Abstract: The copper coordination compound Cu(phen)Cl₂ was prepared by the reaction of 1,10-phenanthroline with cupric chloride in the mixed solution of methanol and ethanol and was characterized by infrared spectroscopy, thermogravimetric analysis, and temperature-programmed reduction. Their catalytic performance for the oxidative carbonylation of methanol to dimethyl carbonate (DMC) was investigated. The results showed that Cu(phen)Cl₂ had the high thermal stability and exhibited the high catalytic performance due to the effect of the σ-π coordination bond between phen and Cu(II). The turnover number (TON) could reach 51.5 mol of DMC per mol of Cu, under the conditions of reaction temperature 150 °C, total pressure 4.0 MPa, p(CO)/p(O₂) = 19 (below the explosion limit of CO) and the catalyst concentration in methanol 0.011 mol/L. It was also found that there was an induction period at the early reaction stage, and the change of TON was the “M” type with the increase of temperature. Further, a novel reaction mechanism was suggested.

Key words: dimethyl carbonate, methanol, oxidative carbonylation, cupric chloride, phenanthroline, complex