The reactions leading to the (interfacial) products observed With the discussion above in mind, we propose the following set of equations for CO2 reduction processes occurring at the Au electrode in the BMMIM-NTf2-MeCN electrolyte : CO2 (sol) + e - + * + BMMIM+ (sol) = *(CO2-BMMIM) 1 1[solvation/hydrogen bonding mediated with imidazolium cation] *(CO2-BMMIM) + e - + CO2 (sol) = CO3 2- (sol) + *(CO) + BMMIM+ (sol) *(CO) = *+CO (sol) *2(CO2-BMMIM) = *C2O4 2- + 2 BMMIM+ (sol) *C2O4 2- = C2O4 2- (sol) *(CO2-BMMIM) + e - + H+ (sol) = HCO2 - (sol) + BMMIM+ (sol) Conclusion In this chapter, we presented infrared spectroscopic evidence of the formation of various species at the electrode-electrolyte interface. Initially, when CO2 reduction is conducted in acetonitrile containing 2-methylated imidazolium, both CO and (bi)carbonate species are formed near an Au cathode. Furthermore, the appearance of a novel feature at ~1720 cm-1 and a robust peak at 1330 cm-1 suggests the generation of oxalate and formate species, respectively. The identification of formate was also confirmed through NMR analysis of solid products obtained from electrolysis experiments. However, a comprehensive analysis is needed to accurately attribute the observed ATR-FTIR peaks to surface intermediates. This would involve a dedicated investigation, possibly employing other in-situ spectroscopy techniques like Raman
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