Polymer-Covered Copper Catalysts Alter the Reaction Pathway of the Electrochemical CO 2 Reduction Reaction.

The electrochemical CO 2 reduction reaction (CO 2 RR) has attracted considerable attention recently due to the potential conversion of atmospheric CO 2 into useful organic products by utilizing electricity from renewable energy sources. However, the selective formation of desired products only via CO 2 RR has been elusive due to the presence of a myriad of competing reaction pathways, thus calling for effective strategies controlling the reaction coordinates. The control of binding energies of the reaction intermediate, such as *CO, is pivotal to manipulating reaction pathways, and various attempts have been made to accomplish this goal. Herein, we introduce recent endeavors to increase the catalytic selectivity of Cu-based catalysts by surface modification with polymer coating, which can change the local pH, hydrophilicity/hydrophobicity, reaction concentration, etc. The polymer conjugation also contributed to the enhanced electrocatalytic stability of Cu-based catalysts during the CO 2 RR. We also point to the remaining challenges and provide perspectives on the further development of Cu-polymer hybrid catalysts for the practical CO 2 RR.