Catalytic oxidation of benzene over Mn modified TiO2/ZSM-5 under vacuum UV irradiation

Abstract

Vacuum ultraviolet (VUV) irradiation was used to improve photocatalytic degradation of gaseous benzene. A multi-functional photocatalyst of 0.1%Mn/TiO2/ZSM-5 was developed by a modified sol-gel method for the elimination and utilization of O3, the by-product generated from VUV irradiation. O3 was completely removed and efficiently used to enhance catalytic oxidation of benzene via ozone-assisted catalytic oxidation (OZCO). Under VUV irradiation, benzene removal efficiency was stably kept at 100% over 0.1%Mn/TiO2/ZSM-5, however, it was only about 50% and much O3 was residual over commercial TiO2 (P25). 0.1%Mn/TiO2/ZSM-5 perfectly synergized with VUV irradiation. It provides more efficient pathways besides photocatalytic oxidation, for benzene degradation. The possible mechanism of benzene degradation over 0.1%Mn/TiO2/ZSM-5 with VUV irradiation was proposed. This is the first report of an efficient photocatalyst with superior performance for O3 elimination and utilization.