CO2 electroreduction performance of transition metals supported on g-C(CN)(3) monolayer with specific TMN3 active sites

Electrochemical reduction of CO2 (CO2RR) represents a fascinating route for converting atmospheric CO2 to valuable chemicals, and a variety of intermediates are involved in the different CO2 RR pathways. However, it has been hampered by the lack of highly effective electrocatalysts so far. Here, the performance of single 3d nonprecious transition metals supported on g-C(CN)(3) monolayers [TM-C(CN)(3), TM = Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, respectively] as CO2 RR electrocatalysts was systematically investigated by using density functional theory (DFT) calculations. The data indicate that all these TM atoms can strongly interact with the g-C(CN)(3) substrate, and the TM active sites possess high CO2 RR activity and specific selectivity through *OCHO intermediate. Particularly, Sc-, Co-, and Ni-C(CN)(3) monolayers are identified as effective CO2 RR electrocatalysts due to the low limiting potentials (- 0.28, - 0.42, and - 0.46 V, respectively), whose excellent performances are mainly attributed to the specific TMN3 active sites. Therefore, this work sheds light on g-C(CN)(3) monolayer as an excellent supporting material, and will motivate more experimental and theoretical researches to further explore other potential two-dimensional porous carbon-based materials with specific TMN3 active sites for CO2 RR.