Coverage-dependent oxidation and reduction of vanadium supported on anatase TiO2(1 0 1)
(2018) In Journal of Catalysis 360. p.118-126- Abstract
- © 2018 Elsevier Inc. Using a multi-technical approach, we studied the oxidation of anatase TiO 2 (1 0 1)-supported vanadium (V) clusters at room temperature. We found by ex situ XPS that the highest oxidation state is +4 at sub-monolayer coverage regardless of the O 2 pressure, and STM studies revealed that the initial oxidation proceeds through oxygen-induced disintegration of V clusters into monomeric VO 2 species. By contrast, for ∼2 monolayer V coverage, a partial oxidation to V 5+ is achieved. By in situ APXPS measurements, we found that V can be maintained in the V 5+ oxidation state irrespective of the coverage; however, in the sub-monolayer range, an O 2 pressure of at least ∼1 × 10 −5 mbar is needed. Our results suggest an... (More)
- © 2018 Elsevier Inc. Using a multi-technical approach, we studied the oxidation of anatase TiO 2 (1 0 1)-supported vanadium (V) clusters at room temperature. We found by ex situ XPS that the highest oxidation state is +4 at sub-monolayer coverage regardless of the O 2 pressure, and STM studies revealed that the initial oxidation proceeds through oxygen-induced disintegration of V clusters into monomeric VO 2 species. By contrast, for ∼2 monolayer V coverage, a partial oxidation to V 5+ is achieved. By in situ APXPS measurements, we found that V can be maintained in the V 5+ oxidation state irrespective of the coverage; however, in the sub-monolayer range, an O 2 pressure of at least ∼1 × 10 −5 mbar is needed. Our results suggest an enhanced reducibility of V in direct contact with the TiO 2 support compared to V in the 2nd layer, which is in line with the observed optimum V 2 O 5 loading in catalytic applications just slightly below a full monolayer. (Less)
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https://lup.lub.lu.se/record/41638f0f-52cf-4c9f-ae66-9c471e57d76b
- author
- Koust, Stig ; Reinecke, Benjamin N. ; Adamsen, Kræn C. ; Beinik, Igor ; Handrup, Karsten LU ; Li, Zheshen ; Moses, Poul G. ; Schnadt, Joachim LU ; Lauritsen, Jeppe V. and Wendt, Stefan
- organization
- publishing date
- 2018-04-01
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Ambient pressure X-ray photoelectron spectroscopy (APXPS), Anatase TiO (1 0 1) 2, Oxidation, Scanning tunneling microscopy (STM), SCR catalysis, Vanadium, X-ray photoelectron spectroscopy (XPS)
- in
- Journal of Catalysis
- volume
- 360
- pages
- 9 pages
- publisher
- Elsevier
- external identifiers
-
- scopus:85042112637
- ISSN
- 0021-9517
- DOI
- 10.1016/j.jcat.2018.01.016
- language
- English
- LU publication?
- yes
- id
- 41638f0f-52cf-4c9f-ae66-9c471e57d76b
- date added to LUP
- 2018-03-05 12:42:51
- date last changed
- 2022-03-25 00:28:33
@article{41638f0f-52cf-4c9f-ae66-9c471e57d76b, abstract = {{© 2018 Elsevier Inc. Using a multi-technical approach, we studied the oxidation of anatase TiO 2 (1 0 1)-supported vanadium (V) clusters at room temperature. We found by ex situ XPS that the highest oxidation state is +4 at sub-monolayer coverage regardless of the O 2 pressure, and STM studies revealed that the initial oxidation proceeds through oxygen-induced disintegration of V clusters into monomeric VO 2 species. By contrast, for ∼2 monolayer V coverage, a partial oxidation to V 5+ is achieved. By in situ APXPS measurements, we found that V can be maintained in the V 5+ oxidation state irrespective of the coverage; however, in the sub-monolayer range, an O 2 pressure of at least ∼1 × 10 −5 mbar is needed. Our results suggest an enhanced reducibility of V in direct contact with the TiO 2 support compared to V in the 2nd layer, which is in line with the observed optimum V 2 O 5 loading in catalytic applications just slightly below a full monolayer.}}, author = {{Koust, Stig and Reinecke, Benjamin N. and Adamsen, Kræn C. and Beinik, Igor and Handrup, Karsten and Li, Zheshen and Moses, Poul G. and Schnadt, Joachim and Lauritsen, Jeppe V. and Wendt, Stefan}}, issn = {{0021-9517}}, keywords = {{Ambient pressure X-ray photoelectron spectroscopy (APXPS); Anatase TiO (1 0 1) 2; Oxidation; Scanning tunneling microscopy (STM); SCR catalysis; Vanadium; X-ray photoelectron spectroscopy (XPS)}}, language = {{eng}}, month = {{04}}, pages = {{118--126}}, publisher = {{Elsevier}}, series = {{Journal of Catalysis}}, title = {{Coverage-dependent oxidation and reduction of vanadium supported on anatase TiO2(1 0 1)}}, url = {{http://dx.doi.org/10.1016/j.jcat.2018.01.016}}, doi = {{10.1016/j.jcat.2018.01.016}}, volume = {{360}}, year = {{2018}}, }