Oxygen surface exchange properties and electrochemical activity of lanthanum nickelates.
In: Journal of Solid State Chemistry, Jg. 312 (2022-08-01), S. N.PAG
academicJournal
Zugriff:
Oxygen surface exchange properties of lanthanum nickelates La 2 NiO 4+δ , La 3 Ni 2 O 7-δ and La 4 Ni 3 O 10-δ (LNOs) have been investigated using the Pulsed Isotope 18O/16O Exchange (PIE) technique in the temperature range 300–700 °C. The evaluation of the oxygen exchange rate from these lanthanum nickelates was conducted by measurement of isotope fractions 18O 2 , 16O18O, and 16O 2 in the effluent pulse at the exhaust from the reactor with a packed bed. The rates of oxygen heterogenous surface exchange (r H), dissociative adsorption (r a) and incorporation (r i) were calculated. The oxygen surface exchange was found to vary between the three nickelates, with r H decreasing between samples La 3 Ni 2 O 7-δ > La 4 Ni 3 O 10-δ > La 2 NiO 4+δ , which was attributed to a decreasing presence of Ni cations on the particle surfaces. Despite possessing the lowest oxygen surface exchange, La 2 NiO 4+δ had the best electrode electrochemical performance, which was attributed to highly mobile interstitial oxygen atoms leading to the largest r i (surface oxygen incorporation rate into the bulk) of the nickelates. This study reveals the key limiting factors determining lanthanum nickelate cathode performance in SOFCs, and we suggest avenues to improve these materials towards functional cathodes in devices. [Display omitted] • La 2 NiO 4 oxygen surface exchange is limited by dissociative adsorption of oxygen. • For La 3 Ni 2 O 7 , La 4 Ni 3 O 10 oxygen surface exchange is limited by oxygen incorporation. • Low presence of Ni on the particle surfaces decreases oxygen surface exchange rate. [ABSTRACT FROM AUTHOR]
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Oxygen surface exchange properties and electrochemical activity of lanthanum nickelates.
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Autor/in / Beteiligte Person: | Majewski, Artur J. ; Khodimchuk, Anna ; Zakharov, Dmitriy ; Porotnikova, Natalia ; Ananyev, Maxim ; Johnson, Ian D. ; Darr, Jawwad A. ; Slater, Peter R. ; Steinberger-Wilckens, Robert |
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Zeitschrift: | Journal of Solid State Chemistry, Jg. 312 (2022-08-01), S. N.PAG |
Veröffentlichung: | 2022 |
Medientyp: | academicJournal |
ISSN: | 0022-4596 (print) |
DOI: | 10.1016/j.jssc.2022.123228 |
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