Catalyst with improved hydrothermal stability

Patent metadata

Field	Value
Publication number	US-9611774-B2
Application number	US-201414467250-A
Country	US
Kind code	B2
Filing date	Aug 25, 2014
Priority date	Mar 13, 2013
Publication date	Apr 4, 2017
Grant date	Apr 4, 2017

Abstract

A catalyst for the treatment of exhaust gas emissions is disclosed. The catalyst can comprise ceria-alumina particles having a ceria phase present in a weight percent of the composite in the range of about 20% to about 80% on an oxide basis, an alkaline earth metal component supported on the ceria-alumina particles, wherein the CeO 2 is present in the form of crystallites that are hydrothermally stable and have an average crystallite size less than 160 Å after aging at 950° C. for 5 hours in 2% O 2 and 10% steam in N 2 .

First claim

What is claimed is:

1. An emission treatment system comprising:
a catalyst including a catalyst composition comprising ceria-alumina particles having a ceria phase present in a weight percent of the particles in the range of about 20% to about 80% on an oxide basis, an alkaline earth metal component supported on the ceria-alumina particles, wherein the CeO 2 is present in the form of crystallites that are hydrothermally stable and have an average crystallite size of less than 160 Å after aging at 950° C. for 5 hours in 2% O 2 and 10% steam in N 2 ; a lean burn engine located upstream from the catalyst composition; and a second, different catalyst.

2. The emission treatment system of claim 1 , further comprising a particulate filter.

3. The emission treatment system of claim 1 , wherein the second, different catalyst is selected from a three-way catalyst (TWC), a gasoline particulate filter (GPF), a selective catalytic reduction (SCR) catalyst, a lean NO x trap (LNT), an ammonia oxidation (AMOX) catalyst, a SCR on a filter (SCRoF), and combinations thereof.

4. The emission treatment system of claim 1 , wherein the alkaline earth metal component comprises a barium component.

5. The emission treatment system of claim 4 , wherein the barium component is selected from the group consisting of barium oxide and barium carbonate.

6. The emission treatment system of claim 4 , further comprising at least one platinum group metal selected from the group consisting of platinum, palladium, rhodium, iridium, and mixtures thereof, supported on the ceria-alumina particles.

7. The emission treatment system of claim 6 , wherein the platinum group metal is selected from platinum, palladium, rhodium, and mixtures thereof.

8. The emission treatment system of claim 6 , wherein the platinum group metal consists essentially of platinum and palladium.

9. The emission treatment system of claim 6 , wherein the platinum group metal consists essentially of platinum.

10. The emission treatment system of claim 4 , wherein the barium component is present in an amount in of about 0.5% to 50% by weight on an oxide basis.

11. The emission treatment system of claim 10 , wherein the barium component is present in an amount of about 5% to 30% by weight on an oxide basis.

12. The emission treatment system of claim 1 , wherein the ceria-alumina particles are a composite of ceria and alumina.

13. The emission treatment system of claim 12 , wherein the composite of ceria and alumina contains ceria in an amount of about 30% to 80% by weight on an oxide basis.

14. The emission treatment catalyst of claim 12 , wherein the composite of ceria and alumina contains ceria in an amount of about 50% to 80% by weight on an oxide basis.

Assignees

• Basf Corp

Inventors

• Xue Wen-Mei
• Wei Xinyi
• Hilgendorff Marcus
• Burk Patrick

Classifications

• B01J35/77

  Compounds characterised by their crystallite size · CPC title

• B01J35/45

  Nanoparticles · CPC title

• B01J2235/15

  X-ray diffraction · CPC title

• B01J35/30

  characterised by their physical properties · CPC title

• B01J37/0248 Primary

  Coatings comprising impregnated particles · CPC title