XPS and TPR study of sol-gel derived M/TiO2 powders (M=Co, Cu, Mn, Ni)

Abstract

Produced by templated sol-gel method mesoporous nanosized titania powders modified with 3d-metal ions have been characterized by XPS and TPR methods. Metal species formed on the titania surface were investigated. The TPR analysis showed that reduction behaviors of the M n+ /TiO 2 were strongly affected by the synthesis method, preparation conditions and interactions between the dopant metal and TiO 2 matrix. It was found that Ti–O–M– bonds formation during sol-gel synthesis with applying nonionic triblock copolymer Pluronic P123 as organic template and calcination at 550 °C promoted high-dispersion states of doped 5 % metals. The XPS and TPR showing dopants exist as divalent and trivalent ions for M n+ /TiO 2 , where M=Co, Ni, Mn, and as monovalent and divalent ions in the case of Cu/TiO 2 .