An exhaust gas treatment system for treating an exhaust gas stream exiting a gasoline engine
OwnerKarifala DUMBUYA, Holger SCHWEKENDIEK +2inventors
InventorsKarifala DUMBUYA, Holger SCHWEKENDIEK, Markus KINNE, Matthew T. CAUDLE
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Abstract
The present invention relates to an exhaust gas treatment system for treating an exhaust gas stream exiting a gasoline engine, the system comprising a first catalyst, namely a three-way conversion catalyst, a second catalyst, namely a four-way conversion catalyst and a third catalyst comprising a SCR coating. The present invention further relates to a method for treating an exhaust gas stream exiting a gasoline engine using said exhaust gas treatment system.
Claims18
An exhaust gas treatment system for treating an exhaust gas stream exiting a gasoline engine, said exhaust gas treatment system having an upstream end for introducing said exhaust gas stream into said exhaust gas treatment system, wherein said exhaust gas treatment system comprises
- (i) a first catalyst, being a three-way conversion catalyst, having an inlet end and an outlet end and comprising a coating disposed on a substrate, wherein the coating comprises a platinum group metal component supported on a porous oxidic material;
- (ii) a second catalyst, being a four-way conversion catalyst, having an inlet end and an outlet end and comprising a coating disposed on a wall flow filter substrate, wherein the coating comprises a platinum group metal component supported on a porous oxidic material;
- (iii) a third catalyst having an inlet end and an outlet end, wherein the third catalyst comprises a substrate and a coating for the selective catalytic reduction of NOx, wherein the SCR coating comprises a zeolitic material comprising one or more of Fe and Cu,
- wherein at most 0.0001 weight-% of said SCR coating consists of platinum group metal;
- wherein the first catalyst according to (i) is the first catalyst of the exhaust gas treatment system downstream of the upstream end of the exhaust gas treatment system and wherein the inlet end of the first catalyst is arranged upstream of the outlet end of the first catalyst;
- wherein in the exhaust gas treatment system, the second catalyst according to (ii) is located downstream of the first catalyst according to (i) and wherein the inlet end of the second catalyst is arranged upstream of the outlet end of the second catalyst;
- wherein in the exhaust gas treatment system, the third catalyst according to (iii) is located downstream of the second catalyst according to (ii) and wherein the inlet end of the third catalyst is arranged upstream of the outlet end of the third catalyst.
Dependencies are inferred from the claim text.