Photocatalytic Oxidation of Gaseous Benzene under VUV Irradiation over TiO2/Zeolites Catalysts

Abstract Volatile organic compounds (VOCs) present a great risk to the atmospheric environmental as well as the public health and safety. In this study, a series of TiO 2 /zeolites catalysts were synthesized by sol-gel method. They showed much better photocatalytic activity for benzene degradation under UV irradiation compared with commercial TiO 2 (P25), which suffered from typical catalyst deactivation. Vacuum ultraviolet (VUV) irradiation was used to further enhance photocatalytic oxidation of benzene. The VUV-PCO process obtained much higher benzene removal efficiency (nearly 100%) than conventional UV-PCO (less than 10%). Besides photocatalytic oxidation, photolysis and ozone-assisted catalytic oxidation was also involved in the VUV-PCO process and they contributed much to benzene degradation. Most of the removed benzene was oxidized into CO 2 . Among the prepared photocatalysts, TiO 2 /ZSM-5 with Si/Al ratio of 200 obtained the best catalytic activity due to its appropriate porous structure and framework, which led to superior capacity for benzene absorption and ozone decomposition.