Room temperature selective (photo) catalytic oxidation of ethanol to acetaldehyde over Pt/WO3
Paper ID : 1165-ICNS
Authors:
Rezvaneh Amrollahi Buky *
a Department of Physics, Iran University of Science and Technology, Tehran, Iran
Abstract:
Abstract: 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 photo electron spectroscopy. Illumination has very little effect on surface reactivity and selectivity, but promotes formation of gas phase acetaldehyde.
The activity and selectivity of Pt/WO3 materials depend strongly on the nature of the Pt species. By impregnation, a significant fraction of Pt was formed (approximately 50% of Pt was in the metallic state) and this resulted in an effective catalyst. The activity could be further improved by hydrogenation of the impregnated sample, which contained exclusively. The rate of formation of surface adsorbed acetaldehyde was not much affected by the absence or presence of light, while the gas phase production rate was significantly higher in the presence of light. We propose this is due to light stimulated desorption of the product acetaldehyde.
Keywords:
Photo catalyst, Selective oxidation, Nano materials, Pt/WO3
Status : Abstract Accepted (Poster Presentation)