Figure 10. (a) Fourier transformation of the EXAFS spectra at R space for Ni/Fe-N-C, Ni-N-C, Ni-Pc, and Ni foil. (b) FECO of Ni/Fe-N-C, Ni-N-C, Fe-N-C at various applied potentials. (c) The calculated free energy diagrams for CO2 reduction to CO on different catalysts. Reproduced with permission.[116] Copyright 2019, Wiley-VCH. (d) Schematic illustration of the preparation process of Ni7/Fe3-N-C samples. (e) Free energy profiles on simulated models. Reproduced with permission.[117] Copyright 2021, Royal Society of Chemistry. (f) Atomic structure of dual metal 2N-bridged (Fe-Ni)N6 sites embedded in a graphene layer. The gray, blue, golden, and cyan balls represent C, N, Fe, and Ni atoms, respectively. (g) Predicted free energy evolution on various dual metal Fe-Ni sites. (h) Predicted limiting potential difference between ECR and HER on various single-metal and dual-metal sites. Reproduced with permission.[118] Copyright 2022, Wiley-VCH.