A highly active and anti-coking Pd-Pt/SiO2 catalyst for catalytic combustion of toluene at low temperature

Abstract Catalytic combustion has been identified as one of the most efficient and economically feasible routes for removing volatile organic compounds. In this work, supported noble-metal (Pd and Pt) catalysts for catalytic combustion of toluene were prepared by an improved incipient wetness impregnation method. Controlled amounts of oleic acid (OA) were introduced into the aqueous solution of metal salts in this new preparation method, which improved Pd and Pt dispersion remarkably on SiO 2 , as confirmed by XRD and TEM. XPS results showed that introduction of OA in the catalyst preparation resulted in increased proportion of metallic palladium. All of the activities in catalysts with OA were much higher than those of the catalysts without OA in the same catalyst system. Among the catalysts prepared, the 0.25%Pd-0.25%Pt/SiO 2 –OA catalyst exhibited the best catalytic activity for toluene oxidation, and the T 98 of toluene was only 160 °C under the conditions of toluene concentration at 1000 ppm and SV at 60,000 mL/(g h). Furthermore, the 0.25%Pd-0.25%Pt/SiO 2 –OA catalyst maintained high catalytic activity in the active stability test at 160 °C, and the result of TG indicated that no coke was formed on the spent catalyst.