Compositions of lean NO;trap (LNT) systems and methods of making and using same

• US 9,517,448 B2
• Filed: 10/22/2014
• Issued: 12/13/2016
• Est. Priority Date: 10/22/2013
• Status: Active Grant

• Current Assignee: Umicore AG & Company KG (Umicore S.A.)
• Original Assignee: SDC Materials,Inc.
• Inventors: Kearl, Bryant, Yin, Qinghua, Qi, Xiwang, Leamon, David, Biberger, Maximilian A.
• Primary Examiner(s): Nguyen, Cam N.
• Application Number:
  US14/521,334
• Publication Number:
  US 20150165418A1
• Time in Patent Office: 783 Days
• Field of Search: 502302-304, 502327-328, 502332-334, 502/339, 502/349, 502/355, 502/415, 502/439, 502/527.12, 502/527.13, 423/212, 422/177, 602/72, 602/73
• US Class Current: 1/1
• CPC Class Codes: B01D 2255/1021 Platinum
• CPC Class Codes: B01D 2255/1023 Palladium
• CPC Class Codes: B01D 2255/1025 Rhodium
• CPC Class Codes: B01D 2255/104 Silver
• CPC Class Codes: B01D 2255/2061 Yttrium
• CPC Class Codes: B01D 2255/2063 Lanthanum
• CPC Class Codes: B01D 2255/2065 Cerium
• CPC Class Codes: B01D 2255/20715 Zirconium
• CPC Class Codes: B01D 2255/20738 Iron
• CPC Class Codes: B01D 2255/20776 Tungsten
• CPC Class Codes: B01D 2255/20792 Zinc
• CPC Class Codes: B01D 2255/40 Mixed oxides
• CPC Class Codes: B01D 2255/407 Zr-Ce mixed oxides
• CPC Class Codes: B01D 2255/908 O2-storage component incorporated in the catalyst
• CPC Class Codes: B01D 2255/91 NOx-storage component incorporated in the catalyst
• CPC Class Codes: B01D 2255/9202 Linear dimensions
• CPC Class Codes: B01D 53/9422 for removing nitrogen oxides by NOx storage or reduction by cyclic switching between lean and rich exhaust gases (LNT, NSC, NSR)
• CPC Class Codes: B01D 53/9431 Processes characterised by a specific device
• CPC Class Codes: B01J 23/02 of the alkali- or alkaline earth metals or beryllium
• CPC Class Codes: B01J 23/10 of rare earths
• CPC Class Codes: B01J 23/44 : Palladium
• CPC Class Codes: B01J 23/464 : Rhodium
• CPC Class Codes: B01J 23/63 : with rare earths or actinides
• CPC Class Codes: B01J 35/19 : Catalysts containing parts with different compositions
• CPC Class Codes: B01J 35/23 : in a colloidal state
• CPC Class Codes: B01J 35/393 : Metal or metal oxide crystallite size
• CPC Class Codes: B01J 35/56 : Foraminous structures having flow-through passages or channels, e.g. grids or three-dimensional monoliths
• CPC Class Codes: B01J 37/0236 : Drying, e.g. preparing a suspension, adding a soluble salt and drying
• CPC Class Codes: B01J 37/0244 : Coatings comprising several layers
• CPC Class Codes: B01J 37/0248 : Coatings comprising impregnated particles
• CPC Class Codes: B01J 37/04 : Mixing B01J37/0009, B01J37/0018 take precedence
• CPC Class Codes: B01J 37/349 : making use of flames, plasmas or lasers
• CPC Class Codes: F01N 2370/02 : used in catalytic reactors
• CPC Class Codes: F01N 2570/14 : Nitrogen oxides
• CPC Class Codes: F01N 3/10 : by thermal or catalytic conversion of noxious components of exhaust by using other chemical processes, chemical aspects of catalytic conversion, e.g. using specified catalysts, B01D53/34

Abstract

The present disclosure relates to a substrate comprising nanoparticle catalysts and NO_x storage materials for treatment of gases, and washcoats for use in preparing such a substrate. Also provided are methods of preparation of the nanoparticle catalysts and NO_x storage materials, as well as methods of preparation of the substrate comprising the nanoparticle catalysts and NO_x storage materials. More specifically, the present disclosure relates to a coated substrate comprising nanoparticle catalysts and NO_x storage materials for lean NO_x trap (LNT) systems, useful in the treatment of exhaust gases.

