Fig. 2: Elemental composition and oxidation state.

a HAADF-STEM image and the corresponding EDS elemental mapping of a single structurally ordered PtMg/C-31 NP, showing Pt signal (red), Mg signal (green), and the overlapped signal. b High-resolution Pt 4 f XPS profiles of PtMg/C-31 and commercial Pt/C. c Pt L3 XANES and d Pt L3 K2 – weighted EXAFS spectra of PtMg/C-31, Pt foil, and PtO2.