In principle, it would be desirable to directly fit the kinetic current curves with certain microkinetic models, e.g., the rate expressions of the Heyrovsky-Volmer or Tafel-Volmer mechanisms. However, considering the information provided by the experimental data, such We therefore use a generalized Butler-Volmer model with reaction orders m HOR and m HER for the H 2 -partial-pressure dependencies of the anodic and cathodic branches, respectively,