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