Fig. 3: Structural characterization and mechanistic insights into hierarchical click-sites.

a XRD patterns of InO_x, S−InO_x and Se−InO_x; inset of (a) shows a TEM image of Se−InO_x. b, c Aberration-corrected HAADF-STEM images along the [100] direction; inset of (c) shows an intensity line scan for the atoms within the yellow boxed area. d Atomic-level STEM-EDS element mapping images of In + O + Se, In + Se, In + O and HAADF + O + Se. e iDPC−STEM image along the [100] direction; wherein yellow and red circles indicate positions of In and O/Se, respectively, and arrows indicate the distortion. f Graphical representation of InO_x and Se−InO_x, wherein blue, pink, and purple dots represent In, O, and Se atoms, respectively. g In-situ ATR−SEIRAS results on InO_x and Se−InO_x surfaces saturated with CO₂, NO₃⁻ and CO₂ + NO₃⁻ under operando potentials. h Experimental (Exp.) and simulated (Sim.) EPR spectra. i FE_HCOOH and FE_NO2- on InO_x, S−InO_x and Se–InO_x surfaces at 50 mA cm⁻². j Proposed catalytic mechanism of hierarchical click catalysis on the Se−InO_x surface. Colour codes: C grey, O red, N blue, H white, In orchid, Se light green. Source data are provided as a Source data file.