Design and synthesis of magnesium-modified copper oxide nanosheets as efficient electrocatalysts for CO2 reduction†
Abstract
Electroreduction of carbon dioxide (CO2) to multiple carbon products plays a significant role in carbon neutrality and the production of valuable chemicals. Herein, we developed a magnesium-modified copper oxide nanosheet catalyst (Mg–CuO) using a post-impregnation method. Comprehensive elemental analysis demonstrated the effective incorporation of magnesium into CuO nanosheets, resulting in a noticeable alteration of the electron density of Cu atoms. Consequently, the Mg–CuO nanosheets exhibited an increased efficiency for CO2 electroreduction in comparison with the unmodified CuO nanosheets. The optimized Mg–CuO catalyst exhibited faradaic efficiencies of 46.33% for ethylene production and 62.64% for C2+ production at −1.3 V vs. reversible hydrogen electrode (RHE). DFT proved that the introduction of Mg species could increase the charge density of Cu and decrease the adsorption energy of *CO, which promoted C–C coupling and enhanced the selectivity of C2+ products. This study presents an effective way to adjust the electronic structure of common copper-based electrocatalysts and the corresponding interaction with *CO, resulting in an improved faradaic efficiency of C2+ products.