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Size Effect Of Ruthenium Nanoparticles In Catalytic Carbon Monoxide Oxidation, Sang Hoon Joo, Jeong Y. Park, J. Russell Renzas, Derek R. Butcher, Wenyu Huang, Gabor A. Somorjai 2010 University of California - Berkeley

Size Effect Of Ruthenium Nanoparticles In Catalytic Carbon Monoxide Oxidation, Sang Hoon Joo, Jeong Y. Park, J. Russell Renzas, Derek R. Butcher, Wenyu Huang, Gabor A. Somorjai

Wenyu Huang

Carbon monoxide oxidation over ruthenium catalysts has shown an unusual catalytic behavior. Here we report a particle size effect on CO oxidation over Ru nanoparticle (NP) catalysts. Uniform Ru NPs with a tunable particle size from 2 to 6 nm were synthesized by a polyol reduction of Ru(acac)3 precursor in the presence of poly(vinylpyrrolidone) stabilizer. The measurement of catalytic activity of CO oxidation over two-dimensional Ru NPs arrays under oxidizing reaction conditions (40 Torr CO and 100 Torr O2) showed an activity dependence on the Ru NP size. The CO oxidation activity increases with NP size, and the 6 nm …


Highly Active Heterogeneous Palladium Nanoparticle Catalysts For Homogeneous Electrophilic Reactions In Solution And The Utilization Of A Continuous Flow Reactor, Wenyu Huang, Jack Hung Chang Liu, Pinar Alayoglu, Yimin Li, Cole A. Whitman, Chia-Kuang Tsung, F. Dean Toste, Gabor A/ Somorjai 2010 University of California - Berkeley

Highly Active Heterogeneous Palladium Nanoparticle Catalysts For Homogeneous Electrophilic Reactions In Solution And The Utilization Of A Continuous Flow Reactor, Wenyu Huang, Jack Hung Chang Liu, Pinar Alayoglu, Yimin Li, Cole A. Whitman, Chia-Kuang Tsung, F. Dean Toste, Gabor A/ Somorjai

Wenyu Huang

highly active heterogeneous Pd-nanoparticle catalyst for the intramolecular addition of phenols to alkynes was developed and employed in a continuous flow reaction system. Running the reaction in flow mode revealed reaction kinetics, such as the activation energy and catalyst deactivation, and provides many potential practical advantages.


Seedless Polyol Synthesis And Co Oxidation Activity Of Monodisperse (111)- And (100)-Oriented Rhodium Nanocrystals In Sub-10 Nm Sizes, Yawen Zhang, Michael E. Grass, Wenyu Huang, Gabor A. Somoraji 2010 University of California - Berkeley

Seedless Polyol Synthesis And Co Oxidation Activity Of Monodisperse (111)- And (100)-Oriented Rhodium Nanocrystals In Sub-10 Nm Sizes, Yawen Zhang, Michael E. Grass, Wenyu Huang, Gabor A. Somoraji

Wenyu Huang

Monodisperse sub-10 nm (6.5 nm) sized Rh nanocrystals with (111) and (100) surface structures were synthesized by a seedless polyol reduction in ethylene glycol, with poly(vinylpyrrolidone) as a capping ligand. When using [Rh(Ac)2]2 as the metal precursor, (111)-oriented Rh nanopolyhedra containing 76% (111)-twinned hexagons (in 2D projection) were obtained; whereas, when employing RhCl3 as the metal precursor in the presence of alkylammonium bromide, such as tetramethylammonium bromide and trimethyl(tetradecyl)ammonium bromide, (100)-oriented Rh nanocubes were obtained with 85% selectivity. The {100} faces of the Rh nanocrystals are stabilized by chemically adsorbed Br− ions from alkylammonium bromides, which led to (100)-oriented nanocubes. …


Furan Hydrogenation Over Pt(111) And Pt(100) Single-Crystal Surfaces And Pt Nanoparticles From 1 To 7 Nm: A Kinetic And Sum Frequency Generation Vibrational Spectroscopy Study, Christopher J. Kliewer, Cesar Aliaga, Marco Bieri, Wenyu Huang, Chia-Kuang Tsung, Jennifer B. Wood, Kyriankos Komvopoulos, Gabor A. Somorjai 2010 University of California - Berkeley

Furan Hydrogenation Over Pt(111) And Pt(100) Single-Crystal Surfaces And Pt Nanoparticles From 1 To 7 Nm: A Kinetic And Sum Frequency Generation Vibrational Spectroscopy Study, Christopher J. Kliewer, Cesar Aliaga, Marco Bieri, Wenyu Huang, Chia-Kuang Tsung, Jennifer B. Wood, Kyriankos Komvopoulos, Gabor A. Somorjai

