The promoted effect of UV irradiation on preferential oxidation of CO in an H2-rich stream over Au/TiO2

The catalytic oxidation of CO over Au/TiO2 in an H2-rich stream was performed under UV irradiation. It is found that UV irradiation over Au/TiO2 promotes the preferential oxidation of CO in the H2-rich stream. The respective chemisorption of CO, H2 and O2 at Au/TiO2 can be described as a process of forming –OH or H2O species. UV irradiation over Au/TiO2 enhances the chemisorption of CO but suppresses the chemisorption of H2 both at TiO2 and Au surface. It is proposed that the photogenerated electrons from TiO2 will cause the change of the chemisorption of CO, H2 and O2 at Au/TiO2, which promotes the preferential oxidation of CO in an H2-rich stream.