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Title: Energy level shifts at the silica/Ru(0001) heterojunction driven by surface and interface dipoles

Abstract

Charge redistribution at heterogeneous interfaces is a fundamental aspect of surface chemistry. Manipulating the amount of charges and the magnitude of dipole moments at the interface in a controlled way has attracted tremendous attention for its potential to modify the activity of heterogeneous catalysts in catalyst design. Two-dimensional ultrathin silica films with well-defined atomic structures have been recently synthesized and proposed as model systems for heterogeneous catalysts studies. R. Wlodarczyk et al. (Phys. Rev. B, 85, 085403 (2012)) have demonstrated that the electronic structure of silica/Ru(0001) can be reversibly tuned by changing the amount of interfacial chemisorbed oxygen. Here we carried out systematic investigations to understand the underlying mechanism through which the electronic structure at the silica/Ru(0001) interface can be tuned. As corroborated by both in situ X-ray photoelectron spectroscopy and density functional theory calculations, the observed interface energy level alignments strongly depend on the surface and interfacial charge transfer induced dipoles at the silica/Ru(0001) heterojunction. These observations may help to understand variations in catalytic performance of the model system from the viewpoint of the electronic properties at the confined space between the silica bilayer and the Ru(0001) surface. As a result, the same behavior is observed for the aluminosilicatemore » bilayer, which has been previously proposed as a model system for zeolites.« less

Authors:
 [1];  [2];  [2];  [2];  [2];  [2];  [2]
  1. Brookhaven National Lab. (BNL), Upton, NY (United States); Stony Brook Univ., Stony Brook, NY (United States)
  2. Brookhaven National Lab. (BNL), Upton, NY (United States)
Publication Date:
Research Org.:
Brookhaven National Laboratory (BNL), Upton, NY (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1328366
Report Number(s):
BNL-112657-2016-JA
Journal ID: ISSN 1022-5528; R&D Project: 16068; KC0403020
Grant/Contract Number:
SC00112704
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Topics in Catalysis
Additional Journal Information:
Journal Name: Topics in Catalysis; Journal ID: ISSN 1022-5528
Publisher:
Springer
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 2D zeolites; charge transfer; surface and interface dipoles; energy level shift; density functional theory; in situ x-ray photoelectron spectroscopy

Citation Formats

Wang, Mengen, Zhong, Jian -Qiang, Kestell, John, Waluyo, Iradwikanari, Stacchiola, Dario J., Boscoboinik, J. Anibal, and Lu, Deyu. Energy level shifts at the silica/Ru(0001) heterojunction driven by surface and interface dipoles. United States: N. p., 2016. Web. doi:10.1007/s11244-016-0704-x.
Wang, Mengen, Zhong, Jian -Qiang, Kestell, John, Waluyo, Iradwikanari, Stacchiola, Dario J., Boscoboinik, J. Anibal, & Lu, Deyu. Energy level shifts at the silica/Ru(0001) heterojunction driven by surface and interface dipoles. United States. doi:10.1007/s11244-016-0704-x.
Wang, Mengen, Zhong, Jian -Qiang, Kestell, John, Waluyo, Iradwikanari, Stacchiola, Dario J., Boscoboinik, J. Anibal, and Lu, Deyu. 2016. "Energy level shifts at the silica/Ru(0001) heterojunction driven by surface and interface dipoles". United States. doi:10.1007/s11244-016-0704-x. https://www.osti.gov/servlets/purl/1328366.
@article{osti_1328366,
title = {Energy level shifts at the silica/Ru(0001) heterojunction driven by surface and interface dipoles},
author = {Wang, Mengen and Zhong, Jian -Qiang and Kestell, John and Waluyo, Iradwikanari and Stacchiola, Dario J. and Boscoboinik, J. Anibal and Lu, Deyu},
abstractNote = {Charge redistribution at heterogeneous interfaces is a fundamental aspect of surface chemistry. Manipulating the amount of charges and the magnitude of dipole moments at the interface in a controlled way has attracted tremendous attention for its potential to modify the activity of heterogeneous catalysts in catalyst design. Two-dimensional ultrathin silica films with well-defined atomic structures have been recently synthesized and proposed as model systems for heterogeneous catalysts studies. R. Wlodarczyk et al. (Phys. Rev. B, 85, 085403 (2012)) have demonstrated that the electronic structure of silica/Ru(0001) can be reversibly tuned by changing the amount of interfacial chemisorbed oxygen. Here we carried out systematic investigations to understand the underlying mechanism through which the electronic structure at the silica/Ru(0001) interface can be tuned. As corroborated by both in situ X-ray photoelectron spectroscopy and density functional theory calculations, the observed interface energy level alignments strongly depend on the surface and interfacial charge transfer induced dipoles at the silica/Ru(0001) heterojunction. These observations may help to understand variations in catalytic performance of the model system from the viewpoint of the electronic properties at the confined space between the silica bilayer and the Ru(0001) surface. As a result, the same behavior is observed for the aluminosilicate bilayer, which has been previously proposed as a model system for zeolites.},
doi = {10.1007/s11244-016-0704-x},
journal = {Topics in Catalysis},
number = ,
volume = ,
place = {United States},
year = 2016,
month = 9
}

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  • Core-ionization potentials (CIP's) are computed for Be(0001). Three core features are observed in corresponding photoelectron spectra, with CIP's shifted relative to the bulk core level by [minus]0.825, [minus]0.570, and [minus]0.265 eV. The computed CIP shifts for the outer and subsurface layers, [minus]0.60 and [minus]0.29 eV, respectively, agree with the latter two of these. It is surmised that the [minus]0.825-eV shift is associated with a surface defect. The negative signs of the Be(0001) surface core-level shifts do not fit into the thermochemical picture widely used to explain CIP shifts. The reason is that a core-ionized Be atom is too small tomore » bond effectively to the remainder of the unrelaxed Be lattice.« less
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  • No abstract prepared.