Highly selective electrocatalytic reduction of carbon dioxide to ethylene on CuCl-derived Cu

Abstract

Traditional fossil energy consumption gives rise to the increase of CO2 emissions, and then causes the greenhouse effect and other global issues. Among the CO2 conversion technologies, the electrocatalytic reduction of CO2 into fuels and chemicals, which has been attracted much attention owing to its advantageous ability, is an effective way to solve the energy crisis and weaken the greenhouse effect. However, common products of the electrochemical reduction of CO2 are the two-electrons products, such as H2, CO and formate, whilst the faradaic efficiency of other multielectron products is generally very low. The electrocatalytic reduction of CO2 into C2H4 is very interesting. Here, CuCl-derived Cu/Cu foil electrodes were prepared by means of an electrodeposition method and they were tested in a three-electrode electrocatalytic reaction system to investigate their performances for the electrocatalytic reduction of CO2. The Faradaic effciency of C2H4 over the CuCl-derived Cu reached 25% at −1.4 V vs. RHE in 0.1 M KHCO3, which was much higher than that of Cu2O-derived Cu and CuO-derived Cu. The electrodeposition time for the CuCl-derived Cu/Cu foil electrode was further researched. The highest Faradaic efficiency of C2H4 was reached with an electrodeposition time of 10 min, that was assumed as the optimum value. Compared with the Na2SO4 and K2CO3 electrolyte, the KHCO3 electrolyte was more beneficial to the CO2 reduction and revealed higher electrocatalytic activity. The introduction of CuCl-derived Cu could enhance the catalytic performance of the electrocatalytic reduction of CO2 and contribute to the C–C coupling for the production of C2H4. The results of this study can provide strong support for achieving the goal of “carbon peaking and carbon neutral”.