Journal article
Theoretical Explanation of Pt Trimers Observed by Z-Contrast STEM
MRS proceedings, v 589
1999
Abstract
First-principles quantum-mechanical calculations on γ-alumina have revealed a fascinating “reactive sponge” phenomenon. γ-alumina can store and release water, but in a unique, “reactive” way. This “reactive sponge process” facilitates the creation of aluminum and oxygen vacancies in the alumina surface. Earlier atomic-resolution Z-contrast STEM images of ultradispersed Pt atoms on a γ-alumina support showed the individual atoms to form dimers and trimers with preferred spacings and orientations that are apparently dictated by the underlying support[1]. In turn, the reactive sponge property of γ-alumina is the key to understanding the Pt clusters. Our calculations demonstrate that if three Pt atoms fill three vacancies created during the reactive sponge process, the resulting geometry precisely matches that of the Pt trimers observed in the Z-STEM images. Understanding the initial nucleation of small clusters on the complex gamma alumina surface is an essential first step in determining the origins of catalytic activity.
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Details
- Title
- Theoretical Explanation of Pt Trimers Observed by Z-Contrast STEM
- Creators
- Karl Sohlberg - Oak Ridge National LaboratorySokrates T. Pantelides - Vanderbilt UniversityStephen J. Pennycook - Vanderbilt University
- Contributors
- C. Allen (Editor)J. Bentley (Editor)U. Dahmen (Editor)I. Petrov (Editor)
- Publication Details
- MRS proceedings, v 589
- Publisher
- Cambridge University Press
- Number of pages
- 6
- Resource Type
- Journal article
- Language
- English
- Academic Unit
- Chemistry
- Other Identifier
- 991019222800804721