Influence of surface atomic structure demonstrated on oxygen incorporation mechanism at a model perovskite oxide

Author(s)
Michele Riva, Markus Kubicek, Xianfeng Hao, Giada Franceschi, Stefan Gerhold, Michael Schmid, Herbert Hutter, Juergen Fleig, Cesare Franchini, Bilge Yildiz, Ulrike Diebold
Abstract

Perovskite oxide surfaces catalyze oxygen exchange reactions that are crucial for fuel cells, electrolyzers, and thermochemical fuel synthesis. Here, by bridging the gap between surface analysis with atomic resolution and oxygen exchange kinetics measurements, we demonstrate how the exact surface atomic structure can determine the reactivity for oxygen exchange reactions on a model perovskite oxide. Two precisely controlled surface reconstructions with (4 x 1) and (2 x 5) symmetry on 0.5 wt.% Nb-doped SrTiO3(110) were subjected to isotopically labeled oxygen exchange at 450 degrees C. The oxygen incorporation rate is three times higher on the (4 x 1) surface phase compared to the (2 x 5). Common models of surface reactivity based on the availability of oxygen vacancies or on the ease of electron transfer cannot account for this difference. We propose a structure-driven oxygen exchange mechanism, relying on the flexibility of the surface coordination polyhedra that transform upon dissociation of oxygen molecules.

Organisation(s)
Computational Materials Physics
External organisation(s)
Technische Universität Wien, Yanshan University, Massachusetts Institute of Technology
Journal
Nature Communications
Volume
9
No. of pages
9
ISSN
2041-1723
DOI
https://doi.org/10.1038/s41467-018-05685-5
Publication date
09-2018
Peer reviewed
Yes
Austrian Fields of Science 2012
Materials chemistry, Materials physics
Keywords
Portal url
https://ucris.univie.ac.at/portal/en/publications/influence-of-surface-atomic-structure-demonstrated-on-oxygen-incorporation-mechanism-at-a-model-perovskite-oxide(2e19f43a-fd76-488d-8593-41ee23e9a7cc).html