moderator for energy requirements during the initial electron transfer, the utilization of electrolyte cations to engineer the kinetics of CO2 reduction appears to be a promising approach. Among the electrolyte cations, imidazolium cations have shown great promise for CO2 reduction in both aqueous and non-aqueous media. Rosen et al. reported a 96% faradaic efficiency for CO formation on an Ag electrode in an ethyl methyl imidazolium-water mixture (18 mol % EMIM BF4 in water) with a cell voltage of 1.5 Volts (+0.2 V overpotentials)50. Following this seminal work, various attempts have been made to utilize imidazolium-type molecules to enhance CO2 reduction in non-aqueous media. Lau et al. employed C2functionalized imidazolium cations to achieve an onset potential of around -2.0 V vs. Fc/Fc+ for CO2 reduction over an Ag electrode in acetonitrile 8, and Atifi et al. reported the use of butyl methyl imidazolium hexafluorophosphate for the conversion of CO2 to CO with 85% FE using a Bi electrode51. Sung et al. also demonstrated the improved efficiency of a molecular Lehntype catalyst through the incorporation of imidazolium species into the secondary coordination sphere52. Despite these efforts, the reported onset potentials and associated energy losses in imidazolium solutions remain relatively high. Moreover, the fundamental understanding of the function of imidazolium cations is limited, and several hypotheses regarding the promotion mechanism have been proposed. These hypotheses include: i) the coordination of the cation with the adsorbed CO2 intermediate, the nature of which still requires clarification 3, 50, ii) the suppression of the H2 evolution reaction 53-54, , iii) the formation of an intermediate imidazolium carboxylate providing a low-energy pathway for the conversion of CO2 to CO3-4, 55, or iv) the stabilization of the high-energy *CO2¯ intermediate (on Ag surfaces) through hydrogen bonding via the C4-H or C5-H functionality of C2-substituted imidazolium cations (Figure 1.1) 8. However, different reaction conditions have been previously applied, including variations in applied salts (different anions and C2-substituted imidazolium cations) and variable water
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