Preparation Of SBA-15 Supported Perovskite Catalysts And Catalytic Combustion Performance

No-noble metal oxides catalysts with perovskite structure were widely used in the catalytic combustion of volatile organic emissions. The catalyst has a strong catalytic oxidation and can completely oxidize many VOCs into CO2 and H2O. However, surface area of these catalysts is very small, and surface area increase is an important evalution standard for these catalysts. An effective method to improve the surface area is loading the active component on the surface of the porous material. However, the pore might be blocked with high amount of active components.Therefore, step coating NH3/water vapor-induced internal hydrolysis (VIH) method was studied in this paper and highly loaded LaMnOx/SBA-15 catalyst was prepared. The results showed that the VIH process improved the distribution of the LaMnOx active phase in the pores of SBA-15 and improved its reduction properties. The catalytic performance of LaMnOx/SBA-15 catalyst for toluene was clearly increased. The optimal VIH conditions were a temperature of 60℃ and a processing time of 30 min.Then, a series of supported perovskites LSM/SBA-15 catalysts were prepared by VIH method. Their catalytic performance for toluene combustion was evaluated and similar results are obtained. The step coating NH3/water vapor-induced internal hydrolysis method was effectively maintained the surface and pore structure of SBA-15. The formation of perovskite structure, produced high valence of Mn species and structure defects, which changed the concentration of oxygen vacancies.To further increasing the activity of LSM/SBA-15 catalyst, Pd doping was adopted and Pd-LSM/SBA-15 catalyst was prepared by VIH method. The experimental results show that Pd-doped was 0.01%, the toluene conversion on the Pd-LSM/SBA-15 was more than 70% at 260℃. The catalytic performance of Pd-LSM/SBA-15 catalysts for toluene combustion are improved.