Cobalt(II)-complex modified Ag electrode for efficient and selective electrochemical reduction of CO2 to CO

Electrochemical conversion of CO2 into CO, powered by renewable electricity, offers one means to address the need for the storage of intermittent renewable energy. However, it is challenging because the competing HER is hard to avoid, which significantly compromises the selectivity to CO and reduces the efficiency of CO2RR de -vices. This study reports a cooperative catalyst design of metal-molecule catalyst interfaces with the goal of high local concentration of CO2 and stabilizing the intermediate, which improves the electrosynthesis of CO. The strategy is implemented by functionalizing the silver surface with cobalt (II)-complexes to promote the selective electrolysis of CO2 to CO. We report a CO2-to-CO Faradaic efficiency of 98.5 % and a partial current density of 16.52 mA cm-2 at -1.1 V vs. RHE. Mechanism studies reveal that the catalytic performance of the Ag/Co(bpy)32+ correlates with the metal-molecule interaction, which provide new opportunities for construction and design of high-efficient catalysts toward CO2 reduction.