Catalytic behaviour of gallium-containing mesoporous silicas (MCM-41) in the acetylation reaction

Abstract

Liquid phase acetylation of 1,2-dimethoxybenzene with acetic anhydride has been examined for a series of acid gallium-mesoporous materials (MCM-41) with different Si/Ga ratios (Si/Ga = 80, 50 and 10) synthesized by microwave irradiation method. Physical adsorption of nitrogen, inductively coupled plasma, and the X-ray diffraction techniques, transmission electron microscopy, Fourier transform infrared spectroscopy, and a temperature-programmed desorption of pyridine were applied to characterize the catalysts. A mesoporous sample with Si/Ga = 10 showed better performance in the acid-cataiyzed acetylation of 1,2-dimethoxybenzene with acetic anhydride as an acylating agent. In addition, the kinetics of the reaction in the presence of these catalysts has been investigated.