-2.4 V (vs. Ag/Ag+). This observation indicates that the reduction of imidazolium is not influenced by the nature of the electrode, suggesting it is most likely a non-catalytic reductive process. This reinforces the notion that the variation in CO2 reduction activity among different transition metals should be explained by variations in the interaction of the electrode with the CO2 (reactant) or CO (product) molecules. To further explore these differences, we employed DFT calculations to determine the desorption energies of CO for a range of metals. The results were then compared with CO2 reduction activities obtained through experiments (as depicted in Figure 5.3). Upon analyzing the results presented in Figure 5.3, a volcano relationship was discovered between the strength of CO binding and the overall CO2 reduction activities in anhydrous acetonitrile. Specifically, we observe that Au is located at the apex of the volcano, exhibiting an ideal binding strength for CO and demonstrating the highest CO2 reduction activity among the catalysts tested. Previous studies have investigated the volcano-shaped activity trend for CO2 reduction in aqueous media through DFT calculations 15-16. These studies have shown a similar trend for CO2 activation, albeit with lower faradaic efficiencies, as demonstrated by Jaramillo's work. One significant difference between this study and previous studies in aqueous media, which will be discussed in detail later, is the relative activities among the different catalysts, which do not align with those observed in previous studies in aqueous media.
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