“…S5†) displayed deconvolution peaks at 284.0, 284.8, 286.0, 288.2, and 290.1 eV, corresponding to CC, C–C, C–O, CO, and O–CO, respectively, serving as calibration benchmarks. 19,22 Meanwhile, deconvolution peaks near 281.0 and 285.1 eV represented 3d 5/2 and 3d 3/2 of metal Ru, respectively, 23 and the peaks at about 282.4 and 286.6 eV were 3d 5/2 and 3d 3/2 of RuO 2 , respectively, owing to unavoidable oxidation by exposure to air. 24 Additionally, the high-resolution XPS spectra of Ru 3p further revealed the valence state of Ru.…”