fig3

Figure 3. The atomically dispersed asymmetrical metallic structure. (A-C) H₂-O₂ titration profiles of AC, PMA/AC and Pt-PMA/AC. Reprinted with permission from Ref.^[31]. Copyright 2016, WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim. (D) HAADF image of A-CoPt-NC after fast Fourier transformation filtering. The bright yellow spots are metal atoms, and the cyan spots are carbon atoms. Reprinted with permission from Ref.^[32]. Copyright 2018, American Chemical Society. (E) Model of the configuration of the two metal atoms trapped in the defect, reconstructed from the observed atomic structure in (a). Purple circles mark metal atoms. The carbon atoms adjacent to metal atoms #1 and #2 are linked with a red line. Reprinted with permission from Ref.^[32]. Copyright 2018, American Chemical Society. (F) Top view of the charge densities of a(Co-Pt)@N₈V₄, the pink area represents strong electron accumulation. Reprinted with permission from Ref.^[32]. Copyright 2018, American Chemical Society.