Efficient Electrochemical Reduction of CO2 on g‐C3N4 Monolayer‐supported Metal Trimer Catalysts: A DFT Study

The electrochemical reduction of CO2 into valuable chemicals and fuels is a promising but challenging method to realize the carbon cycle. In this work, a series of transition metal trimer clusters supported on g-C3 N4 catalysts (M3 @g-C3 N4 , M=Cr, Mn, Fe, Co, Ni, Cu, and Ru) for electrochemical CO2 reduction (CO2 RR) toward C1 and C2 products were systemically studied using density functional theory (DFT) calculations. Our results show that CO2 could be adsorbed and activated effectively on M3 @g-C3 N4 from adsorption configurations and electronic structures analyses. Cu3 @g-C3 N4 is a promising electrocatalyst for CH4 production with a limiting potential of -0.42 V. Cr3 @g-C3 N4 , Fe3 @g-C3 N4 , and Co3 @g-C3 N4 produce a low limiting potential of -0.64 V, -0.45 V, and -0.64 V for C2 H4 production, respectively. Hydrogen evolution reaction is refrained on Cu3 @g-C3 N4 , Cr3 @g-C3 N4 , and Co3 @ g-C3 N4 . This work provides useful insights into transition metal trimer cluster catalysts with enhanced activity and selectivity in CO2 RR.