Photocatalytic CO oxidation with water over Pt/TiO2 catalysts

Abstract

This paper reports that Pt/TiO2 and to some extent, Pt/Al2O3 and Pt/SiO2 catalysts show some activity in the photocatalytic oxidation of CO by water at low temperature (< 100 °C) in the absence of oxygen. For Pt/TiO2 catalysts, CO conversion is dependent on the Pt loading as well as the temperature of their reduction. There are an optimal platinum loading (5 wt%) and catalyst reduction temperature (500 °C) ensuring the best photocatalytic efficiency. Catalytic performance results from the combined effects of electron–hole photogeneration and partial photodesorption of CO from the platinum surface, followed by the adsorption and subsequent dissociation of H2O. The probable mechanism of photooxidation of CO by H2O was proposed.