Electrochemical reduction of CO2 in methanol with aid of CuO and Cu2O

The electrochemical reduction of CO2 in methanol-based electrolyte was investigated with zinc particle-pressed electrodes. In order to evaluate the characteristic of copper oxide catalysts for the electrochemical reduction of CO2, zinc particles mixed with CuO and Cu2O powders were pressed for fabricating a disk plate of electrode. Without copper oxide particles, only formic acid and carbon monoxide were formed in the electrochemical reduction of CO2, and the formation of hydrocarbons could scarcely be observed. On the other hand, hydrocarbons were obtained for the zinc particle-pressed electrodes containing copper oxide particles. At CuO/Zn particle-pressed electrode, the Faradic efficiency of ethylene was better relative to that of methane at all conditions tested. With Cu2O/Zn powder-pressed electrode, the current efficiency of methane was larger compared with that of ethylene in the low content range of Cu2O (1–2.5%). The maximum formation efficiencies of methane and ethylene were of 7.5% and 6.8% with the electrode consisted of Cu2O/Zn, respectively. It was found that copper oxide catalysts (CuO and Cu2O) were effective for the formation of hydrocarbons, especially ethylene, in the electrochemical reduction of CO2 in methanol-based electrolyte.