Details
| Original language | English |
|---|---|
| Pages (from-to) | 255-264 |
| Number of pages | 10 |
| Journal | Journal of catalysis |
| Volume | 385 |
| Early online date | 5 Apr 2020 |
| Publication status | Published - May 2020 |
Abstract
Recent advances in in situ microscopy allow to follow the reaction dynamics during a catalytic surface reaction from ultra-high vacuum to 0.1 mbar, thus bridging a large part of the pressure gap. Submonolayer vanadium oxide films on Rh(1 1 1) have been studied during catalytic methanol oxidation in situ with spatially resolving imaging techniques. At 10−6–10−4 mbar VOx condenses into macroscopic circular islands that exhibit a substructure, consisting of a reduced island core and an oxidized outer ring. This substructure arises due to an oxygen gradient inside the VOx islands, which results in different coexisting 2D-phases of VOx on Rh(1 1 1). This substructure is also responsible for a “breathing-like” oscillatory expansion and contraction that the islands undergo under stationary conditions. Using density functional theory, the 2D-phase diagram of VOx on Rh(1 1 1) has been computed. The oscillatory behavior can be understood as a periodic phase transition between two 2D phases of VOx. With a newly developed near ambient pressure – low-energy electron microscope, it was shown that VOx islands disintegrate at 10−2 mbar, resulting in turbulent dynamics.
Keywords
- Heterogeneous catalysis, Inverse catalyst, Methanol oxidation, Near ambient pressure low-energy electron microscope, Pressure gap, Restructuring, Vanadium oxide
ASJC Scopus subject areas
- Chemical Engineering(all)
- Catalysis
- Chemistry(all)
- Physical and Theoretical Chemistry
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In: Journal of catalysis, Vol. 385, 05.2020, p. 255-264.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Reaction dynamics of metal/oxide catalysts
T2 - Methanol oxidation at vanadium oxide films on Rh(1 1 1) from UHV to 10−2 mbar
AU - von Boehn, Bernhard
AU - Penschke, Christopher
AU - Li, Xiaoke
AU - Paier, Joachim
AU - Sauer, Joachim
AU - Krisponeit, Jon Olaf
AU - Flege, Jan Ingo
AU - Falta, Jens
AU - Marchetto, Helder
AU - Franz, Torsten
AU - Lilienkamp, Gerhard
AU - Imbihl, Ronald
N1 - Funding Information: This work was supported by a computer grant from the North German Computing Alliance Berlin?Hannover (HLRN). B. v. B. would like to thank the Department of Inorganic Chemistry of the Fritz Haber Institute of the Max Planck Society for financial support.
PY - 2020/5
Y1 - 2020/5
N2 - Recent advances in in situ microscopy allow to follow the reaction dynamics during a catalytic surface reaction from ultra-high vacuum to 0.1 mbar, thus bridging a large part of the pressure gap. Submonolayer vanadium oxide films on Rh(1 1 1) have been studied during catalytic methanol oxidation in situ with spatially resolving imaging techniques. At 10−6–10−4 mbar VOx condenses into macroscopic circular islands that exhibit a substructure, consisting of a reduced island core and an oxidized outer ring. This substructure arises due to an oxygen gradient inside the VOx islands, which results in different coexisting 2D-phases of VOx on Rh(1 1 1). This substructure is also responsible for a “breathing-like” oscillatory expansion and contraction that the islands undergo under stationary conditions. Using density functional theory, the 2D-phase diagram of VOx on Rh(1 1 1) has been computed. The oscillatory behavior can be understood as a periodic phase transition between two 2D phases of VOx. With a newly developed near ambient pressure – low-energy electron microscope, it was shown that VOx islands disintegrate at 10−2 mbar, resulting in turbulent dynamics.
AB - Recent advances in in situ microscopy allow to follow the reaction dynamics during a catalytic surface reaction from ultra-high vacuum to 0.1 mbar, thus bridging a large part of the pressure gap. Submonolayer vanadium oxide films on Rh(1 1 1) have been studied during catalytic methanol oxidation in situ with spatially resolving imaging techniques. At 10−6–10−4 mbar VOx condenses into macroscopic circular islands that exhibit a substructure, consisting of a reduced island core and an oxidized outer ring. This substructure arises due to an oxygen gradient inside the VOx islands, which results in different coexisting 2D-phases of VOx on Rh(1 1 1). This substructure is also responsible for a “breathing-like” oscillatory expansion and contraction that the islands undergo under stationary conditions. Using density functional theory, the 2D-phase diagram of VOx on Rh(1 1 1) has been computed. The oscillatory behavior can be understood as a periodic phase transition between two 2D phases of VOx. With a newly developed near ambient pressure – low-energy electron microscope, it was shown that VOx islands disintegrate at 10−2 mbar, resulting in turbulent dynamics.
KW - Heterogeneous catalysis
KW - Inverse catalyst
KW - Methanol oxidation
KW - Near ambient pressure low-energy electron microscope
KW - Pressure gap
KW - Restructuring
KW - Vanadium oxide
UR - http://www.scopus.com/inward/record.url?scp=85082707953&partnerID=8YFLogxK
U2 - 10.1016/j.jcat.2020.03.016
DO - 10.1016/j.jcat.2020.03.016
M3 - Article
AN - SCOPUS:85082707953
VL - 385
SP - 255
EP - 264
JO - Journal of catalysis
JF - Journal of catalysis
SN - 0021-9517
ER -