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Thermally-Induced Microstructural Changes in a Three-Way Automotive Catalyst
ISSN: 0148-7191, e-ISSN: 2688-3627
Published October 01, 1997 by SAE International in United States
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The use of advanced electron microscopy techniques to characterize both the bulk and near-atomic level microstructural evolution of catalyst materials during different dynamometer/vehicle aging cycles is an integral part of understanding catalyst deactivation. The study described here was undertaken to evaluate thermally-induced microstructural changes which caused the progressive loss of catalyst performance in a three-way automotive catalyst. Several different catalyst processing variables, for example changing the washcoat ceria content, were also evaluated as a function of aging cycle and thermal history. A number of thermally-induced microstructural changes were identified using high resolution electron microscopy techniques that contributed to the deactivation of the catalyst, including sintering of all washcoat constituents, γ-alumina transforming to α-, β-, and δ-alumina, precious metal redistribution, and constituent encapsulation. The data accumulated in this study have been used to correlate microstructural evolution with thermal history and catalyst performance during various aging cycles and to subsequently evaluate different washcoat formulations for increased thermal stability.
- Karren L. More - Oak Ridge National Lab.
- Edward A. Kenik - Oak Ridge National Lab.
- Dorothy W. Coffey - Oak Ridge National Lab.
- Thomas S. Geer - Oak Ridge National Lab.
- William J. LaBarge - Delphi Automotive Systems
- Richard Beckmeyer - Delphi Automotive Systems
- Joseph Theis - Delphi Automotive Systems
CitationMore, K., Kenik, E., Coffey, D., Geer, T. et al., "Thermally-Induced Microstructural Changes in a Three-Way Automotive Catalyst," SAE Technical Paper 972905, 1997, https://doi.org/10.4271/972905.
SAE 1997 Transactions - Journal of Fuels and Lubricants
Number: V106-4; Published: 1998-09-15
Number: V106-4; Published: 1998-09-15
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