Effect of transition metal element addition upon liquid phase reforming of methanol with water over TiO2 supported Pt catalysts

Addition effects of various transition metal elements were investigated upon catalysis of TiO2 supported Pt metal for the liquid phase reforming of methanol. Addition of Mo or Fe increased the catalytic activity and selectivity of Pt/TiO2 remarkably, while added Ni or Co showed poor improvement. The addition methods of transition metal elements, i.e. co-impregnation or successive impregnation, also exhibited significant effect on the catalytic behavior. XRD, XPS, FT-IR and XAFS measurements revealed that the added Mo or Fe species that formed a low valent thin oxide layer over TiO2 surface and Pt metal were highly dispersed on the layer, while added Ni or Co formed alloys with Pt. Pt species on the oxide overlayer are supported as highly dispersed stable cationic particles, and their cationic state may depress the inhibition with strongly adsorbed CO for the reforming reaction. (C) 2010 Elsevier B.V. All rights reserved.