Simultaneous coating of benzotriazole and polyvinyl chloride on Cu for improved CO2 electroreduction toward C2 products

Electroreduction of carbon dioxide (CO 2 ) to valuable chemicals provides a promising solution to reducing CO 2 emissions and alleviating energy crisis. Coating or grafting catalyst with organic molecules or polymers could effectively improve the Faradaic efficiency (FE) of C 2 products in CO 2 electroreduction (CO 2 ER). However, to date, most efforts have focused on single-component coatings to enhance the FE of C 2 products in CO 2 ER. Herein, the surface of copper (Cu) catalyst is simultaneously coated with a thin layer composed of both small molecule of benzotriazole (BTA) and polymer of polyvinyl chloride (PVC). This BTA&PVC-coated Cu catalyst demonstrates a high FE of C 2 products up to 71.0 ± 5.6% in an H-type electrochemical cell, in contrast to the FE of ~36% for bare Cu. The improved CO 2 ER performance is attributed to the effective stabilization of key reaction intermediates and optimized electronic structure on Cu surface, facilitated by the synergistic effect of the simultaneously coated BTA&PVC film. In addition, the BTA molecules could be perfectly confined within PVC matrix, resulting in a high catalytic stability. In summary, this work provides an effective strategy to effectively improve the FE of C 2 products in CO 2 ER and this strategy could be easily migrated to many other catalytic systems.