS mutants with alanine substitutions in the D{sup 307}DTYD{sup 311} and D{sup 451}DVAE{sup 455} segments reveal the contributions of these segments to catalysis.

Gennadios, Heather A.; Gonzalez, Veronica; Di Costanzo, Luigi; Li, Amang; Yu, Fanglei; Miller, David J.; Allemann, Rudolf K.; Christianson, David W.; (UPENN); (Cardiff); (UC)

2009-09-11T23:59:59.000Z

248

Protonation effect on the electronic properties of 2-pyridone monomer, dimer and its water clusters: A theoretical study  

SciTech Connect (OSTI)

The CC2 (second order approximate coupled cluster method) has been applied to investigate protonation effect on electronic transition energies of 2-pyridone (2PY), 2-pyridone dimer, and micro-solvated 2-pyridone (0-2 water molecules). The PE profiles of protonated 2-pyridone (2PYH{sup +}) as well as monohydrated 2PYH{sup +} at the different electronic states have been investigated. The {sup 1}??* state in protonated species (2PYH{sup +}) is a barrier free and dissociative state along the O-H stretching coordinate. In this reaction coordinate, the lowest lying {sup 1}??* predissociates the bound S{sub 1}({sup 1}??*) state, connecting the latter to a conical intersection with the S{sub 0} state. These conical intersections lead the {sup 1}??* state to proceed as predissociative state and finally direct the excited system to the ground state. Furthermore, in presence of water molecule, the {sup 1}??* state still remains dissociative but the conical intersection between {sup 1}??* and ground state disappears. In addition, according to the CC2 calculation results, it has been predicted that protonation significantly blue shifts the S{sub 1}-S{sub 0} electronic transition of monomer, dimer, and microhydrated 2-pyridone.

Saed, Behnaz [Department of Chemistry, University of Isfahan, 81746-73441 Isfahan (Iran, Islamic Republic of)] [Department of Chemistry, University of Isfahan, 81746-73441 Isfahan (Iran, Islamic Republic of); Omidyan, Reza, E-mail: r.omidyan@sci.ui.ac.ir, E-mail: reza.omidyan@u-psud.fr [Department of Chemistry, University of Isfahan, 81746-73441 Isfahan (Iran, Islamic Republic of) [Department of Chemistry, University of Isfahan, 81746-73441 Isfahan (Iran, Islamic Republic of); Centre Laser de l’Université Paris Sud (LUMAT, FR, 2764), Bât. 106, Univ. Paris-Sud 11, 91405 Orsay Cedex (France)

2014-01-14T23:59:59.000Z

249

Charge transfer from an adsorbed ruthenium-based photosensitizer through an ultra-thin aluminium oxide layer and into a metallic substrate  

E-Print Network [OSTI]

The interaction of the dye molecule N3 (cis-bis(isothiocyanato)bis(2,2-bipyridyl-4,4'-dicarboxylato)-ruthenium(II)) with the ultra-thin oxide layer on a AlNi(110) substrate, has been studied using synchrotron radiation based photoelectron spectroscopy, resonant photoemission spectroscopy (RPES) and near edge X-ray absorption fine structure spectroscopy (NEXAFS). Calibrated X-ray absorption and valence band spectra of the monolayer and multilayer coverages reveal that charge transfer is possible from the molecule to the AlNi(110) substrate via tunnelling through the ultra-thin oxide layer and into the conduction band edge of the substrate. This charge transfer mechanism is possible from the LUMO+2&3 in the excited state but not from the LUMO, therefore enabling core-hole clock analysis, which gives an upper limit of $6.0\\pm$2.5fs for the transfer time. This indicates that ultra-thin oxide layers are a viable material for use in dye-sensitized solar cells (DSSC), which may lead to reduced recombination effe...

Gibson, Andrew J; Handrup, Karsten; Weston, Matthew; Mayor, Louise C; O'Shea, James N

2014-01-01T23:59:59.000Z

250

Benchmark Theoretical Study of the ?–? Binding Energy in the Benzene Dimer  

SciTech Connect (OSTI)

We establish a new estimate for the interaction energy between two benzene molecules in the parallel displaced (PD) conformation by systematically converging (i) the intra- and intermolecular geometry at the minimum geometry, (ii) the expansion of the orbital basis set and (iii) the level of electron correlation. The calculations were performed at the second order Møller - Plesset perturbation (MP2) and the Coupled Cluster including Singles, Doubles and a perturbative estimate of Triples replacements [CCSD(T)] levels of electronic structure theory. At both levels of theory, by including results corrected for Basis Set Superposition Error (BSSE), we have estimated the Complete Basis Set (CBS) limit by employing the family of Dunning’s correlation consistent polarized valence basis sets. The largest MP2 calculation was performed with the cc-pV6Z basis set (2,772 basis functions), whereas the largest CCSD(T) calculation with the cc-pV5Z basis set (1,752 basis functions). The cluster geometries were optimized with basis sets up to quadruple-? quality, observing that both its intra- and inter-molecular parts have practically converged with the triple-? quality sets. The use of converged geometries was found to play an important role for obtaining accurate estimates for the CBS limits. Our results demonstrate that the binding energies with the families of the plain (cc-pVnZ) and augmented (aug-cc-pVnZ) sets converge [to within < 0.01 kcal/mol for MP2 and < 0.15 kcal/mol for CCSD(T)] to the same CBS limit. In addition, the average of the uncorrected and BSSEcorrected binding energies was found to converge to the same CBS limit must faster than either of the two constituents (uncorrected or BSSE-corrected binding energies). Due to the fact that the family of augmented basis sets (especially for the larger sets) causes serious linear dependency problems, the plain basis sets (for which no linear dependencies were found) are deemed as a more efficient and straightforward path for obtaining an accurate CBS limit. We considered extrapolations of the uncorrected (?𝐸) and BSSE-corrected (?𝐸!") binding energies, their average value (?𝐸!"#) as well as the average of the latter over the plain and augmented sets (?𝐸!"#) with the cardinal number of the basis set n. Our best estimate of the CCSD(T)/CBS limit for the ?-? interaction energy in the PD benzene dimer is De = 2.65 ± 0.02 kcal/mol. The best CCSD(T)/cc-pV5Z calculated value is 2.62 kcal/mol, just 0.03 kcal/mol away from the CBS limit. For comparison, the MP2/CBS limit estimate is 5.00 ± 0.01 kcal/mol, demonstrating a 90% overbinding with respect to CCSD(T). The Spin-Component-Scaled (SCS) MP2 variant was found to closely reproduce the CCSD(T) results for each basis set, while Scaled-Opposite-Spin (SOS) yielded results that are too low when compared to CCSD(T).

Miliordos, Evangelos; Apra, Edoardo; Xantheas, Sotiris S.

2014-09-04T23:59:59.000Z

251

2,2[prime]:4,4[double prime]:4[prime],4[prime][double prime]-quaterpyridyl: A building block for the preparation of novel redox reagents. 2. Bis(2,2[prime]-bipyridine)ruthenium(II) complexes  

SciTech Connect (OSTI)

The syntheses and properties of three new ruthenium(II) complexes based on the ligand 2,2[prime]:4,4[double prime]:4[prime],4[prime][double prime]-quaterpyridyl (qpy) are reported. Each new complex is of the type [Ru(bpy)[sub 2]L][sup n+], where L is the parent qpy ligand or is qpy derivatized by the methylation of one or both of the non-[alpha]-diimine nitrogen atoms and n = 2, 3, or 4. The photophysical and electrochemical properties of the new complex ions are reported. The parent ion [Ru(bpy)[sub 2]qpy][sup 2+] is strongly luminescent and has a relatively long lifetime, e.g. in excess of 1400 ns in acetonitrile solution. In contrast, the lifetime of the dimethyl derivative [Ru(bpy)[sub 2](qpyme[sub 2])][sup 4+] is less than 100 ns. This dimethylated complex has some novel properties. The excited state produced by M-L excitation to the qpyme[sub 2][sup 2+] ligand can be considered in terms of a Ru(III) core and a positively charged ligand. Typically, the excited states of other ruthenium(II) diimine complexes have had neutral or negatively charged ligands. Further, in structural terms, the complex can be considered as an intramolecular assembly of a ruthenium(II) diimine site and a viologen site. Cyclic voltammetry indicates that the first two electrons added to the complex enter the viologen-like acceptor site constituted by the qpyme[sub 2][sup 2+] ligand.

Bierig, K.; Morgan, R.J.; Tysoe, S.; Gafney, H.D.; Strekas, T.C.; Baker, A.D. (City Univ. of New York, Flushing (United States))

1991-12-25T23:59:59.000Z

252

Nuclear Factor-KB Dimer Exchange Promotes a p21waf1/cip1 Superinduction Response in Human T Leukemic Cells  

E-Print Network [OSTI]

Nuclear Factor-KB Dimer Exchange Promotes a p21waf1/cip1 Superinduction Response in Human ability to induce p21waf1/cip1 . Here, we provide evidence that sequential NF-KB-activating signals induce heightened NF-KB DNA binding and p21waf1/cip1 induction in CEM and additional T leukemic cell lines

Miyamoto, Shigeki

253

Effect of dimerization on dynamics of spin-charge separation in Pariser-Parr-Pople model: A time-dependent DMRG study  

E-Print Network [OSTI]

We investigate the effect of static electron-phonon coupling, on real-time dynamics of spin and charge transport in $\\pi$-conjugated polyene chains. The polyene chain is modeled by the Pariser-Parr-Pople Hamiltonian with dimerized nearest-neighbor parameter $t_{0}(1+\\delta)$ for short bonds and $t_{0}(1-\\delta)$ for long bonds, and long-range electron-electron interactions. We follow the time evolution of the spin and charge using time-dependent DMRG technique, when a hole is injected at one end of the chain in its ground state. We find that spin and charge dynamics followed through spin and charge velocities, depend both on chain length and extent of dimerization, $\\delta$. Analysis of the results requires focusing on physical quantities such as average spin and charge polarizations, particularly in the large dimerization limit. In the dimerization range 0.0 $\\le$ $\\delta$ $\\le$ 0.15, spin-charge dynamics is found to have a well defined behavior, with spin-charge separation (measured as the ratio of charge v...

Dutta, Tirthankar

2011-01-01T23:59:59.000Z

254

THE JOURNAL OF CHEMICAL PHYSICS VOLUME 58, NUMBER 2 15 JANUARY 1973 Internal state distribution of alkali dimers in supersonic nozzle beams*  

E-Print Network [OSTI]

of alkali dimers in supersonic nozzle beams* M. P. Sinha, A. Schultzt, and R. N. Zare Department o the white light and laser-induced fluorescence excited in a nozzle beam of Na2 molecules, we have measured beams with various stagnation pressures (50-240 torr) of alkali metal and with nozzles of different

Zare, Richard N.

255

High Throughput Sample Preparation and Analysis for DNA Sequencing, PCR and Combinatorial Screening of Catalysis Based on Capillary Array Technique  

SciTech Connect (OSTI)

Sample preparation has been one of the major bottlenecks for many high throughput analyses. The purpose of this research was to develop new sample preparation and integration approach for DNA sequencing, PCR based DNA analysis and combinatorial screening of homogeneous catalysis based on multiplexed capillary electrophoresis with laser induced fluorescence or imaging UV absorption detection. The author first introduced a method to integrate the front-end tasks to DNA capillary-array sequencers. protocols for directly sequencing the plasmids from a single bacterial colony in fused-silica capillaries were developed. After the colony was picked, lysis was accomplished in situ in the plastic sample tube using either a thermocycler or heating block. Upon heating, the plasmids were released while chromsomal DNA and membrane proteins were denatured and precipitated to the bottom of the tube. After adding enzyme and Sanger reagents, the resulting solution was aspirated into the reaction capillaries by a syringe pump, and cycle sequencing was initiated. No deleterious effect upon the reaction efficiency, the on-line purification system, or the capillary electrophoresis separation was observed, even though the crude lysate was used as the template. Multiplexed on-line DNA sequencing data from 8 parallel channels allowed base calling up to 620 bp with an accuracy of 98%. The entire system can be automatically regenerated for repeated operation. For PCR based DNA analysis, they demonstrated that capillary electrophoresis with UV detection can be used for DNA analysis starting from clinical sample without purification. After PCR reaction using cheek cell, blood or HIV-1 gag DNA, the reaction mixtures was injected into the capillary either on-line or off-line by base stacking. The protocol was also applied to capillary array electrophoresis. The use of cheaper detection, and the elimination of purification of DNA sample before or after PCR reaction, will make this approach an attractive alternative to current methods for genetic analysis and disease diagnosis.

Yonghua Zhang

2002-05-27T23:59:59.000Z

256

Low-temperature emission spectra of 9-alkylanthracene esters: Dimer photodecomposition and monomer pair interactions in polymer hosts  

SciTech Connect (OSTI)

Effects due to variation in the alkyl chain length of photodimers of 9-alkylanthracene esters on their photodecomposition efficiencies at 12 K and, by implication, the photoproduct migration as a function of temperature within polymer hosts are investigated. It is shown that dimers with longer alkyl chains have a lower photodecomposition efficiency. The extent of photoproduct migration within the polymer following photodecomposition was also studied as a function of alkyl chain length. This migration and its modulation of the interaction between the separating monomers is shown to affect the emission spectrum. Thus, monomer migration was studied in temperature cycling experiments. It was also found, for the polymer hosts investigated - poly(methyl methacrylate), poly(vinyl chloride), and polystyrene - that these properties are host dependent. This result is probably due to the void space differences that exist among these polymers. 17 refs., 10 figs.

Salt, K.; Scott, G.W. (Univ. of California, Riverside, CA (United States))

1994-10-06T23:59:59.000Z

257

Ruthenium bis-Diimine Complexes with a Chelating Thioether Ligand: Delineating 1,10-Phenanthrolinyl and 2,2'-Bipyridyl Ligand Substituent Effects  

SciTech Connect (OSTI)

A new series of ruthenium(II) bis-diimine complexes with a chelating thioether donor ligand has been prepared: Ru(diimine)2(dpte)2+ (diimine=1,10-phenanthroline (phen) (1); 5-CH3-phen (2), 5-Cl-phen (3); 5-Br-phen (4); 5-NO2-phen (5); 3,4,7,8-tetramethyl-phen (6); 4,7-diphenyl-phen (7); 5,5'-dimethyl-2,2'-bipyridine (8); 4,4'-di-tert-butyl-2,2'-bipyridine (9)). Crystal structures of 2, 5, 7 and 9 show that the complexes form 2 of the 12 possible conformational/configurational isomers, adopting compact C2-symmetric structures with short intramolecular transannular interactions between the diimine ligands and dpte phenyl groups; crystals of 2 and 5 contain non-statistical distributions of geometric isomers. In keeping with the ?-acidity of the dpte, the Ru(III/II) couple, E°'(Ru3+/2+), occurs at relatively high potentials (1.4-1.7 V vs Ag/AgCl), and the lowest spin-allowed MLCT absorption band occurs near 400 nm. Surprisingly, the complexes also exhibit fluid-solution luminescence originating from a lowest MLCT excited state with lifetimes in the 140-750 ns time range; in acetonitrile, compound 8 undergoes photo-induced solvolysis. Variations in the MLCT energies and redox potentials are quantitatively described using a summative Hammett parameter (?T), as well as using Lever's electrochemical parameters (EL). Recommended parameterizations for 2,2'-bipyridyl and 1,10-phenanthrolinyl ligands were derived from analysis of correlations based on 199 measurements of E°'(Ru3+/2+) for 99 homo- and heteroleptic ruthenium(II) tris-diimine complexes. Variations in E°'(Ru3+/2+) due to substituents at the 4- and 4'-positions of bipyridyl ligands and 4- and 7-positions of phenanthrolinyl ligands are significantly more strongly correlated with ?p+ than either ?m or ?p. Substituents at the 5- and 6-positions of phenanthrolinyl ligands are best described by ?m and have effects comparable to those of substituents at the 3- and 8-positions. Correlations of EL with ?T for 20 1,10-phenanthrolinyl ligands and for 35 2,2'-bipyridyl ligands show similar results, except that ?p and ?p+ are almost equally effective in describing the influence of substituents at the 4- and 4'-positions of bipyridyl ligands. For complexes 1-5 having an X-substituent at the 5-position of the phenanthrolinyl ligand, the MLCT absorption and emission energies, as well as the d5/d6-electron redox couple, are correlated with values for several other series of d6-electron metal complexes and give slopes that can be rationalized in terms of the relative number of diimine ligands and X-substituents.

Al-Rawashdeh, Nathir A.; Chatterjee, Sayandev; Krause, Jeanette A.; Connick, William B.

2014-01-01T23:59:59.000Z

258

Effect of dimerization on dynamics of spin-charge separation in Pariser-Parr-Pople model: A time-dependent density matrix renormalization group study  

E-Print Network [OSTI]

We investigate the effect of static electron-phonon coupling, on real-time dynamics of spin and charge transport in $\\pi$-conjugated polyene chains. The polyene chain is modeled by the Pariser-Parr-Pople Hamiltonian with dimerized nearest-neighbor parameter $t_{0}(1+\\delta)$ for short bonds and $t_{0}(1-\\delta)$ for long bonds, and long-range electron-electron interactions. We follow the time evolution of the spin and charge using time-dependent density matrix renormalization group technique, when a hole is injected at one end of the chain in its ground state. We find that spin and charge dynamics followed through spin and charge velocities, depend both on chain length and extent of dimerization, $\\delta$. Analysis of the results requires focusing on physical quantities such as average spin and charge polarizations, particularly in the large dimerization limit. In the dimerization range 0.0 $\\le$ $\\delta$ $\\le$ 0.15, spin-charge dynamics is found to have a well defined behavior, with spin-charge separation (measured as the ratio of charge velocity to spin velocity) as well as, the total amount of charge and spin transported in a given time, along the chain, decreasing as dimerization increases. However, in the range 0.3 $\\le$ $\\delta$ $\\le$ 0.5, it is observed that the dynamics of spin and charge transport becomes complicated. It is observed that for large $\\delta$ values, spin-charge separation is suppressed and the injected hole fails to travel the entire length of the chain.

