Figure 4.4 (left) displays the LSVs recorded for MM and TetraMe cations under a CO2 atmosphere. The LSV results uncover a slightly higher apparent activity for CO2 reduction associated with the MM cation, although the distinction appears marginal. This observation is substantiated by the VDD charge analysis map depicted in Figure 4.4 (right). Comparatively, MM is characterized as a more electron-deficient cation than TetraMe. As a result, TetraMe is expected to display reduced acidity at the C2-H position, aligning with the anticipated lower activity. Electrolysis at -1 mA/cm2 under CO2 purge conditions demonstrated a 100% FE for CO formation with both cations when employed under the same salinity. For MM, achieving the same FE coincided with a reduction of the requisite reductive potential by 90 mV. This reduction is consistent with outcomes derived from the LSV results, the electron density map, and the 13C NMR analysis (Figure 4.3, indicated by blue letters). Figure 4.3. 13C NMR spectra of the five cations investigated in this chapter. Refer to Figure 4.2 for the molecular structures of the cations. Cations with similar functional group arrangements are indicated by the same color. R: CH3 R: Cl R:4-CH3OPh R: Ph R: H
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