Details
| Original language | English |
|---|---|
| Article number | e202400186 |
| Number of pages | 11 |
| Journal | CHEMPHYSCHEM |
| Volume | 25 |
| Issue number | 16 |
| Early online date | 22 May 2024 |
| Publication status | Published - 20 Aug 2024 |
Abstract
Chemical wave patterns and V-oxide redistribution in catalytic methanol oxidation on a VOx/Rh(110) surface have been investigated in the 10−4 mbar range with low-energy electron microscopy (LEEM) and micro spot low-energy electron diffraction (micro-LEED) as in situ methods. V coverages of θV=0.2 and 0.4 MLE (monolayer equivalents) were studied. Pulses display a c(2×2) pattern in the reduced part and (1×2) and c(2×8) structures in the oxidized part of the surface. At θV=0.4 MLE (1×2)/(1×4) patterns with streaks along the [001]-direction at the 1/8 positions are present on the oxidized part of the surface. This phase can be assigned to V-oxide. On a tentative basis, an excitation mechanism for pulses is presented, Annealing the surface to 990 K under reaction conditions results in a macroscopic hole pattern in which holes of low VOx coverage are surrounded by a V-oxide layer. Chemical waves propagate inside the holes as well as on the VOx covered parts of the surface. The results demonstrate for the first time that also in supported oxidic overlayers selforganization processes can take place leading to chemical waves and a large scale redistribution of the oxide.
Keywords
- chemical wave pattern, heterogeneous catalysis, LEEM, methanol oxidation, rhodium, vanadium oxide
ASJC Scopus subject areas
- Physics and Astronomy(all)
- Atomic and Molecular Physics, and Optics
- Chemistry(all)
- Physical and Theoretical Chemistry
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In: CHEMPHYSCHEM, Vol. 25, No. 16, e202400186, 20.08.2024.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - In situ Low-Energy Electron Microscopy of Chemical Waves on a Composite V-oxide/Rh(110) Surface
AU - von Boehn, Bernhard
AU - Krisponeit, Jon Olaf
AU - Falta, Jens
AU - Imbihl, Ronald
N1 - Publisher Copyright: © 2024 The Authors. ChemPhysChem published by Wiley-VCH GmbH.
PY - 2024/8/20
Y1 - 2024/8/20
N2 - Chemical wave patterns and V-oxide redistribution in catalytic methanol oxidation on a VOx/Rh(110) surface have been investigated in the 10−4 mbar range with low-energy electron microscopy (LEEM) and micro spot low-energy electron diffraction (micro-LEED) as in situ methods. V coverages of θV=0.2 and 0.4 MLE (monolayer equivalents) were studied. Pulses display a c(2×2) pattern in the reduced part and (1×2) and c(2×8) structures in the oxidized part of the surface. At θV=0.4 MLE (1×2)/(1×4) patterns with streaks along the [001]-direction at the 1/8 positions are present on the oxidized part of the surface. This phase can be assigned to V-oxide. On a tentative basis, an excitation mechanism for pulses is presented, Annealing the surface to 990 K under reaction conditions results in a macroscopic hole pattern in which holes of low VOx coverage are surrounded by a V-oxide layer. Chemical waves propagate inside the holes as well as on the VOx covered parts of the surface. The results demonstrate for the first time that also in supported oxidic overlayers selforganization processes can take place leading to chemical waves and a large scale redistribution of the oxide.
AB - Chemical wave patterns and V-oxide redistribution in catalytic methanol oxidation on a VOx/Rh(110) surface have been investigated in the 10−4 mbar range with low-energy electron microscopy (LEEM) and micro spot low-energy electron diffraction (micro-LEED) as in situ methods. V coverages of θV=0.2 and 0.4 MLE (monolayer equivalents) were studied. Pulses display a c(2×2) pattern in the reduced part and (1×2) and c(2×8) structures in the oxidized part of the surface. At θV=0.4 MLE (1×2)/(1×4) patterns with streaks along the [001]-direction at the 1/8 positions are present on the oxidized part of the surface. This phase can be assigned to V-oxide. On a tentative basis, an excitation mechanism for pulses is presented, Annealing the surface to 990 K under reaction conditions results in a macroscopic hole pattern in which holes of low VOx coverage are surrounded by a V-oxide layer. Chemical waves propagate inside the holes as well as on the VOx covered parts of the surface. The results demonstrate for the first time that also in supported oxidic overlayers selforganization processes can take place leading to chemical waves and a large scale redistribution of the oxide.
KW - chemical wave pattern
KW - heterogeneous catalysis
KW - LEEM
KW - methanol oxidation
KW - rhodium
KW - vanadium oxide
UR - http://www.scopus.com/inward/record.url?scp=85198141217&partnerID=8YFLogxK
U2 - 10.1002/cphc.202400186
DO - 10.1002/cphc.202400186
M3 - Article
C2 - 38775199
AN - SCOPUS:85198141217
VL - 25
JO - CHEMPHYSCHEM
JF - CHEMPHYSCHEM
SN - 1439-4235
IS - 16
M1 - e202400186
ER -