Full Free Energy Diagram of an Electrocatalytic Reaction over a Single‐Crystalline Model Electrode

Abstract A long‐term aim of chemical kinetics is to gain detailed information on the full free energy diagram along the reaction coordinate of electrocatalytic processes such as those encountered in fuel cells, batteries, and industrial electrolysis. We present here a universal approach to construct the free energy landscape of an electrocatalyzed reaction over a single‐crystalline model electrode without relying on full kinetics from first principles, a highly computer‐resource‐demanding approach. The free energies of the transition states are determined by a dedicated evaluation scheme of experimental Tafel plots, whereas ab initio thermodynamics calculations provide the free energies of the reaction intermediates. We exemplified this approach with the chlorine and oxygen evolution reactions over a well‐defined RuO 2 (110) model electrode, both reactions constitute large‐scale industrial processes.