Enhancing performance of Co/CeO 2 catalyst by Sr doping for catalytic combustion of toluene

Abstract Cobalt-based catalyst supported on strontium-doped ceria was prepared by impregnation method. The physical and chemical properties were investigated by various technologies and the catalytic combustion of toluene was evaluated at fixed-bed. The possible reaction process of toluene oxidation on Co/Sr-CeO2 was also investigated. The results showed that Sr doping enlarges the specific surface area of CeO2, accompanied by strong interaction between Co and Ce and high dispersion of Co oxides. Sr doping increases the lattice defects of CeO2, which creates oxygen vacancies and enhances the oxygen mobility in Co/Sr-CeO2. Sr doping also changes the electronic characteristics of Co on CeO2 and improves the redox properties of Co/CeO2. The introduction of Sr to Co/CeO2 catalyst may improve the catalytic performance in total oxidation of toluene. In addition, Co/Sr-CeO2 catalyst shows lower light-off temperature than Co/CeO2 catalyst and has good thermal stability in the long-term testing. Toluene is degraded into phenyl and methyl groups at 235 °C for Co/Sr-CeO2 and 255 °C for Co/CeO2 because of the cleavage of C–C between the benzene ring and methyl, and it is completely oxidized into CO2 and H2O at 330 °C for Co/Sr-CeO2 and 380 °C for Co/CeO2.