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Simulations of the Oxidation and Degradation of Platinum Electrocatalysts

Kirchhoff, Björn; Braunwarth, Laura; Jung, Christoph 1; Jónsson, Hannes; Fantauzzi, Donato 1; Jacob, Timo 1
1 Karlsruher Institut für Technologie (KIT)

Abstract:
Improved understanding of the fundamental processes leading to degradation of platinum nanoparticle electrocatalysts is essential to the continued advancement of their catalytic activity and stability. To this end, the oxidation of platinum nanoparticles is simulated using a ReaxFF reactive force field within a grand‐canonical Monte Carlo scheme. 2–4 nm cuboctahedral particles serve as model systems, for which electrochemical potential‐dependent phase diagrams are constructed from the thermodynamically most stable oxide structures, including solvation and thermochemical contributions. Calculations in this study suggest that surface oxide structures should become thermodynamically stable at voltages around 0.80–0.85 V versus standard hydrogen electrode, which corresponds to typical fuel cell operating conditions. The potential presence of a surface oxide during catalysis is usually not accounted for in theoretical studies of Pt electrocatalysts. Beyond 1.1 V, fragmentation of the catalyst particles into [Pt$_{6}$O$_{8}$]$^{4-}$ clusters is observed. Density functional theory calculations confirm that [Pt$_{6}$O$_{8}$]$^{4-}$ is indeed stable and hydrophilic. ... mehr


Verlagsausgabe §
DOI: 10.5445/IR/1000105564
Veröffentlicht am 02.03.2021
Originalveröffentlichung
DOI: 10.1002/smll.201905159
Scopus
Zitationen: 15
Web of Science
Zitationen: 13
Dimensions
Zitationen: 16
Cover der Publikation
Zugehörige Institution(en) am KIT Helmholtz-Institut Ulm (HIU)
Publikationstyp Zeitschriftenaufsatz
Publikationsdatum 06.02.2020
Sprache Englisch
Identifikator ISSN: 1613-6810, 1613-6829
KITopen-ID: 1000105564
HGF-Programm 37.01.01 (POF III, LK 01) Fundamentals and Materials
Erschienen in Small
Verlag John Wiley and Sons
Band 16
Heft 5
Seiten Art.Nr. 1905159
Vorab online veröffentlicht am 26.12.2019
Nachgewiesen in Scopus
Web of Science
Dimensions
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