Electrochemical reduction of CO2 using Cu electrode in methanol/LiClO4 electrolyte.

Electrochemical reduction of CO 2 under high pressure in cold methanol (243 K) medium containing LiClO 4 as supporting electrolyte was studied using Cu wire electrode. The major reduction products formed were methane, CO, ethylene and HCOOCH 3 . The experiments were carried out at different operating potential ranging from −3.0 to −4.0 V and the results were discussed in terms of their faradaic efficiencies. The different applied potentials employed invariably favored methane formation in the presence of Li + , at 243 K and 4 atm and, among which, the most negative potential (−4.00 V) showed relatively better efficiency than the less negative potentials. However, the H 2 formation, an undesirable reduction product, was found to be as high as 60.2% at −4.00 V. The effective formation of methane and CO were discussed in terms of influence of the size of the cation of the supporting electrolyte used. [ABSTRACT FROM AUTHOR]