Investigation of benzylation of benzene with benzyl alcohol in the presence of heterogeneous catalyst

In this study, the benzylation of benzene with benzyl alcohol (BnOH) to synthesize diphenylmethane (DPM) was performed in the presence of heterogenous catalyst. The MCM-22 zeolite used as a catalyst in this reaction was produced by hydrothermal synthesis method. Furthermore, the deposition of Ni and Cu metals on H-MCM-22 catalyst was carried out by wet impregnation method. All the prepared catalysts were characterized by using X-ray diffraction (XRD), scanning electron microscopy (SEM), inductively coupled plasma spectroscopy (ICP-MS, N2 - adsorption/desorption and NH3-TPD methods. The prepared catalysts were used in the benzylation of benzene with benzyl alcohol under the same reaction conditions and their catalytic activities were compared with each other. It was observed that H-MCM-22 catalyst shows the best catalytic activity among the preapared catalysts used in the reaction. The effects of catalyst amount on the reaction rate and yield of diphenylmethane were investigated in the presence of H-MCM-22 at 80 ℃ of reaction temperature, benzene/benzyl alcohol molar ratio of 56/1 and optimum catalyst amount was determined. The effects of reaction temperature (70, 75 and 80 0C) and reactant-mol ratio (30/1, 56/1 and 80/1) on the reaction rate and yield of diphenylmethane were investigated in the presence of H-MCMC-22 at the optimum catalysts amount. At the end of three hours of reaction time, the conversion of benzyl alcohol and yield of diphenylmethane were obtained as % 99,3 and %92,1, respectively, for the temperature reaction of 80 ℃, benzene/benzyl alcohol molar ratio of 56/1 and mkatalizör (mg)/VBnOH (ml) rate of 360. Additionally, the reusability of H-MCM-22 catalyst was investigated for this reaction. Keywords: H-MCM-22, metal impregnation, benzylation, benzyl alcohol, diphenylmethane, dibenzylether, polyalkylated benzene