Tirthankar Dutta; S. Ramasesha

2011-12-29T23:59:59.000Z

259

Electrochemical Oxidation of H2 Catalyzed by Ruthenium Hydride Complexes Bearing P2N2 Ligands With Pendant Amines as Proton Relays  

SciTech Connect (OSTI)

Two Ru hydride complexes (Cp*Ru(PPh2NBn2)H, 1-H and (Cp*Ru(PtBu2NBn2)H, 2-H) supported by cyclic PR2NR'2 ligands (Cp* = ?5-C5Me5; 1,5-diaza-3,7-diphosphacyclooctane, where R = Ph or tBu and R' = Bn) have been synthesized and fully characterized. Both complexes are demonstrated to be electrocatalysts for oxidation of H2 (1 atm, 22 °C) in the presence of external base, DBU (1,8-diazabicyclo[5.4.0]undec-7-ene). The turnover frequency of 2-H is 1.2 s-1, with an overpotential at Ecat/2 of 0.45 V, while catalysis by 1-H has a turnover frequency of 0.6 s-1 and an overpotential of 0.6 V at Ecat/2. Addition of H2O facilitates oxidation of H2 by 2-H and increases its turnover frequency to 1.9 s-1 while , H2O slows down the catalysis by 1-H. The different effects of H2O for 1-H and 2-H are ascribed to different binding affinities of H2O to the Ru center of the corresponding unsaturated species, [Cp*Ru(PPh2NBn2)]+ and [Cp*Ru(PPh2NBn2)]+. In addition, studies of Cp*Ru(dmpm)H (where dmpm = bis(dimethylphosphino)methane), a control complex lacking pendent amines in its diphosphine ligand, confirms the critical roles of the pendent amines of P2N2 ligands for oxidation of H2. We thank the U.S. Department of Energy, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences and Biosciences, for supporting initial parts of the work. Current work is supported by the Center for Molecular Electrocatalysis, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences. Pacific Northwest National Laboratory is operated by Battelle for the U.S. Department of Energy.

Liu, Tianbiao L.; Rakowski DuBois, Mary; DuBois, Daniel L.; Bullock, R. Morris

2014-11-03T23:59:59.000Z

260

Migration and Directional Change of Interstitial Clusters in ?-Fe: Searching for Transition States by the Dimer Method  

SciTech Connect (OSTI)

The interstitial clusters produced by cascades in metals have very high mobility and exhibit thermally activated, one-dimensional glide along the crowdion direction, as revealed by molecular dynamics (MD) simulations. Only small interstitial clusters (<4) are observed to change their glide direction during the period of MD simulations ({approx} 10 ns), but the directional change for larger clusters is inaccessible to MD due to the limited time-scale. In order to overcome the ''time barrier'' in MD simulations, the dimer method is employed to search for possible transition states of interstitials and small interstitial clusters in alpha-Fe. The method uses only the first derivatives of the potential energy to find saddle points without knowledge of the final state of the transition. The possible transition states are studied as a function of interstitial cluster size, and the lowest energy barriers correspond to defect migration along (111) directions, as seen in MD simulations. Small clusters change their direction by a (110) fragment mechanism involving rotation of each crowdion into and out of the (110) dumbbell configuration, whereas the directional change for larger clusters is a two-step process consisting of translation along a <100> direction and rotation into an equivalent (111) direction. The mechanism of changing direction for a tri-interstitial cluster is also investigated using MD simulations.

Gao, Fei; Heinisch, Howard L.; Kurtz, Richard J.; Osetsky, Yuri N.; Hoagland, Richard G.

2005-02-01T23:59:59.000Z

Note: This page contains sample records for the topic "ruthenium dimer catalysis" 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

Three-body recombination of two-component cold atomic gases into deep dimers in an optical model  

E-Print Network [OSTI]

We consider three-body recombination into deep dimers in a mass-imbalanced two-component atomic gas. We use an optical model where a phenomenological imaginary potential is added to the lowest adiabatic hyper-spherical potential. The consequent imaginary part of the energy eigenvalue corresponds to the decay rate or recombination probability of the three-body system. The method is formulated in details and the relevant qualitative features are discussed as functions of scattering lengths and masses. We use zero-range model in analyses of recent recombination data. The dominating scattering length is usually related to the non-equal two-body systems. We account for temperature smearing which tends to wipe out the higher-lying Efimov peaks. The range and the strength of the imaginary potential determine positions and shapes of the Efimov peaks as well as the absolute value of the recombination rate. The Efimov scaling between recombination peaks is calculated and shown to depend on both scattering lengths. Reco...

Mikkelsen, M; Fedorov, D V; Zinner, N T

2015-01-01T23:59:59.000Z

262

The structural basis for partitioning of the XRCC1/DNA ligase III-[alpha] BRCT-mediated dimer complexes  

SciTech Connect (OSTI)

The ultimate step common to almost all DNA repair pathways is the ligation of the nicked intermediate to form contiguous double-stranded DNA. In the mammalian nucleotide and base excision repair pathways, the ligation step is carried out by ligase III-{alpha}. For efficient ligation, ligase III-{alpha} is constitutively bound to the scaffolding protein XRCC1 through interactions between the C-terminal BRCT domains of each protein. Although structural data for the individual domains has been available, no structure of the complex has been determined and several alternative proposals for this interaction have been advanced. Interpretation of the models is complicated by the formation of homodimers that, depending on the model, may either contribute to, or compete with heterodimer formation. We report here the structures of both homodimer complexes as well as the heterodimer complex. Structural characterization of the heterodimer formed from a longer XRCC1 BRCT domain construct, including residues comprising the interdomain linker region, revealed an expanded heterodimer interface with the ligase III-{alpha} BRCT domain. This enhanced linker-mediated binding interface plays a significant role in the determination of heterodimer/homodimer selectivity. These data provide fundamental insights into the structural basis of BRCT-mediated dimerization, and resolve questions related to the organization of this important repair complex.

Cuneo, Matthew J.; Gabel, Scott A.; Krahn, Joseph M.; Ricker, Melissa A.; London, Robert E. (NIH)

2011-11-17T23:59:59.000Z

263

The Structural Basis for Partitioning of the XRCC1/DNA Ligase III-alpha BRCT-mediated Dimer Complexes  

SciTech Connect (OSTI)

The ultimate step common to almost all DNA repair pathways is the ligation of the nicked intermediate to form contiguous double-stranded DNA. In the mammalian nucleotide and base excision repair pathways, the ligation step is carried out by ligase III-{alpha}. For efficient ligation, ligase III-{alpha} is constitutively bound to the scaffolding protein XRCC1 through interactions between the C-terminal BRCT domains of each protein. Although structural data for the individual domains has been available, no structure of the complex has been determined and several alternative proposals for this interaction have been advanced. Interpretation of the models is complicated by the formation of homodimers that, depending on the model, may either contribute to, or compete with heterodimer formation. We report here the structures of both homodimer complexes as well as the heterodimer complex. Structural characterization of the heterodimer formed from a longer XRCC1 BRCT domain construct, including residues comprising the interdomain linker region, revealed an expanded heterodimer interface with the ligase III-{alpha} BRCT domain. This enhanced linker-mediated binding interface plays a significant role in the determination of heterodimer/homodimer selectivity. These data provide fundamental insights into the structural basis of BRCT-mediated dimerization, and resolve questions related to the organization of this important repair complex.

M Cuneo; S Gabel; J Krahn; M Ricker; R London

2011-12-31T23:59:59.000Z

264

Calculation of two-centre two-electron integrals over Slater-type orbitals revisited. III. Case study of the beryllium dimer  

E-Print Network [OSTI]

In this paper we present results of ab-initio calculations for the beryllium dimer with basis set of Slater-type orbitals (STOs). Nonrelativistic interaction energy of the system is determined using the frozen-core full configuration interaction calculations combined with high-level coupled cluster correction for inner-shell effects. Newly developed STOs basis sets, ranging in quality from double to sextuple zeta, are used in these computations. Principles of their construction are discussed and several atomic benchmarks are presented. Relativistic effects of order ${\\alpha}^2$ are calculated perturbatively by using the Breit-Pauli Hamiltonian and are found to be significant. We also estimate the leading-order QED effects. Influence of the adiabatic correction is found to be negligible. Finally, the interaction energy of the beryllium dimer is determined to be 929.0$\\,\\pm\\,$1.9 $cm^{-1}$, in a very good agreement with the recent experimental value. The results presented here appear to be the most accurate ab-initio calculations for the beryllium dimer available in the literature up to date and probably also one of the most accurate calculations for molecular systems containing more than four electrons.

Micha? Lesiuk; Micha? Przybytek; Monika Musia?; Bogumi? Jeziorski; Robert Moszynski

2015-01-20T23:59:59.000Z

265

Catalysis over activated zeolites  

SciTech Connect (OSTI)

A process is provided for conducting organic compound conversion over a catalyst composition comprising a supported crystalline zeolite having a high initial silica-to-alumina mole ratio, said supported zeolite being prepared by compositing said crystalline zeolite with alumina, reacting the composite with a particular hydrogen fluoride solution in a specified way, drying the hydrogen fluoride reacted composite, treating the dried composite by hydrolysis, ammonolysis and/or by contact with an ammonium salt solution, and calcining the resulting material.

Miale, J.N.; Chang, C.D.

1985-02-19T23:59:59.000Z

266

Catalysis over activated zeolites  

SciTech Connect (OSTI)

A process is provided for conducting organic compound conversion over a catalyst comprising a crystalline zeolite which has been treated by impregnation with an ammoniacal aluminum fluoride solution, contact with an ammonium salt solution, and calcination.

Miale, J. N.; Chang, C. D.

1985-02-19T23:59:59.000Z

267

HETEROGENEOUS CATALYSIS RESEARCH MEETING  

E-Print Network [OSTI]

synthesis gas by coal gasification is very expensive andin the cost of coal gasification would have a significantas K co , to promote gasification would be beneficial s1nce

Authors, Various

2011-01-01T23:59:59.000Z

268

In situ catalysis | EMSL  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Leads No leads are available at this time. Local environment and composition of magnesium gallium layered double hydroxides determined from solid-state 1H and 71Ga NMR...

269

HETEROGENEOUS CATALYSIS RESEARCH MEETING  

E-Print Network [OSTI]

Activity of Transition-Metal Carbides Wendell S. Williamsand testing of transition-metal carbide electrodes forproperties of transition metal carbides in the writervs

Authors, Various

2011-01-01T23:59:59.000Z

270

2012 Catalysis Lectures  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLasDelivered‰PNGExperience hands-onASTROPHYSICS H. I. Park, L.2 Wed, 12/19/20122

271

Computational Catalysis and Electrocatalysis  

E-Print Network [OSTI]

· Hydrogen storage · Photocatalysis #12;Fuel cell electrocatalysts Parallelism between bimetallics;Applications from our research · Fuel cell electrocatalysts · Controlled growth of carbon nanostructures-- Another fuel cell challenge #12;Predictions and challenges Using molecular dynamics simulations we showed

272

Theoretical Studies in Heterogenous Catalysis: Towards a Rational Design of Novel Catalysts for Hydrodesulfurization and Hydrogen Production  

SciTech Connect (OSTI)

Traditionally, knowledge in heterogeneous catalysis has come through empirical research. Nowadays, there is a clear interest to change this since millions of dollars in products are generated every year in the chemical and petrochemical industries through catalytic processes. To obtain a fundamental knowledge of the factors that determine the activity of heterogeneous catalysts is a challenge for modern science since many of these systems are very complex in nature. In principle, when a molecule adsorbs on the surface of a heterogeneous catalyst, it can interact with a large number of bonding sites. It is known that the chemical properties of these bonding sites depend strongly on the chemical environment around them. Thus, there can be big variations in chemical reactivity when going from one region to another in the surface of a heterogeneous catalyst. A main objective is to understand how the structural and electronic properties of a surface affect the energetics for adsorption processes and the paths for dissociation and chemical reactions. In recent years, advances in instrumentation and experimental procedures have allowed a large series of detailed works on the surface chemistry of heterogeneous catalysts. In many cases, these experimental studies have shown interesting and unique phenomena. Theory is needed to unravel the basic interactions behind these phenomena and to provide a general framework for the interpretation of experimental results. Ideally, theoretical calculations based on density-functional theory have evolved to the point that one should be able to predict patterns in the activity of catalytic surfaces. As in the case of experimental techniques, no single theoretical approach is able to address the large diversity of phenomena occurring on a catalyst. Catalytic surfaces are usually modeled using either a finite cluster or a two-dimensionally periodic slab. Many articles have been published comparing the results of these two approaches. An important advantage of the cluster approach is that one can use the whole spectrum of quantum-chemical methods developed for small molecules with relatively minor modifications. On the other hand, the numerical effort involved in cluster calculations increases rather quickly with the size of the cluster. This problem does not exist when using slab models. Due to the explicit incorporation of the periodicity of the crystal lattice through the Bloch theorem, the actual dimension of a slab calculation depends only on the size of the unit cell. In practical terms, the slab approach is mainly useful for investigating the behavior of adsorbates at medium and high coverages. Very large unit cells are required at the limit of low to zero coverage, or when examining the properties and chemical behavior of isolated defect sites in a surface. In these cases, from a computational viewpoint, the cluster approach can be much more cost effective than the slab approach. Slab and cluster calculations can be performed at different levels of sophistication: semi-empirical methods, simple ab initio Hartree-Fock, ab initio post-Hartree-Fock (CI, MP2, etc), and density functional theory. Density-functional (DF) based calculations frequently give adsorption geometries with a high degree of accuracy and predict reliable trends for the energetics of adsorption reactions. This article provides a review of recent theoretical studies that deal with the behavior of novel catalysts used for hydrodesulfurization (HDS) reactions and the production of hydrogen (i.e. catalytic processes employed in the generation of clean fuels). These studies involve a strong coupling of theory and experiment. A significant fraction of the review is focused on the importance of size-effects and correlations between the electronic and chemical properties of catalytic materials. The article begins with a discussion of results for the desulfurization of thiophene on metal carbides and phosphides, systems which have the potential to become the next generation of industrial HDS catalysts. Then, systematic studies con

Rodriguez,J.A.; Liu, P.

2008-10-01T23:59:59.000Z

273

Design, Synthesis and Mechanistic Evaluation of Iron-Based Catalysis for Synthesis Gas Conversion to Fuels and Chemicals  

SciTech Connect (OSTI)

This project extends previously discovered Fe-based catalysts to hydrogen-poor synthesis gas streams derived from coal and biomass sources. These catalysts have shown unprecedented Fischer-Tropsch synthesis rates and selectivities for synthesis gas derived from methane. During the first reporting period, we certified a microreactor, installed required analytical equipment, and reproduced synthetic protocols and catalytic results previously reported. During the second reporting period, we prepared several Fe-based compositions for Fischer-Tropsch Synthesis and tested the effects of product recycle under both subcritical and supercritical conditions. During the third and fourth reporting periods, we improved the catalysts preparation method, which led to Fe-based materials with the highest FTS reaction rates and selectivities so far reported, a finding that allowed their operation at lower temperatures and pressures with high selectivity to desired products (C{sub 5+}, olefins). During the fifth and sixth reporting period, we studied the effects of different promoters on catalytic performance, specifically how their sequence of addition dramatically influenced the performance of these materials in the Fischer-Tropsch synthesis. We also continued our studies of the kinetic behavior of these materials during the sixth reporting period. Specifically, the effects of H{sub 2}, CO, and CO{sub 2} on the rates and selectivities of Fischer-Tropsch Synthesis reactions led us to propose a new sequence of elementary steps on Fe and Co Fischer-Tropsch catalysts. Finally, we also started a study of the use of colloidal precipitation methods for the synthesis small Co clusters using recently developed methods to explore possible further improvements in FTS rates and selectivities. We found that colloidal synthesis makes possible the preparation of small cobalt particles, although large amount of cobalt silicate species, which are difficult to reduce, were formed. During this seventh reporting period, we have explored several methods to modify the silanol groups on SiO{sub 2} by using either a homogeneous deposition-precipitation method or surface titration of Si-OH on SiO{sub 2} with zirconium (IV) ethoxide to prevent the formation of unreducible and unreactive CoO{sub x} species during synthesis and FTS catalysis. We have synthesized monometallic Co/ZrO{sub 2}/SiO{sub 2} catalysts with different Co loadings (11-20 wt%) by incipient wetness impregnation methods and characterized the prepared Co supported catalysts by H{sub 2} temperature-programmed reduction (H{sub 2}-TPR) and H{sub 2}-chemisorption. We have measured the catalytic performance in FTS reactions and shown that although the hydroxyl groups on the SiO{sub 2} surface are difficult to be fully titrated by ZrO{sub 2}, modification of ZrO{sub 2} on SiO{sub 2} surface can improve the Co clusters dispersion and lead to a larger number of exposed Co surface atoms after reduction and during FTS reactions. During this seventh reporting period, we have also advanced our development of the reaction mechanism proposed in the previous reporting period. Specifically, we have shown that our novel proposal for the pathways involved in CO activation on Fe and Co catalysts is consistent with state-of-the-art theoretical calculations carried out in collaboration with Prof. Manos Mavrikakis (University of Wisconsin-Madison). Finally, we have also worked on the preparation of several manuscripts describing our findings about the preparation, activation and mechanism of the FTS with Fe-based catalysts and we have started redacting the final report for this project.

Akio Ishikawa; Manuel Ojeda; Nan Yao; Enrique Iglesia

2007-03-31T23:59:59.000Z

274

Electronic structure and reactivity in water splitting of the iron oxide dimers and their hexacarbonyls: A density functional study  

SciTech Connect (OSTI)

The iron oxide dimers (FeO){sub 2} and their peroxide isomers are studied with the B3LYP density functional as bare clusters and as hexacarbonyls. Among the bare clusters the planar four-member ring structures are more stable than the non-planar ones and the rhombic dioxide Fe{sub 2}O{sub 2} with antiferromagnetically ordered electrons on iron centers is the global minimum. Water adsorption on the bare diiron dioxide is exothermic, but dissociation does not occur. Carbonylation favors a non-planar Fe{sub 2}O{sub 2} ring for both the dioxides and the peroxides and high electron density at the Fe centers is induced, evidenced by the natural charge distribution, the high proton affinity, and the values of global electronegativity and hardness. The iron dioxide hexacarbonyl Fe{sub 2}O{sub 2}(CO){sub 6} is diamagnetic in the state of the global minimum. It is separated from the next low-lying triplet state by a small energy gap of 0.22 eV. Time-dependent density functional theory methods were applied to examine electron excitations from the ground state to the low-lying triplet states in the hexacarbonyls and their adsorption complexes with water. Singlet-to-triplet state excitations occur via ligand-to-metal charge transfer in the hexacarbonyls; in the adsorption complexes excitations from the oxygen lone pairs to the adsorption center also occur and they appear in the IR-visible region. The lowest energy singlet and triplet state reaction paths for water splitting were followed. On the singlet potential energy surface (PES), water splitting is spontaneous, while for the triplet PES an activation barrier of 14.1 kJ mol{sup ?1} was determined.