Claims

1. A coated substrate comprising:

a substrate;

a washcoat layer comprising oxidative catalytically active micron-particles, the oxidative catalytically active micron-particles comprising oxidative composite nanoparticles bonded to a first micron-sized carrier particle, the oxidative composite nanoparticles comprising a first support nanoparticle and an oxidative catalytic nanoparticle;

a washcoat layer comprising reductive catalytically active micron-particles, the reductive catalytically active micron-particles comprising reductive composite nanoparticles bonded to a second micron-sized carrier particle, the reductive composite nanoparticles comprising a second support nanoparticle and a reductive catalytic nanoparticle; and

a washcoat layer comprising NO_x trapping particles, the NO_x trapping particles comprising a micron-sized cerium oxide-containing material.

2. The coated substrate of claim 1, wherein the micron-sized cerium oxide-containing material comprises cerium oxide, cerium-zirconium oxide, cerium-lanthanum oxide, cerium-yttrium oxide, cerium-zirconium-lanthanum oxide, cerium-zirconium-yttrium oxide, cerium-lanthanum-yttrium oxide, or cerium-zirconium-lanthanum-yttrium oxide.

3. The coated substrate of claim 2, wherein the micron-sized cerium oxide-containing material comprises cerium-zirconium-lanthanum oxide or cerium-zirconium-lanthanum-yttrium oxide.

4. The coated substrate of claim 1, wherein the washcoat layer comprising reductive catalytically active micron-particles is located closer to the substrate than the washcoat layer comprising oxidative catalytically active micron-particles.

5. The coated substrate of claim 4, wherein the washcoat layer comprising oxidative catalytically active micron-particles is located closer to the substrate than the washcoat layer comprising NO_x trapping particles.

6. The coated substrate of claim 1, wherein the NO_x trapping particles further comprise barium oxide impregnated in the micron-sized cerium oxide-containing material.

7. The coated substrate of claim 6, wherein the barium oxide is impregnated in the micron-sized cerium oxide or the micron-sized cerium oxide-containing material by wet chemistry.

8. The coated substrate of claim 1, wherein the NO_x trapping particles further comprise platinum or palladium impregnated in the micron-sized cerium oxide-containing material.

9. The coated substrate of claim 8, wherein the platinum or palladium is plasma-generated.

10. The coated substrate of claim 8, wherein the platinum or palladium is impregnated in the micron-sized cerium oxide-containing material by wet chemistry.

11. The coated substrate of claim 1, wherein the NO_x trapping particles further comprise the perovskite FeBaO₃ impregnated in the micron-sized cerium oxide-containing material.

12. The coated substrate of claim 1, wherein the NO_x trapping particles further comprise metal oxides selected from the group consisting of samarium, zinc, copper, iron, and silver oxides impregnated in the micron-sized cerium oxide-containing material.

13. The coated substrate of claim 1, wherein the washcoat layer comprising NO_x trapping particles further comprises micron-sized aluminum oxide particles.

14. The coated substrate claim 1, wherein the oxidative catalytically active micron-particles comprise a material selected from the group comprising platinum, palladium, or a platinum-palladium alloy.

15. The coated substrate of claim 1, wherein the NO_x trapping particles further comprise zirconium oxide.

16. The coated substrate of claim 1, wherein the first micron-sized carrier particle, first micron-sized porous carrier, or first support particle comprises aluminum oxide.

17. The coated substrate of claim 1, wherein the second micron-sized carrier particle, second micron-sized porous carrier, or second support particle comprises cerium oxide.

18. The coated substrate of claim 1, wherein the washcoat layer comprising oxidative catalytically active micron-particles or the washcoat layer comprising reductive catalytically active micron-particles further comprises filler particles or boehmite particles;

wherein the filler particles are metal oxide particles.

19. The coated substrate according to claim 1, wherein the micron-sized cerium oxide-containing material comprises cerium oxide.

