Equilibrium coverage of OHad in correlation with platinum catalyzed fuel cell reactions in HClO4

•We study the adsorption of oxygenated species on platinum under steady state conditions.•We employ stripping voltammetry and parameterize the results.•At steady state, OHad forms a monolayer at 0.95 VRHE.•At steady state, Oad forms a monolayer at 1.10 VRHE, followed by Pt-oxide.•The ORR inhibition correlates with the formation of a monolayer of OHad.

We employ a recently developed stripping protocol to examine the equilibrium coverage of oxygenated species and their influence on the oxygen reduction reaction (ORR) and the hydrogen oxidation reaction (HOR). In particular we aim to distinguish between dynamic and steady state conditions and establish if distinctive potential regions exist where the different respective oxygenated species OHad, Oad and Pt-oxide dominate.