Efficient electrochemical CO2 reduction on C2N monolayer supported transition metals trimer catalysts: A DFT study

The capture and catalytic conversion of CO2 into value-added chemicals is a promising and sustainable approach to resolve the increasingly severe global warming and energy crisis. However, the catalytic efficiency for CO2 reduction is seriously restricted by the free energy changes of the intermediate reaction. Herein, using density functional theory (DFT), the electrocatalytic CO2 reduction reaction (CRR) was applied towards making C1 products (CO, HCOOH, CH3OH, HCHO, and CH4) on monolayer C2N frameworks with M3 (M = Fe, Co, Ni, Cu) metal clusters introduction. Analyses of the adsorption configurations and electronic structures suggested that CO2 could be chemically adsorbed on Fe3@C2N, Co3@C2N, Ni3@C2N and Cu3@C2N. The H2 evolution reaction (HER), as a suppression of CRR, was investigated, and results showed that the CRR selectivity of Fe3@C2N, Co3@C2N, Ni3@C2N and Cu3@C2N is higher than that of HER. The CRR reaction produces different C1 products in different reaction paths due to proton transfer on Fe3@C2N, Co3@C2N, Ni3@C2N and Cu3@C2N. Free energy profiles demonstrate that Cu3@C2N and Co3@C2N were identified to be effective in catalyzing CRR with lowered overpotentials (0.51 V-0.67 V).