In other words, Ag and Au can make CO, in qualitative agreement with experiments, due to the presence of monodentate intermediates on the surface. This is to our knowledge the first DFT calculation setup that contains CO-producing intermediates as the most stable phase on Ag and Au. While the phase diagrams for Ag and Au reproduce experimental trends, at least qualitatively, for the method to be robust it also needs to work for the other major product types in Fig. . For this reason, we did the same analysis on other metal calysts (see SI section "Additional Coverage Analysis Results"). As an example, Pb (Fig. ) shows the expected result of full bidentate HCOO** coverage, barring a short blip of monodentate HCOO* around -0.6 V vs. RHE. As bidentate HCOO** exclusively produces HCOOH, this is also in agreement with the metal's actual product selectivity. Another thing to note is that the potential at which CO 2 RR begins according to these calculations, i.e. where there is both *H and either monodentate species for CO formation, agrees qualitatively with the onset potentials calculated by Hori et al. For example, Hori et al.