Uzunova, Ellie L., E-mail: ellie@svr.igic.bas.bg [Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, Sofia 1113 (Bulgaria); Mikosch, Hans [Institute for Chemical Technologies and Analytics, Vienna University of Technology, Getreidemarkt 9/E164-EC, 1060 Vienna (Austria)] [Institute for Chemical Technologies and Analytics, Vienna University of Technology, Getreidemarkt 9/E164-EC, 1060 Vienna (Austria)

2014-01-14T23:59:59.000Z

275

WGS Catalysis and In Situ Studies of CoO1-x, PtCon/Co3O4, and PtmCom/CoO1-x Nanorod Catalysts  

E-Print Network [OSTI]

cells is one solution for on-board purification of hydrogen sources for low-temperature fuel cell technology, since the CO tolerance of fuel cell electrodes is only 50 ppm or lower.1-5 DevelopmentWGS Catalysis and In Situ Studies of CoO1-x, PtCon/Co3O4, and PtmCom/CoO1-x Nanorod Catalysts

Frenkel, Anatoly

276

Design of an efficient single photon source from a metallic nanorod dimer: a quasinormal mode finite-difference time-domain approach  

E-Print Network [OSTI]

We describe how the finite-difference time-domain (FDTD) technique can be used to compute the quasinormal mode (QNM) for metallic nano-resonators, which is important for describing and understanding light-matter interactions in nanoplasmonics. We use the QNM to model the enhanced spontaneous emission rate for dipole emitters near a gold nanorod dimer structure using a newly developed QNM expansion technique. Significant enhanced photon emission factors of around 1500 are obtained with large output $\\beta$-factors of about $60\\%$.

Ge, Rong-Chun

2015-01-01T23:59:59.000Z

277

CRM1-dependent nuclear export and dimerization with hMSH5 contribute to the regulation of hMSH4 subcellular localization  

SciTech Connect (OSTI)

MSH4 and MSH5 are members of the MutS homolog family, a conserved group of proteins involved in DNA mismatch correction and homologous recombination. Although several studies have provided compelling evidences suggesting that MSH4 and MSH5 could act together in early and late stages of meiotic recombination, their precise roles are poorly understood and recent findings suggest that the human MSH4 protein may also exert a cytoplasmic function. Here we show that MSH4 is present in the cytoplasm and the nucleus of both testicular cells and transfected somatic cells. Confocal studies on transfected cells provide the first evidence that the subcellular localization of MSH4 is regulated, at least in part, by an active nuclear export pathway dependent on the exportin CRM1. We used deletion mapping and mutagenesis to define two functional nuclear export sequences within the C-terminal part of hMSH4 that mediate nuclear export through the CRM1 pathway. Our results suggest that CRM1 is also involved in MSH5 nuclear export. In addition, we demonstrate that dimerization of MSH4 and MSH5 facilitates their nuclear localization suggesting that dimerization may regulate the intracellular trafficking of these proteins. Our findings suggest that nucleocytoplasmic traffic may constitute a regulatory mechanism for MSH4 and MSH5 functions.

Neyton, Sophie; Lespinasse, Francoise; Lahaye, Francois [Equipe M3R, UMR 6543, Universite de Nice Sophia-Antipolis, CNRS, Faculte de Medecine, Avenue de Valombrose 06107, Nice Cedex 2 (France); Staccini, Pascal [Stic, Universite de Nice-Sophia Antipolis, Faculte de Medecine, Avenue de Valombrose 06107, Nice Cedex 2 (France); Paquis-Flucklinger, Veronique [Equipe M3R, UMR 6543, Universite de Nice Sophia-Antipolis, CNRS, Faculte de Medecine, Avenue de Valombrose 06107, Nice Cedex 2 (France); Santucci-Darmanin, Sabine [Equipe M3R, UMR 6543, Universite de Nice Sophia-Antipolis, CNRS, Faculte de Medecine, Avenue de Valombrose 06107, Nice Cedex 2 (France)], E-mail: santucci@hermes.unice.fr

2007-10-15T23:59:59.000Z

278

Visible-Light Photoredox Catalysis: Selective Reduction of Carbon Dioxide to Carbon Monoxide by a Nickel N-Heterocyclic Carbene-Isoquinoline Complex  

SciTech Connect (OSTI)

The solar-driven reduction of carbon dioxide to value-added chemical fuels is a longstanding challenge in the fields of catalysis, energy science, and green chemistry. In order to develop effective CO2 fixation, several key considerations must be balanced, including (1) catalyst selectivity for promoting CO2 reduction over competing hydrogen generation from proton reduction, (2) visible-light harvesting that matches the solar spectrum, and (3) the use of cheap and earth-abundant catalytic components. In this report, we present the synthesis and characterization of a new family of earth-abundant nickel complexes supported by N-heterocyclic carbene amine ligands that exhibit high selectivity and activity for the electrocatalytic and photocatalytic conversion of CO2 to CO. Systematic changes in the carbene and amine donors of the ligand have been surveyed, and [Ni(Prbimiq1)]2+ (1c, where Prbimiq1 = bis(3-(imidazolyl)isoquinolinyl)propane) emerges as a catalyst for electrochemical reduction of CO2 with the lowest cathodic onset potential (Ecat = 1.2 V vs SCE). Using this earth-abundant catalyst with Ir(ppy)3 (where ppy = 2-phenylpyridine) and an electron donor, we have developed a visible-light photoredox system for the catalytic conversion of CO2 to CO that proceeds with high selectivity and activity and achieves turnover numbers and turnover frequencies reaching 98,000 and 3.9 s1, respectively. Further studies reveal that the overall efficiency of this solar-to-fuel cycle may be limited by the formation of the active Ni catalyst and/or the chemical reduction of CO2 to CO at the reduced nickel center and provide a starting point for improved photoredox systems for sustainable carbon-neutral energy conversion.

Thoi, VanSara; Kornienko, Nick; Margarit, C; Yang, Peidong; Chang, Christopher

2013-06-07T23:59:59.000Z

279

Characterization of fundamental catalytic properties of MoS2/WS2 nanotubes and nanoclusters for desulfurization catalysis - a surface temperature study  

SciTech Connect (OSTI)

The prior project consisted of two main project lines. First, characterization of novel nanomaterials for hydrodesulfurization (HDS) applications. Second, studying more traditional model systems for HDS such as vapor-deposited silica-supported Mo and MoSx clusters. In the first subproject, we studied WS2 and MoS2 fullerene-like nanoparticles as well as WS2 nanotubes. Thiophene (C4H4S) was used as the probe molecule. Interestingly, metallic and sulfur-like adsorption sites could be identified on the silica-supported fullerene-particles system. Similar structures are seen for the traditional system (vapor-deposited clusters). Thus, this may be a kinetics fingerprint feature of modern HDS model systems. In addition, kinetics data allowed characterization of the different adsorption sites for thiophene on and inside WS2 nanotube bundles. The latter is a unique feature of nanotubes that has not been reported before for any inorganic nanotube system; however, examples are known for carbon nanotubes, including prior work of the PI. Although HDS has been studied for decades, utilizing nanotubes as nanosized HDS reactors has never been tried before, as far as we know. This is of interest from a fundamental perspective. Unfortunately, the HDS activity of the nanocatalysts at ultra-high vacuum (UHV) conditions was close to the detection limit of our techniques. Therefore, we propose to run experiments at ambient pressure on related nanopowder samples as part of the renewal application utilizing a now-available GC (gas chromatograph) setup. In addition, Ni and Co doped nanocatalyts are proposed for study. These dopants will boost the catalytic activity. In the second subproject of the prior grant, we studied HDS-related chemistry on more traditional supported cluster catalysts. Mo clusters supported by physical vapor deposition (PVD) on silica have been characterized. Two reaction pathways are evident when adsorbing thiophene on Mo and MoSx clusters: molecular adsorption and dissociation. PVD Mo clusters turned out to be very reactive toward thiophene bond activation. Sulfur and carbon residuals form, which poison the catalyst and sulfide the Mo clusters. Sulfided silica-supported MoSx samples are not reactive toward thiophene bond activation. In addition to S and C deposits, H2, H2S, and small organic molecules were detected in the gas phase. Catalyst reactivation procedures, including O2 and atomic hydrogen treatments, have been tested. Cluster size effects have been seen: thiophene adsorbs molecularly with larger binding energies on smaller clusters. However, larger clusters have smaller activation energy for C4H4S bond activation than smaller clusters. The latter is consistent with early catalysis studies. Kinetics and dynamics parameters have been determined quantitatively. We spent a significant amount of time on upgrades of our equipment. A 2nd-hand refurbished X-ray photoelectron spectrometer (XPS) has been integrated into the existing molecular beam scattering system and is already operational (supported by the DoE supplemental grant available in October 2009). We also added a time of flight (TOF) system to the beam scattering apparatus and improved on the accessible impact energy range (new nozzle heater and gas mixing manifold) for the beam scattering experiments. In addition, a GC-based powder atmospheric flow reactor for studies on powder samples is now operational. Furthermore, a 2nd UHV kinetics system has been upgraded as well. In summary, mostly single crystal systems have so far been considered in basic science studies about HDS. Industrial catalysts, however, can be better approximated with the supported cluster systems that we studied in this project. Furthermore, an entirely new class of HDS systems, namely fullerene-like particles and inorganic nanotubes, has been included. Studying new materials and systems has the potential to impact science and technology. The systems investigated are closely related to energy and environmental-related surface science/catalysis. This prior project, conducted at NDSU by a sma

U. Burghaus

2012-07-05T23:59:59.000Z

280

Scanning tunneling microscopy of dimeric and polymeric products of electroreduced (Re(CO) sub 3 (4-vinyl,4 prime -methyl-2,2 prime -bipyridine)Cl)  

SciTech Connect (OSTI)

Scanning tunneling microscopy (STM) was used to image adsorbed products resulting from electroreduction of (Re(CO){sub 3}(vbpy)Cl) (vbpy = 4-vinyl,4{prime}-methyl-2,2{prime}-bipyridine) on highly oriented pyrolytic graphite (HOPG). STM images, in air, of HOPG electrodes following electroreduction of (Re(CO){sub 3}(vbpy)Cl) (in acetonitrile/0.1 M tetra-n-butylammonium perchlorate) by cycling the potential between 0 and {minus}2.0 V vs a sodium saturated colomel electrode (SSCE) show molecular species uniformly distributed on the surface including approximately dumbbell shaped molecules ({approx} 40 {times} 20 {angstrom}). The size and shape of these aggregates is consistent with products derived from vinyl-vinvyl coupling of Re-Re bonded dimers: ((vbpy)(CO){sub 3}Re-Re(CO){sub 3}(vbpyH-vbpyH)(CO){sub 3}Re-Re(CO){sub 3}(vbpy)). STM images of electrodes prepared by cycling the potential between 0 and {minus}1.45 V vs SSCE (less reducing conditions) show highly nonuniform coating of the surface by polymer. Several polymer morphologies were observed with polymer nucleation preferentially occurring at step sites on HOPG.

Snyder, S.R.; White, H.S. (Univ. of Minnesota, Minneapolis (USA)); Lopez, S.; Abruna, H.D. (Cornell Univ., Ithaca, NY (USA))

1990-02-14T23:59:59.000Z

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


281

Global-to-local incompatibility, monogamy of entanglement, and ground-state dimerization: Theory and observability of quantum frustration in systems with competing interactions  

E-Print Network [OSTI]

Frustration in quantum many body systems is quantified by the degree of incompatibility between the local and global orders associated, respectively, to the ground states of the local interaction terms and the global ground state of the total many-body Hamiltonian. This universal measure is bounded from below by the ground-state bipartite block entanglement. For many-body Hamiltonians that are sums of two-body interaction terms, a further inequality relates quantum frustration to the pairwise entanglement between the constituents of the local interaction terms. This additional bound is a consequence of the limits imposed by monogamy on entanglement shareability. We investigate the behavior of local pair frustration in quantum spin models with competing interactions on different length scales and show that valence bond solids associated to exact ground-state dimerization correspond to a transition from generic frustration, i.e. geometric, common to classical and quantum systems alike, to genuine quantum frustration, i.e. solely due to the non-commutativity of the different local interaction terms. We discuss how such frustration transitions separating genuinely quantum orders from classical-like ones are detected by observable quantities such as the static structure factor and the interferometric visibility.

S. M. Giampaolo; B. C. Hiesmayr; F. Illuminati

2015-01-25T23:59:59.000Z

282

Photoionization of cold gas phase coronene and its clusters: Autoionization resonances in monomer, dimer, and trimer and electronic structure of monomer cation  

SciTech Connect (OSTI)

Polycyclic aromatic hydrocarbons (PAHs) are key species encountered in a large variety of environments such as the Interstellar Medium (ISM) and in combustion media. Their UV spectroscopy and photodynamics in neutral and cationic forms are important to investigate in order to learn about their structure, formation mechanisms, and reactivity. Here, we report an experimental photoelectron-photoion coincidence study of a prototypical PAH molecule, coronene, and its small clusters, in a molecular beam using the vacuum ultraviolet (VUV) photons provided by the SOLEIL synchrotron facility. Mass-selected high resolution threshold photoelectron (TPES) and total ion yield spectra were obtained and analyzed in detail. Intense series of autoionizing resonances have been characterized as originating from the monomer, dimer, and trimer neutral species, which may be used as spectral fingerprints for their detection in the ISM by VUV absorption spectroscopy. Finally, a full description of the electronic structure of the monomer cation was made and discussed in detail in relation to previous spectroscopic optical absorption data. Tentative vibrational assignments in the near-threshold TPES spectrum of the monomer have been made with the support of a theoretical approach based on density functional theory.

Bréchignac, Philippe, E-mail: philippe.brechignac@u-psud.fr; Falvo, Cyril; Parneix, Pascal; Pino, Thomas; Pirali, Olivier [Institut des Sciences Moléculaires d’Orsay, CNRS UMR8214, Univ Paris-Sud, F-91405 Orsay (France); Garcia, Gustavo A.; Nahon, Laurent [Synchrotron SOLEIL, L’Orme des Merisiers, Saint-Aubin, B.P. 48, F-91192 Gif-sur-Yvette (France); Joblin, Christine; Kokkin, Damian; Bonnamy, Anthony [IRAP, Université de Toulouse 3 - CNRS, 9 Av. Colonel Roche, B.P. 44346, F-31028 Toulouse Cedex 4 (France); Mulas, Giacomo [INAF - Osservatorio Astronomico di Cagliari, via della scienza 5, I-09047 Selargius (Italy)

2014-10-28T23:59:59.000Z

283

Acid Catalysis in Modern Organic  

E-Print Network [OSTI]

catalyst for organic synthesis". That is the starting sentence of this book by Yamamoto and Ishihara, which follows their earlier book "Lewis Acids in Organic Synthesis (2000)", and covers the new developments book that should be available in every well-equipped chemistry library. It will certainly be helpful

Snyder, Scott A.

284

Neutrons for Catalysis Neutrons as  

E-Print Network [OSTI]

) decompressor are needed to see this picture. pilot plant new products and processes Q uickTim eTM and a TI FF ( Uncom pr essed) decom pr essor ar e needed t o see t his pict ur e. bench scale cast film in

Pennycook, Steve

285

Center for Environmentally Beneficial Catalysis  

E-Print Network [OSTI]

to Hone Your Wri·ng Skills Thursday, December 4, 2014 9:00-10:30 a.m. Conference Room B CEBC Building B, novel media and separa!ons to develop sustainable technologies for industrially significant chemicals of College Reading and Learning, and the Wri·ng Center Journal. With Rebecca Babcock, she co

286

Reaction Selectivity in Heterogeneous Catalysis  

E-Print Network [OSTI]

possible adsorption modes of acrolein to a Pt(111) surface,possible adsorption structures of acrolein on Pt(111) energyand 2 Langmuir exposure of acrolein to Pt(111). Figure taken

Somorjai, Gabor A.

2010-01-01T23:59:59.000Z

287

"Nanocrystal bilayer for tandem catalysis"  

E-Print Network [OSTI]

Hydrogenolysis of Ethane, Propane, n-Butane and iso-Butanethe Hydroformylation of Propane over Silica-supported Groupproduct and small amount of propane, which is likely to be

Yamada, Yusuke

2012-01-01T23:59:59.000Z

288

This journal is c The Royal Society of Chemistry 2011 Chem. Commun. Cite this: DOI: 10.1039/c0cc05303a  

E-Print Network [OSTI]

05303a One-pot efficient synthesis of dimeric, trimeric, and tetrameric BODIPY dyes for panchromatic for potential solar cell and other applications. In this communication, we report efficient synthesis of dimeric derivatives (3) with an excess of 2,4-dimethyl- pyrrole under acid catalysis, followed by oxidation with 2

Pandey, Ravi

289

Solution Structure of the 128 kDa Enzyme I Dimer from Escherichia coli and Its 146 kDa Complex with HPr Using Residual Dipolar Couplings and Small- and Wide-Angle X-ray Scattering  

SciTech Connect (OSTI)

The solution structures of free Enzyme I (EI, {approx}128 kDa, 575 x 2 residues), the first enzyme in the bacterial phosphotransferase system, and its complex with HPr ({approx}146 kDa) have been solved using novel methodology that makes use of prior structural knowledge (namely, the structures of the dimeric EIC domain and the isolated EIN domain both free and complexed to HPr), combined with residual dipolar coupling (RDC), small- (SAXS) and wide- (WAXS) angle X-ray scattering and small-angle neutron scattering (SANS) data. The calculational strategy employs conjoined rigid body/torsion/Cartesian simulated annealing, and incorporates improvements in calculating and refining against SAXS/WAXS data that take into account complex molecular shapes in the description of the solvent layer resulting in a better representation of the SAXS/WAXS data. The RDC data orient the symmetrically related EIN domains relative to the C{sub 2} symmetry axis of the EIC dimer, while translational, shape, and size information is provided by SAXS/WAXS. The resulting structures are independently validated by SANS. Comparison of the structures of the free EI and the EI-HPr complex with that of the crystal structure of a trapped phosphorylated EI intermediate reveals large ({approx}70-90{sup o}) hinge body rotations of the two subdomains comprising the EIN domain, as well as of the EIN domain relative to the dimeric EIC domain. These large-scale interdomain motions shed light on the structural transitions that accompany the catalytic cycle of EI.

