Fig. 4. (a) Comparison of overpotentials and metal element numbers. Reproduced with permission.66 Copyright 2021, Wiley-VCH. (b) Schematic illustration of the HOR over HEA SNWs/C. Reproduced with permission.67 Copyright 2021, Springer Nature. (c) Synthesis of Pt34Fe5Ni20Cu31Mo9Ru HEA. Reproduced with permission.68 Copyright 2022, Wiley-VCH. (d) The application of np-12 in the HER, OER and ORR. Reproduced with permission.69 Copyright 2022, American Chemical Society. (e) The mechanism diagram of RuFeCoNiCu NPs in the NRR. Reproduced with permission.71 Copyright 2021, Wiley-VCH. (f) In situ normalized XANES spectra at the Pt L3-edge. (g) The binding strength of H to the Rh site, Fe–Co–Ni site and Pt site. Reproduced with permission.18 Copyright 2021, American Chemical Society. (h) The projected density of states (PDOS) of the HEA surface. Reproduced with permission.72 Copyright 2021, Royal Society of Chemistry. (i) The stability tests at 10 mA cm−2. Reproduced with permission.75 Copyright 2022, Wiley-VCH.
