Catalysis Letters, Vol.143, No.5, 411-417, 2013
Catalytic Combustion of Lean Methane at Low Temperature Over Palladium on a CoOx-SiO2 Composite Support
A composite support of CoOx-SiO2 was obtained through modifying silica with cobalt of different loadings; with CoOx-SiO2 as the support, a series of Pd/CoOx-SiO2 catalysts were prepared for the combustion of lean methane at low temperature. The effects of CoO loading and palladium precursor on the catalytic performance of Pd/CoOx-SiO2 were investigated. The Pd/CoOx-SiO2 catalyst containing 20 wt% CoO and 1 wt% Pd with acetate as palladium precursor performs excellently in lean methane combustion; over it a complete conversion of methane can be achieved at 420 degrees C and the activity does not show any decline in a long-term test of 120 h. Various characterizations suggested that cobalt species are highly dispersed on the silica of high surface area and there exists a synergetic interaction between palladium and cobalt species, which improves the redox properties of Pd/CoOx-SiO2 and contributes to the excellent catalytic performance in lean methane combustion.