Advances in autoexhaust catalysts
- N.E. Chemcat Corp., Numazu (Japan)
Exhaust emission standards were set by the Clean Air Act Amendments of 1970 requiring automobile manufacturers to control the amount of hydrocarbons (HC), carbon monoxide (CO) and oxides of nitrogen (NO{sub x}) emitted from vehicles. These emissions from vehicles have been significantly reduced in the 20 years since auto exhaust catalysts was first used. Non-methane hydrocarbons and NO{sub x} emissions from vehicles, which are the root causes of photochemical smog, come under more stringent control year by year. Hydrocarbon emissions are required to be reduced to less than one-fifth of their present levels by the year 2000. To meet this stringent hydrocarbon emission standards, one of the cold start strategies is to use a quick light-off catalyst which is mounted at a close-coupled manifold position. In this application, it is inevitable that current TWC catalysts manifold position is thermally deactivated, because the catalyst is exposed to high temperatures, 100-150{degrees}C higher than the catalyst would encounter at the underfloor position. Our future catalyst development has focused on minimizing thermal deactivation via stabilization of ceria (CeO{sub 2}), which is used as an oxygen storage component (OSC) in TWC catalysis.
- OSTI ID:
- 577519
- Report Number(s):
- CONF-9604124--
- Country of Publication:
- United States
- Language:
- English
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