the catalytic oxidation of toluene over copper oxide supported on natural diatomite was investigated. the catalyst was prepared by the wet impregnation method and characterized by using the brunauer emmett teller (bet), field emission scanning electron microscopy (fesem), x-ray diffraction (xrd), x-ray fluorescence (xrf) and temperature-programmed reduction (tpr) analysis. the highest catalytic ...

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...

The surface electronic structure and CO-oxidation activity of Pt and Pt alloys, Pt3T (T = Ti, Hf, Ta, Pt), were investigated. At temperatures below 538 K, the CO-oxidation activities of Pt and Pt3T increased in the order Pt < Pt3Ti < Pt3hHf < Pt3Ta. The center-of-gravity of the Pt d-band (the d-band center) of Pt and Pt3T was theoretically calculated to follow the trend Pt3Ti < Pt3Ta < Pt3Hf < ...

Combined X-ray absorption spectroscopy (XAS) and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) were applied to investigate the interaction between reaction atmosphere, adsorbates and Pt oxidation state of Pt/Al2O3 model diesel oxidation catalysts under CO/NO oxidation conditions. The Pt oxidation state was correlated to the adsorbates on the catalyst’s surface. Even at lo...

A water oxidation catalyst generated via electrodeposition from aqueous solutions containing phosphate and Co(2+) (Co-Pi) has been studied by in situ X-ray absorption spectroscopy. Spectra were obtained for Co-Pi films of two different thicknesses at an applied potential supporting water oxidation catalysis and at open circuit. Extended X-ray absorption fine structure (EXAFS) spectra indicate t...

The present study deals with analysis of the activity of catalysts prepared by addition of different metals to Copper and Cobalt based catalysts for CO oxidation and the variation in activity caused by changes in composition. A series of catalysts were prepared with Cu:Co molar ratio 1:4 and a third metal (M= Ce, Ni, Au, Mg) was added in three different quantities. Compositions were prepared by...

We report results on the catalytic oxidation of carbon monoxide (CO) over clean Ir surfaces that are prepared reversibly from the same crystal in situ with different surface morphologies, from planar to nanometer-scale facets of specific crystal orientations and various sizes. Our temperature-programmed desorption (TPD) data show that both planar Ir(210) and faceted Ir(210) are very active for ...

Oxidation of SiC produces SiO(2) while CO is released. A "reoxidation" step at lower temperatures is, however, necessary to produce high-quality SiO(2). This step is believed to cleanse the oxide of residual C without further oxidation of the SiC substrate. We report first-principles calculations that describe the nucleation and growth of O-deficient C clusters in SiO(2) under oxidation conditi...

The catalytic low-temperature oxidation of CO to CO2 with molecular oxygen is of particular industrial and ecological interest. Gas-phase reaction kinetics measurements in conjunction with first-principles calculations provide comprehensive insight into the mechanisms and energetics of the low-temperature CO combustion reaction catalyzed by small free palladium clusters Pdx + (x = 2−7). Similar...