fig7

Figure 7. (A) Schematic of DACs showing the distance change of inter-NiFe on different models with SAC as a comparison; (B) AC HAADF-STEM image of NiFe-N bridge and 3D intensity surface plot; (C) Atomic resolution EELS mapping of NiFe-N bridge; (A-C) Reproduced with permission from Ref.^[99]. Copyright 2024, Wiley-VCH; (D) R-space curve-fitting and corresponding fitted structure of the Fe and Cu atoms; (E) ELF analysis for FeN₄ and FeCuN₇; (D-E) Reproduced with permission from Ref.^[123]. Copyright 2024, Wiley-VCH; (F) Illustration of axial oxygen bridged In-N₆-Ni structure for electrochemical CO₂ reduction; (G) The EELS spectra of In-Ni atomic pair; (F-G) Reproduced with permission from Ref.^[124]. Copyright 2023, Wiley-VCH; (H) 3D model of Cu-S-Ni sites and structural model of Cu-S-Ni/SNC; (I) Electron density difference plot of Cu-S-Ni site; (H-I) Reproduced with permission from Ref.^[103]. Copyright 2024, Wiley-VCH; (J) The preparation for Cu-2; (K) Cu 2p XPS spectra; (J-K) Reproduced with permission from Ref.^[128]. Copyright 2024, Springer Nature. DACs: Dual-atom catalysts; AC HAADF-STEM: aberration-corrected high-angle annular dark-field scanning transmission electron microscopy; 3D: three-dimensional; EELS: electron energy-loss spectroscopy.