From a process perspective, this thesis discussed the inherent advantages of non-aqueous imidazolium-acetonitrile electrolytes. Among these benefits is the enhancement in CO2 solubility, reported to be 8 times higher than that of water under atmospheric conditions, accompanied by the concurrent suppression of the competing hydrogen evolution reaction. Under conditions of mass transfer control, the heightened CO2 absorption capacity of MeCNimidazolium electrolyte facilitates an improved CO2 conversion rate compared to aqueous media. Another significant characteristic of a non-aqueous imidazolium electrolyte is its wide electrochemical window (as illustrated in Figure 8.1). The stability of this electrolyte offers opportunities to integrate desired oxidation reactions with the CO2 reduction process. For instance, examples include the electrosynthesis of acetophenone142 and the oxidative dimerization of stilbene in acetonitrile 143. As long as the reactants and products of the oxidation reaction do not interfere with the CO2 co-catalyzed reduction reaction, a membrane-free cell can also be envisaged for such a paired electrolysis system. Figure 8.1 Electrochemical window of 1,3-dimethyl imidazolium (MM)-acetonitrile vs MM-water. LSVs for Au disk electrode under a purge of He in water with 0.5 mol% of MM Cl (red) and in acetonitrile with 0.5 mol% of MM NTf2. The broad electrochemical window of nonaqueous imidazolium-acetonitrile enables the incorporation of oxidation reactions that possess kinetics distinct from those of water oxidation, which is dominant in aqueous media.
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