with the linear charge sensitivity parameter ∆ i a being a measure of the charge transfer during adsorption (or electrosorption valency). The charge sensitivity parameter for CO 2 adsorption is by far larger than the coefficients for *COOH and *CO formation. This is due to the strong interfacial dipole moment created among CO 2 adsorption which is stabilized by the surrounding electric double layer field. The remaining potential-and pH terms stem from the CHE-expression for the thermodynamic energy of a PCET. Finally, Eq. 2b denotes the surface charging relation, for which we again assumed a plate capacitor. In this expression, the gap capacitance is assumed to be constant across metals (≈ 20 µF/cm 2 ) and the PZC which is well known to be proportional to the Fermi level, is derived from the calculated Fermi level of each surface plus a constant offset of 4.92 V obtained from fitting the Fermi level to the experimental PZC data (cf. Supplementary Materials Fig. ). From the energy expression above, all formation energies are determined by three material specific parameters for each intermediate, the formation energy at the PZC, ∆ i E 0 , the parameters measuring the sensitivity of the intermediate with respect to surface charging ∆ i a, and the PZC U PZC . For this, we assumed that the ZPE and finite temperature corrections are roughly independent of the surface.