Gas-phase photocatalytic oxidation of NO over palladium modified TiO2 catalysts

This study has been undertaken to investigate the influences of the valence states of doped. palladium on the photocatalytic oxidation behaviors of NO over palladium modified TiO2 catalysts. These Pd/TiO2 catalysts were prepared by thermal impregnation method and characterized by XRD, BET, XPS and UV-Vis diffuse reflectance spectra. It was found that Pd dopant existed as Pd2+ in as-prepared photocatalysts. And after photocatalytic oxidation reaction, both Pd-0 and Pd4+ could be detected. The activity tests showed that the modification of Pd could enhance the photocatalytic activity. And it was concluded that Pd4+ could be attributed to the improvement of activity. (C) 2008 Elsevier B.V. All rights reserved.