Preparation of CuCl/1,10-phenanthroline immobilized on polystyrene and catalytic performance in oxidative carbonylation of methanol

The heterogenization of homogeneous catalysts combines the advantages of both heterogeneous and homogeneous catalysis systems. In oxidative carbonylation of methanol to dimethyl carbonate (DMC), a novel heterogenization of a homogeneous catalyst system, CuCl/1,10-phenanthroline immobilized on polystyrene, was investigated. Characterizations with FTIR, XPS, EA, TGA and AA revealed that CuCl was successfully immobilized on polystyrene modified 1,10-phenanthroline (Phen-PS) through chelating between the N–N bidentate ligand and Cu. The catalytic performance of the CuCl/Phen-PS catalyst tested proved that it is an efficient heterogenized catalyst for the oxidative carbonylation of methanol. The conversion of methanol, the selectivity to DMC and the yield of DMC based on O2 were 15.5%, 96.4% and 78.2%, respectively, at 120 °C, 5 h, 3.0 MPa, and PCO:PO2=9:1PCO:PO2=9:1. The CuCl/Phen-PS catalyst retains its catalytic activity after seven recycles. The average weight loss of CuCl/Phen-PS was about 2.2%, and the leaching of copper was about 0.68% in each recycle.

Graphical abstractAn immobilized catalyst CuCl/Phen-PS was synthesized, and the catalyst exhibited high catalytic activity, excellent stability in consecutive catalytic runs, easy separation from reaction mixture and low leaching of active metal species in oxidative carbonylation of methanol.Figure optionsDownload full-size imageDownload as PowerPoint slide