Modification of Au/TiO(2) Nanosystems by SiO(2) Monolayers: Toward the Control of the Catalyst Activity and Stability

Journal Article · Fri Jan 01 04:00:00 EST 2010 · Journal of Physical Chemistry C

OSTI ID:1044705

Dai, Sheng ^[1]; Rashkeev, Sergey ^[1]

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1. ORNL

The activity and stability of Au/TiO{sub 2} catalysts depend on several different factors such as the anchoring strength of the Au particles at the TiO{sub 2} surface, the particle sintering, and the surface mobility of individual gold atoms and/or gold particles. Au/TiO{sub 2} catalysts can be made resistant to sintering by atomic layer deposition (ALD) of a layer of SiO{sub 2} onto the catalysts. In this study, first-principles density-functional calculations are used to investigate how the stability of Au nanoparticles is modified when a partial monolayer of SiO{sub 2} is deposited on a Au/TiO{sub 2} catalyst. We find that SiO{sub 2} structures deposited on a pure TiO{sub 2} substrate exhibit lattice-mismatch instabilities that result in the formation of additional strong anchoring sites for Au atoms/nanoparticles. An atomic-scale roughness introduced by a partial monolayer of SiO{sub 2} can slow the atomic surface diffusion and inhibit Au nanoparticle growth/sintering, in agreement with previous experimental results.

• Research Organization: Oak Ridge National Laboratory (ORNL)
• Sponsoring Organization: SC USDOE - Office of Science (SC)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 1044705
• Journal Information: Journal of Physical Chemistry C, Journal Name: Journal of Physical Chemistry C Journal Issue: 7 Vol. 114; ISSN 1932-7447
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
ATOMS
CATALYSTS
DEPOSITION
DIFFUSION
FASTENING
GOLD
MODIFICATIONS
ROUGHNESS
SINTERING
STABILITY
SUBSTRATES