We do not claim to provide new insights into this intricate reaction system, nor do we assume that the presented mechanism is complete. The case study serves purely as a demonstration purpose. Pt(111) was chosen as a model surface as it has a large amount of experimental data for ∆ f H of adsorbates . The * indicates that the species is bound to the surface. If it is on the lefthand side of an atom, it indicates that the species is bound to the surface through this atom (e.g., *OH). .