Fig. 2: XPS and XAS characterizations for NxM0.2-xRO samples.

a Ru 3d XPS spectra of N0.1M0.1RO, NRO, MRO, and HM-RuO2. b Ru K-edge spectra of Ru foil, RuCl3, and N0.1M0.1RO along with pure RuO2. c Mn K-edge spectra of Mn foil, Mn2O3, N0.1M0.1RO, and MRO along with pure MnO2. d Fourier-transformed Ru/Mn K-edge EXAFS in R spaces of N0.1M0.1RO, MRO, compared with Ru foil, RuCl3, RuO2, MnO2, and Mn2O3 references. e Ru K-edge WT-EXAFS for C-RuO2. f Ru K-edge WT-EXAFS for N0.1M0.1RO. g Mn K-edge WT-EXAFS for N0.1M0.1RO. h O K-edge XAS spectra collected from N0.1M0.1RO, NRO, MRO, compared with that of C-RuO2 reference.