To complement the IR measurements, operando Raman spectroscopy was utilized. The resultant spectra were more complex than the IR spectra but could provide deeper information into the surface bound intermediates and nature of the Cuintermediate binding motif. At open circuit potentials, NO3 -could be easily seen at 1049 cm -1 as well as a broad band around 420 cm -1 (Fig. ). This could stem from Cu-OH vibrations as Cu(OH)2 has a similar strong band near this region. As the potential was shifted more negative, new bands at 615 and 291 cm -1 were noticed and attributed to Cu-O vibrational modes of O-bound intermediates. As the potential continued to move more negative, these bands decreased and gave way to a 232 cm -1 band attributed to Cu-N modes of N-bound intermediates. This assignment is supported by the redshift of this band when 15 NO3 -was used as the reactant instead (Fig. ). The broad bands here and their non-gaussian, non-symmetric shape may indicate the presence of several surface binding motifs of the intermediates to the active sites.