This work makes an attempt to correlate experimentally observed Tafel slopes from the oxygen reduction reaction in both model rotating disk electrode and polymer electrolyte fuel cell measurements, respectively, with the kinetic description of a coverage dependent current- potential relationship. It is shown that the potential dependent OHad coverage can be used as a descriptor of potential dependent Tafel slopes, pointing to the validity of underlying Temkin- Frumkin adsorption properties in combination with the Butler-Volmer approach.