Efficient electrocatalytic reduction of CO2 to CO via mechanochemical synthesized copper-based composite metallic oxide catalyst

Abstract

Electrocatalysis serves as a highly effective approach to both mitigate greenhouse gas emissions and produce high-value chemicals. Copper-based catalysts have garnered considerable attention due to their immense potential in this domain, improving the selectivity and activity through optimizing preparation strategies is of paramount importance. In this study, mechanochemical method was rst used for preparing copper-based composite metallic oxide electrocatalysts. Spherical CuO, Sn-CuO, and Sn-In-CuO catalysts were prepared and their electrochemical carbon dioxide reduction performance was evaluated.Among them, the Sn-In-CuO catalyst demonstrated the best performance in reducing carbon dioxide to carbon monoxide products. Within the potential range of -0.6 V to -1.1 V vs. RHE, the Faradaic e ciency of carbon monoxide product was consistently above 93.56%, with a maximum Faradaic e ciency of 96.11% achieved at -0.9 V vs. RHE. Sn-In-CuO also exbibts good stability with high Faradaic e ciency of carbon monoxide above 87.97% for a duration of 6 hours under the potential of -0.6 V vs. RHE in a 0.1 M KHCO 3 electrolyte. The excellent performance is speculated to be attributed to the generation of a large number of defects and the introduction of metal doping, which increases the number of active sites through the mechanochemical method.