Operational criteria affecting the design of thermally stable single-bed three-way catalysts
The successful utilization of single-bed three way catalysts is dependent upon high initial catalyst activity and maintenance of this activity after exposure to a wide range of exhaust composition and temperature. A review of performance after aging under a variety of engine dynamometer and thermal cycles indicates high temperature aging is particularly detrimental to CO conversion while HC conversion is most sensitive to chemical poisoning. Results on individual Platinum Group Metal Catalysts show Platinum has good chemical poison resistance, but is sensitive to thermal deactivation. Palladium shows good thermal stability, but exhibits more deactivation by chemical poisoning. Rhodium is significantly deactivated by lean high temperature aging. These results have been used to compare and contrast the deactivation of bimetallic and trimetallic catalyst formulations. A new generation of catalysts has been developed utilizing the above information. These catalysts exhibit substantially improved performance and thermal stability.
- OSTI ID:
- 5761118
- Report Number(s):
- TP-850128
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
54 ENVIRONMENTAL SCIENCES
CARBON MONOXIDE
AIR POLLUTION ABATEMENT
CATALYTIC CONVERTERS
DESIGN
OPERATION
PERFORMANCE TESTING
HYDROCARBONS
AGING
CATALYSTS
COMPARATIVE EVALUATIONS
DEACTIVATION
DYNAMOMETERS
EXHAUST GASES
PLATINUM
RHODIUM
TEMPERATURE EFFECTS
THERMAL CYCLING
THERMAL EQUILIBRIUM
CARBON COMPOUNDS
CARBON OXIDES
CHALCOGENIDES
ELEMENTS
EQUILIBRIUM
EQUIPMENT
FLUIDS
GASEOUS WASTES
GASES
MEASURING INSTRUMENTS
METALS
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PLATINUM METALS
POLLUTION ABATEMENT
POLLUTION CONTROL EQUIPMENT
TESTING
TRANSITION ELEMENTS
WASTES
330702* - Emission Control- Carbon Monoxide
330704 - Emission Control- Hydrocarbons
500200 - Environment
Atmospheric- Chemicals Monitoring & Transport- (-1989)