The Tafel region of the HER The classical HOR/HER paths predict that the alkaline HER current in the Tafel region should not vary with pH, as its reactant is only water (Fig. ). We nevertheless find an almost Nernstian shift with pH of the HER Tafel region for pure alkali metal hydroxides. This is a remarkable finding that, at least in the case of pure alkali metal hydroxides, forces one to dismiss both classical paths, despite their dominance in the discussion of the HOR/HER over the last century. In the presence of additional anions (Cl, ClO4) the pH dependence becomes rather intricate and inconclusive, for which we will propose an explanation later in this work. Section summary Our results paint a very consistent picture of the HOR/HER reaction orders at 𝐸 𝑒𝑞 , revealing a rather minor influence of the electrolyte composition. Although the determined 𝑖 0,𝑚𝑖𝑐𝑟𝑜 in the alkaline region confirms the substantial reduction in HER/HOR activity compared to acidic conditions reported previously , we find no major influence of the type or concentration of cations or anions at the microkinetic region. This contrasts with previous studies reporting a strong "cation effect". Taking a closer look at these studies, we find that only the study by Huang et al. reports the "cation effect" in the micropolarization region showing only minor differences between Li, Na, and K, in line with our findings. Regarding the HER region, the accumulation of cations near the interface has been previously associated with the modulation of the HER activity under alkaline conditions. We do find that different combinations of cations and anions play a role in the Tafel region of the HER, but the effect is not very pronounced, and no clear trends could be identified. In a related study, the authors reported very pronounced cation type and concentration effects on polycrystalline Pt, but also remarkably slow HER kinetics in some of the datasets, with a puzzling shift in HER onset of around 200 mV relative to the RHE potential (Fig. ). They also reported a substantial reduction in HER kinetics when more KClO4 was added at pH 11 and 12, a phenomenon that we have never observed. Another study (Fig. ) that reports a clear trend in the HER current with respect to cation size, adopts a partial compensation for the electrolyte resistance (85%, likely for an online iR-compensation), with the remaining 15% being expected to differ somewhat for the different electrolytes. Furthermore, the HER was only probed in the region of small overpotentials, where varying intermediate coverages may be expected, which complicates interpretation (Fig. ). Importantly, like the case in Fig. , the absence of a defined Nernst potential makes it impossible to verify if the measurements are truly conducted at the same potential range due to possible variations in pH. Finally, as the i-V curves for the different cations have different slopes, the effect of cations will be different at different potentials, and similar changes may be expected at different pH values (Fig. ), questioning the value of interpreting such a narrow set of conditions.