Modeling Anion Poisoning during Oxygen Reduction on Pt Near-Surface Alloys
Petersen, Amanda S. (University of Copenhagen. Department of Chemistry)
Jensen, Kim D. (University of Copenhagen. Department of Chemistry)
Wan, Hao (Fritz-Haber-Institut der Max-Planck-Gesellschaft)
Bagger, Alexander (Imperial College London. Department of Materials)
Chorkendorff, Ib (Technical University of Denmark. Department of Physics, Surface Physics and Catalysis)
Stephens, Ifan E. L. (Imperial College London. Department of Materials)
Rossmeisl, Jan (University of Copenhagen. Department of Chemistry)
Escudero-Escribano, María (Institut Català de Nanociència i Nanotecnologia)

Date:	2023
Abstract:	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.
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Language:	Anglès
Document:	Article ; recerca ; Versió acceptada per publicar
Subject:	Oxygen reduction reaction ; Platinum ; Near-surface alloys ; Density functional theory ; Anion ; Adsorption
Published in:	ACS catalysis, Vol. 13, Issue 4 (February 2023) , p. 2735-2743, ISSN 2155-5435

DOI: 10.1021/acscatal.2c04808

Postprint 36 p, 4.3 MB

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Research literature > UAB research groups literature > Research Centres and Groups (research output) > Experimental sciences > Catalan Institute of Nanoscience and Nanotechnology (ICN2)
Articles > Research articles
Articles > Published articles