fig3

Figure 3. (A) The preparation strategy for dinuclear Ni₂/NC and atomically dispersed Ni₂ species highlighted by red circles. Reproduced with permission from Ref.^[67]. Copyright 2021, American Chemical Society; (B) The synthesis strategy for Pd₂ DAC. Reproduced with permission from Ref.^[70]. Copyright 2021, Wiley-VCH; (C) Schematic of synthesis of dual-atom Ni/Fe on carbon blacks. Reproduced with permission from Ref.^[73]. Copyright 2021, Wiley-VCH; (D) Atomic scale identified the brightness of Pt and Co dual atoms in the selected area; (E) Schematically illustration of random atomic sites; (D-E) Reproduced with permission from Ref.^[75]. Copyright 2021, Wiley-VCH. DACs: Dual-atom catalysts; SACs: single-atom catalysts.