Schwieters, Charles D.; Suh, Jeong-Yong; Grishaev, Alexander; Ghirlando, Rodolfo; Takayama, Yuki; Clore, G. Marius (NIH)

2010-09-17T23:59:59.000Z

290

Model Catalysis of Ammonia Synthesis ad Iron-Water Interfaces - ASum Frequency Generation Vibrational Spectroscopic Study of Solid-GasInterfaces and Anion Photoelectron Spectroscopic Study of Selected Anionclusters  

SciTech Connect (OSTI)

The ammonia synthesis reaction has been studied using single crystal model catalysis combined with sum frequency generation (SFG) vibrational spectroscopy. The adsorption of gases N{sub 2}, H{sub 2}, O{sub 2} and NH{sub 3} that play a role in ammonia synthesis have been studied on the Fe(111) crystal surface by sum frequency generation vibrational spectroscopy using an integrated Ultra-High Vacuum (UHV)/high-pressure system. SFG spectra are presented for the dissociation intermediates, NH{sub 2} ({approx}3325 cm{sup -1}) and NH ({approx}3235 cm{sup -1}) under high pressure of ammonia or equilibrium concentrations of reactants and products on Fe(111) surfaces. Special attention was paid to understand how potassium promotion of the iron catalyst affects the intermediates of ammonia synthesis. An Fe(111) surface promoted with 0.2 monolayers of potassium red shifts the vibrational frequencies of the reactive surface intermediates, NH and NH{sub 2}, providing evidence for weakened the nitrogen-hydrogen bonds relative to clean Fe(111). Spectral features of these surface intermediates persisted to higher temperatures for promoted iron surfaces than for clean Fe(111) surfaces implying that nitrogen-iron bonds are stronger for the promoted surface. The ratio of the NH to NH{sub 2} signal changed for promoted surfaces in the presence of equilibrium concentrations of reactants and products. The order of adding oxygen and potassium to promoted surfaces does not alter the spectra indicating that ammonia induces surface reconstruction of the catalyst to produce the same surface morphology. When oxygen is co-adsorbed with nitrogen, hydrogen, ammonia or potassium on Fe(111), a relative phase shift of the spectra occurs as compared to the presence of adsorbates on clean iron surfaces. Water adsorption on iron was also probed using SFG vibrational spectroscopy. For both H{sub 2}O and D{sub 2}O, the only spectral feature was in the range of the free OH or free OD. From the absence of SFG spectra of ice-like structure we conclude that surface hydroxides are formed and no liquid water is present on the surface. Other than model catalysis, gas phase anion photoelectron spectroscopy of the Cl + H{sub 2} van der Waals well, silicon clusters, germanium clusters, aluminum oxide clusters and indium phosphide clusters were studied. The spectra help to map out the neutral potential energy surfaces of the clusters. For aluminum oxide, the structures of the anions and neutrals were explored and for silicon, germanium and indium phosphide the electronic structure of larger clusters was mapped out.

Ferguson, Michael James

2005-12-15T23:59:59.000Z

291

Ruthenium Aluminides: Deformation Mechanisms and Substructure Development  

SciTech Connect (OSTI)

Structural and functional materials that can operate in severe, high temperature environments are key to the operation of a wide range of energy generation systems. Because continued improvements in the energy efficiency of these systems is critical, the need for new materials with higher temperature capabilities is inevitable. Intermetallic compounds, with strong bonding and generally high melting points offer this possibility for a broad array of components such as coatings, electrode materials, actuators and/or structural elements. RuAl is a very unusual intermetallic compound among the large number of B2compounds that have been identified and investigated to date. This material has a very high melting temperature of 2050?C, low thermal expansion, high thermal conductivity and good corrosion resistance. Unlike most other high temperature B2 intermetallics, RuAl possesses good intrinsic deformability at low temperatures. In this program fundamental aspects of low and high temperature mechanical properties and deformation mechanisms in binary and higher order RuAl-based systems have been investigated. Alloying additions of interest included platinum, boron and niobium. Additionally, preliminary studies on high temperature oxidation behavior of these materials have been conducted.

Tresa M. Pollock

2005-05-11T23:59:59.000Z

292

Synthesis and Hydrodeoxygenation Properties of Ruthenium Phosphide  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security AdministrationcontrollerNanocrystallineForeign Object Damage 3 B. L.

293

Catalysis over activated high silica zeolites  

SciTech Connect (OSTI)

A process is provided for conducting organic compound conversion over a catalyst composition comprising a crystalline zeolite having a high initial silica-to-alumina mole ratio, said zeolite being prepared by calcining the zeolite, contacting said calcined zeolite with solid aluminum fluoride, and coverting said aluminum fluoride contacted material to hydrogen form.

Chang, C. D.; Miale, N.

1985-07-23T23:59:59.000Z

294

Plasma Assisted Catalysis System for NOx Reduction  

Broader source: Energy.gov (indexed) [DOE]

SCHEMATIC Catalyst for NOx Reduction Plasma Region Exhaust Flow Solid State Pulser Power Modulator Motor Generator ENGINE Air Diesel Fuel Converter NO X + HC(Diesel) NO 2 +...

295

BERKELEY CATALYSIS CENTER November 11, 2005  

E-Print Network [OSTI]

the internal combustion engine to the fuel cell: Moving towards the hydrogen economy" ABSTRACT: The control of carbon monoxide, hydrocarbons and nitric oxides emitted from the gasoline internal combustion engine has to be made in new internal combustion engine technologies the world is moving towards fuel cells which

Iglesia, Enrique

296

A BRIEF HISTORY OF INDUSTRIAL CATALYSIS  

E-Print Network [OSTI]

More recently, Air Products and Chemicals Corporation hasProcess Division of Air Products & Chemicals, Inc. HC Q)air oxidation of isobutane. T-butyl alcohol is a co- product

Heinemann, Heinz

2013-01-01T23:59:59.000Z

297

Nanoscale Advances in Catalysis and Energy Applications  

E-Print Network [OSTI]

 J.Y.  Park,   The  nanoscience  revolution:  Merging  Nanocatalysis.   Nanoscience  and  technology,.    The  impact  of  nanoscience  on  heterogeneous  

Li, Yimin

2011-01-01T23:59:59.000Z

298

CATALYSIS IN BIOPOLYMER CHEMISTRY Joseph Bartholomew Binder  

E-Print Network [OSTI]

-organic solvent mixtures. The combination of the second-generation Hoveyda-Grubbs complex and solvents such as 1 civilization. Production of renewable building blocks through such transformations is the focus of the second yields the liquid fuel 2,5-dimethylfuran, offering a two-step direct route from biomass to biofuels

Raines, Ronald T.

299

Biochemical Conversion: Using Hydrolysis, Fermentation, and Catalysis...  

Energy Savers [EERE]

BETO works with the emerging U.S. bioindustry to sustainably convert non-food biomass resources into cost-competitive biofuels, biopower, and bioproducts....

300

Method for producing catalysis from coal  

DOE Patents [OSTI]

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

Farcasiu, Malvina (Pittsburgh, PA); Derbyshire, Frank (Lexington, KY); Kaufman, Phillip B. (Library, PA); Jagtoyen, Marit (Lexington, KY)

1998-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "ruthenium dimer catalysis" 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

Workshop: Synchrotron Applications in Chemical Catalysis | Stanford...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

It is also a great time to interact with other scientists, potential colleagues, and vendors of light source related products and services. For more information, please visit...

302

Electron Microscopy Catalysis Projects: Success Stories from...  

Broader source: Energy.gov (indexed) [DOE]

interactive behavior of Pt-Re bimetallic clusters supported on multi-walled carbon nanotubes serving as model catalyst for aqueous phase reforming process (new)" * Prof....

303

EMSL and Institute for Integrated Catalysis (IIC)  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

catalytic conditions that could not be sustained at most universities. * The ongoing maintenance and development of computer codes, such as NWChem, could provide as-yet unrealized...

304

A BRIEF HISTORY OF INDUSTRIAL CATALYSIS  

E-Print Network [OSTI]

glycol, propylene oxide, acrolein, acrylic acid, and1n 1948 the product1on of acrolein from propylene and oxygenIdol who reported yields of acrolein than those obtained in

Heinemann, Heinz

2013-01-01T23:59:59.000Z

305

Nanomaterials Engineering and Applications in Catalysis  

E-Print Network [OSTI]

The degradation of organic pollutants under UV, visibledegradation reactions of a number of organic compounds under UV,degradation reactions of a number of organic compounds under UV,

Zhang, Qiao

2012-01-01T23:59:59.000Z

306

Nanomaterials Engineering and Applications in Catalysis  

E-Print Network [OSTI]

Chem. Soc. 1998, (18) Kónya, Z. ; Puntes, V. F. ; Kiricsi,2006, 128, 3027. (20) Zhu, J. ; Konya, Z. ; Puntes, V. F. ;

Zhang, Qiao

2012-01-01T23:59:59.000Z

307

A BRIEF HISTORY OF INDUSTRIAL CATALYSIS  

E-Print Network [OSTI]

HYDROGENATIONS VINYL CHLORIDE MONOMER ( OXYCHLORINA'I'ION)and other monomers, such as vinyl- chloride, which cannot be

Heinemann, Heinz

2013-01-01T23:59:59.000Z

308

Postdoctoral Scholar position Area: Heterogeneous Catalysis  

E-Print Network [OSTI]

: Immediately Salary: $40,000-$50,000 per year(plus benefits) The Department of Chemical and Petroleum with high performance and novel catalytic processes for efficient energy utilization in an economical evaluation as well as reactor system design and fabrication Creative problem-solving and strong critical

de Leon, Alex R.

309

A BRIEF HISTORY OF INDUSTRIAL CATALYSIS  

E-Print Network [OSTI]

Dealkylation Catalytic Coal Liquefaction and Gasification a)Liquefaction Gasification c) IX Methanation Heterogeneous~IQUEFACTION AND GASIFICATION a) Liquefaction Production of

Heinemann, Heinz

2013-01-01T23:59:59.000Z

310

Lean NOx Catalysis Research and Development  

Broader source: Energy.gov (indexed) [DOE]

4 Lean-NOx Catalyst Materials T NOx active T NOx selective Noble metals (ex. PtAl 2 O 3 ) highly active, stable narrow temperature range, poorly selective (N 2 O) ...

311

Two component-three dimensional catalysis  

DOE Patents [OSTI]

This invention relates to catalytic reactor membranes having a gas-impermeable membrane for transport of oxygen anions. The membrane has an oxidation surface and a reduction surface. The membrane is coated on its oxidation surface with an adherent catalyst layer and is optionally coated on its reduction surface with a catalyst that promotes reduction of an oxygen-containing species (e.g., O.sub.2, NO.sub.2, SO.sub.2, etc.) to generate oxygen anions on the membrane. The reactor has an oxidation zone and a reduction zone separated by the membrane. A component of an oxygen containing gas in the reduction zone is reduced at the membrane and a reduced species in a reactant gas in the oxidation zone of the reactor is oxidized. The reactor optionally contains a three-dimensional catalyst in the oxidation zone. The adherent catalyst layer and the three-dimensional catalyst are selected to promote a desired oxidation reaction, particularly a partial oxidation of a hydrocarbon.

Schwartz, Michael (Boulder, CO); White, James H. (Boulder, CO); Sammells, Anthony F. (Boulder, CO)

2002-01-01T23:59:59.000Z

312

BERKELEY CATALYSIS CENTER Friday November 18, 2005  

E-Print Network [OSTI]

. The catalyst employed was silica-supported manganese oxide (MnO2/SiO2) because of the well-known activity it is a common industrial solvent, and the health risks associated with acetone are similar to those of many other VOCs. In order to obtain molecular level information about the various steps in the catalytic

Iglesia, Enrique

313

UNCORRECTEDPROOF Catalysis Today xxx (2003) xxxxxx  

E-Print Network [OSTI]

most interest- ing crystallographic form of titanium dioxide. Results are compared to the extensively in the adsorption/desorption behavior of water and methanol. The anatase (1 0 0) surface has the second formation on well-characterized anatase surfaces. So 41 far, surface science investigations for titanium

Diebold, Ulrike

314

BERKELEY CATALYSIS CENTER March 29, 2005  

E-Print Network [OSTI]

or their combination with perovskite-like mixed oxides. Monolithic substrates are made of refractory alloy foil of reforming process (selective oxidation by the oxygen of air, autothermal or steam reforming

Iglesia, Enrique

315

Nanoscale Advances in Catalysis and Energy Applications  

E-Print Network [OSTI]

State  Dye-­‐Sensitized  Solar  Cells.   Chemsuschem, in  dye-­‐sensitized  solar  cells  with  energy by  dye-­‐sensitized  photovoltaic  cells.  

Li, Yimin

2011-01-01T23:59:59.000Z

316

Catalysis: Fundamentals and Impact | Argonne National Laboratory  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

food, chemicals, fuels, pharmaceuticals and engineered materials including almost all plastics, polymers, and fibers. Catalysts are able to transform large quantities of matter...

317

Catalysis: UHV Model Catalysts, High Pressure | EMSL  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc DocumentationP-Series to someone6Energy,MUSEUM DISPLAYCareers TheEmailCatalog of Data

318

CNEEC - TRG3: Nanoscale Control in Catalysis  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation Proposed New Substation Sites Proposed Route BTRIC CNMS CSMBLynda NicelyAnalysis

319

Workshop: Synchrotron Applications in Chemical Catalysis | Stanford  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLasDelivered energy consumption byAbout SRNL Home SRNL main campus Working

320

BNL | CFN: Interface Science & Catalysis  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc DocumentationP-Series to someone6 M. Babzien, I. Ben-Zvi, P. Catravas, J. M.Interface Science

Note: This page contains sample records for the topic "ruthenium dimer catalysis" 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

Basic Research Needs: Catalysis for Energy  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary)morphinanInformation InInformationCenterResearch HighlightsToolsBES ReportsExperimentBasic EnergyChemical

322

Pacific Coast Catalysis Society Meeting 2015 | EMSL  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas Conchas recoveryLaboratorySpeedingOptimizingToolsto control intense heat3 -

323

Applications of Chiral Anions in Asymmetric Catalysis  

E-Print Network [OSTI]

without further purification. Small-scale reactions werewithout further purification. Small-scale reactions werewithout further purification. Small-scale reactions were

Hamilton, Gregory Lawrence

2011-01-01T23:59:59.000Z

324

Matching, Edge-Colouring, Dimers Alexander Schrijver  

E-Print Network [OSTI]

into PZrMDEA blends. We2 December 2002 Vol. 48, No. 12 AIChE Journal2788 #12;specifically target exp

Schrijver, Alexander

325

Dimerization specificities of leucine zipper mutants  

E-Print Network [OSTI]

and dominant negative 8 repressor-leucine zipper fusion proteins. Cells that were immune to infection by phage 8 contain homodimeric fusion proteins. Cells that were sensitive to infection by phage 8 are forming heterodimeric fusion proteins. The two...

Rieker, Jennifer Dawn

2013-02-22T23:59:59.000Z

326

Catalysis Today 9395 (2004) 615618 Synthesis and catalysis of nanometer-sized bimodal mesoporous  

E-Print Network [OSTI]

-particle pore. As a result of the special properties of the present material, the hydrothermal stability diffusion if its particle size is in microm- eter scale. As a result, cumulated carbon species can be easily, the hydrothermal stability of the MCM-41 is known to be too weak to use it for catalytic applications

Kim, Ji Man

327

Molecular water oxidation catalyst  

DOE Patents [OSTI]

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

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

1993-01-01T23:59:59.000Z

328

PLATINUM-GROUP METALS (Platinum, palladium, rhodium, ruthenium, iridium, osmium)  

E-Print Network [OSTI]

by companies in Texas and Utah. Catalysts for air pollution abatement continued to be the largest demand sector in the manufacture of catalytic converters. Catalysts were also used in other air-pollution-abatement processes in kilograms, unless otherwise noted) Domestic Production and Use: The Stillwater and East Boulder Mines

329

PLATINUM-GROUP METALS (Platinum, palladium, rhodium, ruthenium, iridium, osmium)  

E-Print Network [OSTI]

by companies in Texas and Utah. Catalysts for air-pollution- abatement continued to be the leading demand industry in the manufacture of catalytic converters. Catalysts were also used in other air-pollution in kilograms unless otherwise noted) Domestic Production and Use: The Stillwater and East Boulder Mines

330

PLATINUM-GROUP METALS (Platinum, palladium, rhodium, ruthenium, iridium, osmium)  

E-Print Network [OSTI]

for air-pollution abatement in both light- and heavy-duty vehicles. PGMs are also used in the chemical in kilograms unless otherwise noted) Domestic Production and Use: The Stillwater and East Boulder Mines in south-central Montana were the only primary platinum-group metals (PGMs) mines in the United States

331

PLATINUM-GROUP METALS (Platinum, palladium, rhodium, ruthenium, iridium, osmium)  

E-Print Network [OSTI]

. Catalysts for air pollution abatement continued to be the largest demand sector for PGM. In the United of catalytic converters. Catalysts were also used in other air-pollution-abatement processes to remove organic in kilograms, unless otherwise noted) Domestic Production and Use: The Stillwater Mine is the only primary

332

PLATINUM-GROUP METALS (Platinum, palladium, rhodium, ruthenium, iridium, osmium)  

E-Print Network [OSTI]

are also used in other air pollution abatement processes to remove organic vapors, odors, or carbon platinum-group metals (PGM) mine. The mine, located near Nye, MT, processed more than 400,000 metric tons and biomedical devices. Salient Statistics--United States: 1995 1996 1997 1998 1999e Mine production:1 Platinum 1

333

PLATINUM-GROUP METALS (Platinum, palladium, rhodium, ruthenium, iridium, osmium)  

E-Print Network [OSTI]

automobile exhaust emissions. Oxidation catalysts are also used in many air pollution abatement processes platinum-group metals (PGM) mine. The mine, located near Nye, MT, processed about 430,000 metric tons--United States: 1994 1995 1996 1997 1998e Mine production: Platinum 1,960 1,590 1,840 2,610 3,5001 Palladium 6

334

PLATINUM-GROUP METALS (Platinum, palladium, rhodium, ruthenium, iridium, osmium)  

E-Print Network [OSTI]

refining by companies in Texas and Utah. Catalysts for air- pollution abatement continued to be the leading demand sector for PGMs. Catalysts were also used in other air- pollution-abatement processes to remove in kilograms unless otherwise noted) Domestic Production and Use: The Stillwater and East Boulder Mines

335

PLATINUM-GROUP METALS (Platinum, palladium, rhodium, ruthenium, iridium, osmium)  

E-Print Network [OSTI]

for air-pollution abatement in both light- and heavy-duty vehicles. PGMs are also used in the chemical in kilograms unless otherwise noted) Domestic Production and Use: The Stillwater and East Boulder Mines in south-central Montana are the only primary platinum-group metals (PGMs) mines in the United States

336

PLATINUM-GROUP METALS (Platinum, palladium, rhodium, ruthenium, iridium, osmium)  

E-Print Network [OSTI]

. Automobile catalysts for air pollution abatement continued to be the largest demand sector for PGM of catalysts. Catalysts are also used in other air-pollution-abatement processes to remove organic vapors in kilograms, unless otherwise noted) Domestic Production and Use: The Stillwater Mine is the only primary

337

PLATINUM-GROUP METALS (Platinum, palladium, rhodium, ruthenium, iridium, osmium)  

E-Print Network [OSTI]

. Catalysts for air pollution abatement continued to be the leading demand sector for PGMs. In the United of catalytic converters. Catalysts were also used in other air-pollution-abatement processes to remove organic in kilograms unless otherwise noted) Domestic Production and Use: The Stillwater and East Boulder Mines

338

PLATINUM-GROUP METALS (Platinum, palladium, rhodium, ruthenium, iridium, osmium)  

E-Print Network [OSTI]

of catalysts. Oxidation catalysts are also used in other air-pollution-abatement processes to remove organic in kilograms, unless otherwise noted) Domestic Production and Use: The Stillwater Mine is the only primary platinum-group metals (PGM) producer in the United States. The mine, located near Nye, MT, processed more

339

PLATINUM-GROUP METALS (Platinum, palladium, rhodium, ruthenium, iridium, osmium)  

E-Print Network [OSTI]

automobile exhaust emissions. Oxidation catalysts are also used in many air pollution abatement processes platinum-group metals (PGM) mine. The mine, located near Nye, MT, processed about 350,000 metric tons--United States: 1993 1994 1995 1996 1997e Mine production: Platinum 2,050 1,960 1,590 1,840 2,5002 Palladium 6

340

Selective Lability of Ruthenium(II) Arene Amino Acid Complexes  

E-Print Network [OSTI]

(DAP) 1 -NH2 2 L-2,4-diamino-butanoic acid (DAB) 2 -NH2 3 L-Ornithine 3 -NH2 4 L-Lysine 4 -NH2 5 L-Histidine 2 -Imidazole 6 L-Methionine 2 -SMe 7 * L-Aspartate 2 -COO- Table 1: Summary of the tridentate amino acid complexes under investigation...