Wenyu Huang

Sum frequency generation surface vibrational spectroscopy and kinetic measurements using gas chromatography have been used to systematically study the adsorption and hydrogenation of furan over Pt(111) and Pt(100) single-crystal surfaces and size-controlled 1.0-nm, 3.5-nm and 7.0-nm Pt nanoparticles at Torr pressures (10 Torr of furan, 100 Torr of H2) to form dihydrofuran, tetrahydrofuran, and the ring-cracking products butanol and propylene. As determined by SFG, the furan ring lies parallel to all Pt surfaces studied under hydrogenation conditions. Upright THF and the oxametallacycle intermediate are observed over the nanoparticle catalysts under reaction conditions. Butoxy increases in surface concentration over Pt(111) with …


Tuning Σ-Holes: Charge Redistribution In The Heavy (Group 14) Analogues Of Simple And Mixed Halomethanes Can Impose Strong Propensities For Halogen Bonding, Kelling J. Donald, Bernard K. Wittmaack, Chad Crigger 2010 University of Richmond

Tuning Σ-Holes: Charge Redistribution In The Heavy (Group 14) Analogues Of Simple And Mixed Halomethanes Can Impose Strong Propensities For Halogen Bonding, Kelling J. Donald, Bernard K. Wittmaack, Chad Crigger

Chemistry Faculty Publications

Halogen bonding between halide sites (in substituted organic molecules or inorganic halides) and Lewis bases is a rapidly progressing area of exploration. Investigations of this phenomenon have improved our understanding of weak intermolecular interactions and suggested new possibilities in supramolecular chemistry and crystal engineering. The capacity for halogen bonding is investigated at the MP2(full) level of theory for 100 compounds, including all 80 MH4-nXn systems (M = C, Si, Ge, Sn, and Pb; X = F, Cl, Br, and I). The charge redistribution in these molecules and the (in)stability of the σ-hole at X as …


Shorter Still: Compressing C-C Single Bonds, Gerarso Martinez-Guajardo, Kelling J. Donald, Bernard K. Wittmaack, Miguel Angel Vazquez, Gabriel Merino 2010 University of Richmond

Shorter Still: Compressing C-C Single Bonds, Gerarso Martinez-Guajardo, Kelling J. Donald, Bernard K. Wittmaack, Miguel Angel Vazquez, Gabriel Merino

Chemistry Faculty Publications

How short can a C-C single bond get? The bonding in a set of molecules that are related structurally to previously synthesized or theoretically examined systems with short C-C bonds is investigated. According to calculations, a single C-C bond could be compressed to 1.313 A! To the best of our knowledge, this is the shortest single C-C bond reported to date. This shortening is a consequence of a change in the C-C-C bond angle, θ, to minimize strain in the cages and an effort to offset the tension in the surrounding bridges.


Process For Preparation Of Conducting Polymers, Reuben D. Rieke 2010 Lincoln, NE

Process For Preparation Of Conducting Polymers, Reuben D. Rieke

Chemistry Department: Faculty Publications

Methods of preparing conducting polymers and the conductive polymers prepared therefrom are provided. The method includes a) combining a monomer-metal complex together with a manganese (II) halide to provide a monomer-manga nese complex, and b) combining the monomer-manganese complex together with a metal catalyst to provide the conductive polymer. Electronic devices can be made using the polymers prepared as described herein.


Corrosion Of Steel Shipwrecks In The Marine Environment: Uss Arizona—Part 2, Donald L. Johnson, Brent M. Wilson, James D. Carr, Matthew A. Russell, Larry E. Murphy, David L. Conlin 2010 National Park Service

Corrosion Of Steel Shipwrecks In The Marine Environment: Uss Arizona—Part 2, Donald L. Johnson, Brent M. Wilson, James D. Carr, Matthew A. Russell, Larry E. Murphy, David L. Conlin

Chemistry Department: Faculty Publications

This article is a continuation of Part 1 (October 2006 MP) on the USS Arizona hull. It discusses additional methods being investigated for use in determining corrosion rates with a minimal impact on the existing structure. Marine biofouling (concretion) has accumulated on the hull. Concretion samples have been studied using x-ray diffraction, environmental electron microscopy, and corrosion potential (Ecorr) to characterize the relationship between concretion and the steel substrate. The data presented in this study confirm the viability of concretion analysis as a minimum-impact procedure to estimate the corrosion rate of mild steel in seawater.


