Understanding the evolution of ternary alloyed nanoparticles during reversible exsolution from double perovskite oxides

López-García A, Carrillo AJ, Jiménez CE, Anzorena RS, Garcia-Diez R, Pérez-Dieste V, Villar-Garcia IJ, Hungría AB, Bär M, Serra JM (2024)

Publication Type: Journal article

Publication year: 2024

Journal

Journal of Materials Chemistry A Royal Society of Chemistry

DOI: 10.1039/d4ta03146f

Abstract

Multicomponent nanoparticle exsolution has emerged as a promising process for obtaining highly active catalysts supported on perovskite oxides. For instance, FeCoNi alloys can be exsolved from Sr2FeCo0.2Ni0.2Mn0.1Mo0.5O6−δ, boosting the electrocatalytic properties of these electrodes. However, due to differences in cation diffusion properties, the composition of the nanoparticles is uneven and strongly affected by process conditions such as temperature. An additional key feature of exsolution is its reversibility, which could help in catalyst regeneration if poisoned. Nevertheless, there is little knowledge on the reversibility mechanisms of multicomponent exsolved alloys. For that purpose, a combination of synchrotron-based in situ X-ray Diffraction (XRD) and Near-Ambient Pressure X-ray Photoelectron Spectroscopy (NAP-XPS) was employed in this work to uncover these missing aspects of multicomponent alloyed exsolution. These techniques allowed determination of the crystallographic and surface-related phenomena occurring during reversible exsolution both to the nanoparticles and the perovskite oxide support. This enabled the identification of the exsolution onset temperature and the range at which the double perovskite to Ruddlesden-Popper transition occurred, a process that has notable implications for the electrocatalytic performance. Finally, in combination with microscopy analyses, it was possible to reveal the morphological and compositional changes that the exsolved nanoparticles experienced upon reduction-oxidation cycles. This resulted in a re-arrangement of the surface species and a variation in the composition (Fe enrichment) of the regenerated ternary alloyed exsolved nanoparticles. These results indicate that reversible exsolution might alter the catalytic properties of the exsolved nanoparticles, with profound implications in the performance of (electro)catalytic processes.

Authors with CRIS profile

Marcus Bär

Involved external institutions

CELLS ALBA Synchrotron (Consorcio para la Construcción, Equipamiento y Explotación del Laboratorio de Luz de Sincrotrón) ES Spain (ES) Universidad de Cádiz (UCA) ES Spain (ES) Helmholtz-Zentrum Berlin für Materialien und Energie (HZB) DE Germany (DE) Instituto de Tecnología Química ITQ ES Spain (ES)

How to cite

APA:

López-García, A., Carrillo, A.J., Jiménez, C.E., Anzorena, R.S., Garcia-Diez, R., Pérez-Dieste, V.,... Serra, J.M. (2024). Understanding the evolution of ternary alloyed nanoparticles during reversible exsolution from double perovskite oxides. Journal of Materials Chemistry A. https://doi.org/10.1039/d4ta03146f

MLA:

López-García, Andrés, et al. "Understanding the evolution of ternary alloyed nanoparticles during reversible exsolution from double perovskite oxides." Journal of Materials Chemistry A (2024).

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