The promotional mechanism of Ce substituted A-site cation over YMn2O5 for toluene oxidation

Mullite-type YMn2O5 oxides have considerable potential for the removal of VOCs due to the abundance of lattice oxygen and the stability. The present study investigated the promotional mechanism of toluene oxidation by Asite cations of YMn2O5 with Ce. Y1-xCexMn2O5 was synthetized by sol-gel method and characterized with various techniques. The results revealed that samples doping with Ce could notably enhanced the toluene oxidation performance, and the toluene conversion of Y0.97Ce0.03Mn2O5 was 32% higher than that of YMn2O5 at 300 degree celsius. Detailed characterizations demonstrated that the modification of Ce produced an interface between YMn2O5 and YMnO3, the strong interactions at the interface improved the content of Mn3+ and oxygen vacancies, which promoted the toluene oxidation performance. Furthermore, the intermediate of toluene oxidation on Y0.97Ce0.03Mn2O5 was performed by in-situ DRIFTS. Toluene was sequentially oxidized to benzaldehyde, benzoic acid and maleic anhydride, ultimately produced H2O and CO2. This work offered a material science basis for the development of manganese-based mullite in thermal catalytic oxidation of toluene.