Details
| Original language | English |
|---|---|
| Article number | 146568 |
| Journal | Applied surface science |
| Volume | 525 |
| Early online date | 6 May 2020 |
| Publication status | Published - 30 Sept 2020 |
Abstract
Au-based materials are remarkably efficient catalysts in the domain of partial oxidation reactions. Nonetheless, questions remain about the physico-chemical phenomena involved at the molecular level. In this work, the catalytic properties of Au-Ag samples, in the form of ultrathin Ag layers on a Au(1 1 1) surface and Au-based model nanoparticles, have been investigated with different microscopy techniques. Using photoemission electron microscopy (PEEM), the exposure of a Au(1 1 1) single crystal doped with various amounts of Ag (0 to 3 monolayers) to O2/H2 and O2/CH3OH gas mixtures did not lead to any specific spatiotemporal pattern formation. In contrast, the use of curved nanoscopic Au and Au-8.8 at.% Ag tip-samples analysed by field emission microscopy (FEM) under similar experimental conditions indicates the presence of catalytic activity. The influence of the silver concentration and of the morphology on the reactivity is discussed. This work highlights the necessity of different experimental approaches aimed at bridging the materials gap often encountered between surface science studies and applied catalysis.
Keywords
- Au-Ag, Field emission microscopy, Gold catalysis, In situ microscopy, Photoemission electron microscopy
ASJC Scopus subject areas
- Chemistry(all)
- General Chemistry
- Physics and Astronomy(all)
- Condensed Matter Physics
- Physics and Astronomy(all)
- General Physics and Astronomy
- Physics and Astronomy(all)
- Surfaces and Interfaces
- Materials Science(all)
- Surfaces, Coatings and Films
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In: Applied surface science, Vol. 525, 146568, 30.09.2020.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - On the importance of the structure in the catalytic reactivity of Au-based catalysts
AU - Jacobs, Luc
AU - von Boehn, Bernhard
AU - Homann, Mathias
AU - Barroo, Cédric
AU - Visart de Bocarmé, Thierry
AU - Imbihl, Ronald
N1 - Funding Information: L.J. and C.B. thank the Fonds de la Recherche Scientifique (F.R.S.-FNRS) for financial support: PhD grant from FRIA (L.J.) and postdoctoral fellowship from FNRS (C.B.). L.J. also thanks the Wallonie-Bruxelles International (Excellence grant WBI.WORLD) for financial support. B. v. B. thanks the Department of Inorganic Chemistry of the Fritz Haber Institute of the Max Planck Society for financial support.
PY - 2020/9/30
Y1 - 2020/9/30
N2 - Au-based materials are remarkably efficient catalysts in the domain of partial oxidation reactions. Nonetheless, questions remain about the physico-chemical phenomena involved at the molecular level. In this work, the catalytic properties of Au-Ag samples, in the form of ultrathin Ag layers on a Au(1 1 1) surface and Au-based model nanoparticles, have been investigated with different microscopy techniques. Using photoemission electron microscopy (PEEM), the exposure of a Au(1 1 1) single crystal doped with various amounts of Ag (0 to 3 monolayers) to O2/H2 and O2/CH3OH gas mixtures did not lead to any specific spatiotemporal pattern formation. In contrast, the use of curved nanoscopic Au and Au-8.8 at.% Ag tip-samples analysed by field emission microscopy (FEM) under similar experimental conditions indicates the presence of catalytic activity. The influence of the silver concentration and of the morphology on the reactivity is discussed. This work highlights the necessity of different experimental approaches aimed at bridging the materials gap often encountered between surface science studies and applied catalysis.
AB - Au-based materials are remarkably efficient catalysts in the domain of partial oxidation reactions. Nonetheless, questions remain about the physico-chemical phenomena involved at the molecular level. In this work, the catalytic properties of Au-Ag samples, in the form of ultrathin Ag layers on a Au(1 1 1) surface and Au-based model nanoparticles, have been investigated with different microscopy techniques. Using photoemission electron microscopy (PEEM), the exposure of a Au(1 1 1) single crystal doped with various amounts of Ag (0 to 3 monolayers) to O2/H2 and O2/CH3OH gas mixtures did not lead to any specific spatiotemporal pattern formation. In contrast, the use of curved nanoscopic Au and Au-8.8 at.% Ag tip-samples analysed by field emission microscopy (FEM) under similar experimental conditions indicates the presence of catalytic activity. The influence of the silver concentration and of the morphology on the reactivity is discussed. This work highlights the necessity of different experimental approaches aimed at bridging the materials gap often encountered between surface science studies and applied catalysis.
KW - Au-Ag
KW - Field emission microscopy
KW - Gold catalysis
KW - In situ microscopy
KW - Photoemission electron microscopy
UR - http://www.scopus.com/inward/record.url?scp=85084422644&partnerID=8YFLogxK
U2 - 10.1016/j.apsusc.2020.146568
DO - 10.1016/j.apsusc.2020.146568
M3 - Article
AN - SCOPUS:85084422644
VL - 525
JO - Applied surface science
JF - Applied surface science
SN - 0169-4332
M1 - 146568
ER -