Fig. 2: Intermediate detection on the PTV-Cu electrode for CO2 activation.

a, b. In-situ Raman spectra of a. bare Cu electrode and b PTV-Cu electrode scanning from 0.17 V to -0.63 V vs. RHE. c, d. In-situ FTIR spectra of c bare Cu electrode and d PTV-Cu electrode scanning from 0.17 to -0.63 V vs. RHE. The electrolytes used are 1 M K2CO3.