With the theoretical background clarified, we investigated the HOR/HER kinetics in the pH range from 1 to 14.5 in various electrolytes, see Tab. 2. All potential values are given on the SHE-scale, are iR-corrected and the currents are referred to the geometrical disc surface area (For the Pt specific area the roughness factor estimate is 1.3). While we have optimized the measuring protocol to obtain consistent electrochemical values, the Pt(pc) surface is subject to variations during and in-between measurements; potential limits were set relative to the equilibrium potential, which means that the potential limits varied on the SHE scale. Through the coming section we dominantly use the SHE scale in contrast to the commonly used, and recommended, RHE scale . The practice of using the RHE scale stems from the expectation that the HER/HOR i-V curves will shift proportionally to the pH and activity of molecular hydrogen (59 mV/pH and 29.5 mV/pH2 at standard conditions). However, this is only true for the open circuit potential (OCP), where the overall reaction is in equilibrium. Instead, the i-V curves in the respective Tafel regions would be expected to have different dependencies: E.g., in the often-studied alkaline HER, water is consumed and the activity of either hydronium, hydroxyl, or molecular hydrogen play no role in the magnitude of its current. Since we are referring to the micropolarization region as well as the H-upd and HER/HOR Tafel regions, we choose to use the SHE scale.