fig3

Figure 3. Single atoms are anchored at doped heteroatoms(A-D), defect sites(E-G) and metal atoms(H-K): (A) anchoring diagram of CuC₄/CoN₄@HC. (B) FT k³-weighted EXAFS spectra for the Co K-edge of CuC₄/CoN₄@HC, Co foil, CoO, and Co₃O₄. (C) Model of CoN₄ sites and fitting curves of CuC₄/CoN₄@HC. (D) Top view of the differential charge densities of CuC₄/CoN₄@HC. Reproduced with permission from Ref.^[58] Copyright 2021, American Chemical Society. (E) The electron density differences in the C-MoS₂, the structure model of C-M-Mo. (F and G) AC TEM images of C-Co-MoS₂. Reproduced with permission from Ref.^[63] Copyright 2023, Wiley-VCH. (H) The model structure of Fe-Rh interbonds. Reproduced with permission from Ref.^[67] Copyright 2020, Wiley-VCH. (I) Plot of the H adsorption free energy versus η₁₀. (J and K) The differential charge densities of Sn-MoS_xO_y (J), RhSn-MoS_xO_y (K). Reproduced with permission from Ref.^[68] Copyright 2022, Wiley-VCH.