Diesel oxidation catalyst

Patent metadata

Field	Value
Publication number	US-9370769-B2
Application number	US-201113877764-A
Country	US
Kind code	B2
Filing date	Oct 19, 2011
Priority date	Oct 26, 2010
Publication date	Jun 21, 2016
Grant date	Jun 21, 2016

Abstract

The present invention relates to a catalytically active material consisting of an inner core ( 1 ) and an outer shell ( 2 ) surrounding this core, the core being formed from palladium and gold fixed together on a first support oxide, and the shell comprising platinum fixed on a second support oxide, to a diesel oxidation catalyst comprising this catalytically active material, and to an exhaust gas cleaning system comprising this diesel oxidation catalyst.

First claim

The invention claimed is:

1. A catalytically active material comprising an inner core ( 1 ) and an outer shell ( 2 ) surrounding this core, the core being formed from palladium and gold fixed together on a first support oxide, and the shell comprising platinum fixed on a second support oxide, wherein particles comprised of the inner core ( 1 ) and the outer shell ( 2 ) are approximately spherical and have a mean diameter of 1 to 12 μm.

2. The catalytically active material as claimed in claim 1 , wherein the outer shell ( 2 ) comprises palladium as a further noble metal.

3. The catalytically active material as claimed in claim 1 , wherein the outer shell ( 2 ) comprises a zeolite compound with HC-storing properties.

4. The catalytically active material as claimed in claim 3 , wherein the zeolite compound is selected from the group consisting of FAU, MOR, zeolite beta, NMI and mixtures thereof.

5. The catalytically active material as claimed in claim 3 , wherein the zeolite compound is present in a proportion of 10 to 60% by weight, based on the total weight of the outer shell ( 2 ).

6. The catalytically active material as claimed in claim 1 , wherein the first and/or second support oxide is selected from the group consisting of cerium oxide, zirconium oxide, aluminum oxide, silicon oxide and mixed oxides and/or mixtures thereof.

7. The catalytically active material as claimed in claim 1 , wherein the proportion by volume of the inner core ( 1 ) in a spherical particle is 50 to 80%.

8. A diesel oxidation catalyst comprising a catalytically inert support body and at least one catalytically active coating applied thereto, wherein the coating comprises the catalytically active material as claimed in claim 1 .

9. The diesel oxidation catalyst as claimed in claim 8 , wherein the coating comprises a zeolite compound with HC-storing properties selected from the group consisting of FAU, MOR, zeolite beta, MFI and mixtures thereof.

10. The diesel oxidation catalyst as claimed in claim 9 , wherein the proportion of the zeolite compound in the coating is 15 to 45% by weight, based on the total weight of the coating.

11. The diesel oxidation catalyst as claimed in claim 8 , wherein the catalytically inert support body is selected from the group of the ceramic and metallic flow honeycombs or from the group of the ceramic wall flow filter substrates.

12. A method for reducing the level of carbon monoxide and/or hydrocarbons in the exhaust gas of a diesel engine, comprising:
passing the exhaust gas over the diesel oxidation catalyst of claim 8 .

13. An exhaust gas cleaning system for treatment of the exhaust gases of diesel engines, comprising the diesel oxidation catalyst of claim 8 .

14. The exhaust gas cleaning system as claimed in claim 13 , further comprising a diesel particulate filter which is connected downstream of the diesel oxidation catalyst in flow direction of the exhaust gas to be cleaned.

15. A method of producing an exhaust gas cleaning system comprising:
arranging the diesel oxidation catalyst of claim 8 in an exhaust gas contact location within an exhaust gas passageway.

16. The method of claim 15 , further comprising positioning a diesel particle filter within the exhaust gas passageway downstream of the diesel oxidation catalyst in a flow direction of the exhaust gas to be cleaned.

17. The catalytically active material as claimed in claim 2 , wherein the outer shell ( 2 ) comprises a zeolite compound with HC-storing properties.

18. The catalytically active material as claimed in claim 17 , wherein the zeolite compound is selected from the group consisting of FAU, MOR, zeolite beta, MFI and mixtures thereof.

19. The catalytically active material as claimed in claim 4 , wherein the zeolite compound is present in a proportion of 10 to 60% by weight, based on the total weight of the outer shell ( 2 ).

Assignees

• Schuetze Frank-Walter
• Woerz Anke
• Jeske Gerald
• Umicore Ag & Co Kg

Inventors

• Schuetze Frank-Walter
• Woerz Anke
• Jeske Gerald

Classifications

• B01J35/53

  with a core-shell structure · CPC title

• B01D53/944 Primary

  Simultaneously removing carbon monoxide, hydrocarbons or carbon making use of oxidation catalysts (three-way-catalysts [TWC] B01D53/9445) · CPC title

• B01J35/56

  Foraminous structures having flow-through passages or channels, e.g. grids or three-dimensional [3D] monoliths · CPC title

• B01J35/393

  Metal or metal oxide crystallite size · CPC title

• B01D2255/912

  HC-storage component incorporated in the catalyst · CPC title