Propan-1-ol Oxidation Reaction on Au/TiO2 Catalysts

  • A Nuhu
Keywords: Gold Catalysis, Propan-1-ol Oxidation, TPD, TPFRP, XRD

Abstract

Alcohols such as propanol and n- butanol have been oxidised to aldehydes by resin- supported gold in the liquid phase, and several other primary and secondary alcohols have been oxidised with very high selectivity in vapour phase over a 1wt% Au/SiO2 catalyst between 373- 573K. In this work, the adsorption of propan-1-ol was carried over 1%Au/TiO2 catalysts prepared by deposition precipitation method. This was further investigated using Pulse Flow reactor, TPFRP, TPD, and XRD,. The adsorption of propan-1-ol over TiO2 (P25) indicated a full monolayer with much of it in a dissociated state, forming propoxy group on the cationic site and hydroxyl group at anions. The propoxy is relatively stable until about 250oC, at which dehydration to propene occurs by bimolecular surface reaction. As the concentration of propoxy on the surface disappear, so mechanism reverts to a decomposition pathway, producing CO2 and H2O. However, the presence of gold on the catalyst is marked with complete conversion of propan-1-ol at low temperature (230oC) lower than Titania (300oC). Similarly, propan-1-ol oxidation on Au/TiO2 catalyst was followed by dehydration to propene at 300oC (Characteristic of TiO2) and dehydrogenation to propanal at high temperature. The evolution of CO2 and H2 appear to be due to the production of formate species on the surface of the catalyst. This formate species is mainly involved in the complete oxidation reaction of propan-1-ol on the catalysts.

Keywords: Gold Catalysis, Propan-1-ol Oxidation, TPD, TPFRP, XRD

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Articles

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eISSN: 2384-6028
print ISSN: 2276-707X