Modification of the Co-oxo cores of cobalt-polyoxometalate water oxidation catalysts is detectable by X-ray absorption spectroscopy (XAS) as demonstrated by comparison of Na10[Co4(H2O)2(PW9O34)2] (1) and Na17[((Co(H2O))Co2PW9O34)2(PW6O26)] (2). XAS reveals the integrity of 1 uncompromised by oxidant-driven water oxidation, which proceeds without formation of catalytic cobalt oxide.

We use density functional theory calculations of Pt@Cu core@shell nanoparticles (NPs) to design bifunctional poison-free CO oxidation catalysts. By calculating the adsorption chemistry under CO oxidation conditions, we find that the Pt@Cu NPs will be active for CO oxidation with resistance to CO-poisoning. The CO oxidation pathway at the Pt-Cu interface is determined on the Pt NP covered with a...

The interaction and mechanism for CO oxidation on a Ru-modified CeO2 surface have been investigated by using periodic density functional theory calculations corrected with the on-site Coulomb interaction via a Hubbard term (DFT + U). Our calculations showed that (i) the Ru dopant facilitates oxygen vacancy formation, while the Ru adatoms may suppress oxygen vacancy formation. (ii) Physisorbed C...

Introduction For emissions control of multicomponent exhaust gas streams, catalytic converters have to perform three functions: the catalytic oxidation of carbon monoxide to carbon dioxide, the destruction of Volatile Organic Carbon compounds (VOC’s), and NOx abatement. State-of-art catalysts for CO oxidation are based on CuMn2O4 (hopcalite), for VOC combustion on Pt/alumina, and for DeNOx eith...

Optical infrared-visible sum-frequency generation (IR-VIS SFG) surface vibrational spectros-copy was employed for in situ detection of chemisorbed CO during CO adsorption and catalytic CO oxidation on a rhodium (111) catalyst in the substrate temperature range T s = 300– 800 K. CO adsorption studies performed over 12 orders of magnitude in CO pressure (p CO = 10-8 –1000 mbar) demonstrated the r...

Rates and selectivities for the oxidation of various organosulfur compounds with tert-butyl hydroperoxide were measured on CoAPO-5 (APO = aluminophosphate; Co/P = 0.05), Co/H-Y (Co/Al = 0.15), and MoO(x)/Al2O3 (15 % wt MoO3). Rates increased with increasing electron density at the sulfur atom (methyl phenyl sulfide>diphenyl sulfide>4-methyldibenzothiophene>2,5-dimethyl thiophene). Rates (per me...

Hydrogen peroxide is a cell signaling agent that inactivates protein tyrosine phosphatases (PTPs) via oxidation of their catalytic cysteine residue. PTPs are inactivated rapidly during H(2)O(2)-mediated cellular signal transduction processes, but, paradoxically, hydrogen peroxide is a rather sluggish PTP inactivator in vitro. Here we present evidence that the biological buffer bicarbonate/CO(2)...

Spatial coupling during catalytic ignition of CO oxidation on μm-sized Pt(hkl) domains of a polycrystalline Pt foil has been studied in situ by PEEM (photoemission electron microscopy) in the 10(-5) mbar pressure range. The same reaction has been examined under similar conditions by FIM (field ion microscopy) on nm-sized Pt(hkl) facets of a Pt nanotip. Proper orthogonal decomposition (POD) of t...

The catalytic activity of deposited Pt(7) clusters has been studied as a function of the reduction state of the TiO(2)(110)-(1 × 1) support for the CO oxidation reaction. While a slightly reduced support gives rise to a high catalytic activity of the adparticles, a strongly reduced one quenches the CO oxidation. This quenching is due to thermally activated diffusion of Ti(3+) interstitials from...

Gold-based catalysts have been of intense interests in recent years, being regarded as a new generation of catalysts due to their unusually high catalytic performance. For example, CO oxidation on Au/TiO(2) has been found to occur at a temperature as low as 200 K. Despite extensive studies in the field, the microscopic mechanism of CO oxidation on Au-based catalysts remains controversial. Aimin...