The electrodeposition of copper on copper electrodes was used to increase the copper active surface area available for the electrochemical conversion of CO2 to C2 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 KHCO3 0.1 mol dm-3. The hydrocarbons C2H4 and C 2H6 are formed in the presence of honeycomb-like and foam structures, whilst CH4 formation is suppressed and it was concluded that the structure of the copper electrodeposits has a major effect on the electrochemical conversion of CO2. 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. © 2013 Elsevier Ltd. All rights reserved.
Year of publication: 2013