20. A catalytic converter comprising a coated substrate of claim 1.

21. An exhaust treatment system comprising a conduit for exhaust gas and a catalytic converter according to claim 20.

22. A vehicle comprising an exhaust treatment system according to claim 21.

23. A vehicle comprising a catalytic converter according to claim 20.

24. A method of treating an exhaust gas, comprising contacting the coated substrate of claim 1 with the exhaust gas.

25. A method of treating an exhaust gas, comprising contacting the coated substrate of claim 1 with the exhaust gas, wherein the substrate is housed within a catalytic converter configured to receive the exhaust gas.

26. A coated substrate comprising:

a substrate;

a washcoat layer comprising oxidative catalytically active micron-particles, the oxidative catalytically active micron-particles comprising oxidative composite nanoparticles embedded in a first micron-sized porous carrier, the oxidative composite nanoparticles comprising a first support nanoparticle and an oxidative catalytic nanoparticle;

a washcoat layer comprising reductive catalytically active micron-particles, the reductive catalytically active micron-particles comprising reductive composite nanoparticles embedded in a second micron-sized porous carrier, the reductive composite nanoparticles comprising a second support nanoparticle and a reductive catalytic nanoparticle; and

a washcoat layer comprising NO_x trapping particles, and the NO_x trapping particles comprising a micron-sized cerium oxide-containing material.

27. The coated substrate of claim 26, wherein the micron-sized cerium oxide-containing material comprises cerium oxide, cerium-zirconium oxide, cerium-lanthanum oxide, cerium-yttrium oxide, cerium-zirconium-lanthanum oxide, cerium-zirconium-yttrium oxide, cerium-lanthanum-yttrium oxide, or cerium-zirconium-lanthanum-yttrium oxide.

28. The coated substrate of claim 27, wherein the micron-sized cerium oxide-containing material comprises cerium-zirconium-lanthanum oxide or cerium-zirconium-lanthanum-yttrium oxide.

29. The coated substrate of claim 26, wherein the washcoat layer comprising reductive catalytically active micron-particles is located closer to the substrate than the washcoat layer comprising oxidative catalytically active micron-particles.

30. The coated substrate of claim 29, wherein the washcoat layer comprising oxidative catalytically active micron-particles is located closer to the substrate than the washcoat layer comprising NO_x trapping particles.

31. The coated substrate of claim 26, wherein the NO_x trapping particles further comprise barium oxide impregnated in the micron-sized cerium oxide-containing material.

32. The coated substrate of claim 31, wherein the barium oxide is impregnated in the micron-sized cerium oxide or the micron-sized cerium oxide-containing material by wet chemistry.

33. The coated substrate of claim 26, wherein the NO_x trapping particles further comprise platinum or palladium impregnated in the micron-sized cerium oxide-containing material.

34. The coated substrate of claim 33, wherein the platinum or palladium is plasma-generated.

35. The coated substrate of claim 33, wherein the platinum or palladium is impregnated in the micron-sized cerium oxide-containing material by wet chemistry.

36. The coated substrate of claim 26, wherein the NO_x trapping particles further comprise the perovskite FeBaO₃ impregnated in the micron-sized cerium oxide-containing material.

37. The coated substrate of claim 26, wherein the NO_x trapping particles further comprise metal oxides selected from the group consisting of samarium, zinc, copper, iron, and silver oxides impregnated in the micron-sized cerium oxide-containing material.

38. The coated substrate of claim 26, wherein the washcoat layer comprising NO_x trapping particles further comprises micron-sized aluminum oxide particles.

39. The coated substrate claim 26, wherein the oxidative catalytically active micron-particles comprise a material selected from the group comprising platinum, palladium, or a platinum-palladium alloy.

40. The coated substrate of claim 26, wherein the NO_x trapping particles further comprise zirconium oxide.

41. The coated substrate of claim 26, wherein the first micron-sized carrier particle, first micron-sized porous carrier, or first support particle comprises aluminum oxide.

42. The coated substrate of claim 26, wherein the second micron-sized carrier particle, second micron-sized porous carrier, or second support particle comprises cerium oxide.

