Understanding electrochemical switchability of perovskite-type exsolution catalysts.
Nat Commun
; 11(1): 4801, 2020 Sep 23.
Article
em En
| MEDLINE
| ID: mdl-32968079
ABSTRACT
Exsolution of metal nanoparticles from perovskite-type oxides is a very promising approach to obtain catalysts with superior properties. One particularly interesting property of exsolution catalysts is the possibility of electrochemical switching between different activity states. In this work, synchrotron-based in-situ X-ray diffraction experiments on electrochemically polarized La0.6Sr0.4FeO3-δ thin film electrodes are performed, in order to simultaneously obtain insights into the phase composition and the catalytic activity of the electrode surface. This shows that reversible electrochemical switching between a high and low activity state is accompanied by a phase change of exsolved particles between metallic α--Fe and Fe-oxides. Reintegration of iron into the perovskite lattice is thus not required for obtaining a switchable catalyst, making this process especially interesting for intermediate temperature applications. These measurements also reveal how metallic particles on La0.6Sr0.4FeO3-δ electrodes affect the H2 oxidation and H2O splitting mechanism and why the particle size plays a minor role.
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Coleções:
01-internacional
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MEDLINE
Idioma:
En
Ano de publicação:
2020
Tipo de documento:
Article