Chinese Journal of Chemical Engineering, Vol.22, No.10, 1117-1121, 2014
Oxidative Carbonylation of Methanol to Dimethyl Carbonate Over Cu(II)-1,10-Phenanthroline Bromide Complexes
In order to develop the catalysts with low corrosiveness for the oxidative carbonylation of methanol to dimethyl carbonate (DMC), CuBr2 was selected as the metal source to prepare Cu coordination compounds, Cu(phen) Br-2, [Cu( phen)(2)Br]Br and [Cu(phen)(3)]Br-2 (phen = 1,10-phenanthroline). These complexes were characterized by thermogravimetric analysis and temperature-programmed reduction. Their catalytic performances were investigated. It was found that the metal coordination environments and thermal stability of the complexes played an important role in their catalytic activities. Cu(phen) Br-2 exhibited the highest activity due to the lowest steric hindrance, the most positions occupied by the bromide ions and the highest thermal stability. The turnover number was up to 47.6DMC mol.(Cu mol)(-1) with selectivity of 92.8% under conditions of 120 degrees C, ratio of partial pressure of CO to O-2 of 19:1 (below the explosion limit of CO) and catalyst concentration of 0.011 mol.L- 1. Furthermore, a plausible reaction mechanism was suggested on the basis of the experimental data. (C) 2014 The Chemical Industry and Engineering Society of China, and Chemical Industry Press. All rights reserved.