Three way conversion catalysts for automotive pollution abatement
- Engelhard Corp., Iselin, NJ (United States)
The revisions to the Clean Air Act of 1990 and recent regulatory actions taken by the California Air Resources Board mandate the development of automobiles with much lower tailpipe emissions. For the original equipment manufacturers (OEM`s) to meet the target fleet emissions numbers for automobiles defined in California`s Low Emission Vehicle program, the OEM`s must qualify each model into one of the emissions categories defined in Table 1. The emissions are calculated using the Federal Test Procedure (FTP) protocol wherein a test vehicle fitted with a catalytic converter is driven on a chassis rolls over a tightly defined driving cycle. A key feature of the evaluation is that the FTP is conducted after the catalyst has dealt with 50,000 - 100,000 miles of raw engine exhaust. During the FTP, 50 - 90% of the total pollutants emitted to the atmosphere by the vehicle occurs immediately following the startup of the engine when the engine block and manifold am cold, and the catalytic converter has not reached high conversion efficiencies, and are known as {open_quotes}cold start{close_quotes} emissions. The stringency of the regulations becomes evident when to qualify for either Low Emission Vehicle (LEV) or Ultra Low Emission Vehicle (ULEV) status, the hydrocarbon engine out emissions of 2.0 g/mile, typical for a six cylinder vehicle, must be reduced over the entire FTP by 970/9 and 99%, respectively. These regulations spurred a variety of new technology thrusts aimed at attacking the cold start hydrocarbons including electrically heated catalysts, hydrocarbon traps, exhaust gas burners, and close coupled catalysts. This report describes the performance of palladium catalysts for the air pollution control of nitrogen oxides.
- OSTI ID:
- 420515
- Report Number(s):
- CONF-960807-; ISSN 0569-3772; TRN: 97:000002-0016
- Journal Information:
- Preprints of Papers, American Chemical Society, Division of Fuel Chemistry, Vol. 41, Issue 3; Conference: 212. national meeting of the American Chemical Society (ACS), Orlando, FL (United States), 25-30 Aug 1996; Other Information: PBD: 1996
- Country of Publication:
- United States
- Language:
- English
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