Ceria modified three-dimensionally ordered macro-porous Pt/TiO2 catalysts for water-gas shift reaction

Three-dimensionally ordered macro-porous (3DOM) TiO2 and ceria-modified 3DOM TiO2 Supported platinum catalysts were prepared with template and impregnation methods, and the resultant samples were characterized by scanning electron microscopy(SEM), X-ray diffractometer(XRD), high-resolution transmission electron microscopy(HRTEM) and temperature programmed reduction(TPR) techniques. The catalytic performances over the platinum-based catalysts were investigated for water-gas shift (WGS) reaction in a wide temperature range (180-360 degrees C). The results showed that 3DOM Pt/TiO2 catalyst exhibited obviously better catalytic performance than the corresponding non macro-porous catalyst, owing to the macro-porous structure favoring mass transfer. Addition of ceria into 3DOM Pt/TiO2 led to improvement of catalytic activity. TPR and HRTEM results showed that the interaction existed between ceria and titanium oxide and addition of ceria promoted the reducibility of platinum oxide and TiO2 on the interface of platinum and TiO2 particles, which contributed to high activity of the ceria modified catalysts. The results indicated that ceria-modified 3DOM Pt/TiO2 was a promising candidate of fuel cell oriented WGS catalyst.