Electrochemical Reduction of Carbon Dioxide on an Indium Wire in a KOH/Methanol-Based Electrolyte at Ambient Temperature and Pressure

The electrochemical reduction of CO2 in a KOH/methanol-based electrolyte was investigated with an indium (In) wire electrode at ambient temperature and pressure. Formic acid, carbon monoxide, and methane were the main products from the CO2. The formation of formic acid from the CO2 predominated in all the potential ranges studied. Under the optimum experimental conditions, 76.0% Faradaic efficiency formic acid, 41.4% CO, and 0.2% methane were produced from CO2 by the electrochemical reduction. Hydrogen evolution, in competition with CO2 reduction, was observed at only 0.2% Faradaic efficiency. The partial current density for CO2 reduction was more than 429 times larger than that for hydrogen evolution. This research can contribute to the application in the conversion of CO2-saturated methanol into useful products and the large-scale removal of CO2 from the atmosphere. Key words: Electrochemical reduction; carbon dioxide; indium wire electrode; KOH/methanol-based electrolyte; global warming