Modelling Anion Poisoning during Oxygen Reduction on Pt Near-Surface Alloys

Abstract

Electrolyte effects play an important role on the activity of the oxygen reduction reaction (ORR) of Pt-based electrodes. Herein, we combine a computational model and rotating disk electrode measurements to investigate the effects from phosphate anion poisoning for the ORR on well-defined extended Pt surfaces. We construct a model including the poisoning effect from phosphate species on Pt(111) and Cu/Pt(111) based on density functional theory simulations. We have investigated the effect of adsorbed phosphate species at low overpotentials when tuning *OH binding energies. Our work shows that, regardless of the surface site blockage from phosphate, the trend in catalytic oxygen reduction activity is predominately governed by the *OH binding.