Fig. 3

Images for various metal single-atom catalysts. Aberration-corrected high-angle annular dark-field scanning transmission electron microscopy for a Cr-SAC, b Mn-SAC, c Fe-SAC, d Co-SAC, e Ni-SAC, f Cu-SAC, g Zn-SAC, h Ru-SAC, and i Pt-SAC. Scale bar: 5 nm