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Title: Hydration and reduction of molecular beam epitaxy grown VO[subscript x]/a-Fe[subscript 2]O[subscript 3] (0001): Ambient pressure study

Abstract

Supported vanadium oxides processed under ambient environments have been studied by using X-ray standing wave (XSW) analysis of X-ray fluorescence spectroscopy and X-ray photoelectron spectroscopy (XPS). For the VO{sub x}/{alpha}-Fe{sub 2}O{sub 3}(0001) system, hydration and hydrogen annealing have been carried out under ambient pressure. Vanadium in the hydrated oxide phase occupies two high-symmetry surface adsorption sites with distinct adsorption heights, which resembles the adsorption geometry of fully oxidized vanadium. Reduction by the hydrogen annealing enhanced the V overlayer ordering by relocating a portion of the disordered V to high-symmetry sites. The V atoms located closer to the substrate oxygen layer in the hydrated phase moved toward the substrate after hydrogen reduction, while the V in the higher adsorption site stayed at the same height. The different responses of two adsorption sites to the reduction process are discussed and related to activities of the two sites.

Authors:
; ; ;
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1005465
Resource Type:
Journal Article
Journal Name:
J. Phys. Chem. C
Additional Journal Information:
Journal Volume: 113; Journal Issue: (4) ; 01, 2009; Journal ID: ISSN 1932-7447
Country of Publication:
United States
Language:
ENGLISH
Subject:
08 HYDROGEN; 36 MATERIALS SCIENCE; ADSORPTION; ANNEALING; ATOMS; FLUORESCENCE SPECTROSCOPY; GEOMETRY; HYDRATION; HYDROGEN; MOLECULAR BEAM EPITAXY; OXIDES; OXYGEN; STANDING WAVES; SUBSTRATES; VANADIUM; VANADIUM OXIDES; X-RAY PHOTOELECTRON SPECTROSCOPY

Citation Formats

Kim, C -Y, Klug, J A, Stair, P C, Bedzyk, M J, and NWU). Hydration and reduction of molecular beam epitaxy grown VO[subscript x]/a-Fe[subscript 2]O[subscript 3] (0001): Ambient pressure study. United States: N. p., 2009. Web. doi:10.1021/jp804133s.
Kim, C -Y, Klug, J A, Stair, P C, Bedzyk, M J, & NWU). Hydration and reduction of molecular beam epitaxy grown VO[subscript x]/a-Fe[subscript 2]O[subscript 3] (0001): Ambient pressure study. United States. https://doi.org/10.1021/jp804133s
Kim, C -Y, Klug, J A, Stair, P C, Bedzyk, M J, and NWU). 2009. "Hydration and reduction of molecular beam epitaxy grown VO[subscript x]/a-Fe[subscript 2]O[subscript 3] (0001): Ambient pressure study". United States. https://doi.org/10.1021/jp804133s.
@article{osti_1005465,
title = {Hydration and reduction of molecular beam epitaxy grown VO[subscript x]/a-Fe[subscript 2]O[subscript 3] (0001): Ambient pressure study},
author = {Kim, C -Y and Klug, J A and Stair, P C and Bedzyk, M J and NWU)},
abstractNote = {Supported vanadium oxides processed under ambient environments have been studied by using X-ray standing wave (XSW) analysis of X-ray fluorescence spectroscopy and X-ray photoelectron spectroscopy (XPS). For the VO{sub x}/{alpha}-Fe{sub 2}O{sub 3}(0001) system, hydration and hydrogen annealing have been carried out under ambient pressure. Vanadium in the hydrated oxide phase occupies two high-symmetry surface adsorption sites with distinct adsorption heights, which resembles the adsorption geometry of fully oxidized vanadium. Reduction by the hydrogen annealing enhanced the V overlayer ordering by relocating a portion of the disordered V to high-symmetry sites. The V atoms located closer to the substrate oxygen layer in the hydrated phase moved toward the substrate after hydrogen reduction, while the V in the higher adsorption site stayed at the same height. The different responses of two adsorption sites to the reduction process are discussed and related to activities of the two sites.},
doi = {10.1021/jp804133s},
url = {https://www.osti.gov/biblio/1005465}, journal = {J. Phys. Chem. C},
issn = {1932-7447},
number = (4) ; 01, 2009,
volume = 113,
place = {United States},
year = {Tue Feb 10 00:00:00 EST 2009},
month = {Tue Feb 10 00:00:00 EST 2009}
}