Efficient electrochemical CO_2 reduction on C_2N monolayer supported transition metals trimer catalysts: A DFT study

摘要

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 C-1 products (CO, HCOOH, CH3OH, HCHO, and CH4) on monolayer C2N frameworks with M-3 (M = Fe, Co, Ni, Cu) metal clusters introduction. Analyses of the adsorption configurations and electronic structures suggested that CO2 could be chemically adsorbed on Fe-3@C2N, Co-3@C2N, Ni-3@C2N and Cu-3@C2N. The H-2 evolution reaction (HER), as a suppression of CRR, was investigated, and results showed that the CRR selectivity of Fe-3@C2N, Co-3@C2N, Ni-3@C2N and Cu-3@C2N is higher than that of HER. The CRR reaction produces different C-1 products in different reaction paths due to proton transfer on Fe-3@C2N, Co-3@C2N, Ni-3@C2N and Cu-3@C2N. Free energy profiles demonstrate that Cu-3@C2N and Co-3@C2N were identified to be effective in catalyzing CRR with lowered overpotentials (0.51 V-0.67 V).