fig8

Figure 8. In situ ATR-SEIRAS spectra of HY-Cu₂O (100) (A-C) and Cu₂O (100) (D-F) collected at different applied potentials: under Ar atmosphere (A and D) and CO₂ atmosphere (B and E), all spectra were recorded over the range of 2,250-1,250 cm^-1. Electrochemical in situ infrared spectra of *CO adsorption intermediates on (C) HY-Cu₂O (100) and (F) Cu₂O (100) electrodes at different applied potentials; Peak area of surface *CO on the electrode at different applied potentials (G), peak area intensity ratio of *CO (H), and stretching vibrational frequency of *CO (cm^-1) (I). ATR-SEIRAS: Attenuated total reflection surface-enhanced infrared absorption spectroscopy; RHE: reversible hydrogen electrode.