Fig. 1: Structural characterization of the catalysts.

a The schematic of the preparation of amorphous catalysts. b, c The TEM images of 8-Cu-12. d HR-TEM images of the 8-Cu-12. e HAADF-STEM images of the 8-Cu-12. f EELS maps of Cu and CuxO and their overlay in 8-Cu-12. g The XANES spectra at the Cu K-edge for different catalysts. h Cu K-edge extended XAFS oscillation function k3c(k). i Fourier-transformed Cu K-edge EXAFS spectra for different catalysts.