common aqueous media for CO2 reduction, in particular for metals active in H2 formation. The drawback of using anhydrous media is that carbohydrates are not produced, and oxygenated products (such as EtOH) can only be formed in the presence of water. To support results from electrolysis experiments, Figure 5.2 (left) shows the LSV results for all five catalysts under CO2 atmosphere. Cu shows the lowest overpotential, but shows a distinctively different, shallow i-V curve. To further support the i-V curve of Cu electrode for CO2 reduction, comparison of LSV results under He and CO2 purging are also displayed (Figure 5.2, right). Although less evident, also for Ni the i-V curve is shallower in comparison to the other metals, with Au clearly showing the highest current densities at equivalent potentials. The shape of the LSV curves of Cu and Ni could suggest a possible difference in the CO2reduction mechanism for these two catalysts in comparison to the other metals investigated. The results obtained during He purging (Supporting Information Figure S5.7) demonstrate a remarkably similar activity for Au, Zn, and Ni electrodes, with onset potentials at approximately Figure 5.2. Left: LSV results for CO2 reduction for 5 different transition metal catalysts in anhydrous acetonitrile. 0.5 mol% of MM NTf2 was used as both electrolyte and co-catalyst. Right: comparison of LSV results for Cu electrode under He and CO2 purging.
RkJQdWJsaXNoZXIy MTk4NDMw