Scrase, Tom G.; O’Neill, Michael J.; Peel, Andrew J.; Senior, Paul W.; Matthews, Peter D.; Shi, Heyao; Boss, Sally R.; Barker, Paul D.

2015-02-16T23:59:59.000Z

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


341

LASER TRANSFERRED HYDROUS RUTHENIUM OXIDE ELECTRODES FOR MICRO-ULTRACAPACITORS  

E-Print Network [OSTI]

products and telecommunication devices to electric/hybrid vehicles and stand-by power systems is also critical for the operation of autonomous microelectronic systems such as microsensors. These requirements are unable to be met by the current generation of microbatteries or micro-fuel cells alone (4, 5

Arnold, Craig B.

342

Electrooxidation of Alcohols Catalyzed by Amino Alcohol Ligated Ruthenium Complexes  

E-Print Network [OSTI]

Alcohols are attractive chemical fuels for fuel cells due to their high energy densities, established, even the most highly optimized alcohol electrooxidation catalysts suffer from kinetic limitations

Zare, Richard N.

343

PLATINUM-GROUP METALS (Platinum, palladium, rhodium, ruthenium, iridium, osmium)  

E-Print Network [OSTI]

chemicals; in the petroleum refining sector; and in laboratory equipment, including crucibles for growing Defense Stockpile remained suspended through FY 2013. Stockpile Status--9­30­13 4 Uncommitted Authorized; iridium prices were stable until midyear and then decreased markedly toward yearend, reportedly owing

344

Thermoelectric Properties of Rare-Earth-Ruthenium-Germanium Compounds |  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas ConchasPassiveSubmittedStatus TomAboutManusScienceThe LifeNewThermalInnovationEnergy Frontier

345

Ruthenium on Carbon Nanostructures for Supercapacitor Electrodes - Energy  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 -the Mid-Infrared0 Resource ProgramEnergyMaterials:BillRussell Hulse, theInnovation

346

Study of Copper Diffusion Through Ruthenium Thin Film by Photoemission  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security AdministrationcontrollerNanocrystalline Gallium Oxide Thin Films.AdministrationAerosol

347

PLATINUM-GROUP METALS (Platinum, palladium, rhodium, ruthenium, iridium, osmium)  

E-Print Network [OSTI]

refining. The leading demand sector for PGMs continued to be catalysts to decrease harmful emissions refining sector; and in the fabrication of laboratory equipment. In the electronics sector, PGMs are used toward the middle of the year, then decreased. The slowly recovering global economy in 2010, compared

348

PLATINUM-GROUP METALS (Platinum, palladium, rhodium, ruthenium, iridium, osmium)  

E-Print Network [OSTI]

refining. The leading demand sector for PGMs continued to be catalysts to decrease harmful emissions refining sector; and in laboratory equipment, including crucibles for growing high-purity single crystals­7708, ploferski@usgs.gov] #12;121 PLATINUM-GROUP METALS Events, Trends, and Issues: The global economy continued

349

PLATINUM-GROUP METALS (Platinum, palladium, rhodium, ruthenium, iridium, osmium)  

E-Print Network [OSTI]

refining. The leading demand sector for PGMs continued to be catalysts to decrease harmful emissions refining sector; and in laboratory equipment, including crucibles for growing high-purity single crystals-7708, ploferski@usgs.gov] #12;121 PLATINUM-GROUP METALS Events, Trends, and Issues: The global economy continued

350

A Low Noise Thermometer Readout for Ruthenium Oxide Resistors  

E-Print Network [OSTI]

The thermometer and thermal control system, for the Absolute Radiometer for Cosmology, Astrophysics, and Diffuse Emission (ARCADE) experiment, is described, including the design, testing, and results from the first flight of ARCADE. The noise is equivalent to about 1 Omega or 0.15 mK in a second for the RuO_2 resistive thermometers at 2.7 K. The average power dissipation in each thermometer is 1 nW. The control system can take full advantage of the thermometers to maintain stable temperatures. Systematic effects are still under investigation, but the measured precision and accuracy are sufficient to allow measurement of the cosmic background spectrum. Journal-ref: Review of Scientific Instruments Vol 73 #10 (Oct 2002)

D. J. Fixsen; P. G. A. Mirel; A. Kogut; M. Seiffert

2002-08-30T23:59:59.000Z

351

Computational Design of Lignin Depolymerization Catalysts  

SciTech Connect (OSTI)

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

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

2012-01-01T23:59:59.000Z

352

Fundamental studies of reactive intermediates in homogeneous catalysis  

SciTech Connect (OSTI)

The studies involve dissociation of Fe(CO){sub n}{sup {minus}}, Ni(CO){sub n}{sub {minus}}, and other carbonyl anions; decarboxylation of (CO){sub 4}FeCOOH{sup {minus}} to form CO{sub 2} and (CO){sub 4}FeH{sup {minus}} in the water gas shift reaction; gas-phase bimolecular reactions of carbonyl anions and O{sub 2}; reaction of O{sub 2} with CpMn(CO){sub 2}{sup {minus}}; gas-phase chemistry of fullerene anions; and gas-phase thermochemistry of bicarbonate ion, bisulfite ion, and their conjugate acids (sulfonate ion was produced).

Not Available

1993-10-01T23:59:59.000Z

353

Neutron Catalysis of Resonance Fusion in Stellar Matter  

E-Print Network [OSTI]

Within the framework of resonance fusion study in stellar matter the features of system consisted of two alpha particles and one neutron have been investigated at astrophysical energies. Consideration of three body scattering has been carried out on base of well-known Faddeev's equations. It is found that under certain conditions the series of resonance states appear in this system at very low energies. The lifetimes of these three body resonances are close to the lifetime of unstable nucleus 8Be. The simple forms of two body repulsive potentials are taken into account to describe the parameters of the alpha, alpha resonance and to satisfy n, alpha scattering data at very low energies. The explanation of resonance phenomena in n, alpha, alpha system is offered on base of physical model. The effect results from resonance quantum phenomena in few body dynamics. In turn, the resonance fusion can give influence on many astrophysical phenomena. The possibility of catalyzing this new mode of fusion by free neutrons in alpha particle matter is considered too.

Nurgali Takibayev

2005-08-22T23:59:59.000Z

354

Low-Temperature Hydrocarbon/CO Oxidation Catalysis in Support...  

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

2009 DOE Hydrogen Program and Vehicle Technologies Program Annual Merit Review and Peer Evaluation Meeting, May 18-22, 2009 -- Washington D.C. acep03...

355

Low-Temperature Hydrocarbon/CO Oxidation Catalysis in Support...  

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

Presentation from the U.S. DOE Office of Vehicle Technologies "Mega" Merit Review 2008 on February 25, 2008 in Bethesda, Maryland. merit08...

356

Homogeneous Catalysis Selective Oxidation of Methane to Methanol  

E-Print Network [OSTI]

oxidizing agent than SVI ions (Eo = 1.5 V SeO4 2À /H2SeO3, Eo = 0.17 V SO4 2À /H2SO3, respec- tively) and, critically, the hydrated form, selenic acid (H2SeO4), is known to oxidize gold metal.[7] Equally impor- tant

Goddard III, William A.

357

Fuel Synthesis Catalysis Laboratory (Fact Sheet), NREL (National...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

areas of emphasis are hydrocarbon synthesis from biomass- derived syngas and pyrolysis vapors. Many other catalyst systems can be studied by making minor system modifications. The...

358

Transition-metal catalysis of cyclocarbonylation and cycloisomerization reactions  

E-Print Network [OSTI]

Chapter 1. The asymmetric Pauson-Khand cyclization of nitrogen-containing enynes using carbon monoxide and a catalytic amount of (EBTHI)TiMe2 was examined. The influence of the nitrogen substituent and the concentration ...

Sturla, Shana Jocette, 1975-

2001-01-01T23:59:59.000Z

359

Charge Transfer and Catalysis at the Metal Support Interface  

E-Print Network [OSTI]

carbon monoxide oxidation on platinum nanoparticles supported on stoichiometric titaniumTitanium Oxide as an Electronically Active Support for Platinum in the Catalytic Oxidation of Carbon Monoxide ..Titanium Oxide as an Electronically Active Support for Platinum in the Catalytic Oxidation of Carbon Monoxide

Baker, Lawrence Robert

2014-01-01T23:59:59.000Z

360

Charge Transfer and Catalysis at the Metal-Support Interface  

E-Print Network [OSTI]

carbon monoxide oxidation on platinum nanoparticles supported on stoichiometric titaniumTitanium Oxide as an Electronically Active Support for Platinum in the Catalytic Oxidation of Carbon Monoxide ..Titanium Oxide as an Electronically Active Support for Platinum in the Catalytic Oxidation of Carbon Monoxide

Baker, Lawrence Robert

2012-01-01T23:59:59.000Z

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


361

Charge Transfer and Support Effects in Heterogeneous Catalysis  

E-Print Network [OSTI]

Titanium  Oxide  as  an  Electronically  Active  Support  for  Platinum in the Catalytic Oxidation of Carbon Monoxide.  .  .  .  .  .  .  .  .  .  .  .  .  carbon  monoxide  oxidation  on  platinum  nanoparticles  supported  on  stoichiometric  titanium Titanium Oxide as an Electronically Active  Support for Platinum in  the Catalytic Oxidation of Carbon  Monoxide   

Hervier, Antoine

2012-01-01T23:59:59.000Z

362

Mechanism of iron catalysis of carbon monoxide decomposition in refractories  

SciTech Connect (OSTI)

The authors discuss the catalytic effects of selected iron phases (metals, oxides, sulfides, and carbides) on the Boudouard reaction studied in an effort to more fully understand the disintegration of refractories when exposed to CO for long periods of time. It was found that active Fe atoms generated from the reduction of the iron oxides, especially {alpha}-Fe/sub 2/O/sub 3/, are the actual catalysts for the Boudouard reaction. The catalytic process confirmed by thermodynamic calculations, kinetic data, and X-ray diffraction data, consists of adsorption and decomposition of CO simultaneously forming carbides of iron. The chemisorption and subsequent decomposition of the iron carbides, rather than diffusion, constitute the rate-controlling process for carbon deposition.

Xu, M.W.P.; Brown, J.J. Jr. (Virginia Polytechnic Inst. and State Univ., Blacksburg, VA (USA). Dept. of Materials Engineering)

1989-01-01T23:59:59.000Z

363

Alkali monolayers on transition metal surfaces: electronic promotion in catalysis  

SciTech Connect (OSTI)

Potassium monolayers on the platinum (111) crystal surface were studied most extensively. Ultraviolet photoelectron spectroscopy showed a large decrease in the work function of the surface when potassium was adsorbed. The heat of desorption of potassium decreased with increasing coverage. Low energy electron diffraction (LEED) showed that potassium forms hexagonal (close packed) overlayer structures. The effects of potassium on the chemisorption of various small molecules on Pt(111) were studied. Oxygen and nitric oxide were readily adsorbed and dissociated by potassium, forming stable potassium-oxide complexes on the surface. Adsorption heat of carbon monoxide on Pt(111) increased with potassium coadsorption. High resolution electron energy loss spectroscopy showed that the carbon-oxygen bond of adsorbed carbon monoxide was weakened by potassium. Adsorption heat of benzene, however, was decreased by coadsorbed potassium. A molecular orbital explanation was given to explain the effects of potassium. CO hydrogenation reactions performed on metal foils showed that the addition of alkali adlayers tends to decrease the overall rate of reaction. Changes in selectivity were noted, shifting the product distribution in favor of higher molecular weight species and from alkanes to alkenes.

Garfunkel, E.

1983-08-01T23:59:59.000Z

364

Reduced ternary molybdenum and tungsten sulfides and hydroprocessing catalysis therewith  

DOE Patents [OSTI]

New amorphous molybdenum/tungsten sulfides with the general formula M{sup n+}{sub 2x/n}(L{sub 6}S{sub 8})S{sub x}, where L is molybdenum or tungsten and M is a ternary metal, has been developed. Characterization of these amorphous materials by chemical and spectroscopic methods (IR, Raman, PES) shows that the (M{sub 6}S{sub 8}){sup 0} cluster units are present. Vacuum thermolysis of the amorphous Na{sub 2x}(Mo{sub 6}S{sub 8})S{sub x}{hor_ellipsis}yMeOH first produces poorly crystalline NaMo{sub 6}S{sub 8} by disproportionation at 800 C and well-crystallized NaMo{sub 6}S{sub 8} at {>=} 900 C. Ion-exchange of the sodium material in methanol with soluble M{sup 2+} and M{sup 3+} salts (M=Sn, Co, Ni, Pb, La, Ho) produces the M{sup n+}{sub 2x/n}(Mo{sub 6}S{sub 8})S{sub x}{hor_ellipsis}yMeOH compounds. Additionally, the new reduced ternary molybdenum sulfides with the general formula M{sup n+}{sub 2x/n}Mo{sub 6}S{sub 8+x}(MeOH){sub y}[MMOS] (M=Sn, Co, Ni) is an effective hydrodesulfurization (HDS) catalyst both as-prepared and after a variety of pretreatment conditions. Under specified pretreatment conditions with flowing hydrogen gas, the SnMoS type catalyst can be stabilized, and while still amorphous, can be considered as ``Chevrel phase-like`` in that both contain Mo{sub 6}S{sub 8} cluster units. Furthermore, the small cation NiMoS and CoMoS type pretreated catalyst is shown to be very active HDS catalysts with rates that exceeded the model unpromoted and cobalt-promoted MoS{sub 2} catalysts. 9 figs.

Hilsenbeck, S.J.; McCarley, R.E.; Schrader, G.L.; Xie, X.B.

1999-02-16T23:59:59.000Z

365

Reduced ternary molybdenum and tungsten sulfides and hydroprocessing catalysis therewith  

DOE Patents [OSTI]

New amorphous molybdenum/tungsten sulfides with the general formula M.sup.n+.sub.2x/n (L.sub.6 S.sub.8)S.sub.x, where L is molybdenum or tungsten and M is a ternary metal, has been developed. Characterization of these amorphous materials by chemical and spectroscopic methods (IR, Raman, PES) shows that the (M.sub.6 S.sub.8).sup.0 cluster units are present. Vacuum thermolysis of the amorphous Na.sub.2x (Mo.sub.6 S.sub.8)S.sub.x .multidot.yMeOH first produces poorly crystalline NaMo.sub.6 S.sub.8 by disproportionation at 800.degree. C. and well-crystallized NaMo.sub.6 S.sub.8 at .gtoreq. 900.degree. C. Ion-exchange of the sodium material in methanol with soluble M.sup.2+ and M.sup.3+ salts (M=Sn, Co, Ni, Pb, La, Ho) produces the M.sup.n+.sub.2x/n (Mo.sub.6 S.sub.8)S.sub.x .multidot.yMeOH compounds. Additionally, the new reduced ternary molybdenum sulfides with the general formula M.sup.n+.sub.2x/n Mo.sub.6 S.sub.8+x (MeOH).sub.y ›MMOS! (M=Sn, Co, Ni) is an effective hydrodesulfurization (HDS) catalyst both as-prepared and after a variety of pretreatment conditions. Under specified pretreatment conditions with flowing hydrogen gas, the SnMoS type catalyst can be stabilized, and while still amorphous, can be considered as "Chevrel phase-like" in that both contain Mo.sub.6 S.sub.8 cluster units. Furthermore, the small cation NiMoS and CoMoS type pretreated catalyst showed to be very active HDS catalysts with rates that exceeded the model unpromoted and cobalt-promoted MoS.sub.2 catalysts.

Hilsenbeck, Shane J. (Ames, IA); McCarley, Robert E. (Ames, IA); Schrader, Glenn L. (Ames, IA); Xie, Xiaobing (College Station, TX)

1999-02-16T23:59:59.000Z

366

Nanostructured transition metal oxides useful for water oxidation catalysis  

DOE Patents [OSTI]

The present invention provides for a composition comprising a nanostructured transition metal oxide capable of oxidizing two H.sub.2O molecules to obtain four protons. In some embodiments of the invention, the composition further comprises a porous matrix wherein the nanocluster of the transition metal oxide is embedded on and/or in the porous matrix.

Frei, Heinz M; Jiao, Feng

2013-12-24T23:59:59.000Z

367

Tandem Catalysis in Nanocrystal Interfaces | Department of Energy  

Broader source: Energy.gov (indexed) [DOE]

Recently, researchers at the Department's Lawrence Berkeley National Laboratory (LBNL) created bilayered nanocrystals of metal-oxide metal that are first to feature multiple...

368

Hangman Catalysis for Photo- and Photoelectro- Chemical Activation of Water  

SciTech Connect (OSTI)

The focus of this DOE program is solar fuels – specifically the chemistry for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) from water and the oxygen reduction reaction (ORR) to water These three reactions are at the heart of renewable energy conversion. The bond-making and bond-breaking chemistry that underpins these transformations is not well understood. We are developing insight into such chemistry by creating a series of ligand constructs that poise an acid-base functionality over a redox active metal platform. These “hangman” ligands utilize the acid-base functionality to form a secondary coordination sphere that can assist proton movement and facilitate substrate assembly and activation within the molecular cleft. The grant period funding cycle focused on synthesis and reactivity of hangman porphyrins and corroles for HER, OER and ORR.

