Fig. 2: Insight of the Pt species transformation during the generation of Pt SACs/PCN and Pt NPs/PCN.

Temperature-dependent in-situ aberration-corrected HAADF-STEM images of (a) Pt SACs/PCN and (b) Pt NPs/PCN, the scale bar represents 5 nm. c, d Pt L-edge FT EXAFS spectra and (e, f) XANES spectra of samples annealed at different temperatures in (c, e) vacuum and (d, f) Ar. g Pt 4 f XPS spectra of samples annealed at different temperatures in vacuum and Ar.