Correcting Errors in the Adsorbed Intermediates of CO ₂ Electroreduction

Density functional theory (DFT) has helped propel the advance of electrocatalysis in the past two decades. In view of its massive use, it is worth asking how reliable DFT is for the prediction of adsorption energies, which are paramount in computational electrocatalysis models. Here, we provide an experimental‐computational approach to break down overall adsorption‐energy errors into separate gas‐phase and adsorbed‐phase contributions. The method is evaluated using experimental data and various exchange‐correlation functionals and materials for C‐ and O‐containing species. Our main conclusion is that no functional is simultaneously accurate for adsorbates and molecules, as adsorbed‐phase errors are visibly different from gas‐phase errors. Importantly, total, gas‐phase, and adsorbed‐phase errors are correlated, revealing intrinsic DFT limitations and enabling the elaboration of swift correction routines. To illustrate the benefits of our approach, we deconvolute and correct all errors in CO 2 electroreduction to CO and find an agreement with experiments close to chemical accuracy for numerous transition‐metal electrodes and all scrutinized functionals.