Reaction mechanism on Ni-C2-NS single-atom catalysis for the efficient CO2 reduction reaction

Ni-based single-atom catalysis (Ni-SAC) has been experimentally reported with superior performance in reducing CO2 to CO. However, due to the ambiguities in its structures, the active sites of Ni-SAC that are responsible for superior performance have not yet been resolved. This work investigates the CO2 reduction reaction (CO2RR) mechanism on Ni-SAC by carrying out quantum mechanics (QM) simulation to consider both solvation effects. After exploring multiple possible combinations of N, S, and C, we distinguish a Ni-SAC site with two C, one S, and one N, representing the best performance. The predicted formation energy is closely consistent with experimental onset potential. Our prediction also suggests further improvement by finely tuning the electronics state of metal sites by changing the SAC support.