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This content will become publicly available on September 12, 2017

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

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
 [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:
OSTI Identifier:
Report Number(s):
Journal ID: ISSN 1022-5528; R&D Project: 16068; KC0403020
Grant/Contract Number:
Accepted Manuscript
Journal Name:
Topics in Catalysis
Additional Journal Information:
Journal Name: Topics in Catalysis; Journal ID: ISSN 1022-5528
Research Org:
Brookhaven National Laboratory (BNL), Upton, NY (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
36 MATERIALS SCIENCE 2D zeolites; charge transfer; surface and interface dipoles; energy level shift; density functional theory; in situ x-ray photoelectron spectroscopy