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Less noble or more noble: how strain affects the binding of oxygen on gold
Publikationstyp
Journal Article
Date Issued
2015-09-09
Sprache
English
Author(s)
TORE-URI
Volume
54
Issue
44
Start Page
12981
End Page
12985
Citation
Angewandte Chemie - International Edition 44 (54): 12981-12985 (2015-10-01)
Publisher DOI
Scopus ID
Publisher
Wiley-VCH
Many heterogeneous catalysts exploit strained active layers to modulate reactivity and/or selectivity. It is therefore significant that density functional theory, as well as experimental approaches, find that tensile strain makes the gold surface more binding for oxygen, in other words, less noble. We show that this behavior does not apply when re-structuring of the gold surface is allowed to occur simultaneously with the adsorption of oxygen. In situ cantilever-bending studies show the surface stress to increase when oxygen species adsorb on a (111)-textured gold surface in aqueous H2SO4. This implies a positive sign of the electrocapillary coupling parameter and, hence, a trend for weaker oxygen binding in response to tensile strain. These conflicting findings indicate that different electrosorption processes, and specifically oxygen species adsorption on the bulk-terminated surface, exhibit fundamentally different coupling between the chemistry and the mechanics of the surface.
Subjects
electrocapillary coupling
electrochemistry
oxysorption
surface mechanics
DDC Class
540: Chemie
600: Technik
More Funding Information
Funded by Deutsche Forschungsgemeinschaft, grant WE1424/16-1. Q.D. acknowledges support by the China Scholarship Council.