43. The coated substrate of claim 26, wherein the washcoat layer comprising oxidative catalytically active micron-particles or the washcoat layer comprising reductive catalytically active micron- particles further comprises filler particles or boehmite particles;

wherein the filler particles are metal oxide particles.

44. The coated substrate according to claim 26, wherein the micron-sized cerium oxide-containing material comprises cerium oxide.

45. A catalytic converter comprising a coated substrate of claim 26.

46. An exhaust treatment system comprising a conduit for exhaust gas and a catalytic converter according to claim 45.

47. A vehicle comprising a catalytic converter according to claim 46.

48. A vehicle comprising an exhaust treatment system according to claim 47.

49. A method of treating an exhaust gas, comprising contacting the coated substrate of claim 26 with the exhaust gas.

50. A method of treating an exhaust gas, comprising contacting the coated substrate of claim 26 with the exhaust gas, wherein the substrate is housed within a catalytic converter configured to receive the exhaust gas.

51. A coated substrate comprising:

a substrate;

a washcoat layer comprising oxidative catalytically active composite nanoparticles attached to a first micron-sized support particle, the oxidative catalytically active composite nanoparticles being plasma-generated and comprising a first support nanoparticle and an oxidative catalytic nanoparticle;

a washcoat layer comprising reductive catalytically active composite nanoparticles attached to a second micron-sized support particle, the reductive catalytically active composite nanoparticles being plasma-generated and comprising a second support nanoparticle and a reductive catalytic nanoparticle; and

a washcoat layer comprising NO_x trapping particles, and the NO_x trapping particles comprising a micron-sized cerium oxide-containing material.

52. The coated substrate according to claim 51, wherein the micron-sized cerium oxide-containing material comprises cerium oxide.

53. A method of forming a coated substrate, the method comprising:

a) coating a substrate with a washcoat composition comprising oxidative catalytically active micron-particles, the oxidative catalytically active micron-particles comprising composite oxidative nanoparticles bonded to a first micron-sized carrier particle, the oxidative composite nanoparticles comprising a first support nanoparticle and an oxidative catalytic nanoparticle;

b) coating the substrate with a washcoat composition comprising reductive catalytically active micron-particles, the reductive catalytically active micron-particles comprising reductive composite nanoparticles bonded to a second micron-sized carrier particle, the reductive composite nanoparticles comprising a second support nanoparticle and a reductive catalytic nanoparticle; and

c) coating the substrate with a washcoat composition comprising NO_x trapping particles, the NO_x trapping particles comprising a micron-sized cerium oxide-containing material.

54. A method of forming a coated substrate, the method comprising:

a) coating a substrate with a washcoat composition comprising oxidative catalytically active micron-particles, the oxidative catalytically active micron-particles comprising oxidative composite nanoparticles embedded in a first micron-sized porous carrier, the oxidative composite nanoparticles comprising a first support nanoparticle and an oxidative catalytic nanoparticle;

b) coating the substrate with a washcoat composition comprising reductive catalytically active micron-particles, the reductive catalytically active micron-particles comprising reductive composite nanoparticles embedded in a second micron-sized porous carrier, the reductive composite nanoparticles comprising a second support nanoparticle and reductive catalytic nanoparticle; and

c) coating the substrate with a washcoat composition comprising NO_x trapping particles, the NO_x trapping particles comprising a micron-sized cerium oxide-containing material.

55. A method of forming a coated substrate, the method comprising:

a) coating a substrate with a washcoat composition comprising oxidative catalytically active composite nanoparticles attached to a first micron-sized support particle, the oxidative catalytically active composite nanoparticles being plasma-generated and comprising a first support nanoparticle and an oxidative catalytic nanoparticle;

b) coating the substrate with a washcoat composition comprising reductive catalytically active composite nanoparticles attached to a second micron-sized support particle, the reductive catalytically active composite nanoparticles being plasma-generated and comprising a second support nanoparticle and a reductive catalytic nanoparticle; and

c) coating the substrate with a washcoat composition comprising NO_x trapping particles, the NO_x trapping particles comprising a micron-sized cerium oxide-containing material.

