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A single model for the thermodynamics and kinetics of metal exsolution from perovskite oxides

Bonkowski, Alexander ; Wolf, Matthew J. ; Wu, Ji ; Parker, Stephen C. ; Klein, Andreas ; De Souza, Roger A. (2024)
A single model for the thermodynamics and kinetics of metal exsolution from perovskite oxides.
In: Journal of the American Chemical Society
doi: 10.1021/jacs.4c03412
Artikel, Bibliographie

Kurzbeschreibung (Abstract)

Exsolution has emerged as an outstanding route for producing oxide-supported metal nanoparticles. For ABO3-perovskite oxides, various late transition-metal cations can be substituted into the lattice under oxidizing conditions and exsolved as metal nanoparticles after reduction. A consistent and comprehensive description of the point-defect thermodynamics and kinetics of this phenomenon is lacking, however. Herein, supported by hybrid density-functional-theory calculations, we propose a single model that explains diverse experimental observations, such as why substituent transition-metal cations (but not host cations) exsolve from perovskite oxides upon reduction; why different substituent transition-metal cations exsolve under different conditions; why the metal nanoparticles are embedded in the surface; why exsolution occurs surprisingly rapidly at relatively low temperatures; and why the reincorporation of exsolved species involves far longer times and much higher temperatures. Our model’s foundation is that the substituent transition-metal cations are reduced to neutral species within the perovskite lattice as the Fermi level is shifted upward within the bandgap upon sample reduction. The calculations also indicate unconventional influences of oxygen vacancies and A-site vacancies. Our model thus provides a fundamental basis for improving existing, and creating new, exsolution-generated catalysts.

Typ des Eintrags: Artikel
Erschienen: 2024
Autor(en): Bonkowski, Alexander ; Wolf, Matthew J. ; Wu, Ji ; Parker, Stephen C. ; Klein, Andreas ; De Souza, Roger A.
Art des Eintrags: Bibliographie
Titel: A single model for the thermodynamics and kinetics of metal exsolution from perovskite oxides
Sprache: Englisch
Publikationsjahr: 2024
Verlag: ACS Publications
Titel der Zeitschrift, Zeitung oder Schriftenreihe: Journal of the American Chemical Society
Kollation: 10 Seiten
DOI: 10.1021/jacs.4c03412
URL / URN: https://pubs.acs.org/doi/10.1021/jacs.4c03412
Kurzbeschreibung (Abstract):

Exsolution has emerged as an outstanding route for producing oxide-supported metal nanoparticles. For ABO3-perovskite oxides, various late transition-metal cations can be substituted into the lattice under oxidizing conditions and exsolved as metal nanoparticles after reduction. A consistent and comprehensive description of the point-defect thermodynamics and kinetics of this phenomenon is lacking, however. Herein, supported by hybrid density-functional-theory calculations, we propose a single model that explains diverse experimental observations, such as why substituent transition-metal cations (but not host cations) exsolve from perovskite oxides upon reduction; why different substituent transition-metal cations exsolve under different conditions; why the metal nanoparticles are embedded in the surface; why exsolution occurs surprisingly rapidly at relatively low temperatures; and why the reincorporation of exsolved species involves far longer times and much higher temperatures. Our model’s foundation is that the substituent transition-metal cations are reduced to neutral species within the perovskite lattice as the Fermi level is shifted upward within the bandgap upon sample reduction. The calculations also indicate unconventional influences of oxygen vacancies and A-site vacancies. Our model thus provides a fundamental basis for improving existing, and creating new, exsolution-generated catalysts.

Freie Schlagworte: cations, defects in solids, energy, lattices, perovskites
Fachbereich(e)/-gebiet(e): 11 Fachbereich Material- und Geowissenschaften
11 Fachbereich Material- und Geowissenschaften > Materialwissenschaft
11 Fachbereich Material- und Geowissenschaften > Materialwissenschaft > Elektronische Materialeigenschaften
DFG-Sonderforschungsbereiche (inkl. Transregio)
DFG-Sonderforschungsbereiche (inkl. Transregio) > Sonderforschungsbereiche
DFG-Sonderforschungsbereiche (inkl. Transregio) > Sonderforschungsbereiche > SFB 1548: FLAIR – Fermi Level Engineering Applied to Oxide Electroceramics
Hinterlegungsdatum: 14 Aug 2024 05:25
Letzte Änderung: 14 Aug 2024 09:10
PPN: 520631897
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