Fig. 2. Charge-corrected descriptor-based volcano for the CO₂RR to CO activity at -1 V vs. SHE (pH 6.8).

Contour lines depict the turnover frequency for CO₂ to CO conversion from the descriptor-based kinetic model as a function of PZC and CO adsorption energy (relative to CO gas and without ZPE, free energy and gas corrections). Solid contour lines represent iso-lines of the absolute value of the hydrogen adsorption free energy, predicted as a function of the two descriptors. The right panel shows the conventional CO₂RR to CO activity volcano which does not consider the CO₂ intermediate or surface charging. It was generated using the kinetic parameters in this work (black) and the original kinetic model (red)³⁶ taking adsorption energies at the potential of zero charge to be correlated with the CO adsorption energy only. Source data are provided as a Source Data file.