Catalyst for treating exhaust gas

Patent metadata

Field	Value
Publication number	US-9044744-B2
Application number	US-201414212784-A
Country	US
Kind code	B2
Filing date	Mar 14, 2014
Priority date	Mar 15, 2013
Publication date	Jun 2, 2015
Grant date	Jun 2, 2015

Abstract

Provided is a catalyst composition having an aluminosilicate molecular sieve having an AEI structure and a mole ratio of silica-to-alumina of about 20 to about 30 loaded with about 1 to about 5 weight percent of a promoter metal, based on the total weight of the molecular sieve material. Also provided are method, articles, and systems utilizing the catalyst composition.

First claim

What is claimed is:

1. A catalyst composition comprising an aluminosilicate molecular sieve having an AEI structure and a mole ratio of silica-to-alumina of about 20 to about 30 and about 1 to about 5 weight percent of a promoter metal, based on the total weight of the molecular sieve material.

2. The catalyst composition of claim 1 , wherein the molecular sieve has mole ratio of silica-to-alumina of about 20 to about 22.

3. The catalyst composition of claim 1 , wherein the molecular sieve has mole ratio of silica-to-alumina of about 22 to about 25.

4. The catalyst composition of claim 1 , wherein the molecular sieve has mole ratio of silica-to-alumina of about 25 to about 30.

5. The catalyst composition of claim 1 , wherein the promoter metal is selected from the group consisting of copper, nickel, zinc, iron, tungsten, molybdenum, cobalt, titanium, zirconium, manganese, chromium, vanadium, niobium, tin, bismuth, antimony, ruthenium, rhodium, palladium, indium, platinum, gold, silver, or combinations of two or more of these.

6. The catalyst composition of claim 1 , wherein the promoter metal is copper, iron, or a combination of copper and iron.

7. The catalyst composition of claim 1 , wherein the promoter metal is copper.

8. The catalyst composition of claim 1 , wherein the promoter metal is iron.

9. The catalyst composition of claim 1 , wherein the copper is present in a loading of about 2.5 to about 3.5 weight percent, based on the total weight of the zeolite material.

10. The catalyst composition of claim 1 , wherein the copper is present in a loading of about 3.0 to about 3.5 weight percent, based on the total weight of the zeolite material.

11. The catalyst composition of claim 1 , wherein the molecular sieve is a physical mixture of AEI and FAU structures, provided that the molecular sieve is at least 90 mole percent AEI.

12. The catalyst composition of claim 10 , wherein the molecular sieve is at least 99 mole percent AEI.

13. A catalyst composition comprising:
a. an aluminosilicate molecular sieve having an AEI structure and a mole ratio of silica-to-alumina of about 20 to about 30;
b. extra-framework promoter metal (PM) disposed on and/or within the molecular sieve, wherein the promoter metal is present in an atomic ratio of PM to aluminum of about 0.15 to about 1.

14. The catalyst composition of claim 13 wherein the aluminum is framework aluminum.

15. The catalyst composition of claim 1 , wherein the composition is a washcoat comprising the catalyst.

16. A method for treating an exhaust gas comprising:
contacting an exhaust gas comprising NO x and a reductant with a catalyst composition according to claim 1 ;
selectively reducing at least a portion of the NO x to N 2 and H 2 O.

17. The method of claim 16 , wherein the exhaust gas is derived from a lean burn internal combustion engine.

18. The method of claim 16 , wherein the reductant is NH 3 .

19. The method of claim 18 , wherein at least a portion of said NH 3 is derived from a lean NO x trap (LNT), NAC, or a NO x storage material.

20. The method of claim 19 , wherein said exhaust gas contacting the catalyst alternates between rich and lean.

21. A method for treating an exhaust gas comprising:
contacting an exhaust gas comprising a first concentration of NO x and a first concentration of NH 3 with a catalyst to produce a partially treated exhaust gas having a second concentration of NO x and a second concentration of NH 3 , wherein the second concentration of NO x and the second concentration of NH 3 is lower than the first concentration of NO x and a first concentration of NH 3 ,
contacting the partially treated exhaust gas with a catalyst comprising a composition according to claim 1 to oxidize at least a portion of the NH 3 to produce a purified exhaust gas having a third concentration of NH 3 , wherein the third concentration of NH 3 is lower than the second concentration of NH 3 .

22. A catalytic article comprising:
a. a catalyst composition according to claim 1 ;
b. a substrate upon and/or within which the catalyst is disposed.

23. The catalytic article of claim 22 , wherein the substrate is a flow-through monolith.

24. The catalyst article of claim 22 , wherein the substrate is a wall-flow filter.

25. The catalyst article of claim 22 , wherein the catalyst is a washcoat loaded on the substrate.

26. The catalyst article of claim 22 , wherein the substrate is extruded with the catalyst.

27. A system for treating an exhaust gas comprising:
a. a catalyst article according to claim 22 ;
b. one or more upstream components selected from a diesel oxidation catalyst, a NO x absorber catalyst, a lean NOx trap, a filter, an NH 3 injector, and an SCR catalyst; and
c. optionally a downstream ammonia slip catalyst.

Assignees

• Johnson Matthey Plc

Inventors

• Casci John Leonello
• Gaberova Lucia
• Collier Jillian Elaine

Classifications

• B01J29/72

  containing iron group metals, noble metals or copper · CPC title

• B01J29/70 Primary

  of types characterised by their specific structure not provided for in groups B01J29/08 - B01J29/65 · CPC title

• B01J37/0246

  Coatings comprising a zeolite · CPC title

• B01J29/76 Primary

  Iron group metals or copper · CPC title

• B01J29/7049

  containing rare earth elements, titanium, zirconium, hafnium, zinc, cadmium, mercury, gallium, indium, thallium, tin or lead · CPC title