Corrosion Of Steel Shipwreck In The Marine Environment: Uss Arizona—Part 1, Donald L. Johnson, Brent M. Wilson, James D. Carr, Matthew A. Russell, Larry E. Murphy, David L. Conlin 2010 National Park Service

Corrosion Of Steel Shipwreck In The Marine Environment: Uss Arizona—Part 1, Donald L. Johnson, Brent M. Wilson, James D. Carr, Matthew A. Russell, Larry E. Murphy, David L. Conlin

Chemistry Department: Faculty Publications

The USS Arizona has remained submerged in Pearl Harbor, Hawaii, since the Japanese attack on December 7, 1941. The ship presents a potential hazard from fuel oil still present in the ship’s hull. As an important factor in management decisions, the effect of corrosion after nearly 65 years is being studied to determine the integrity of the ship’s structure. Coupon samples from the hull revealed decreasing corrosion rates from ~1 to 3 mpy (0.03 to 0.08 mm/y) from just below the water surface to the mudline. This is about one-third of that expected in the absence of biofouling or concretion. …


Transition States In Ei Reactions, Charles A. Kingsbury 2010 University of Nebraska-Lincoln

Transition States In Ei Reactions, Charles A. Kingsbury

Chemistry Department: Faculty Publications

The pyrolysis of amine oxides, sulfoxides, selenoxides, and esters to form alkenes is believed to be a concerted reaction with a cyclic transition state. Phosphine oxides, sulfones, and nitro compounds are unreactive. This study seeks to identify reasons for the lack of reactivity of the latter. Transition states were located for all substrates progressing from RHF/3-21G* to the MP2/6-31+G(d,p) level (in certain cases). For sulfones and nitro compounds, two possible reasons for lack of reactivity were considered: (1) Atoms approaching one another in the transition state may be considered to participate in a local nOσ*CH …


Copper Thin-Film Dissolution/Precipitation Kinetics In Organic Hf Containing Cleaning Solution, Nabil George Mistkawi, Makarem A. Hussein, Malgorzata Ziomek-Moroz, Shankar B. Rananavare 2010 Portland State University

Copper Thin-Film Dissolution/Precipitation Kinetics In Organic Hf Containing Cleaning Solution, Nabil George Mistkawi, Makarem A. Hussein, Malgorzata Ziomek-Moroz, Shankar B. Rananavare

Chemistry Faculty Publications and Presentations

The corrosion behavior of electrochemically deposited copper thin films in deaerated and non-deaerated commercial cleaning solution containing HF has been investigated. Thin-film copper dissolution and reaction kinetics were investigated by monitoring Cu2+ , employing inductively coupled plasma–mass spectroscopy, and the oxidation states of copper on Si wafer surface, employing X-ray photoelectron spectroscopy. It was determined that the reaction kinetics is first order with respect to both HF and oxygen concentrations. A kinetic scheme involving reduction of oxygen and oxidation of Cu0 and Cu1+ is proposed, which is consistent with the experimentally determined reaction kinetic orders and the …


The Antioxidant Properties Of Whey Permeate Treated Fresh-Cut Tomatoes, Lubna Ahmed, Ana Belen Martin-Diana, Daniel Rico, Catherine Barry-Ryan 2010 Technological University Dublin

The Antioxidant Properties Of Whey Permeate Treated Fresh-Cut Tomatoes, Lubna Ahmed, Ana Belen Martin-Diana, Daniel Rico, Catherine Barry-Ryan

Articles

The aim of this research was to analyse the effects of three types of cheese whey permeate treatment on the antioxidant properties of fresh-cut tomatoes. Tomatoes were treated with whey permeate concentrate (PC), delactosed permeate (DP) and delactosed concentrate (DC), stored at 4 C for 10 days and compared to samples treated with the industry standard, chlorine (120 ppm). Samples treated with DP retained significantly higher antioxidant activity (FRAP) and total phenols (TP), when compared with those treated with PC and DC. DP showed significantly higher results than chlorine for DPPH, FRAP and TP. In DPPH assay, all whey permeate-treated …


New 2-Aminoethylimidazole-Based Dicarboxylic Acid Receptor Derived From Cholestane, Jyoti Ramesh Jadhav, Md Wasi Ahmad, Hong Seok Kim 2009 Kyungpook National University

New 2-Aminoethylimidazole-Based Dicarboxylic Acid Receptor Derived From Cholestane, Jyoti Ramesh Jadhav, Md Wasi Ahmad, Hong Seok Kim

Dr. Mohammad Wasi Ahmad (Md Wasi Ahmad)

A new facial amphiphile cholestane-based receptor 1 containing a 2-imidazolylethylamino moiety at the 3a and 7a positions of cholestane was synthesized. Recognition selectivity of the new receptor 1 with various dicarboxylic acids was assessed by 1H NMR titration. Maleic acid showed the highest binding constant among all the tested acids


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