should provide a valuable tool for engineering the overall rate of CO2 reduction in non-aqueous media. However, the observed 100% selectivity towards CO for all the investigated catalysts suggests that altering the reaction conditions, such as the inclusion of a proton source like water or weak acids, should be the primary approach to influence CO2 reduction selectivity. Explaining the role of imidazolium cation as a co-promoter is also crucial. Our results in Chapter 3 demonstrated that imidazolium cation promotes the reaction by reducing the energy of the adsorbed CO2 intermediate at the Au electrode. However, the question that remains is how imidazolium cation affects the observed volcano trend. To address this, the volcano plot obtained from this study was compared with that from the work of Jaramillo and colleagues7, as depicted in Figure 5.6. Under aqueous conditions, we observe significant differences in activity when comparing Au to other metals, such as Ag, Cu, and Ni. Specifically, we find ratios of Au/Ag ~ 10 and Cu/Ni ~ 30 for the current density associated with CO2 reduction at equivalent potential (Figure 5.6, right). However, in MeCN-imidazolium-assisted CO2 reduction, while greater absolute activities are observed for electrodes such as Ni and Cu, the difference between the activities of different electrodes is much smaller (Figure 5.6, left). For example, the Au/Ag ratio for the activity reported in our work is only 1.66, compared to the Au/Ag ratio of 10 reported in the work of Jaramillo et al. 7
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