On the thermal stability of metal particles supported on a thin alumina film
| Autor: | R. J. Oldman, Sascha Stempel, S. D. Jackson, Sh. K. Shaikhutdinov, Marcus Bäumer, Jörg Libuda, Hans-Joachim Freund, Michael Heemeier |
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| Rok vydání: | 2003 |
| Předmět: |
Nial
Annealing (metallurgy) Oxide Sintering Mineralogy Surfaces and Interfaces Condensed Matter Physics Surfaces Coatings and Films Metal chemistry.chemical_compound Chemical engineering chemistry Transition metal visual_art Materials Chemistry visual_art.visual_art_medium Thermal stability Particle size computer computer.programming_language |
| Zdroj: | Surface Science. 523:103-110 |
| ISSN: | 0039-6028 |
| DOI: | 10.1016/s0039-6028(02)02404-4 |
| Popis: | The structure of metal (Co, Rh, Pd) particles deposited on a thin alumina film grown on a NiAl(1 1 0) substrate were studied as a function of annealing temperature. The results reveal at least three processes to occur upon heating: (a) re-arrangement of metal atoms on the particle surface, (b) sintering of the particles, and (c) metal migration into the substrate. The latter process is probably mediated by the defect structure of the oxide film and dominates at higher temperatures. The thermal stability is found to be better for Co, which strongly interacts with the alumina support, as compared to Pd and Rh. Hydroxylation of the alumina film increases Pd and Rh dispersion and shifts processes (b) and (c) to higher temperatures, likely due to a stronger interaction of the metals with the hydroxylated film. |
| Databáze: | OpenAIRE |
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