Lean NOx traps, trapping materials, washcoats, and methods of making and using the same

Patent metadata

Field	Value
Publication number	US-10124322-B2
Application number	US-201615019828-A
Country	US
Kind code	B2
Filing date	Feb 9, 2016
Priority date	Feb 11, 2015
Publication date	Nov 13, 2018
Grant date	Nov 13, 2018

Abstract

The present disclosure relates to micron-sized particle used for catalyzing and storing NO x gases, such as those found in vehicle exhaust emissions, washcoats employing micron-sized particle used for catalyzing and storing NO x gases, washcoat coated substrates, lean NO x trap (LNT) systems, and vehicles using such systems. Also provided are methods of preparing micron-sized particle used for catalyzing and storing NO x gases, as well as preparation of washcoats and coated substrates. More specifically, the present disclosure relates to a lean NO x trapping materials, wherein the materials include a NO x catalytic component attached to a micron-sized carrier particle and a NO x storage component, as well as washcoats and coated substrates useful in the treatment of exhaust gases. In some embodiments, a portion of the NO x storage component is attached to the micron-sized carrier particle.

First claim

We claim:

1. A NOx storage washcoat composition comprising:
micron-sized oxygen-storage particles;
composite nanoparticles, the composite nanoparticle comprising a support nanoparticle and a catalytic nanoparticle, the catalytic nanoparticle comprising one or more platinum group metals, wherein the composite nanoparticles are not pre-attached to a micron-sized particle when added to the washcoat composition; and
an alkaline earth metal salt or alkaline earth metal oxide.

2. The NOx storage washcoat composition according to claim 1 , wherein a portion of the composite nanoparticles are not covalently bound to the micron-sized oxygen-storage particles.

3. The NOx storage washcoat composition according to claim 1 , wherein a portion of the composite nanoparticles are covalently bound to the micron-sized oxygen-storage particles.

4. The NOx storage washcoat composition according to claim 1 , wherein a portion of the alkaline earth metal oxide is not covalently bound to the micron-sized oxygen-storage particles.

5. The NOx storage washcoat composition according to claim 1 , wherein a portion of the alkaline earth metal oxide is covalently bound to the micron-sized oxygen-storage particles.

6. The NOx storage washcoat composition according to claim 1 , wherein the alkaline earth metal oxide is barium oxide.

7. The NOx storage washcoat composition according to claim 1 , wherein the alkaline earth metal salt is a barium salt.

8. The NOx storage washcoat composition according to claim 1 , wherein the alkaline earth metal salt is barium acetate.

9. A vehicle comprising the NOx storage washcoat composition according to claim 1 .

10. The NOx storage washcoat composition according to claim 1 , wherein the micron-sized oxygen-storage particles comprise cerium oxide; zirconium oxide; lanthanum oxide; yttrium oxide, cerium oxide and zirconium oxide; cerium oxide, zirconium oxide, and lanthanum oxide; cerium oxide, zirconium oxide, and yttrium oxide; or cerium oxide, zirconium oxide, lanthanum oxide, and yttrium oxide.

11. The NOx storage washcoat composition according to claim 1 , wherein the composite nanoparticles are plasma generated.

12. The NOx storage washcoat composition of claim 1 , wherein the catalytic nanoparticle comprises platinum, palladium, or platinum and palladium.

13. The NOx storage washcoat composition according to claim 1 , wherein the support nanoparticle comprises a metal oxide.

14. A coated substrate comprising a substrate coated with the NOx storage washcoat composition according to claim 1 .

15. The coated substrate of claim 14 , wherein the coated substrate further comprises a reducing washcoat layer.

16. A catalytic converter comprising the coated substrate of claim 14 .

17. An exhaust treatment system comprising a conduit for exhaust gas and a catalytic converter according to claim 16 .

18. A vehicle comprising a catalytic converter according to claim 16 .

19. A method of treating exhaust gas, comprising contacting the coated substrate of claim 14 with the exhaust gas.

20. The coated substrate of claim 14 , wherein the washcoat layer is formed by:
combining a first component comprising the oxygen-storage particles, a second component comprising the composite nanoparticles, and a third component comprising the alkaline earth metal salt to form a washcoat slurry, wherein the composite nanoparticles are not pre-attached to a micron-sized particle when added to the washcoat slurry;
coating the washcoat slurry onto the substrate; and
calcining the substrate, thereby:
converting the alkaline earth metal salt into the alkaline earth metal oxide; and
forming the washcoat layer.

21. A method of producing a washcoat composition, the method comprising:
combining a first component comprising a plurality of micron-sized oxygen-storage particles; a second component comprising a plurality of composite nanoparticles, the composite nanoparticle comprising a support nanoparticle and a catalytic nanoparticle, the catalytic nanoparticle comprising one or more platinum group metals, wherein the composite nanoparticles are not pre-attached to a micron-sized particle when added to the washcoat composition; and a third component comprising an alkaline earth metal salt to form the washcoat composition.

22. A method of producing a coated substrate, the method comprising:
coating a substrate with the washcoat composition of claim 21 ; and
calcining the substrate, thereby forming a NOx storage washcoat layer coating the substrate.

Assignees

• Umicore Ag & Co Kg

Inventors

• Biberger Maximilian A
• Kearl Bryant
• Yin Qinghua
• Qi Xiwang
• Leamon David

Classifications

• B01D2255/9202

  Linear dimensions · CPC title

• B01J35/0013

  Operations & Transport · mapped topic

• B01J2523/48

  Zirconium · CPC title

• B01J2523/31

  Aluminium · 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