FIGURE 3 Electrochemical performances of SACs for CO2RR. (A) Schematic of the prepartion of Co–N5/HNPCSs. (B) CO FEs. Reproduced with the permission.[72] Copyright 2018, American Chemical Society. (C) CO FEs and partial CO current densities of Sn-NOC. (D) CO partial current densities of SN-NOC, Sn-PC, and NC. (E) Free energy diagram for electrochemical CO2 reduction to CO on Sn3O and SnN4. Reproduced with the permission.[75] Copyright 2021, John Wiley and Sons. (F) FECO of Fe-SA/BNC using H-cell and (G) using MEA. (H) Electrochemical stability test at −0.7 V vs. RHE. Reproduced with the permission.[81] Copyright 2022, Elsevier