Modeling Anion Poisoning during Oxygen Reduction on Pt Near-Surface Alloys
Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › fagfællebedømt
Electrolyte effects play an important role in 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. By varying the subsurface Cu content of the Cu/Pt(111) alloy, we tune the *OH binding energies on the surface by means of ligand effects, and as a result, we tune the ORR activity. We have investigated the effect of adsorbed phosphate species at low overpotentials when tuning *OH binding energies. Our results display a direct scaling relationship between adsorbed *OH and phosphate species. From the model, we observe how the three-fold binding sites of phosphate anions limit the packing of poisoning phosphate on the surface, thus allowing for *OH adsorption even when poisoned. Our work shows that, regardless of surface site blockage from phosphate, the trend in the catalytic oxygen reduction activity is predominantly governed by the *OH binding.
Originalsprog | Engelsk |
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Tidsskrift | ACS Catalysis |
Vol/bind | 13 |
Udgave nummer | 4 |
Sider (fra-til) | 2735-2743 |
Antal sider | 9 |
ISSN | 2155-5435 |
DOI | |
Status | Udgivet - 2023 |
Bibliografisk note
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© 2023 American Chemical Society.
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