摘要 |
Catalyst composition, apparatus and a method employing such composition for the treatment of engine exhaust gases to reduce pollutants contained therein. The catalyst composition is a three-way catalyst which may be used in a close-coupled or medium-coupled mode. Optionally, one or more downstream catalyst members may also be present. The catalyst composition comprises a mixture of (a) ceria having a weighted numerical average particle size of not greater than about 100 nm and (b) a catalytically effective amount of a platinum-group metal catalytic component such as palladium disposed on a refractory metal oxide support such as activated alumina. The catalyst composition contains substantially no organic compounds nor substantially any zirconia in the form of a composite or a solid solution with said ceria. The catalyst composition is preferably disposed on a carrier such as cordierite.
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