Cu single atoms supported on crystalline graphdiyne porphyrin analogs with dual active sites for enhanced C2 product formation

Developing advanced catalysts for efficient electrochemical CO2 reduction has long been a sought-after objective, but designing catalysts with open porous structures, metal sites, high atom utilization, nanoporosity, and electrical conductivity, remains challenging. Downsizing metal sites to single atoms and supporting them on conductive Covalent Organic Frameworks (COFs) offers a strategic solution to these challenges. Herein, we report a novel catalyst with a combination of copper single-atom sites supported by a highly crystalline graphdiyne porphyrin analog (Cu-SGPA). Computational analysis reveals the presence of 2.34 nm open pores with conducting π-conjugated graphdiyne linkages. The joint action of the dual active sites of Cu single atoms and the adjacent carbon atoms facilitates carbon product formation through uniquely achieved intermediate species. Cu-SGPA demonstrates a remarkable faradaic efficiency (FE) of 70% at optimized potentials of -1.0 V vs RHE, with over 45% FE for C2 products, marking the record reported FE for any single-atom catalyst supported on COFs. This study introduces a promising catalyst design that will inspire future efforts in developing and optimizing similar single-atom catalysts supported on conductive COFs for enhanced CO2 utilization.