Fig. 4: Relationship between ECM selectivity and adsorbed intermediates on ssCuNC100 and CuNC100 SACs.

FE for CO (a) and C2 products (ethylene, acetate and ethanol) (b) at different applied potentials. Error bars represent one standard deviation from three independent samples. The R used for CuNC100 and ssCuNC100 in (a, b) was 2.4 ± 0.15 and 2.2 ± 0.27 Ω, respectively. In situ ATR-FTIR spectra of CuNC100 (c) and ssCuNC100 (d) SACs under different applied potentials. e Stark effect of linearly adsorbed CO (*COL) vibration as a function of potential. f *COL intensity as a function of potential. *COL wavenumbers and intensities in (e) and (f) were derived from spectra (c) and (d). *: Denotes active reaction sites. In situ and ex situ Cu K-edge EXAFS spectra of CuNC100 (g) and ssCuNC100 (h) under different applied current densities. Source data are provided as a Source data file.