OGIER, Tiphaine; PRESTIPINO, Carmelo; FIGUEROA, Santiago; MAUVY, Fabrice; MOUGIN, Julie; GRENIER, Jean-Claude; DEMOURGUES, Alain; BASSAT, Jean-Marc.

doi:10.1016/j.cplett.2019.04.034

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OGIER, Tiphaine
Institut de Chimie de la Matière Condensée de Bordeaux [ICMCB]

PRESTIPINO, Carmelo
Institut des Sciences Chimiques de Rennes [ISCR]

FIGUEROA, Santiago
European Synchrotron Radiation Facility [ESRF]

Langue

Article de revue

Ce document a été publié dans

Chemical Physics Letters. 2019-07, vol. 727, p. 116-120

Elsevier

Résumé en anglais

The mean oxidation state of cationic elements in Pr2NiO4+δ was studied using XANES measurements versus temperature in air. Unexpectedly, praseodymium is solely found as Pr3+ while Pr4+ was also foreseeable. Pr3+ cation is well accommodated in the large rare-earth site with the nine-fold coordination in this K2NiF4 – T-type structure; conversely, the small size of the Pr4+ cation seems not compatible with this site. Moreover, XANES measurements show a progressive decrease of the mean oxidation state of nickel ions when the temperature increases. It is directly correlated to the decrease of the oxygen over-stoichiometry of the material evidenced by TGA measurements.< Réduire

Mots clés en anglais

oxidation states

Pr L III -edge

Ni K-edge

SOEC

SOFC

praseodymium nickelate

K 2 NiF 4 -T-type structure

XANES

DOI

http://dx.doi.org/10.1016/j.cplett.2019.04.034

Project ANR

FIabilisation De l'ELectrolYse de l'eau à haute température pour la production d'Hydrogène - ANR-09-HPAC-0005

Origine

Importé de hal

Unités de recherche

Institut de Chimie de la Matière Condensée de Bordeaux (ICMCB) - UMR 5026