Fig. 1: Electron microscopy and Structural characterization.

a HAADF-STEM images for PtnOx/CeO2, PtLC/CeO2 and PtHC/CeO2. Blue circles highlight the PtnOx cluster, while orange and green circles highlight single-atom Pt species in the SACs. b k2-weighted Fourier-transformed EXAFS and c normalized Pt L3-edge XANES spectra of PtnOx/CeO2, PtLC/CeO2, PtHC/CeO2, Pt foil and PtO2.