CPC B01D 53/945 (2013.01) [B01D 53/9477 (2013.01); B01J 23/464 (2013.01); B01J 23/63 (2013.01); B01J 35/0006 (2013.01); B01J 35/04 (2013.01); B01J 35/108 (2013.01); B01J 37/0244 (2013.01); F01N 3/035 (2013.01); F01N 3/101 (2013.01); B01D 2255/1025 (2013.01); B01D 2255/2065 (2013.01); B01D 2255/407 (2013.01); B01D 2255/908 (2013.01); B01D 2255/9155 (2013.01); B01D 2258/014 (2013.01); F01N 2330/06 (2013.01); F01N 2510/06 (2013.01); F01N 2510/068 (2013.01); F01N 2510/0684 (2013.01); Y02T 10/12 (2013.01)] | 19 Claims |
1. An emission treatment system downstream of a gasoline direct injection engine for treatment of an exhaust stream comprising hydrocarbons, carbon monoxide, nitrogen oxides, and particulates, the emission treatment system comprising:
a close-coupled three-way conversion (TWC) composite comprising a first TWC catalytic material supported on a flow-through substrate; and
a catalyzed particulate filter located downstream of the dose-coupled TWC composite, the catalyzed particulate filter comprising a second TWC catalytic material that permeates walls of a particulate filter,
wherein the second TWC catalytic material comprises rhodium as the only platinum group metal, a support, and an oxygen storage component,
wherein the catalyzed particulate filter has a coated porosity ranging from 75% to 98% of an uncoated porosity of the particulate filter.
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