The relatively limited pH range where the HOR/HER kinetics can be determined with high accuracy challenges the identification of the reaction path, but when comparing the results of Fig. with the expected pH dependence of 𝑚 𝑂𝐻 -and 𝑚 𝐻 2 for the T-V and H-V paths (Fig. ) one can exclude the Volmer step from having the smallest rate constant at high pH. On the other hand, both the T-V and H-V paths with 𝑘 𝑉 ∘≀ ≥ 𝑘 𝑇,𝑓/𝑏 ∘ and 𝑘 𝑉 ∘≀ ≥ 𝑘 𝐻 ∘≀ seem to be in semi-quantitative agreement with the experimental findings, keeping also in mind that Fig. was simulated for 𝐸 𝑉 ∘≀ = 𝐸 𝐻 ∘≀ = 0 and therefore the reaction order patterns will shift somewhat in the pH scale for the actual formal potential values of polycrystalline Pt. Considering that both 𝑘 𝑉 ∘≀ ≈ 𝑘 𝑇,𝑓/𝑏 ∘ and 𝑘 𝑉 ∘≀ ≈ 𝑘 𝐻 ∘≀ are possible descriptions of the experimental findings, these results cannot distinguish between the different reaction paths at 𝐸 𝑒𝑞 .