fig10

Figure 10. (A) The local structure of the M¹M²-DAC; (B) HAADF-STEM image of FeCu-DAC; (C) EELS of an Fe-Cu atomic pair as marked in the red rectangle in the HAADF-STEM image^[78]. Copyright 2023, American Chemical Society; (D) The structure of Cu-N-C SAC; (E) Atomic-resolution STEM-HAADF image; (F) The EELS extracted from the yellow rectangle in STEM-HAADF image^[102]. Copyright 2021, American Chemical Society. DAC: Dual-atom catalyst; HAADF-STEM: high-angle annular dark-field scanning transmission electron microscopy; EELS: electron energy-loss spectroscopy; SAC: single-atom catalyst.