A comparative study of ORR at the Pt electrode in ammonium ion-contaminated H2SO4 and HClO4 solutions

▸ Poisoning of the Pt electrode by low concentration NH4+ ion was investigated in H2SO4 and HClO4 solutions. ▸ Significant poisoning was observed in H2SO4 solution. ▸ An extraordinary recovery of the poisoned electrode was achieved in HClO4 solution. ▸ The Tafel slopes were affected by NH4+ ion in H2SO4 but not in HClO4 solution.