Room Temperature Oxidation of Ethanol to Acetaldehyde over Pt/WO 3

Oxidation of ethanol to acetaldehyde is of relevance to synthetic chemistry and development of sensors for detection of gas phase ethanol. It is demonstrated by gas phase analysis and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) that a Pt/WO3 composite shows significant activity in oxidative dehydrogenation of ethanol to acetaldehyde at room temperature. DRIFTS also demonstrates consecutive surface chemistry occurs, yielding predominantly ethyl acetate. The oxidation state of the most active Pt particles is determined to be Pt0, rather than PtO, by studying variations in catalyst preparation methodology, and characterization of various samples by X-ray photoelectron spectroscopy. Illumination has very little effect on surface reactivity and selectivity, but promotes formation of gas phase acetaldehyde

Photocatalytic oxidation of methane over silver decorated zinc oxide nanocatalysts

The search for active catalysts that efficiently oxidize methane under ambient conditions remains a challenging task for both C1 utilization and atmospheric cleansing. Here, we show that when the particle size of zinc oxide is reduced down to the nanoscale, it exhibits high activity for methane oxidation under simulated sunlight illumination, and nano silver decoration further enhances the photo-activity via the surface plasmon resonance. The high quantum yield of 8% at wavelengths \u3c 400 nm and over 0.1% at wavelengths ¿ 470 nm achieved on the silver decorated zinc oxide nanostructures shows great promise for atmospheric methane oxidation. Moreover, the nano-particulate composites can efficiently photo-oxidize other small molecular hydrocarbons such as ethane, propane and ethylene, and in particular, can dehydrogenize methane to generate ethane, ethylene and so on. On the basis of the experimental results, a two-step photocatalytic reaction process is suggested to account for the methane photo-oxidation