The studies on the Friedel–Crafts acylation of toluene with acetic anhydride over HPW/TiO 2

Abstract

P-methyl acetephenone synthesis from toluene and acetic anhydride over HPW(H 3PW 12O 40)/TiO 2 was carefully studied, and catalysts were characterized by BET, XRD and NH 3-TPD. The characterized results displayed that the interaction between HPW and TiO 2 prevented the loss of acidic protons from HPW to form the weak Lewis acid sites over HPW/TiO 2. The weak acid sites over HPW/TiO 2 came into being in case of much more HPW being loaded onto TiO 2 or HPW/TiO 2 being calcined at high temperature. The reaction results suggest that p-methyl acetephenone yield and selectivity depended on the acidity of catalysts, and the appearance of weak Lewis acid sites over HPW/TiO 2 resulted in p-methyl acetephenone yield decline.