The influence of halogen anions and N‐ligands in CuXn/N‐ligands on the catalytic performance in oxidative carbonylation of methanol

Abstract

AbstractThe catalytic properties of CuXn/N‐ligands (X = Cl, Br and I; n = 1 or 2) in oxidative carbonylation of methanol were investigated. It was found that the interaction of halogen anions, N‐ligands and Cu (I) affected the catalytic performance of copper complex catalyst in the reaction, especially iodide anion and 1,10‐phenanthroline (Phen). When CuI/Phen was used as a catalyst, the conversion of methanol was 42.6%, the selectivity to dimethyl carbonate was 99.2% and the TOF was 13.1 h−1 at an optimized conditions: CuI/Phen 0.2 mol l−1, 120 °C, 2 h, 2.4 MPa, PCO/PO2 = 2:1. Compared with the plain CuI catalyst, the catalytic activity of CuI/Phen increased about 36 times. When CuI/Phen catalyst was immobilized on polystyrene (PS), the heterogenized catalyst, CuI/Phen–NH–PS, also exhibited very high catalytic activity in oxidative carbonylation. The CuI/Phen—NH—PS catalyst remained its high catalytic activity even after seven recycles. The average weight loss of CuI/Phen—NH—PS after reaction was less than 1.0%, and the leaching of copper was only about 0.15% in each recycling test. Copyright © 2010 John Wiley & Sons, Ltd.