Thermally-Induced Microstructural Changes in a Three-Way Automotive Catalyst

972905

10/01/1997

Event
International Fuels & Lubricants Meeting & Exposition
Authors Abstract
Content
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.
Meta TagsDetails
DOI
https://doi.org/10.4271/972905
Pages
11
Citation
More, 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.
Additional Details
Publisher
Published
Oct 1, 1997
Product Code
972905
Content Type
Technical Paper
Language
English