Fig. 3: In situ Raman spectra.

In situ Raman spectra of (a) CuO-SH and (b) CuO obtained in a potential window OCP to −1.4 V, c Potential dependence of the normalized intensity of *CO and FE of C₂H₄ (error bars indicate the standard deviation of three independent measurements), d in situ Raman spectra of CuO-SH and CuO collected at different applied potential.