Exhaust System for a Spark-Ignited Internal Combustion Engine
First Claim
1. An exhaust system for a spark-ignited internal combustion engine comprising:
- (a) a three-way catalyst (TWC) composition including an oxygen storage component, wherein the TWC composition is coated on a flow-through monolith substrate, the substrate comprises a plurality of channels, and each channel has a length extending from an inlet end to an outlet end; and
(b) a single lambda sensor,wherein the substrate comprises a portion of the plurality of channels wherein the TWC composition in at least a part of the length of channels extending from the inlet end has a reduced oxygen storage activity, or no oxygen storage activity, relative to the TWC composition in a remainder of the substrate, the arrangement being such that the single lambda sensor is contacted substantially only with exhaust gas that has first contacted the TWC composition having a reduced oxygen storage activity or no oxygen storage activity.
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Accused Products
Abstract
An exhaust system for a spark-ignited internal combustion engine comprises a three-way catalyst composition including an oxygen storage component, which TWC composition is coated on a flow-through monolith substrate, which substrate comprising a plurality of channels, each channel having a length extending from an inlet end to an outlet end and a single lambda sensor, wherein the substrate comprises a portion of the plurality of channels wherein the TWC composition in at least a part of the length of channels extending from the inlet end has a reduced oxygen storage activity, or no oxygen storage activity, relative to the TWC composition in a remainder of the substrate, the arrangement being such that the single lambda sensor is contacted substantially only with exhaust gas that has first contacted the TWC composition having a reduced oxygen storage activity or no oxygen storage activity.
24 Citations
13 Claims
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1. An exhaust system for a spark-ignited internal combustion engine comprising:
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(a) a three-way catalyst (TWC) composition including an oxygen storage component, wherein the TWC composition is coated on a flow-through monolith substrate, the substrate comprises a plurality of channels, and each channel has a length extending from an inlet end to an outlet end; and (b) a single lambda sensor, wherein the substrate comprises a portion of the plurality of channels wherein the TWC composition in at least a part of the length of channels extending from the inlet end has a reduced oxygen storage activity, or no oxygen storage activity, relative to the TWC composition in a remainder of the substrate, the arrangement being such that the single lambda sensor is contacted substantially only with exhaust gas that has first contacted the TWC composition having a reduced oxygen storage activity or no oxygen storage activity. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 13)
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- 11. A flow-through monolith substrate comprising a plurality of channels coated with a three-way catalyst composition including an oxygen storage component, each channel having a length extending from a first end to a second end, wherein at least a part of the length of channels extending from the first end in a portion of the plurality of channels is coated with a catalyst composition comprising at least one platinum group metal having a reduced oxygen storage activity relative to a remainder of the substrate.
Specification