Details
| Translated title of the contribution | Zur Promotion katalytischer Reaktionen durch akustische Oberflächenwellen |
|---|---|
| Original language | English |
| Pages (from-to) | 20224-20229 |
| Number of pages | 6 |
| Journal | Angewandte Chemie |
| Volume | 59 |
| Issue number | 45 |
| Early online date | 30 Jul 2020 |
| Publication status | Published - 26 Oct 2020 |
Abstract
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.
Keywords
- heterogeneous catalysis, LEEM, PEEM, Surface acoustic waves, work function
ASJC Scopus subject areas
- Chemical Engineering(all)
- Catalysis
- Chemistry(all)
- General Chemistry
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In: Angewandte Chemie , Vol. 59, No. 45, 26.10.2020, p. 20224-20229.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - On the Promotion of Catalytic Reactions by Surface Acoustic Waves
AU - von Boehn, Bernhard
AU - Foerster, Michael
AU - von Boehn, Moritz
AU - Prat, Jordi
AU - Macià, Ferran
AU - Casals, Blai
AU - Khaliq, Muhammad Waqas
AU - Hernández-Mínguez, Alberto
AU - Aballe, Lucia
AU - Imbihl, Ronald
N1 - Funding Information: The authors thank Werner Seidel for technical support in the fabrication of the IDTs, Rolf J. Haug, Hannover, for help in preparation of the samples, and Leo Zhigilei for carefully reading the manuscript. The research leading to this result has been supported by the project CALIPSOplus under Grant Agreement 730872 from the EU Framework Programme for Research and Innovation HORIZON 2020. LA and MF acknowledge support from Spanish MINECO through Grant No. RTI2018‐095303‐B‐C53. FM and BC acknowledges support from Spanish MINECO through Grants No. RYC‐2014‐16515, No. MAT2015‐69144‐P, No. SEV‐2015‐0496 and No. MAT2017‐85232‐R. Open access funding enabled and organized by Projekt DEAL.
PY - 2020/10/26
Y1 - 2020/10/26
N2 - 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.
AB - 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.
KW - heterogeneous catalysis
KW - LEEM
KW - PEEM
KW - Surface acoustic waves
KW - work function
UR - http://www.scopus.com/inward/record.url?scp=85089899993&partnerID=8YFLogxK
U2 - 10.1002/anie.202005883
DO - 10.1002/anie.202005883
M3 - Article
C2 - 32729648
AN - SCOPUS:85089899993
VL - 59
SP - 20224
EP - 20229
JO - Angewandte Chemie
JF - Angewandte Chemie
SN - 1433-7851
IS - 45
ER -