Elucidating the structure-activity relationship of Cu-Ag bimetallic catalysts for electrochemical CO2 reduction

Developing bimetallic catalysts is an effective strategy for enhancing the activity and selectivity of electrochemical CO2 reduction reactions, where understanding the structure-activity relationship is essential for catalyst design. Herein, we prepared two Cu-Ag bimetallic catalysts with Ag nanoparticles attached to the top or the bottom of Cu nanowires. When tested in a flow cell, the Cu-Ag catalyst with Ag nanoparticles on the bottom achieved a faradaic efficiency of 54% for ethylene production, much higher than the catalyst with Ag nanoparticles on the top. The catalysts were further studied in the H-cell and zero-gap MEA cell. It was found that placing the two metals in the intensified reaction zone is crucial to triggering the tandem reaction of bimetallic catalysts. Our work elucidates the structure-activity relationship of bimetallic catalysts for CO2 reduction and demonstrates the importance of considering both catalyst structures and cell characteristics to achieve high activity and selectivity.