Modification of Au/TiO2 nanosystems by SiO2 monolayers: Toward the control of the catalyst activity and stability
The activity and stability of Au/TiO2 catalysts depend on several different factors such as the anchoring strength of Au particles at the TiO2 surface, the particle sintering, and the surface mobility of individual gold atoms and/or gold particles. Au/TiO2 catalysts can be made resistant to sintering by ALD deposition of a layer of SiO2 onto the catalysts. In this study, first-principles density-functional calculations are used to investigate how stability of Au nanoparticles is modified when a partial monolayer of SiO2 is deposited on a Au/TiO2 catalyst. We find that SiO2 structures deposited on a pure TiO2 substrate exhibits lattice-mismatch instabilities which result in a formation of additional strong anchoring sites for Au atoms/nanoparticles. An atomic-scale roughness introduced by a partial monolayer of SiO2 may slow down the atomic surface diffusion and inhibit Au nanoparti-cles growth/sintering, in agreement with previous experimental results.
- Research Organization:
- Idaho National Laboratory (INL)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC07-05ID14517
- OSTI ID:
- 977192
- Report Number(s):
- INL/JOU-09-16811
- Journal Information:
- The Journal of Physical Chemistry C (Nanomaterials, Interfaces, Hard Matter), Journal Name: The Journal of Physical Chemistry C (Nanomaterials, Interfaces, Hard Matter) Journal Issue: 7 Vol. 114
- Country of Publication:
- United States
- Language:
- English
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