Efficient CO2 Electrochemical Reduction by a Robust Electrocatalyst Fabricated by Electrodeposition of Indium and Zinc over Copper Foam

Electrochemical reduction of CO2 comprising the CO2 reduction reactuib (CO2RR) and oxygen evolution reaction (OER) is one of the most promising technologies for electrification of the chemical process industry. Here, the performance of a electrocatalyst with a three-dimensional structure of InZnCu on Cu foam (CF) is presented. This electrocatalyst was fabricated by electrodeposition of In and Zn over Cu and exhibited a superior reduction of CO2 to CO at a Faradaic efficiency of 93.7% at −0.7 V and an excellently long duration of 100 h. Due to the synergy of the thin In layer, the Zn nanosheets provided a high surface-active area and strong mechanical robustness during the reaction. Additionally, a two-electrode system was constructed based on the CF-modified surface, which provided valuable guidelines on the overall CO2RR–OER system for further evolution. Furthermore, due to the facile synthesis, the bimetal-layer double hydroxide (LDH) exhibited high conductivity and high OER performance. Hence, the two-electrode system assembled excellent electrocatalysts for the CO2RR–OER (InZnCu/CF||Cu(OH)2 NWs@NiCo-LDH/CF) with high conversions of CO2 to CO of 67% and 88% at 2 and 50 mA cm–2, respectively. Notably, the CO2RR–OER system exhibited excellent stability in a 40 h CO2 conversion with a constant current density of 2 mA cm–2 at an ultralow voltage of 1.59 V. Moreover, the calculation of the energy input converting CO per ton of CO2 resulted in a low energy input range for further development in scalability. This overall CO2RR–OER proposes development in electrochemical CO2 reduction for industrial applications.