Photocatalytic activities for partial oxidation of α-methylstyrene over zeolite-supported titanium dioxide and the influence of water addition to reaction solvent

The photocatalytic reaction in the partial oxidation of α-methylstyrene (α-MS) to acetophenone (AP) was investigated for TiO₂ supported on H-ZSM-5 (H-MFI), H-mordenite (H-MOR), and H-Y-type (H-FAU) zeolites. XRD results demonstrated that the anatase was the stable phase of TiO₂ supported on zeolites. Photocatalytic activities of supported catalysts decreased in the following order: TiO₂/H-MFI >> TiO₂/H-MOR > (TiO₂) > TiO₂/H-FAU >> (blank). TiO₂/H-MFI catalyst exhibited the best performance for photocatalytic oxidation of α-MS to AP. The maximal activity was obtained by 25 wt% TiO₂/H-ZSM-5. The addition of water to the reaction solvent resulted in significantly lowering the photocatalytic activity for TiO₂/H-ZSM-5 catalyst, although its activity for TiO₂ and TiO₂ + H-ZSM-5 mechanical mixture was little influenced by the amount of water added to reaction solvent.