On the promotion of catalytic reactions by surface acoustic waves
Surface acoustic waves (SAW) allow to manipulate surfaces with potential applications in catalysis,sensor and nanotechnology.SAWswere shown to cause astrong increase in catalytic activity and selectivity in many oxidation and decomposition reactions on metallic and oxidic catalysts. However,the prom...
| Autores: | , , , , , , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2020 |
| País: | España |
| Institución: | Universidad de Barcelona |
| Repositorio: | Dipòsit Digital de la UB |
| OAI Identifier: | oai:diposit.ub.edu:2445/174549 |
| Acceso en línea: | https://hdl.handle.net/2445/174549 |
| Access Level: | acceso abierto |
| Palabra clave: | Ones acústiques de superfície Catàlisi Acoustic surface waves Catalysis |
| Sumario: | Surface acoustic waves (SAW) allow to manipulate surfaces with potential applications in catalysis,sensor and nanotechnology.SAWswere shown to cause astrong 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 asub-nano-second work function change during propagation of 500 MHz SAWs on a9nm thick platinum film. We quantify the work function change to 455 meV.Such asmall variation rules out that electronic effects due to elastic deformation (strain) play amajor role in the SAW-induced promotion of catalysis.In asecond set of experiments,SAW-induced intermixing of afive 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 amajor cause for catalytic promotion. |
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