Electrolytic Carbonylation of Methanol over the CuCl2 Anode in the Gas Phase

Electrolytic carbonylation of in the presence of over a ‐added graphite anode was studied in the gas phase at <101 kPa and ambient temperature. No reaction proceeded at applied voltages lower than 1.0 V across the cell (cathode: He). The formation of dimethyl carbonate (DMC) and started at >1.0 V. The rates of these formations showed maxima at ca. 1.4 V. Electrolysis of to dimethoxymethane (DMM) and methylformate (MF) started at <1.4 V, reducing the formation of DMC and markedly. Replacement of He in the cathode compartment with decreased the applied voltage needed for the formation of DMC by ca. 0.6 V. The results of the electrolysis of alone suggested that DMM and MF were formed directly from . However, the formation of at an applied voltage ≤1.4 V (cathode: He) originated from the same precursor of DMC. The anode potentials measured during the reaction suggested that the electrolytic carbonylation of as well as the electrolysis of occur on Cu(II) cations. The reaction scheme assuming a methoxide radical and a carbomethoxide species as the reaction intermediates is suggested on the basis of kinetic studies on the formation of each product.