Raman Studies of Automotive Catalyst Deactivation
2006-01-0409
04/03/2006
- Event
- Content
- Catalyst durability is a major concern in automotive exhaust gas treatment, and can be affected by chemical and thermal history. In this work, applications of in situ UV and visible Raman spectroscopy to a variety of catalyst deactivation issues are demonstrated:
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a)
identification and characterization of CePO4 in three-way catalysts. CePO4 forms from the interaction of phosphorus in engine oil additives with the catalyst washcoat. It affects oxygen storage and decreases catalyst conversion efficiency.
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b)
thermal deactivation in Pd/ceria-zirconia catalysts. A compressive strain on palladium oxide as indicated by its Raman shift can serve as a diagnostic for a thermally-deactivated catalyst and thus the unavailability of the Pd for catalysis.
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c)
sulfur poisoning, thermal deactivation and BaCO3 formation in lean NOx traps (LNT). Spectral features demonstrate sulfation of LNT components, differences in fresh and thermally-aged Pt/Ba/Al2O3 which are consistent with results from activity and chemisorption measurements, and possible correlations of BaCO3 formation to catalyst activity.
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a)
- Pages
- 10
- Citation
- Uy, D., and O'Neill, A., "Raman Studies of Automotive Catalyst Deactivation," SAE Technical Paper 2006-01-0409, 2006, https://doi.org/10.4271/2006-01-0409.