Dual Function Catalytic Filter
First Claim
1. An article for treating an exhaust gas comprising:
- a) a soot filter having an inlet and an outlet,b) a soot oxidation zone on the inlet, wherein the soot oxidation zone comprises a soot oxidation catalytic component consisting essentially of at least one transition metal dispersed on a cerium and zirconium mixed and/or composite oxide, wherein the at least one transition metal is selected from the group consisting of W, Cr, Ce, Mn, Fe, Co, Ni, Cu, and combinations thereof, andc) an SCR zone coated on the outlet, wherein the SCR zone comprises an SCR catalytic component.
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Accused Products
Abstract
A dual function catalytic filter is provided having a soot filter with an inlet and an outlet, a soot oxidation layer on the inlet, wherein the soot oxidation layer comprises a soot oxidation catalytic component consisting essentially of at least one transition metal dispersed on a cerium and zirconium mixed and/or composite oxide, wherein the at least one transition metal is selected from the group consisting of W, Cr, Ce, Mn, Fe, Co, Ni, Cu, and combinations thereof, and an SCR layer coated on the outlet, wherein the SCR layer comprises an SCR catalytic component. Also provided are methods for removing NOx and soot from a lean burn exhaust gas using the dual function catalytic filter.
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Citations
20 Claims
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1. An article for treating an exhaust gas comprising:
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a) a soot filter having an inlet and an outlet, b) a soot oxidation zone on the inlet, wherein the soot oxidation zone comprises a soot oxidation catalytic component consisting essentially of at least one transition metal dispersed on a cerium and zirconium mixed and/or composite oxide, wherein the at least one transition metal is selected from the group consisting of W, Cr, Ce, Mn, Fe, Co, Ni, Cu, and combinations thereof, and c) an SCR zone coated on the outlet, wherein the SCR zone comprises an SCR catalytic component. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. A system for treating NOx in a lean burn exhaust gas comprising:
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a) a nitrogenous reducing agent injector, b) a dual function catalytic filter comprising i. a soot filter having an inlet and an outlet, ii. a soot oxidation zone on the inlet, wherein the soot oxidation zone comprises a soot oxidation catalytic component consisting essentially of at least one transition metal dispersed on a cerium and zirconium mixed and/or composite oxide, wherein the at least one transition metal is selected from the group consisting of W, Cr, Ce, Mn, Fe, Co, Ni, Cu, and combinations thereof, and iii. an SCR zone coated on the outlet, wherein the SCR zone comprises an SCR catalytic component, wherein said injector is disposed upstream of, and is in fluid communication with, said dual function catalytic filter. - View Dependent Claims (17, 18, 19)
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20. A method for treating a lean burn exhaust gas comprising:
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a) flowing a lean burn exhaust gas stream comprising soot, NOx, and a nitrogenous reducing agent through a dual function catalytic filter comprising i. a soot filter having an inlet and an outlet, ii. a soot oxidation zone on the inlet, wherein the soot oxidation zone comprises a soot oxidation catalytic component consisting essentially of at least one transition metal dispersed on a cerium and zirconium mixed and/or composite oxide, wherein the at least one transition metal is selected from the group consisting of W, Cr, Ce, Mn, Fe, Co, Ni, Cu, and combinations thereof, and iii. an SCR zone coated on the outlet, wherein the SCR zone comprises an SCR catalytic component, b) oxidizing at least a portion of the soot at the soot oxidation zone; and c) reducing at least a portion of said NOx at the SCR catalyst zone.
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Specification