Electrochemical conversion of CO2 to C2 hydrocarbons using different ex situ copper electrodeposits

Abstract The electrodeposition of copper on copper electrodes was used to increase the copper active surface area available for the electrochemical conversion of CO 2 to C 2 hydrocarbons and to study the dependence of the reaction on the electrode structure. Different electrodes were developed with dendritic, honeycomb and 3D foam structures and were employed for the reduction process at −1.9 V vs. Ag/AgCl in the presence of KHCO 3 0.1 mol dm −3 . The hydrocarbons C 2 H 4 and C 2 H 6 are formed in the presence of honeycomb-like and foam structures, whilst CH 4 formation is suppressed and it was concluded that the structure of the copper electrodeposits has a major effect on the electrochemical conversion of CO 2 . Additionally, it was found that the less negative the cathodic potential applied (in the range of −1.5 to −1.9 V vs. Ag/AgCl), or the lower the electrolyte concentration (0.03 vs. 0.1 mol dm −3 ), the greater is the increase in the amount of ethane.