56. A coated substrate comprising:

a substrate;

a first washcoat layer comprising oxidative catalytically active micron-particles, the oxidative catalytically active micron-particles comprising oxidative composite nanoparticles bonded to a first micron-sized carrier particle, the oxidative composite nanoparticles comprising a first support nanoparticle and an oxidative catalytic nanoparticle; and

a second washcoat layer comprising reductive catalytically active micron-particles and NO_x trapping particles, the reductive catalytically active micron-particles comprising reductive composite nanoparticles bonded to a second micron-sized carrier particle, the reductive composite nanoparticles comprising a second support nanoparticle and a reductive catalytic nanoparticle, and the NO_x trapping particles comprising a micron-sized cerium oxide-containing material.

57. A coated substrate comprising:

a substrate;

a washcoat layer comprising oxidative catalytically active micron-particles, the oxidative catalytically active micron-particles comprising oxidative composite nanoparticles embedded in a first micron-sized porous carrier, the oxidative composite nanoparticles comprising a first support nanoparticle and an oxidative catalytic nanoparticle; and

a washcoat layer comprising reductive catalytically active micron- particles and NO_x trapping particles, the reductive catalytically active micron-particles comprising reductive composite nanoparticles embedded in a second micron-sized porous carrier, the reductive composite nanoparticles comprising a second support nanoparticle and a reductive catalytic nanoparticle, and the NO_x trapping particles comprising a micron-sized cerium oxide-containing material.

58. A coated substrate comprising:

a substrate;

a washcoat layer comprising oxidative catalytically active composite nanoparticles attached to a first micron-sized support particle, the oxidative catalytically active composite nanoparticles being plasma-generated and comprising a first support nanoparticle and an oxidative catalytic nanoparticle;

and a washcoat layer comprising NO_x trapping particles and reductive catalytically active composite nanoparticles attached to a second micron-sized support particle, the reductive catalytically active composite nanoparticles being plasma-generated and comprising a second support nanoparticle and a reductive catalytic nanoparticle, and the NO_x trapping particles comprising a micron-sized cerium oxide-containing material.

59. A method of forming a coated substrate, the method comprising:

a) coating a substrate with a washcoat composition comprising oxidative catalytically active micron-particles, the oxidative catalytically active micron-particles comprising oxidative composite nanoparticles bonded to a first micron-sized carrier particle, the oxidative composite nanoparticles comprising a first support nanoparticle and an oxidative catalytic nanoparticle; and

b) coating the substrate with a washcoat composition comprising reductive catalytically active micron-particles and NO_x trapping particles, the reductive catalytically active micron-particles comprising reductive composite nanoparticles bonded to second micron-sized carrier particle, the reductive composite nanoparticles comprising a second support nanoparticle and a reductive catalytic nanoparticle, and the NO_x trapping particles comprising a micron-sized cerium oxide-containing material.

60. A method of forming a coated substrate, the method comprising:

a) coating a substrate with a washcoat composition comprising oxidative catalytically active micron-particles, the oxidative catalytically active micron-particles comprising oxidative composite nanoparticles embedded in a first micron-sized porous carrier, the oxidative composite nanoparticles comprising a first support nanoparticle and an oxidative catalytic nanoparticle; and

b) coating the substrate with a washcoat composition comprising reductive catalytically active micron-particles and NO_x trapping particles, the reductive catalytically active micron-particles comprising reductive composite nanoparticles embedded in a second micron-sized porous carrier, the reductive composite nanoparticles comprising a second support nanoparticle and a reductive catalytic nanoparticle, and the NO_x trapping particles comprising a micron-sized cerium oxide-containing material.

61. A method of forming a coated substrate, the method comprising:

a) coating a substrate with a washcoat composition comprising oxidative catalytically active composite nanoparticles attached to a first micron-sized support particle, the oxidative catalytically active composite nanoparticles being plasma-generated and comprising a first support nanoparticle and an oxidative catalytic nanoparticle; and

b) coating the substrate with a washcoat composition comprising NO_x trapping particles and reductive catalytically active composite nanoparticles attached to a second micron-sized support particle, the reductive catalytically active composite nanoparticles being plasma-generated and comprising a second support nanoparticle and a reductive catalytic nanoparticle, and the NO_x trapping particles comprising a micron-sized cerium oxide-containing material.