Nocera, Daniel

2014-04-15T23:59:59.000Z

369

Frontiers in Catalysis Science and Engineering Materials Science  

E-Print Network [OSTI]

, it is imperative to develop new processes for effective use of energy and to develop sustainable and clean energy in synthesizing novel metal oxide nanostructures for energy harvest and storage will also be discussed. More info Professor, Department of Chemistry & Biochemistry Abstract Energy is not only the driver for improving

370

Frontiers in Catalysis Science and Engineering Seminar Series  

E-Print Network [OSTI]

dioxide to liquid fuels using solar and electrical energy is a global challenge that could impact contained in liquid fuels to electrical energy in fuel cell applications. Recent results in the study of the selectivity for H+ vs. CO2 reduction pathways by UV-Vis and FTIR stopped flow kinetics studies will also

371

Charge Transfer and Catalysis at the Metal-Support Interface  

E-Print Network [OSTI]

a sapphire window and consisted of a thin film of either SiO2 thin film (50 nm) was deposited on the sapphire window bywindow containing the Pt nanoparticles supported on SiO 2 or TiO 2 thin films.

Baker, Lawrence Robert

2012-01-01T23:59:59.000Z

372

Light-driven uncoupling of nitrogenase catalysis from ATP hydrolysis  

E-Print Network [OSTI]

C. , Tezcan, F. A. , 2010. ATP- and iron-protein-independentL. E. , Tezcan, F. A. , 2012. ATP-uncoupled, six-electronRuBP activity under ATP turnover conditions. .

Roth, Lauren E.

2012-01-01T23:59:59.000Z

373

Tensor Rank and Stochastic Entanglement Catalysis for Multipartite Pure States  

E-Print Network [OSTI]

The tensor rank (also known as generalized Schmidt rank) of multipartite pure states plays an important role in the study of entanglement classifications and transformations. We employ powerful tools from the theory of homogeneous polynomials to investigate the tensor rank of symmetric states such as the tripartite state $\\ket{W_3}=\\tfrac{1}{\\sqrt{3}}(\\ket{100}+\\ket{010}+\\ket{001})$ and its $N$-partite generalization $\\ket{W_N}$. Previous tensor rank estimates are dramatically improved and we show that (i) three copies of $\\ket{W_3}$ has rank either 15 or 16, (ii) two copies of $\\ket{W_N}$ has rank $3N-2$, and (iii) $n$ copies of $\\ket{W_N}$ has rank O(N). A remarkable consequence of these results is that certain multipartite transformations, impossible even probabilistically, can become possible when performed in multiple copy bunches or when assisted by some catalyzing state. This effect is impossible for bipartite pure states.

Lin Chen; Eric Chitambar; Runyao Duan; Zhengfeng Ji; Andreas Winter

2010-11-10T23:59:59.000Z

374

Continuous Isosorbide Production From Sorbitol Using Solid Acid Catalysis  

SciTech Connect (OSTI)

This is a final report for a project funded by the US Department of Agriculture and managed by the US Department of Energy. The Iowa Corn Promotion Board was the principal contracting entity for the grant. The Iowa Corn Promotion Board subcontracted with General Electric, Pacific Northwest National Lab and New Jersey Institute of Technology to conduct research in this project. The Iowa Corn Promotion Board and General Electric provided cost share for the project. The purpose of this diverse collaboration was to integrate both the conversion and the polymer applications into one project and increase the likelihood of success. This project has led to additional collaborations among other polymer companies. The goals of the project were to develop a renewable route to isosorbide for commercialization that is economically competitive with all existing production technologies and to develop new applications for isosorbide in various products such as polymers and materials. Under this program a novel process for the production of isosorbide was developed and evaluated. The novel process converts corn based sorbitol into isosorbide using a solid catalyst with integrated water removal and product recovery. In addition the work under this program has identified several novel products based on isosorbide chemistries. These market applications include: epoxy resins, UV stabilizers, plasticizers and polyesters. These market applications have commercial interest within the current polymer industry. This report contains an overview summary of the accomplishments. Six inventions and four patent applications have been written as a result of this project. Additional data will be published in the patent applications. The data developed at New Jersey Institute of Technology was presented at two technical conferences held in June of 2006. Several companies have made inquiries about using this material in their products.

Williamson, R.; Holladay,J.; Jaffe, M.; Brunelle, D.

2006-09-29T23:59:59.000Z

375

Phase selectively soluble polymer supports to facilitate homogeneous catalysis  

E-Print Network [OSTI]

Soluble polymers that have phase selective solubility are useful in synthesis because they simplify purification and separation. Such selectively soluble polymers simplify catalyst, reagent, and product recovery and enable the use of Green chemistry...

Ortiz-Acosta, Denisse

2009-05-15T23:59:59.000Z

376

Frontiers in Catalysis Science and Engineering Seminar Series  

E-Print Network [OSTI]

of deoxygenation chemistry on metal carbide catalysts. Specifically, the talk will include a discussion of: (i

377

Plasmonic enhancement of catalysis and solar energy conversion.  

E-Print Network [OSTI]

??This thesis is dedicated to exploring the potential applications of plasmonic metal nanoparticles and understanding their fundamental enhancement mechanisms. Photocatalysis and solar energy conversion are… (more)

Hung, Wei Hsuan

2011-01-01T23:59:59.000Z

378

Method for producing high surface area chromia materials for catalysis  

SciTech Connect (OSTI)

Nanostructured chromium(III)-oxide-based materials using sol-gel processing and a synthetic route for producing such materials are disclosed herein. Monolithic aerogels and xerogels having surface areas between 150 m.sup.2/g and 520 m.sup.2/g have been produced. The synthetic method employs the use of stable and inexpensive hydrated-chromium(III) inorganic salts and common solvents such as water, ethanol, methanol, 1-propanol, t-butanol, 2-ethoxy ethanol, and ethylene glycol, DMSO, and dimethyl formamide. The synthesis involves the dissolution of the metal salt in a solvent followed by an addition of a proton scavenger, such as an epoxide, which induces gel formation in a timely manner. Both critical point (supercritical extraction) and atmospheric (low temperature evaporation) drying may be employed to produce monolithic aerogels and xerogels, respectively.

Gash, Alexander E. (Brentwood, CA); Satcher, Joe (Patterson, CA); Tillotson, Thomas (Tracy, CA); Hrubesh, Lawrence (Pleasanton, CA); Simpson, Randall (Livermore, CA)

2007-05-01T23:59:59.000Z

379

BERKELEY CATALYSIS CENTER Monday, October 10, 2005 4 pm  

E-Print Network [OSTI]

synthesis of sophisticated mixed ceramic and noble metal composite nanoparticles. These materials seemed, Au or Ag) on ceramic (TiO2, SiO2 and Al2O3) nanoparticles will be shown. For example, the open-ray absorbing matrix. The structural identification at such small concentration turned out to be important since

Iglesia, Enrique

380

VISCOELASTICITY OF POLYETHYLENES PRODUCED WITH SINGLE SITE METALLOCENE CATALYSIS  

E-Print Network [OSTI]

of the processability characteristics of these two new LLDPEs. Introduction After initial commercialization in the 1940 in the control of distributions of short chain branching (SCB) and long chain branching (LCB) in the polymer [1

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


381

Quantum Catalysis of Magnetic Phase Transitions in a Quantum Simulator  

E-Print Network [OSTI]

We control quantum fluctuations to create the ground state magnetic phases of a classical Ising model with a tunable longitudinal magnetic field using a system of 6 to 10 atomic ion spins. Due to the long-range Ising interactions, the various ground state spin configurations are separated by multiple first-order phase transitions, which in our zero temperature system cannot be driven by thermal fluctuations. We instead use a transverse magnetic field as a quantum catalyst to observe the first steps of the complete fractal devil's staircase, which emerges in the thermodynamic limit and can be mapped to a large number of many-body and energy-optimization problems.

Philip Richerme; Crystal Senko; Simcha Korenblit; Jacob Smith; Aaron Lee; Rajibul Islam; Wesley C. Campbell; Christopher Monroe

2013-03-27T23:59:59.000Z

382

2004 Catalysis Gordon Conference-June 27-July 2,  

SciTech Connect (OSTI)

The Conference was well-attended with 100 participants (attendees list included). The attendees represented the spectrum of endeavor in this field coming from academia, industry, and government laboratories, U.S. and foreign scientists, senior researchers, young investigators, and students. In designing the formal speakers program, emphasis was placed on current unpublished research and discussion of the future target areas in this field. There was a conscious effort to stimulate lively discussion about the key issues in the field today. Time for formal presentations was limited in the interest of group discussions. In order that more scientists could communicate their most recent results, poster presentation time was scheduled. The formal schedule and speaker program and the poster program is given. In addition to these formal interactions, 'free time' was scheduled to allow informal discussions. Such discussions are fostering new collaborations and joint efforts in the field.

Nancy Ryan Gray

2005-08-17T23:59:59.000Z

383

CATALYSIS AND INHIBITION OF MYCOBACTERIUM TUBERCULOSIS METHIONINE AMINOPEPTIDASE  

E-Print Network [OSTI]

-3 Domain architechture of Methionine Aminopeptidase....................................12 Figure 1-4 Crystal structures of EcMetAP I,PfMetAP IIa and HsMetAP IIb ...................12 Figure 1-5 The dinuc lear metal centers and the amino acid residues... in EcMetAP I, PfMetAP IIa and HsMetAP IIb........................................................................14 Figure 1-6 Proposed reaction mechanism of dimetalated EcMetAP I ..............................16 Figure 1-7 Proposed reaction...

Lu, Jingping

2010-06-04T23:59:59.000Z

384

Light-driven uncoupling of nitrogenase catalysis from ATP hydrolysis  

E-Print Network [OSTI]

77 Figure 4.1. Genes in the major nif cluster from A.plasmids from digested nif gene inserts. Figure 4.5. Two-82 The Nif Gene

Roth, Lauren E.

2012-01-01T23:59:59.000Z

385

Progress in transition metal-based enantioselective catalysis  

E-Print Network [OSTI]

In Chapter 1, the first enantioselective cross-coupling reactions of racemic secondary benzylic halides are described (eq 1). This method was applied to the syntheses of intermediates employed by other groups in the ...

Arp, Forrest O

2008-01-01T23:59:59.000Z

386

7 things you may not know about catalysis | Argonne National...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

to turn raw materials into useful products. Catalysts are integral in making plastics and many other manufactured items. Even the human body runs on catalysts. Many...

387

Catalysis Today 88 (2004) 139151 Hydrodehalogenation with sonochemically prepared  

E-Print Network [OSTI]

to the formation of even more toxic secondary pollutants such as polyhalogenated dioxins and fu- rans [7­11]. Emissions from incineration plants are a major contributor to the 3000 kg of polyhalogenated dioxins

Suslick, Kenneth S.

388

Catalysis of 6? Electrocyclizations & Catalytic Disproportionation of Lignin Model Compounds  

E-Print Network [OSTI]

represent 86% of the total global energy consumed in 2006.source for 1% of the total global energy consumed in 2006, 1the total sustainable global biomass energy production

Bishop, Lee

2010-01-01T23:59:59.000Z

389

Pre-Competitive Catalysis Research: Fundamental Sulfation/Desulfation...  

Broader source: Energy.gov (indexed) [DOE]

Partners * Collaborators and their roles - CLEERS: evaluation protocols - Center for Nano-phase Material Science (CNMS): catalyst synthesis - Umicore: catalyst supplier 3...

390

Hybrid Porous Materials for Controlled Release and Catalysis  

E-Print Network [OSTI]

Catalytic Preparation of Biodiesel ? 7.1. Introduction Duepossible resources, biodiesel, a nonpetroleum-based fuels,solid acid catalysts for biodiesel synthesis based on

Liu, Rui

2010-01-01T23:59:59.000Z

391

Heterogeneous Catalysis DOI: 10.1002/anie.201200699  

E-Print Network [OSTI]

- cial processes unattractive. Several non-noble metal materi- als, such as transition-metal chalcogenides,[2] carbides,[3] and complexes[4] as well as metal alloys[5] have been widely investigated. Nitrides of early transition-metals have been shown to have excellent catalytic activities in a variety

Frenkel, Anatoly

392

Density Functional Theory in Surface Chemistry and Catalysis  

SciTech Connect (OSTI)

Recent advances in the understanding of reactivity trends for chemistry at transition metal surfaces have enabled in silico design of heterogeneous catalysts in a few cases. Current status of the field is discussed with an emphasis on the role of coupling between theory and experiment and future challenges.

Norskov, Jens

2011-05-19T23:59:59.000Z

393

Materials and interfaces for catalysis, separation, storage, and environmental applications  

E-Print Network [OSTI]

and interfaces for a host of sustainable chemical processes that provide renewable (or cleaner) fuels the next generation of catalysts, separation processes, gas and liquid storage technologies, and environmental remediation methods. These materials and technologies are at the heart of industrial processes

Li, Mo

394

Biochemical Conversion: Using Hydrolysis, Fermentation, and Catalysis to  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:Year in Review: Top Five EEREDepartment ofEnergyEnergyBetterMake Fuels and Chemicals |

395

Fundamental Studies in Catalysis Enabled the use of Efficient  

Office of Environmental Management (EM)

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396

Plasma Assisted Catalysis System for NOx Reduction | Department of Energy  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious RankCombustion | Department ofT ib l L d F SSalesOE0000652GrowE-mail onThe2 DOE11.4 Planning andPlant

397

Catalysis Science | U.S. DOE Office of Science (SC)  

Office of Science (SC) Website

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398

University of Delaware | Catalysis Center for Energy Innovation  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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399

Heterogeneous Catalysis on Atomically Dispersed Supported Metals: CO2  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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400

Temperature Transient Effects in Plasma-Catalysis | Department of Energy  

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

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


401

Transmural Catalysis - High Efficiency Catalyst Systems for NOx Adsorbers  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious RankCombustion |Energy Usage »of EnergyThe EnergyDepartment7 thFuel Processor for' %Transmissionand SCR

402

Catalysis of 6? Electrocyclizations & Catalytic Disproportionation of Lignin Model Compounds  

E-Print Network [OSTI]

J. D. ; McNally, T. J. Lignin. In Kirk-Othmer EncyclopediaK. ; Gellerstedt, G. Lignin. In Analytical Methods in Woodof a 1-phenylpropane-1,3-diol lignin model compound via ?-

Bishop, Lee

2010-01-01T23:59:59.000Z

403

Frontiers in Catalysis Science and Engineering Seminar Series  

E-Print Network [OSTI]

Innovation ·Director of Catalytic Science and Technology ·University of Delaware Abstract In this talk clusters. We find that oxygen vacancies are critical in enabling charge transfer and thus molecular oxygen

404

Lean NOx Catalysis Research and Development | Department of Energy  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:YearRound-UpHeatMulti-Dimensionalthe10 DOEWashington,LM-04-XXXXLocated and Methaneof Energy

405

Textured Metal Catalysts for Heterogeneous Catalysis - Energy Innovation  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear SecurityTensile Strain Switched Ferromagnetism in Layered NbS2 and NbSe2 . TensileTevatronPortal Biomass and

406

Theoretical Study on Catalysis by Protein Enzymes and Ribozyme  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear SecurityTensile Strain Switched Ferromagnetism in Layered NbS2 andThe1 Members Theme 1 MemberstheTheoretical Study on

407

Homogeneous and Interfacial Catalysis in 3D Controlled Environment | The  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsingFun withconfinement plasmas inPortal StartupdefaultThe benefits ofEnergyAmes

408

Electron Microscopy Catalysis Projects: Success Stories from the High  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:YearRound-UpHeat PumpRecord ofESPC ENABLE: ECMConstruction andElectrolytes |in Support of

409

Iran Thomas Auditorium, 8600 Environmental Transmission Electron Microscopy for Catalysis  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsingFunInfrared LandResponsesIon/Surface Reactions andOctober 5,

410

Iron Catalysis in Oxidations by Ozone - Energy Innovation Portal  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsingFunInfrared LandResponsesIon/Surface Reactions andOctober 5,OctoberdeepIronIron

411

Pre-Competitive Catalysis Research: Fundamental Sulfation/Desulfation  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious RankCombustion | Department ofT ib l L d FNEPA/309 Reviewers |of ExcellenceStudies of Lean NOx Traps |

412

Catalysis Working Group Meeting: May 2013 | Department of Energy  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:YearRound-Up fromDepartmentTie Ltd:June 20154:04-21-2014Innovative EnergyKick-Off Meeting:

413

Catalysis by Design - Theoretical and Experimental Studies of Model  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:YearRound-Up fromDepartmentTie Ltd:June 20154:04-21-2014Innovative EnergyKick-Off Meeting:Catalysts

414

Catalysis by Design: Bridging the Gap between Theory and Experiments |  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:YearRound-Up fromDepartmentTie Ltd:June 20154:04-21-2014Innovative EnergyKick-OffDepartment of

415

Bimetallic and Ternary Alloys for Improved Oxygen Reduction Catalysis . |  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc DocumentationP-Series to someone6 M. Babzien, I.ProgramBig Sol Big Sol SuperAcid.

416

Biomimetic Chalcogels for Solar Fuel Catalysis | ANSER Center |  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc DocumentationP-Series to someone6 M. Babzien,Biological Imaging by

417

Catalysis Center for Energy Innovation KEY ACCOMPLISHMENTS AND CORE CAPABILITIES  

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AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary)morphinanInformation InInformationCenterResearchCASL Symposium:and Technical Information Catalogue ofKEY

418

Micro and Mesoporous Metal Organic Frameworks for Catalysis Applications. |  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: VegetationEquipment Surfaces andMapping theEnergyInnovationMichael M. May, 1970MichelleinternshipEMSL

419

Thermochemical Conversion: Using Heat and Catalysis to Make Biofuels and  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:YearRound-Up from theDepartment of EnergyThe Sun and Its Energy (11Processes

420

Shining Light on Catalysis | Stanford Synchrotron Radiation Lightsource  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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


421

Control Heterogeneous Catalysis at Atomic and Electronic-level Using  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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422

University of Delaware | Catalysis Center for Energy Innovation | Aromatics  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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423

University of Delaware | Catalysis Center for Energy Innovation | Biomass  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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424

University of Delaware | Catalysis Center for Energy Innovation | Fuel  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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425

University of Delaware | Catalysis Center for Energy Innovation | Furans  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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426

University of Delaware | Catalysis Center for Energy Innovation | Materials  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary)morphinanInformation Desert Southwest RegionatSearchScheduledProductionCCEI AdvisoryVisitingCellsMaterials

427

University of Delaware | Catalysis Center for Energy Innovation | Modeling  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary)morphinanInformation Desert Southwest RegionatSearchScheduledProductionCCEI

428

University of Delaware | Catalysis Center for Energy Innovation | Pyrolysis  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary)morphinanInformation Desert Southwest RegionatSearchScheduledProductionCCEIResearch Thrust Pyrolysis

429

Catalysis | U.S. DOE Office of Science (SC)  

Office of Science (SC) Website

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear SecurityTensile Strain Switched5 IndustrialIsadore Perlman,Bios High Energy Physics AdvisoryCMSNF Carl

430

Integrated Mesoscale Architectures for Sustainable Catalysis (IMASC) | U.S.  

