fig14

Figure 14. (A) Synthetic procedure of non-planar nest-like [Fe₂S₂] cluster sites in the N-doped carbon plane; (B) corresponding Fe K-edge EXAFS fittings of Fe₂S₂@CN and the optimized non-planar nest-like [Fe₂S₂] cluster structure model (inset); (C) Free energy diagram of the ORR process, along with configurations of the corresponding adsorbed intermediates; (D) ORR polarization curves of Fe₂S₂@CN, Fe₂@CN, Fe₁@CN, CN and Pt/C; (E) ORR durability test results of Fe₂S₂@CN after 5,000 and 10,000 cycles (A-E reproduced with permission from Wiley-VCH, copyright 2023)^[161]; (F) Schematic of a synthesis- targeted electrocatalyst; (G) PDOS profiles and corresponding differential charge densities of the samples; (H) free energy changes during each reaction step (F-H reproduced with permission from Wiley-VCH, copyright 2024)^[162]. ORR: Oxygen reduction reaction; EXAFS: extended X-ray absorption fine structure.