Heterogeneous photocatalytic oxidation of benzene, toluene, cyclohexene and cyclohexane in humidified air: comparison of decomposition behavior on photoirradiated TiO2 catalyst

Gas–solid heterogeneous photocatalytic decomposition of benzene, toluene, cyclohexane and cyclohexene over TiO 2 was studied at room temperature, and their reactivities were compared. Catalyst deactivation was ascribed to the formation of the carbon deposits on TiO 2 surface, and the formation and decomposition behavior of the carbon deposits affected the decomposition rate. Deactivated TiO 2 catalysts were photochemically regenerated in the presence of water vapor, and the carbon deposits were decomposed to CO x .