dc.contributor.author |
Rellán-Piñeiro, Marcos |
dc.contributor.author |
López, Núria |
dc.date.accessioned |
2019-07-26T10:31:57Z |
dc.date.available |
2019-07-26T10:31:57Z |
dc.date.issued |
2018-04-27 |
dc.identifier.uri |
http://hdl.handle.net/2072/359772 |
dc.format.extent |
2568 p. |
dc.language.iso |
eng |
dc.rights |
L'accés als continguts d'aquest document queda condicionat a l'acceptació de les condicions d'ús establertes per la següent llicència Creative Commons:http://creativecommons.org/licenses/by-nc-nd/4.0/ |
dc.source |
RECERCAT (Dipòsit de la Recerca de Catalunya) |
dc.subject.other |
54 |
dc.title |
One Oxygen Vacancy, Two Charge States: Characterization of Reduced α‑MoO3(010) through Theoretical Methods |
dc.type |
info:eu-repo/semantics/article |
dc.type |
info:eu-repo/semantics/acceptedVersion |
dc.embargo.terms |
12 mesos |
dc.identifier.doi |
10.1021/acs.jpclett.8b00536 |
dc.rights.accessLevel |
info:eu-repo/semantics/openAccess |
dc.description.abstract |
Molybdenum oxides are finding increasing applications that rely on their
redox character. For the most common polymorph, α-MoO3, oxygen vacancy formation
leaves two electrons on the surface that can be stored as small polarons. Detailed density
functional theory calculations that properly account for the self-interaction term, Ueff = 3.5
eV, show that the vacancy generates two different configurations: either two Mo5+ centers
(Mo5+□ and Mo5+O) or a single double-reduced Mo4+. These states are separated by
0.22 eV with a barrier for interconversion of 0.33 eV, and thus both are populated at
catalytic temperatures, as shown by first-principles molecular dynamics. At higher
reduction levels, vacancies can only be accumulated along a preferential direction and the
energy difference between the 2×Mo5+ and Mo4+ configurations is reduced. These results
point out the need for a revision of the experimental assignments based on our
characterization that includes charges, vibrational frequencies, and XPS signatures |