Office of Science (SC) Website

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear SecurityTensile Strain Switched5 IndustrialIsadore Perlman,Bios High EnergyElianeScienceScience| U.S. DOE(SC)DOE

431

Isolated Palladium Atoms Allow Highly-Selective Catalysis of Hydrogenation  

Office of Science (SC) Website

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear SecurityTensile Strain Switched5 IndustrialIsadore Perlman,Bios High EnergyElianeScienceScience| U.S.Reactions | U.S.

432

The Role of Catalyst Surface Structure in Heterogeneous Catalysis |  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas ConchasPassiveSubmittedStatus TomAboutManusScienceThe Life of EnricoFlickr

433

Polyisobutylene as a Polymer Support for Homogeneous Catalysis  

E-Print Network [OSTI]

of 5 cycles In 2005, Zhang described immobilization of Cinchona alkaloids with an anthraquinone core onto PEG 5000 (eq. 9). 21 This PEG-bound alkaloid 6was used in asymmetric dihydroxylation with various alkenes with high stereoselectivities...

Hongfa, Chayanant

2010-01-14T23:59:59.000Z

434

Materials with supramolecular chirality : liqid crystals and polymers for catalysis  

E-Print Network [OSTI]

Mesomorphic organizations provide a powerful and efficient method for the preorganization of molecules to create synthetic materials with controlled supramolecular architectures. Incorporation of polymerizable groups within ...

Martin, Karen Villazor

2005-01-01T23:59:59.000Z

435

The Interplay of Catalysis and Toxicity by Amyloid  

E-Print Network [OSTI]

Words IAPP, amylin, protein folding, -synuclein, A, mechanism Abstract The dynamics, energies, and structures governing protein folding are critical to biological function. Amyloidoses are a class of disease #12;Contents PROTEIN FOLDING DEFINED . . . 126 PROTEIN MISFOLDING AS A BASIS FOR DISEASE

Miranker, Andrew

436

Catalysis of 6? Electrocyclizations & Catalytic Disproportionation of Lignin Model Compounds  

E-Print Network [OSTI]

groups. 13 Finally, the organosolv process extracts ligninWhile a 70% conversion of organosolv lignin to alkanols such

Bishop, Lee

2010-01-01T23:59:59.000Z

437

This issue of Topics in Catalysis is devoted to ``Nanotechnology in Catalysis'' and covers some of the  

E-Print Network [OSTI]

silica, catalyst supports and catalytic membranes. Nanosized hollow spheres (silica or carbon) have been crystal structures, electronic configurations, or surface compositions that can only be obtained with nano of Nanotechnology. A well-known advan- tage of reducing particle size is the increase in surface area per unit

Resasco, Daniel

438

Anthraquinone-Imide-Based Dimers: Synthesis, Piezochromism, Liquid Crystalline,  

E-Print Network [OSTI]

-Infrared Electrochromic Properties Fengkun Chen, Jie Zhang, Xinhua Wan* Introduction Organic materials that respond, but relatively low applied pressure is preferred for many applications in our daily life. Electrochromic (EC lengths. Their liquid crystalline behaviors, and piezochromic and near-infrared electrochromic properties

Wan, Xin-hua

439

Mercury dimer spectroscopy and an Einstein-Podolsky-Rosen experiment  

E-Print Network [OSTI]

separator (Pellin- Broca prism set); BS: beam splitter; PD: photodiode; PMT: photomultiplier..........................................................................................29 FIGURE... splitter; PD: photodiode; PMT: photomultiplier .....................................45 FIGURE IV-4 The experimental and simulated profiles of the A1+A2=402 (198Hg204Hg is out of the simulation range) isotopic components...

Qu, Xinmei

2009-05-15T23:59:59.000Z

440

Coherence oscillations between weakly coupled Bose-Hubbard dimers  

E-Print Network [OSTI]

We study theoretically the dynamics of two weakly-coupled Bose-Josephson junctions, prepared with the same particle number $N$ and Josephson excitation number $\

Christine Khripkov; Amichay Vardi

2014-05-11T23:59:59.000Z

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


441

Quantum Spin Ice and dimer models with Rydberg atoms  

E-Print Network [OSTI]

Quantum spin ice represents a paradigmatic example on how the physics of frustrated magnets is related to gauge theories. In the present work we address the problem of approximately realizing quantum spin ice in two dimensions with cold atoms in optical lattices. The relevant interactions are obtained by weakly admixing van der Waals interactions between laser admixed Rydberg states to the atomic ground state atoms, exploiting the strong angular dependence of interactions between Rydberg p-states together with the possibility of designing step-like potentials. This allows us to implement Abelian gauge theories in a series of geometries, which could be demonstrated within state of the art atomic Rydberg experiments. We numerically analyze the family of resulting microscopic Hamiltonians and find that they exhibit both classical and quantum order by disorder, the latter yielding a quantum plaquette valence bond solid. We also present strategies to implement Abelian gauge theories using both s- and p-Rydberg states in exotic geometries, e.g. on a 4-8 lattice.

Alexander W. Glaetzle; Marcello Dalmonte; Rejish Nath; Ioannis Rousochatzakis; Roderich Moessner; Peter Zoller

2014-04-21T23:59:59.000Z

442

A structural investigation of the chemokine dimer interface  

E-Print Network [OSTI]

plasmid) were added. PCR products were purified by gel electrophorcsis followed by cleanup with a Qiagen Gel Extraction kit Purified PCR products were then digcstcd in a 31 Eco R I P lac Nsi I sol I on M13 Pst I Hind ill cl oodi 1-132 X los I... by a lac promoter (dark arrow at I:00) This figure is courtesy of Dr. Jim Hu of Texas A&M University. . 32 20pl mixture containing 141tl purified DNA, 21tI New England Biolabs BamH I Buffer, 21tl New England Biolabs 10X BSA buffer, I ltl New England...

Hayes, Garret Lance

2013-02-22T23:59:59.000Z

443

How Magnetic Dimers Interact to Create Long-Range Order  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsingFun withconfinement plasmas inPortalAllBPA addresses EMF B OImproving

444

Selective oxidative synthesis of meso-beta fused porphyrin dimers  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas ConchasPassiveSubmitted forHighlights Nuclear

445

CO adsorption-desorption properties of cation-exchanged NaX zeolite and supported ruthenium  

SciTech Connect (OSTI)

The binding states of carbon monoxide over cation-exchanged NaX zeolites and over corresponding Ru-containing samples have been investigated using thermal desorption spectroscopy. Exchange of sodium with cations such as Li{sup +}, Ca{sup 2+}, Mg{sup 2+}, and La{sup 3+} gave rise to additional CO adsorption states, a higher isosteric heat of CO adsorption, an increased density of acid sites, and an increased amount of adsorbed CO, depending on the nature and ionic radius of the charge-balancing cation. The charge-balancing cations at the zeolite surface (e.g., Ca{sub 2+}, La{sup 3+}) function as additional CO adsorption sites in conjunction with surface acid centers (e.g., the Al{sup 3+} center) and metal sites. In addition to surface sites, CO is also found to be held in structural cavities and macropores of the zeolite matrix. The programmed heating of both the metal-free and Ru-containing zeolites subsequent to room temperature CO adsorption gave desorption peaks due to release of CO at temperatures less than {approximately}500 K while the higher temperature peaks were constituted mainly of CO{sub 2}. Electron spectroscopy results have revealed that the exposure of these samples to CO and subsequent thermal treatment resulted in the formation of surface carbonaceous species. The nature of CO adsorption states giving rise to CO{sub 2} formation is discussed.

Gupta, N.M.; Kamble, V.S.; Rao, K.A.; Iyer, R.M. (Bhabha Atomic Research Centre, Bombay (India))

1989-12-01T23:59:59.000Z

446

Carbon monoxide adsorption/desorption processes over NaX zeolite and supported ruthenium catalyst  

SciTech Connect (OSTI)

The binding states of CO on NaX zeolite and RuNaX were investigated by thermal desorption spectroscopy. Desorption peaks centered at around 390, 430, 490, and 520 K were observed from NaX following room-temperature adsorption of CO. The activation energy values corresponding to these peaks were calculated to be 41.4, 45.7, 53.8, and 57.7 kJ mol{sup {minus}1}, respectively. These peaks were also observed in desorption profiles from RuNaX although their temperatures were higher by 10 to 20 K. In addition, the desorption spectra from RuNaX also comprise two high-temperature peaks at around 575 and 640 K. With both the RuNaX and the NaX samples the temperature and relative intensities of the desorption peaks depended on pretreatment conditions and on the lapsed time between CO exposure to the sample and the commencement of programmed heating. Mass spectral analysis revealed that the gas desorbed at 300-500 K consisted mainly of CO while at higher temperatures CO{sub 2} was the main component. The desorption peaks below 500 K are attributed to the release of carbon monoxide from structural and intragranular or intergranular zeolitic pores. Lewis sites on the zeolite surface are found to facilitate activation of CO, resulting in its transformation to CO{sub 2}. The initial adsorption of carbon monoxide in zeolite pores and subsequent diffusion to metal sites leading to its disproportionation/oxidation is found to play an important role in the CO adsorption/desorption process on RuNaX.

Kamble, V.S.; Gupta, N.M.; Iyer, R.M. (Bhabha Atomic Research Centre, Bombay (India))

1988-10-01T23:59:59.000Z

447

E-Print Network 3.0 - active chiral ruthenium Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

on what has now become a flourishing and dynamic field Source: Zheludev, Nikolay - Optoelectronics Research Centre & School of Physics and Astronomy, University of Southampton...

448

Author's personal copy In situ facile synthesis of ruthenium nanocluster catalyst  

E-Print Network [OSTI]

, and its limited environmental impact [1]. One of the key issues in studies on hydrogen as an energy, QC H3A 2K6, Canada a r t i c l e i n f o Article history: Received 28 June 2012 Received in revised

449

CO oxidation on ruthenium: The nature of the active catalytic surface. |  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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450

Dye Sensitization of Nanocrystalline Titanium Dioxide with Osmium and Ruthenium Polypyridyl Complexes  

E-Print Network [OSTI]

dioxide electrodes.2-4 The highest efficiency reported to date for such systems has been obtained using conversion efficiencies of up to 10% have been reported.4 The approximate energetics for this system while maintaining the excited-state redox potential at the same energy level relative to the TiO2 can

Sauvé, Geneviève

451

Dendrimer-Encapsulated Ruthenium Nanoparticles as Catalysts for Lithium-O2  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc DocumentationP-Series to UserProduct: CrudeOffice ofINLNuclear SecurityBatteries. | EMSL

452

Reply to comment on CO oxidation on ruthenium: the nature of the active  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 -the Mid-Infrared at 278, 298,NIST31 ORV 15051SoilWind EnergyRentalRep.

453

Intramolecular, photoinduced electron transfer in ruthenium(II) bipyridine-quinone complexes  

SciTech Connect (OSTI)

Adsorption spectroscopy and transient emission spectroscopy were used to follow intramolecular electron transfer quenching after metal-to-ligand charge transfer (MLCT) excitation of Ru(II)bipyridine-quinone complexes. Studies of various N-((4{prime}methyl-2-2{prime}-bipyridyl)-4-methyl)-9,10-anthraquinone-2-carboxamide (bpy-AQ) complexes, revealed that these complexes quench by rapid electron transfer from ligand radical excited states to the metal center. A donor-chromophore-acceptor complex with the bpy-AQ ligand and the (10-[4({prime}-methyl-2,2{prime}-bipyridin-4-yl)methylphenothiazine)] (bpy-PTZ) ligand displays redox separation on excitation.

Opperman, K.A.; Mecklenburg, S.L.; Meyer, T.J. [Univ. of North Carolina, Chapel Hill, NC (United States)

1994-11-09T23:59:59.000Z

454

CO adsorption on ion-exchanged Ru zeolite catalysts  

SciTech Connect (OSTI)

CO adsorption on ion-exchanged Ru zeolite catalysts, studied by IR spectroscopy, revealed the existence of three types of ruthenium which adsorbed the carbon monoxide into three different states. The ruthenium types were atomically or highly dispersed ruthenium, ruthenium clusters which formed ruthenium carbonyl, and larger (> 1 nm) particles, probably on the outer zeolite surfaces.

Goodwin, J.G. (Univ. of Pittsburgh); Naccache, G.

1980-08-01T23:59:59.000Z

455

Modification of Gold Catalysis withModification of Gold Catalysis with Aluminum Phosphate for OxygenAluminum Phosphate for Oxygen--Reduction ReactionReduction Reaction  

E-Print Network [OSTI]

Ford Toshiba Samsung Byungwoo Park's Group #12;Scheme of Fuel Cells Load e- e- Hydrogen Methanol + Water (DMFC· Morphology of Au/AlPO4 Nanocomposite Catalyst · Oxygen Reduction Activity ­ Hydrogen Peroxide Intermediate to Gold Seoul National University Yejun Park et al. 22Byungwoo Park's Group #12;Applications of Fuel Cells

Park, Byungwoo

456

The Development of Werner-type Cobalt Complexes in Enantioselective Hydrogen Bond Mediated Catalysis  

E-Print Network [OSTI]

– conditions, ?-(S,S)-3^(3+) 2BF_(4)^(–) Bar_(f)^(-) (10 mol%) catalyzes the Michael addition of 15a to 2-benzyloxy-trans-?-nitrostyrene in acetone at 0 °C in the presence of Et_(3)N (1.0 equiv) to afford dimethyl 2-(2-nitro-1-(2 benzyloxyphenyl...

Lewis, Kyle

2013-12-03T23:59:59.000Z

457

Catalysis Letters Vol. 76, No. 12, 2001 35 Second order isothermal desorption kinetics  

E-Print Network [OSTI]

cycles of controlled heating and cooling of the sample, instead of the standard linear heat- ing rates, the kinetics of CO adsorption and desorption from Pd(110) [5], NH3/Re(0001) [6] monitored by optical second desorption that corresponds to second order de- sorption kinetics. Assuming high enough pumping speed

Asscher, Micha

458

Journal of Catalysis 255 (2008) 134137 www.elsevier.com/locate/jcat  

E-Print Network [OSTI]

, and subsequent filtration, rinsing with deionized water, and treatment in flow- ing dry air (Praxair, extra dry

Iglesia, Enrique

459

Applied Catalysis B: Environmental 37 (2002) 1725 Selective CO oxidation over Pt/alumina catalysts  

E-Print Network [OSTI]

). methanol or partial oxidation of gasoline followed by water gas shift reaction will produce a gas stream al. [11] studied the kinetics of the selective CO oxidation in H2-rich gas on Pt/Al2O3 in detail rich feed gas to proton exchange membrane (PEM) fuel cells can poison the platinum anode electrode

Gulari, Erdogan

460

Catalysis Today 181 (2012) 7581 Contents lists available at ScienceDirect  

E-Print Network [OSTI]

activity, higher chain growth probability, and lower water­gas shift activity. However Co is approximately size distribution and the number of active sites were estimated from the TEM images. Kinetic data was readily oxidized by water vapor, while for the relatively large Co particles (3.5­10.5 nm), such oxidation

Goodman, Wayne

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


461

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

SciTech Connect (OSTI)

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

Somorjai, Gabor A.; Park, Jeong Y.

2008-03-06T23:59:59.000Z

462

ISHHC XIII International Symposium on the Relations between Homogeneous and Heterogeneous Catalysis  

E-Print Network [OSTI]

o P-159 Carbon Dioxide Hydrogenation for Methanol Synthesis:Carbon dioxide activation mechanisms for low temperature partial hydrogenation to methanol

Somorjai Ed., G.A.

2007-01-01T23:59:59.000Z

463

End Functinalization of Polyisobutylenes and their Applications in Dyeing Polyolefins and in Homogeneous Catalysis  

E-Print Network [OSTI]

, in the pharmaceutical industry and in the food industry. Polyisobutylene was first developed by the BASF in 1931 and is sold under the trade name ?Oppanol B? or ?Glissopal? depending on its molecular weight. These commercial materials are produced via cationic... that require carbocationic polymerization, PIB oligomers used in this study were commercially available, inexpensive and available under the trade name Glissopal from BASF (MW = 1000, DP = 18 or MW = 2300, DP = 41). The Bergbreiter group is one of a number...

Boralugodage, Nilusha P

2013-06-05T23:59:59.000Z

464

Carbon-Heteroatom Reductive Elimination and Catalysis Utilizing (POCOP)Rh and (POCOP)Co Complexes  

E-Print Network [OSTI]

-2. 31P{1H} NMR spectra of selected complexes collected in C6D6. (a) Synthesis of (POCOP)Rh(H)(Cl) (205) by a direct route. Small resonance at 157.9 ppm not shown. (b) Reaction of 205 with 0.60 eq. of 204 at RT. The singlet resonance representing.... ...................................................................................... 29 Figure 2-3. 2H NMR spectra of deuterium exchange reactions. (collected in 1,4- dioxane) (a) Exchange of 205 with D2O to give (POCOP)Rh(D)(Cl) (215). (b) 0.53 eq of 204 added to 215 to give 216. (c) After overnight thermolysis of 215 at 115 °C...

Timpa, Samuel D

2014-07-29T23:59:59.000Z

465

Applied Catalysis A: General 243 (2003) 5366 An EXAFS study of the coordination chemistry of hydrogen  

E-Print Network [OSTI]

). 1. Introduction Platinum/aluminum catalysts are vitally important for many chemical processes­66 naphtha reforming in the petroleum industry and ex- haust gas abatement in the automotive industry

Regalbuto, John R.

466

Converting Homogeneous to Heterogeneous in Electrophilic Catalysis using Monodisperse Metal Nanoparticles  

E-Print Network [OSTI]

Synthesis of One Nanometer Rh and Pt Particles Supported on Mesoporous Silica: Catalytic Activity for Ethylene and Pyrrole

Witham, Cole A.

2011-01-01T23:59:59.000Z

467

Consequences of Structure and Composition for Catalysis by Solid and Bronsted Acids  

E-Print Network [OSTI]

3 and treated in air (UHP Praxair; 0.5 cm 3 g -1 s -1 ) atin flowing dry air (UHP Praxair; 0.5 cm 3 g -1 s -1 ) at 323rate) in flowing He (UHP Praxair; 0.83 cm 3 s -1 ) and held

Carr, Robert Ted

2012-01-01T23:59:59.000Z

468

Journal of Catalysis 225 (2004) 190202 www.elsevier.com/locate/jcat  

E-Print Network [OSTI]

tetraammine impregnation of silica 1. The electrostatic nature of platinum adsorption Marc Schreier and John R and precipitated) was studied as a function of pH and concen- tration of platinum in solution. The ability of silica to protonate and deprotonate as a function of pH leads to an electrostatic attraction of the +2

Regalbuto, John R.

