초록 ▼

A sulfur tolerant oxidation catalyst with appreciable NO and HC oxidation capabilities has been developed for use in any component of an exhaust aftertreatment system for a lean-burn engine where the oxidation of at least NO is desired. Several non-exclusive examples of such components where the oxi

A sulfur tolerant oxidation catalyst with appreciable NO and HC oxidation capabilities has been developed for use in any component of an exhaust aftertreatment system for a lean-burn engine where the oxidation of at least NO is desired. Several non-exclusive examples of such components where the oxidation catalyst may be employed include a DOC and a LNT. The oxidation catalyst may comprise perovskite oxide particles that support palladium particles. The ability of the palladium supported perovskite oxide particles to concurrently oxidize NO and HC's can significantly diminish or altogether eliminate the use of platinum in the exhaust aftertreatment system for at least NO oxidation. The oxidation catalyst, moreover, may exhibit superior thermal durability and better NO and HC oxidation activities than platinum in some instances.

대표청구항 ▼

1. An oxidation catalyst for use in a component of an exhaust aftertreatment system where at least NO contained in an exhaust emitted from a lean-burn engine is oxidized, the oxidation catalyst comprising: perovskite oxide particles;palladium particles supported on the perovskite oxide particles at

1. An oxidation catalyst for use in a component of an exhaust aftertreatment system where at least NO contained in an exhaust emitted from a lean-burn engine is oxidized, the oxidation catalyst comprising: perovskite oxide particles;palladium particles supported on the perovskite oxide particles at a weight percent ranging from about 0.5 to about 5.0 based on the weight of the oxidation catalyst; andwherein said perovskite oxide particles comprise at least one of La0.9Sr0.1CoO3 or La0.9Sr0.1MnO3. 2. The oxidation catalyst according to claim 1, wherein the perovskite oxide particles Farther comprise at least one of LaCoO3 or LaMnO3. 3. The oxidation catalyst according to claim 1, wherein the palladium particles are supported on the perovskite oxide particles at a weight percent ranging from about 1.0 to about 2.0 based on the weight of the oxidation catalyst. 4. The oxidation catalyst according to claim 1. wherein the component of the exhaust aftertreatment system is a diesel oxidation catalyst. 5. The oxidation catalyst according to claim 1, wherein the component of the exhaust aftertreatment system is a lean NOX trap. 6. An exhaust aftertreatment system that receives an engine exhaust emitted from a lean-burn engine that is combusting a lean mixture of air and fuel, comprising: a component comprising;a substrate surface over which at least a portion of the engine exhaust passes; andan oxidation catalyst carried by the substrate surface that comprises perovskite oxide particles and palladium particles supported on the perovskite oxide particles, wherein the palladium particles are supported on the perovskite oxide particles at a weight percent ranging from about 0.5 to about 5.0 based on the weight of the oxidation catalyst:wherein said perovskite oxide particles comprise at least one of La0.9Sr0.1CoO3 or La0.9Sr0.1MnO3. 7. The exhaust aftertreatment system according to claim 6, wherein the perovskite oxide particles further comprise at least one of LaCoO3 or LaMnO3. 8. The exhaust aftertreatment system according to claim 6, wherein the palladium particles are supported on the perovskite oxide particles at a weight percent ranging from about 1.0 to about 2.0 based on the weight of the oxidation catalyst. 9. The exhaust aftertreatment system according to claim 6, wherein the component is a diesel oxidation catalyst. 10. The exhaust aftertreatment system according to claim 6, wherein the component is a lean NOX trap. 11. The exhaust aftertreatment system according to claim 6, further comprising free-standing palladium particles, which are not supported by the perovskite oxide particles, carried by the substrate surface. 12. The exhaust aftertreatment system according to claim 6, wherein the oxidation catalyst has no platinum. 13. The exhaust aftertreatment system according to claim 6, wherein the oxidation catalyst is directly applied to the substrate surface. 14. The exhaust aftertreatment system according to claim 6, further comprising a carrier material carried by the substrate surface, wherein the carrier material has a surface area that ranges from about 20 m2/gram to about 300 m2/gram, wherein the carrier material comprises at least one of a mixed cerium and zirconium oxide material (CeO2—ZrO2), alumina (Al2O3), a zeolite, or a combination of one or more of those materials, and wherein the oxidation catalyst is dispersed on the carrier material. 15. The exhaust aftertreatment system according to claim 6, wherein the oxidation catalyst material comprises La0.9Sr0.1CoO3 particles and palladium particles supported on the La0.9Sr0.1CoO3 particles, and wherein the palladium particles are supported on the La0.9Sr0.1CoO3 particles at a weight percent of about 1.5 based on the weight of the oxidation catalyst. 16. The exhaust aftertreatment system according to claim 6, wherein the oxidation catalyst material comprises La0.9Sr0.1 MnO3particles and palladium particles supported on the La0.9Sr0.1MnO3 particles, and wherein the palladium particles are supported on the La0.9Sr0.1MnO3 particles at a weight percent of about 1.5 based on the weight of the oxidation catalyst. 17. The exhaust aftertreatment system according to claim 6, wherein the oxidation catalyst is carried by the substrate material in an amount that ranges from about 50 to 200 grams per liter of volume through which the engine exhaust flows in the presence of the oxidation catalyst. 18. An exhaust aftertreatment system that receives an engine exhaust emitted from a lean-hum engine that is combusting a lean mixture of air and fuel, comprising: a component comprising:a substrate surface over which at least a portion of the engine exhaust passes; andan oxidation catalyst material comprising La0.9Sr0.1CoO3 particles and palladium particles supported on the La0.9Sr0.lCoO3 particles, and wherein palladium particles are supported on the La0.9Sr0.lCoO3 particles at a weight percent of about 1.5 based on the weight of the oxidation catalyst. 19. An exhaust aftertreatment system that receives an engine exhaust emitted from a lean-bum engine that is combusting a lean mixture of air and fuel, comprising: a component comprising;a substrate surface over which at least a portion of the engine exhaust passes; andan oxidation catalyst material comprising La0.9Sr0.1MnO3 particles and palladium particles supported on the La0.9Sr0.1MnO3 particles, and wherein palladium particles are supported on the La0.9Sr0.lMnO3 particles at a weight percent of about 1.5 based on the weight of the oxidation catalyst.