(201b) Suppressing the Hydrogen Evolution on Chiral Cu-Based Catalyst for Efficient Electrochemical Carbon Dioxide Reduction

Catalysts for electrochemical carbon dioxide reduction (CO2R) in aqueous electrolytes suffer from low Faradaic efficiency and selectivity of desired carbon products due to the competing hydrogen evolution from water reduction. Over the few years, a concept of chirality-induced spin selectivity (CISS) has been proposed to improve the efficiency of oxygen evolution reactions by stabilizing only one spin state of charge carriers at the catalyst surface. It was demonstrated that the formation of hydrogen peroxide and singlet oxygen was suppressed during the water oxidation reaction. However, this CISS phenomenon has not been studied during the reduction reaction at the cathode side. In this study, we prepare the chiral Cu-based catalyst via enantiospecific electrodeposition, in which chiral organic molecules act as a chirality inducer in a liquid state. The onset potential of CO2R on chiral Cu catalyst negatively shifts compared to the achiral counterpart despite very similar physical and chemical properties of catalyst films. The electrochemical impedance spectroscopy suggests the altered reaction pathway and sluggish kinetics on chiral Cu catalysts. Our finding provides insights into the potential of chiral catalysts for controlling the selectivity during CO₂R as well as the alternative reduction reaction.