Nitrogen oxides (NOx) storage catalyst

Patent metadata

Field	Value
Publication number	US-10151227-B2
Application number	US-201615205020-A
Country	US
Kind code	B2
Filing date	Jul 8, 2016
Priority date	Jul 9, 2015
Publication date	Dec 11, 2018
Grant date	Dec 11, 2018

Abstract

A catalyst for storing nitrogen oxides (NO x ) in an exhaust gas from a lean burn engine comprising a NO x storage material and a substrate, wherein the NO x storage material comprises a NO x storage component and an NO oxidation promoter on a support material, wherein the NO oxidation promoter is manganese or an oxide, hydroxide or carbonate thereof.

First claim

The invention claimed is:

1. A catalyst for storing nitrogen oxides (NO x ) in an exhaust gas from a lean burn engine comprising a plurality of particles of a NO x storage material, wherein each particle of the NO x storage material comprises at least one particle of a NO x storage component and at least one particle of an NO oxidation promoter, both particles of the NO x storage component and the NO oxidation promoter being disposed on a common particle of a support material, wherein the NO oxidation promoter is manganese or an oxide, hydroxide or carbonate thereof.

2. The catalyst according to claim 1 , wherein the storage material comprises a mixed oxide of magnesium oxide (MgO) and aluminum oxide (Al 2 O 3 ).

3. The catalyst according to claim 1 , wherein the NO x storage component comprises (i) an oxide, a carbonate or a hydroxide of an alkali metal; (ii) an oxide, a carbonate or a hydroxide of an alkaline earth metal; and/or (iii) an oxide, a carbonate or a hydroxide of a rare earth metal.

4. The catalyst according to claim 1 , wherein the NO x storage material further comprises at least one particle of a platinum group metal (PGM) that is platinum, palladium, or a combination of platinum and palladium disposed or supported on the common particle of the support material.

5. The catalyst according to claim 1 , wherein the NO x storage material does not comprise at least one of platinum and palladium.

6. A catalyst body comprising the catalyst according to claim 1 and a substrate, wherein the NO x storage material is dispersed in or disposed on the substrate, so as to form a NO x storage region comprising the NO x storage material.

7. The catalyst body according to claim 6 , wherein the NO x storage region further comprises a NO x treatment material, wherein the NO x treatment material comprises at least one of a first NO x treatment component and a second NO x treatment component.

8. The catalyst body according to claim 7 , wherein the first NO x treatment component comprises a first NO x treatment support material, wherein the first treatment support material comprises ceria or ceria-zirconia.

9. The catalyst body according to claim 7 , wherein first NO x treatment component comprises the NO oxidation promoter disposed in or supported on the first NO x treatment support material.

10. The catalyst body according to claim 7 , wherein the first NO x treatment component comprises a platinum group metal (PGM) disposed or supported on the first NO x treatment support material, wherein the PGM is selected from the group consisting of palladium, rhodium and a combination of palladium and rhodium.

11. The catalyst body according to claim 7 , wherein the first NO x treatment component comprises a NO x storage component disposed or supported on the first NO x treatment support material, wherein the NO x storage component comprises an oxide, a carbonate or a hydroxide of barium (Ba).

12. The catalyst body according to claim 7 , wherein the second NO x treatment component comprises a second NO x treatment support material comprising a mixed oxide of magnesium oxide (MgO) and aluminum oxide (Al 2 O 3 ).

13. The catalyst body according to claim 12 , wherein the second NO x treatment component comprises the NO oxidation promoter disposed or supported on the second NO x treatment support material.

14. The catalyst body according to claim 12 , wherein the second NO x treatment component comprises a NO x storage component disposed or supported on the second NO x treatment support material, wherein the NO x storage component comprises an oxide, a carbonate or a hydroxide of barium (Ba).

15. The catalyst body according to claim 12 , wherein second NO x treatment component comprises a platinum group metal (PGM) disposed or supported on the second NO x treatment support material, wherein the PGM is selected from platinum, palladium and a combination of platinum and palladium.

16. The catalyst body according to claim 6 further comprising a NO x reduction region disposed or supported on the NO x storage region.

17. The catalyst body according to claim 16 , where the NO x reduction region comprises a NO x reduction component, wherein the NO x reduction component comprises rhodium disposed or supported on a NO x reduction support material.

18. The catalyst body according to claim 17 , wherein the NO x reduction support material comprises at least one of an oxide of aluminum and an oxide of cerium.

19. An exhaust system comprising a catalyst as defined in claim 1 and an emissions control device.

20. The catalyst according to claim 1 , wherein the NO x storage component comprises an oxide, a carbonate or a hydroxide of barium (Ba).

21. The catalyst body of claim 6 , wherein the NO x storage material is disposed on the substrate.

Assignees

• Johnson Matthey Plc

Inventors

• Armitage Andrew
• Chiffey Andrew Francis
• Goodwin John Benjamin
• Leeland James
• Lastra-Calvo Nuria
• Moreau Francois
• Phillips Paul Richard
• Reid Stuart David
• Swallow Daniel
• Xuereb David

Classifications

• B01D2255/2092

  Aluminium · CPC title

• B01J23/005

  Spinels · CPC title

• B01D2255/2042

  Barium · CPC title

• B01D53/9422

  for removing nitrogen oxides by NOx storage or reduction by cyclic switching between lean and rich exhaust gases (LNT, NSC, NSR) · CPC title

• B01D2255/2047

  Magnesium · CPC title