Fig. 4: Structural characterization of the Cu|AlOx interface by operando XAS.
From: Hybrid oxide coatings generate stable Cu catalysts for CO2 electroreduction
a–c, Cu K-edge XANES spectra at OCP (dark colour) and at −1.1 V versus RHE (bright colour) for Cu NCs (a, black), Cu@AlOxn=17 (b, blue) and Cu/AlOx (c, purple), respectively, together with Cu foil (pink dashed line) and CuO (orange dashed line) standard. d–i, Evolution of Cux species fraction as a function of the applied potential (d–f) and time at −1.1 V versus RHE (g–i) extracted from linear combination analysis of the XANES spectra for Cu NCs. The data are the average of copper fractions extracted from six consecutive XANES spectra, and the error bars are the calculated standard deviation: Cu NCs (d and g), Cu@AlOxn=17 (e and h) and Cu/AlOx (f and i). j–l, EXAFS data at at OCP (dark colour) and at −1.1 V versus RHE (bright colour) for Cu NCs (j, black), Cu@AlOxn=17 (k, blue) and Cu/AlOx (l, green).
