Figure 2. (a) The CO FEs of Ni-NC_TPA@C, Ni-NC_ATPA@C, and NC_ATPA@C at various applied potentials in 0.5 M KHCO3. (b) Calculation models for Ni (111) and two graphene structures (bridge-top and fcc-top) for Gr/Ni(111). Reproduced with permission.[57] Copyright 2018, Royal Society of Chemistry. (c) The schematic illustration for the preparation of Ni@NCNT. (d) Free-energy profiles of Ni@NCNT, NCNR, and Ni (111) for ECR. Reproduced with permission.[60] Copyright 2021, Elsevier. (e) HRTEM images of Ni@N-C/rGO(4,4′-bipy). (f) The schematic of poison of N active site in Ni@N-C. (g) The schematic of electron transmission from Ni particles to pyrrolic-N doped carbon. Reproduced with permission.[61] Copyright 2022, Elsevier.