TY - JOUR

T1 - Modeling Anion Poisoning during Oxygen Reduction on Pt Near-Surface Alloys

AU - Petersen, Amanda S.

AU - Jensen, Kim D.

AU - Wan, Hao

AU - Bagger, Alexander

AU - Chorkendorff, Ib

AU - Stephens, Ifan E.L.

AU - Rossmeisl, Jan

AU - Escudero-Escribano, María

N1 - Funding Information: We would like to thank the Center for High Entropy Alloy Catalysis (CHEAC) funded by the Danish National Research Foundation (DNRF 149) and the Villum Foundation through the Villum Center for the Science of Sustainable Fuels and Chemicals (no. 9455) for funding this work. M.E.-E. and K.D.J. would like to thank the Independent Research Fund Denmark for the award of a DFF-Research Project 1 grant (9041-00224B) and KDfuelcell. Publisher Copyright: © 2023 American Chemical Society.

PY - 2023

Y1 - 2023

N2 - 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.

AB - 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.

KW - adsorption

KW - anion

KW - density functional theory

KW - near-surface alloys

KW - oxygen reduction reaction

KW - platinum

U2 - 10.1021/acscatal.2c04808

DO - 10.1021/acscatal.2c04808

M3 - Journal article

AN - SCOPUS:85147812967

VL - 13

SP - 2735

EP - 2743

JO - ACS Catalysis

JF - ACS Catalysis

SN - 2155-5435

IS - 4

ER -