Figure 3. Operando structural and chemical characterization during CO₂ electroreduction.

(a) XANES spectra of the O₂ 100 W 2 min treated sample measured under operando conditions in 0.1 M KHCO₃ during the first 15 min and after 1 h of reaction at −1.2 V versus RHE. Bulk Cu, Cu₂O and CuO spectra are plotted as reference. (b) EXAFS spectrum of the as-prepared sample plotted with references. (c) EXAFS spectra and fits (dashed lines) of the sample measured under operando conditions. Fourier transforms are k²-weighted. Fit results are given in Supplementary Table 2.