Electroreduction of CO₂using modified boron-doped diamond electrode as the working electrode

Electroreduction of CO2 becomes a popular study to resolve the problems due to the increase of CO2 in atmosphere. In this work, electroreduction of CO2 was studied using various working electrodes in 0.1 M NaCl solutions. A reduction peak potential around -1.5, -1.1 and -1.2 V, respectively, was observed at BDD, Cu, Cu-BDD, while Cu2O-BDD with different deposition times showed typical peaks at around -1.3 V. Liquid chromatography analysis on the solutions after CO2 electroreduction at the applied potential of -1.3 V (vs Ag/AgCl) showed that by using BDD and Cu electrodes only formic acid and formaldehyde could be produced. However, the use of various Cu2O concentrations deposited on BDD electrodes can produce not only formic acid and formaldehyde, but also acetic acid and methanol with high selectivity of the products, indicating the electrode is promising to have more various products in the electrochemical reduction of CO2.