Fig. 2: Structure characterization of sulfo-oxygen bridged Co-Ru atom sites.

a Schematic illustration of the structure of Cos-SO-Ru. b XRD patterns of different catalysts. c TEM image of Cos-SO-Ru. d Atomic-resolution HAADF-STEM image of Cos-SO-Ru and e corresponding plane intensity profiles labeled with red boxes in (d). f Atomic-resolution HAADF-STEM image of Cos-SO-Ru and corresponding EDX mapping results of Ru and Co elements. g FT-IR spectra of different catalysts. Source data for (b, g) are provided as a Source Data file.