Investigation of the oxygen exchange mechanism on Pt|yttria stabilized zirconia at intermediate temperatures: Surface path versus bulk path

► Oxygen exchange kinetics of Pt on YSZ investigated by means of Pt model electrodes. ► Two different geometry dependencies of the polarization resistance identified. ► At higher temperatures the oxygen exchange reaction proceeds via a Pt surface path. ► At lower temperatures a bulk path through the Pt thin film electrode is discussed.