All metals that weakly bind CO lie in the region where CO 2 adsorption is rate-limiting. In this region, we find negligible coverages of all reaction intermediates (cf. Supplementary Fig. ) in line with experimental works on Au. If CO 2 adsorption is rate-limiting, no pHdependence is expected of the CO partial current on an absolute potential scale, even under acidic conditions, and this has been recently verified on Au, Ag, Sn and In. Previous experimental studies have shown that at -0.7 V vs. SHE, the pH-dependent formation of *COOH becomes rate-limiting on Au. Since we used this experimental result to parametrize the kinetic model (cf. Supplementary Materials Section S2), our model reproduces this transition quantitatively, and the rate-limiting step region of *COOH to *CO moves to more negative PZCs so that it is located exactly over Au at this potential (cf. Supplementary Fig. ). More importantly, however, we can also reproduce that on Ag, a corresponding switch of the rate-limiting step associated with a reduction of the Tafel slope from 120-140 mV/dec to around 80 mV/dec is observed already at around -0.4 V vs. SHE (Supplementary Fig. ). Our model reveals that the physical reason for this earlier switch to CO 2 adsorption being limiting is the less positive PZC of Ag reducing the interfacial electric field and thus the driving force for CO 2 adsorption. The agreement with these trends increases the trust in the transferability of our kinetic model and the developed descriptor space.