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New Automotive Catalyst Developments to Meet Future Emission Standards
Technical Paper
912600
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English
Abstract
The recent decision taken in the USA to further reduce the exhaust emissions from vehicles means a technological challenge for both the designers of engines as well as for the developers of catalytic exhaust aftertreatment systems.
A powerful approach is the simultaneous optimization of the engine raw emissions, of the exhaust pipe and catalytic converter design and of the catalyst formulation. The paper aims at demonstrating this by means of two examples.
New washcoat formulations for Platinum/Rhodium and for Palladium/Rhodium based monolithic catalysts were developed to reach both an improved conversion performance and a better durability.
These catalysts were first evaluated in a model gas reactor using different hydrocarbon species, which were defined by detailed analysis of the vehicle raw emissions during the FTP-75 test cycle. The catalysts were then evaluated on an engine dynamometer, in the fresh and the engine aged state.
For engine aging, several cycles were evaluated to assess the more stringent durability requirements.
Finally the new catalytic exhaust aftertreatment systems were evaluated in the FTP-75 vehicle test procedure using Asian manufactured cars representative of the compact and of the midsize class. In both cases, the new catalytic systems reached emission limits and longer durability which are planned to be introduced in the USA as of model year (MY) 1994.
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Citation
Engler, B., Garr, G., Lox, E., and Jung, M., "New Automotive Catalyst Developments to Meet Future Emission Standards," SAE Technical Paper 912600, 1991.Also In
References
- USA Federal Register - Environmental Protection Agency Part 2, 40 CFR Part 86 June 5 1991 “Control of Air Pollution from New Motor Vehicles and New Motor Vehicle Engines: Gaseous and Particulate Emission Regulations for 1994 and Later Model Year Light Duty Vehicles and Light-Duty Trucks; Final Rule”
- Title 13, California Code of Regulations 1960.1
- Matsumoto M. Saitoh M. Matsumura R. Yukaws F. “Improvement of Lambda Control Based on an Exhaust Emission Simulation Model that Takes in Account Fuel Transportation in the Intake Manifold” SAE Technical Paper Series 900612 1990
- Yamamoto H. Horie H. Kitagawa J. Machida M. “Reduction of Wall Thickness of Ceramic Substrates for Automotive Catalysts” SAE Technical Paper Series 900614 1990
- Ihara K. Murakami H. Ohkubo K. “Improvement of Three-way Catalyst Performance by Optimizing Ceria Impregnation” SAE Technical Paper Series 902168 1990
- Gulati S. Cooper B. Hawker P. Douglas J. Winterborn D. “Optimization of Substrate / Washcoat Interaction for Improved Catalyst Durability” SAE Technical Paper Series 910372 1991
- Sabourin M. Platte L. “U.S. Light-Duty Vehicle Fleet Emissions Performance and The Emissions Impact of Technology Changes” SAE Technical Paper Series 881681 1988
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- Code of Federal Regulations 40 CFR Part 86 July 1 1986
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