On the promotion of catalytic reactions by surface acoustic waves
von Boehn, Bernhard (Leibniz Universität Hannover. Institut für Physikalische Chemie und Elektrochemie)
Foerster, Michael (ALBA Laboratori de Llum de Sincrotró)
von Boehn, Moritz (Leibniz Universität Hannover. Institut für Physikalische Chemie und Elektrochemie)
Prat, Jordi (ALBA Laboratori de Llum de Sincrotró)
Macià, Ferran (Universitat de Barcelona. Departament de Física de la Matèria Condensada)
Casals, Blai (Institut de Ciència de Materials de Barcelona)
Khaliq, Muhammad Waqas (ALBA Laboratori de Llum de Sincrotró)
Hernández-Mínguez, Alberto (Paul Drude Institut für Festkörperelektronik)
Aballe, Lucía (ALBA Laboratori de Llum de Sincrotró)
Imbihl, Ronald (Leibniz Universität Hannover. Institut für Physikalische Chemie und Elektrochemie)

Fecha:	2020
Resumen:	Surface acoustic waves (SAW) allow to manipulate surfaces with potential applications in catalysis, sensor and nanotechnology. SAWs were shown to cause a strong increase in catalytic activity and selectivity in many oxidation and decomposition reactions on metallic and oxidic catalysts. However, the promotion mechanism has not been unambiguously identified. Using stroboscopic X-ray photoelectron spectro-microscopy, we were able to evidence a sub-nanosecond work function change during propagation of 500 MHz SAWs on a 9 nm thick platinum film. We quantify the work function change to 455 μeV. Such a small variation rules out that electronic effects due to elastic deformation (strain) play a major role in the SAW-induced promotion of catalysis. In a second set of experiments, SAW-induced intermixing of a five monolayers thick Rh film on top of polycrystalline platinum was demonstrated to be due to enhanced thermal diffusion caused by an increase of the surface temperature by about 75 K when SAWs were excited. Reversible surface structural changes are suggested to be a major cause for catalytic promotion. Surface acoustic waves (SAWs) are dynamic lattice distortions, which can be excited on piezoelectric materials. For many years a promotion of the catalytic activity and selectivity by SAWs has been known, but no mechanistic understanding has been established yet. We quantify the effect that SAWs have on the electronic and geometric structure of a model catalyst, providing a basis for discussing the promotion mechanism of SAWs in catalytic surface reactions.
Ayudas:	European Commission 730872 Ministerio de Economía y Competitividad RTI2018-095303-B-C53 Ministerio de Economía y Competitividad RYC-2014-16515 Ministerio de Economía y Competitividad MAT2015-69144-P Ministerio de Economía y Competitividad SEV-2015-0496 Ministerio de Economía y Competitividad MAT2017-85232-R
Derechos:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l'obra i la creació d'obres derivades, sempre que no sigui amb finalitats comercials, i sempre que es reconegui l'autoria de l'obra original.
Lengua:	Anglès
Documento:	Article ; recerca ; Versió publicada
Materia:	Heterogeneous catalysis ; LEEM ; PEEM ; Surface acoustic waves ; Work function
Publicado en:	Angewandte Chemie (International ed. Internet), Vol. 59, issue 45 (Nov. 2020) , p. 20224-20229, ISSN 1521-3773

DOI: 10.1002/anie.202005883
PMID: 32729648

6 p, 1.4 MB

El registro aparece en las colecciones:
Documentos de investigación > Documentos de los grupos de investigación de la UAB > Centros y grupos de investigación (producción científica) > Ciencias > El Sincrotrón ALBA
Artículos > Artículos de investigación
Artículos > Artículos publicados