469

Strong Bond Activation with Late Transition-Metal Pincer Complexes as a Foundation for Potential Catalysis  

E-Print Network [OSTI]

introduction for pincer ligands ................................................ 1 1.2 Synthesis of pincer ligated transition metal complexes ........................ 3 1.3 Structural preference for group 9/10 metal complexes (4d and 5d) ...... 9 1... ..................................................................................... 126 V SYNTHESIS, CHARACTERIZATION, AND REACTIVITY OF A RHODIUM DIFLUOROCARBENE COMPLEX SUPPORTED BY PNP PINCER LIGAND ........................................................................................ 144 5.1 Introduction...

Zhu, Yanjun

2012-07-16T23:59:59.000Z

470

The Conserved Active-Site Loop Residues of Ferrochelatase Induce Porphyrin Conformational Changes Necessary for Catalysis  

E-Print Network [OSTI]

, Departamento de Qui´mica, Faculdade de Cie^ncias e Tecnologia, UniVersidade NoVa de Lisboa, 2829-516 Caparica

Shelnutt, John A.

471

ISHHC XIII International Symposium on the Relations between Homogeneous and Heterogeneous Catalysis  

E-Print Network [OSTI]

measurements. With an infrared laser, heating and coolingbeam for detection. Infrared laser heating is a successful

Somorjai Ed., G.A.

2007-01-01T23:59:59.000Z

472

Applied Catalysis B: Environmental 100 (2010) 386392 Contents lists available at ScienceDirect  

E-Print Network [OSTI]

of carbon diox- ide (CO2) from fossil fuel combustion is the major contributor to this phenomenon. Recently, many efforts are made to reduce CO2 emissions through pre- or post-combustion CO2 capture followed t Photoreduction of CO2 to hydrocarbons is a sustainable energy technology which not only mitigates emissions

Li, Ying

473

Analytical modeling of the interaction of enzyme catalysis and diffusion processes at the intracellular level  

E-Print Network [OSTI]

of VD', diffusion fluxes of Model III to Model The effect of VD' (V L /(0 S )) on the S and P concentration profiles, 2 m 0 presented in F1gure 6, was obtained by letting D equal 0. 01 and 0. 02 respectively wh1le holding V , L, and S constant...) ? &( S(K' /K i~. l) ? Y S(K /K -"'e0lj ? z INN I BI 7 I QN P IK/KSI=I. Q) ? 3I P(K. /k -=el) ? K P(K /k =?01 j Z m si m si I . =1 00 ~ I . =100. I . ~10. o o ?3 I c:o ~o LIJ ?0 m tel Cf) W c&R ?o o Z, W X O . 00 1. 00 2. 00 3. 00 %00 6...

Faith, Duane Willbern

2012-06-07T23:59:59.000Z

474

Theoretical Understanding of Enhanced Photoelectrochemical Catalytic Activity of Sn-Doped Hematite: Anisotropic Catalysis and  

E-Print Network [OSTI]

attention in the last three years for its sustainable and carbon- neutral storage of solar energy activity of visible light water splitting. 1. INTRODUCTION The efficient utilization of solar energy is one the accessibility to the amount of useful solar energy to 40%),3-13 hematite (-Fe2O3) has been paid increasing

Goddard III, William A.

475

Journal of Catalysis 252 (2007) 4956 www.elsevier.com/locate/jcat  

E-Print Network [OSTI]

fuel in power generation, food preparation, and space * Corresponding author. E-mail address: iglesia as a replace- ment for liquefied petroleum gas (LPG) and diesel fuel in de- veloping countries [1,2]. Several

Iglesia, Enrique

476

Plasma Catalysis for NOx Reduction from Light-Duty Diesel Vehicles  

SciTech Connect (OSTI)

On behalf of the Department of Energy's Office of FreedomCAR and Vehicle Technologies, we are pleased to introduce the Fiscal Year (FY) 2004 Annual Progress Report for the Advanced Combustion Engine R&D Sub-Program. The mission of the FreedomCAR and Vehicle Technologies Program is to develop more energy efficient and environmentally friendly highway transportation technologies that enable Americans to use less petroleum for their vehicles. The Advanced Combustion Engine R&D Sub-Program supports this mission by removing the critical technical barriers to commercialization of advanced internal combustion engines for light-, medium-, and heavy-duty highway vehicles that meet future Federal and state emissions regulations. The primary objective of the Advanced Combustion Engine R&D Sub-Program is to improve the brake thermal efficiency of internal combustion engines from 30 to 45 percent for light-duty applications by 2010; and 40 to 55 percent for heavy-duty applications by 2012; while meeting cost, durability, and emissions constraints. R&D activities include work on combustion technologies that increase efficiency and minimize in-cylinder formation of emissions, as well as aftertreatment technologies that further reduce exhaust emissions. Work is also being conducted on ways to reduce parasitic and heat transfer losses through the development and application of thermoelectrics and turbochargers that include electricity generating capability, and conversion of mechanically driven engine components to be driven via electric motors. This introduction serves to outline the nature, current progress, and future directions of the Advanced Combustion Engine R&D Sub-Program. The research activities of this Sub-Program are planned in conjunction with the FreedomCAR Partnership and the 21st Century Truck Partnership and are carried out in collaboration with industry, national laboratories, and universities. Because of the importance of clean fuels in achieving low emissions, R&D activities are closely coordinated with the relevant activities of the Fuel Technologies Sub-Program, also within the Office of FreedomCAR and Vehicle Technologies. Research is also being undertaken on hydrogen-fueled internal combustion engines to provide an interim hydrogen-based powertrain technology that promotes the longer-range FreedomCAR Partnership goal of transitioning to a hydrogen-fueled transportation system. Hydrogen engine technologies being developed have the potential to provide diesel-like engine efficiencies with near-zero emissions.

None

2005-12-15T23:59:59.000Z

477

Computational heterogeneous catalysis applied to steam methane reforming over nickel and nickel/silver catalysts  

E-Print Network [OSTI]

The steam methane reforming (SMR) reaction is the primary industrial means for producing hydrogen gas. As such, it is a critical support process for applications including petrochemical processing and ammonia synthesis. ...

Blaylock, Donnie Wayne

2011-01-01T23:59:59.000Z

478

A mini review on the chemistry and catalysis of the water gas shift reaction  

E-Print Network [OSTI]

Water gas shift (WGS) reaction is a chemical reaction in which carbon monoxide reacts with water vapor to form carbon dioxide and hydrogen. It is an important reaction industrially used in conjunction with steam reforming of hydrocarbons for the production of high purity hydrogen. Grenoble et al examined the roles of both active metals and metal oxide support on the kinetics of the WGS reaction. They found out that the turn over numbers of various Al2O3 supported transition metals decreased in the trend of Cu, Re, Co, Ru, Ni, Pt, Os, Au, Fe, Pd, Rh, and Ir, which corresponds nicely to the observed volcano shaped correlation between catalytic activities and respective CO adsorption heat. This is a strong indication that CO gets activated on the metal surface during the reaction and different metals have different activation energies. The authors also observed that the turn over number of Pt/Al2O3 was one order of magnitude higher than that of Pt/SiO2, indicating a strong support effect, which the authors ascri...

Zhao, Zhun

2014-01-01T23:59:59.000Z

479

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

E-Print Network [OSTI]

that characterizes the strength of electrostatic interactions among occupied binding sites in poly(amidoamine) (PAMAM) dendrimers have been obtained by studying the effect of solution pH on the protonation of the dendrimers. The significant finding is that these two...

Niu, Yanhui

2004-09-30T23:59:59.000Z

480

Functionalized Nanoparticles and Surfaces for Controlled Chemical Catalysis and Effective Light Harvesting  

SciTech Connect (OSTI)

We have prepared a range of such arrays as key components for biotechnology and photonic applications. These involve self-assembled arrays of increasing complexity with three-dimensionally disposed multilayer interactions. These arrays also include dendrimers as the distinguishing structural building blocks. These photoactive integrated systems have a regular, highly-branched, three-dimensional architecture. Structural modifications of these units include variation of the core, bridging layers, and terminal groups. These modifications result in a large array of dendritic molecules with potential applications for light harvesting.

Marye Anne Fox, James K. Whitesell

2012-11-02T23:59:59.000Z

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


481

Ylides: Stabilization of Novel, Low Valent Carbon-Based Ligands with Applications in Catalysis  

E-Print Network [OSTI]

SPh 2 Me R 2 P C SPh 2 R = iPr 2 N Scheme 1.1. Synthesis of2 P C SPh 2 H OTf SPh 2 R = iPr 2 N 2 KHMDS CuCl Me R 2 P N(KHMDS P P -HCCl 3 R R R = N(iPr) 2 Scheme 3.1. Synthesis of

Asay, Matt

2009-01-01T23:59:59.000Z

482

High-Throughput In Situ Parametric Studies of Cytochrome P450 Catalysis  

E-Print Network [OSTI]

of data quality in pharmaceutical industry, J Chromatogr Agenerally useful to pharmaceutical industries to facilitateimportance to the pharmaceutical industry in the metabolic

Traylor, Matthew John

2010-01-01T23:59:59.000Z

483

ISHHC XIII International Symposium on the Relations between Homogeneous and Heterogeneous Catalysis  

E-Print Network [OSTI]

due to low solubility of syngas remain a problem for e?cientof methane to form syngas. 2 However, the structure andin the production of syngas and hydrogen from fossil and

Somorjai Ed., G.A.

2007-01-01T23:59:59.000Z

484

Synthesis, properties, and asymmetric catalysis of chiral cyclophanes and their metal complexes  

E-Print Network [OSTI]

in U.S. 1987, (General Electric Co. , USA). Us. p. 4 pp. 45.Pat. Appl. 1988, (General Electric Co. , USA). Ep. p. 13 pp.in U.S. 1989, (General Electric Co. , USA). Us. p. 7 pp. 51.

Choi, So-Young Amy

2006-01-01T23:59:59.000Z

485

Catalysis of Reduction and Oxidation Reactions for Application in Gas Particle Filters  

SciTech Connect (OSTI)

The present study is a first part of an investigation addressing the simultaneous occurrence of oxidation and reduction reactions in catalytic filters. It has the objectives (a) to assess the state of knowledge regarding suitable (types of) catalysts for reduction and oxidation, (b) to collect and analyze published information about reaction rates of both NOx reduction and VOC oxidation, and (c) to adjust a lab-scale screening method to the requirements of an activity test with various oxidation/reduction catalysts.

Udron, L.; Turek, T.

2002-09-19T23:59:59.000Z

486

Electronic Supplementary Information Efficient control of group I intron ribozyme catalysis by DNA constraints  

E-Print Network [OSTI]

M HEPES, pH 7.5, 15 mM NaCl, and 0.1 mM EDTA by heating at 95 °C for 3 min and cooling on ice for 5 min annealing samples were mixed immediately after cooling on ice. The sample was adjusted to final and cooling at room temperature (23 °C) for 10 min. The sample was brought to 50 °C, and 0.7 µL (100 pmol

Silverman, Scott K.

487

340th Catalysis Research Center (CRC) Colloquium NOx Storage Mechanism on NSR Catalysts  

E-Print Network [OSTI]

brought about the lean-burn engine technology with high air/fuel ratio for motor vehicles. However of the leading strategies to tackle this issue. The catalyst works with alternatively lean and rich conditions 1996 to 2003. He was a visiting professor at Kyoto University, Japan, Ecole Normale Superieure de Lyon

Ishii, Hitoshi

488

Progress in nucleophilic catalysis and development of nickel-catalyzed cross-couplings of propargylic halides  

E-Print Network [OSTI]

Chapter 1 describes the development of two organocatalytic processes. The first is a 13-alkylation reaction of Michael acceptors, and represents a novel umpolung process catalyzed by N-heterocyclic carbenes. The second ...

Smith, Sean W. (Sean Wesley)

2009-01-01T23:59:59.000Z

489

Final Report for: "Bis-pi-allylpalladium Complexes in Catalysis of Multicomponent Reactions"  

SciTech Connect (OSTI)

The research project involved the development of new and functionally improved Pd(II) catalyst for a three-component reaction of boronic acids, allenes and imines to afford homoallylic amines that are useful in synthesis of biologically active heterocycles. Furthermore, insights into the reaction mechanism and the structure and reactivity of the catalytically active intermediates involved in this process were sought. As a result of this work, a new type of Pd-catalysts possessing an auxiliary ligand attached to the Pd center via a C-Pd and N-Pd bonds were identified, and found to be more active than the traditional catalysts derived from Pd(OAc)2. The new catalysts provided an access to a broader range of homoallylic amine products. Although the final unequivocal evidence regarding the structure of the Pd(II) complex involved in the nucleophilic transfer of the allyl fragment from the palladium center to the imine could not be obtained, mechanistic insights into the events that are detrimental to the activity of the originally reported Pd(OAc)2-based catalytic systems were uncovered.

Malinakova, H. C.; Shiota, Atsushi

2012-06-29T23:59:59.000Z

490

Ligand Tuning in Asymmetric Catalysis: Mono-and Bis-Phospholanes for a  

E-Print Network [OSTI]

-Catalyzed Asymmetric Allylation Reaction Yuan-Yong Yan and T. V. RajanBabu* Department of Chemistry, The Ohio State Uni of potassium dimethyl malonate to diphenylallyl acetate by the use of Pd(0) complexes of bis of these ligands for Pd- catalyzed asymmetric allylation reactions. The enantioselec- tivity imparted

RajanBabu, T. V. "Babu"

491

First-principles transition-metal catalysis : efficient and accurate approaches for studying enzymatic systems  

E-Print Network [OSTI]

(cont.) We apply our approach to several paradigmatic systems: spin state splittings and structural properties of Fe2 and other small molecules as well as the addition-elimination reactions of hydrogen and methane on FeO+ ...

Kulik, Heather J

2009-01-01T23:59:59.000Z

492

Applied Catalysis A: General 467 (2013) 559567 Contents lists available at ScienceDirect  

E-Print Network [OSTI]

against the degradation of octadecanoic (stearic) acid under UV-A light illumination. The crystallinity: Study of their photocatalytic activity in terms of octadecanoic (stearic) acid degradation G. Kenanakisa photocatalytic activity regarding the degra- dation of octadecanoic (stearic) acid under UV-A light exposure

493

Applied Catalysis A: General 378 (2010) 227233 Contents lists available at ScienceDirect  

E-Print Network [OSTI]

against the degradation of stearic acid under UV-A light illumination (365 nm). All chemically grown Zn degradation of stearic acid by c-axis oriented ZnO nanowires G. Kenanakisa,b,c,d, , N. Katsarakisa heterogeneous photocatalysis, which implies the use of an inert catalyst, non-hazardous oxidants and UV and

494

Applied Catalysis B: Environmental 29 (2001) 327336 Gas-phase photo-oxidation of toluene using  

E-Print Network [OSTI]

for the excellent performance of 6 nm TiO2 catalyst for toluene photo-degradation. The structural differences for the degradation of volatile or- ganic pollutants (VOCs) [1­3]. It allows the oxidation of airborne VOCs) and UV or near-UV light source. When the catalyst absorbs photons having greater en- ergy than the band

495

ISHHC XIII International Symposium on the Relations between Homogeneous and Heterogeneous Catalysis  

E-Print Network [OSTI]

metal composites, nonmetal catalysts such as refractory compounds (borides, carbides,metal-coordination); H 2 -aided deoxygenation giving water plus a surface carbide (

Somorjai Ed., G.A.

2007-01-01T23:59:59.000Z

496

ISHHC XIII International Symposium on the Relations between Homogeneous and Heterogeneous Catalysis  

E-Print Network [OSTI]

112 Koningsberger, D.C. , 3 Konya, Zoltan, 179 Koptyug, IgorImre Labadi § , Zoltan Konya ‡ , Imre Kiricsi ‡ Department

Somorjai Ed., G.A.

2007-01-01T23:59:59.000Z

497

Journal of Catalysis 213 (2003) 1722 www.elsevier.com/locate/jcat  

E-Print Network [OSTI]

the basis of applications such as fuel cells, metal­air batteries, and corrosion, and so has been. Introduction Surfaces modified with monolayers of foreign metals of- ten exhibit unique and interesting properties that are absent in the unmodified bare surfaces. In an electrochemical en- vironment, the metal

Kwak, Juhyoun

498

Quantum Catalysis of Magnetic Phase Transitions in a Quantum Simulator P. Richerme,1  

E-Print Network [OSTI]

a transverse magnetic field as a quantum catalyst to observe the first steps of the complete fractal devil's staircase, which emerges in the thermodynamic limit and can be mapped to a large number of many on to a number of energy minimization problems [25,26], and shows the first steps of the complete devil

Richerme, Phil

499

High Throughput Software for Powder Diffraction and its Application to Heterogeneous Catalysis  

E-Print Network [OSTI]

In this thesis we investigate high throughput computational methods for processing large quantities of data collected from synchrotrons and their application to spectral analysis of powder diffraction data. We also present the main product of this PhD programme, specifically a software called 'EasyDD' developed by the author. This software was created to meet the increasing demand on data processing and analysis capabilities as required by modern detectors which produce huge quantities of data. Modern detectors coupled with the high intensity X-ray sources available at synchrotrons have led to the situation where datasets can be collected in ever shorter time scales and in ever larger numbers. Such large volumes of datasets pose a data processing bottleneck which augments with current and future instrument development. EasyDD has achieved its objectives and made significant contributions to scientific research. It can also be used as a model for more mature attempts in the future. EasyDD is currently in use by a number of researchers in a number of academic and research institutions to process high-energy diffraction data. These include data collected by different techniques such as Energy Dispersive Diffraction, Angle Dispersive Diffraction and Computer Aided Tomography. EasyDD has already been used in a number of published studies, and is currently in use by the High Energy X-Ray Imaging Technology project. The software was also used by the author to process and analyse datasets collected from synchrotron radiation facilities. In this regard, the thesis presents novel scientific research involving the use of EasyDD to handle large diffraction datasets in the study of alumina-supported metal oxide catalyst bodies. These data were collected using Tomographic Energy Dispersive Diffraction Imaging and Computer Aided Tomography techniques.

Taha Sochi

2010-12-20T23:59:59.000Z

500

Catalysis Today 240 (2015) 146152 Contents lists available at ScienceDirect  

E-Print Network [OSTI]

. This is due to the energy acquisition of the procedure [huge amount of contaminant (water/air) necessitates by studying the electrocatalytic oxidation of methanol in an alkaline medium in dark and under UV illumination high amounts of light energy], separation and recovery difficulties of the remained solid precip- itate