Phosphorus tolerant catalyst washcoat structure

Patent metadata

Field	Value
Publication number	US-9919294-B2
Application number	US-201615139726-A
Country	US
Kind code	B2
Filing date	Apr 27, 2016
Priority date	Apr 27, 2016
Publication date	Mar 20, 2018
Grant date	Mar 20, 2018

Abstract

Phosphorus tolerant or resistant three-way catalysts (TWC) are disclosed. The TWC may include a substrate defining a plurality of channels. It may include front and rear washcoat portions overlying the substrate and having respective first and second washcoat loadings, the first washcoat loading being at most 2.0 g/in 3 and less than the second washcoat loading. The front washcoat portion may include a catalyst material supported on a support material comprising a cerium oxide, such as ceria or CZO, or a pre-phosphated material, such as AlPO 4 , or CePO 4 . In one embodiment, the support material may comprise at least 85 wt. % of a cerium oxide or at least 85 wt. % of a phosphate-containing material. The front portion and the underlying substrate may comprise from 3 to 25 vol. % of the three-way catalyst or the front portion may overly up to an initial 15% of an axial length of the substrate.

First claim

What is claimed is:

1. A three-way catalyst, comprising:
a substrate defining a plurality of channels;
front and rear washcoat portions directly overlying the substrate and having respective first and second washcoat loadings, the second washcoat loading being at least 3.0 g/in 3 , the front or rear washcoat portion being exposed on an upper side; and
the front washcoat portion including a catalyst material loaded onto a support material comprising at least 85 wt. % of a cerium oxide and excluding alumina at a loading of at least 25 g/ft 3 .

2. The three-way catalyst of claim 1 , wherein the support material comprises at least 95 wt. % of a cerium oxide.

3. The three-way catalyst of claim 1 , wherein the cerium oxide includes at least one of CeO 2 and a cerium zirconium oxide (CZO).

4. The three-way catalyst of claim 1 , wherein the front washcoat portion and a portion of the substrate that it overlies comprise from 3 to 25 vol. % of the three-way catalyst.

5. The three-way catalyst of claim 1 , wherein the front washcoat portion overlies up to 15% of an axial length of the substrate.

6. The three-way catalyst of claim 1 , wherein the catalyst material includes a platinum group metal (PGM).

7. The three-way catalyst of claim 1 , wherein the front washcoat portion and the rear washcoat portion together overlie substantially an entire axial length of the substrate.

8. A three-way catalyst, comprising:
a substrate defining a plurality of channels;
front and rear washcoat portions directly overlying the substrate and having respective first and second washcoat loadings; and
the front washcoat portion being exposed on an upper side and including a catalyst material loaded onto a support material comprising at least 85 wt. % of a cerium oxide and excluding alumina at a loading of at least 25 g/ft 3 .

9. The three-way catalyst of claim 8 , wherein the support material comprises at least 95 wt. % of a cerium oxide.

10. The three-way catalyst of claim 8 , wherein the cerium oxide includes at least one of CeO 2 and a cerium zirconium oxide (CZO).

11. The three-way catalyst of claim 8 , wherein the front washcoat portion and a portion of the substrate that it overlies comprise from 3 to 25 vol. % of the three-way catalyst.

12. The three-way catalyst of claim 8 , wherein the front washcoat portion overlies up to 15% of an axial length of the substrate.

13. The three-way catalyst of claim 8 , wherein the catalyst material includes a platinum group metal (PGM).

14. A three-way catalyst, comprising:
front and rear washcoat portions directly overlying a substrate and having respective first and second washcoat loadings, the rear washcoat portion being exposed on an upper side, the first washcoat loading being at most 1.5 g/in 3 ; and
the front washcoat portion including a catalyst material supported on a support material comprising at least 85 wt. % of a cerium oxide and excluding alumina at a loading of at least 25 g/ft 3 .

15. The three-way catalyst of claim 14 , wherein the support material comprises at least 95 wt. % of a cerium oxide.

16. The three-way catalyst of claim 14 , wherein the cerium oxide includes at least one of CeO 2 and a cerium zirconium oxide (CZO).

17. The three-way catalyst of claim 14 , wherein the front washcoat portion and a portion of the substrate that it overlies comprise from 3 to 25 vol. % of the three-way catalyst.

18. The three-way catalyst of claim 14 , wherein the front washcoat portion overlies up to 15% of an axial length of the substrate.

19. The three-way catalyst of claim 14 , wherein the catalyst material includes a platinum group metal (PGM).

20. The three-way catalyst of claim 14 , wherein the front washcoat portion and the rear washcoat portion together overlie substantially an entire axial length of the substrate.

Assignees

• Ford Global Tech Llc

Inventors

• Laing Paul M
• Hubbard Carolyn Parks
• Hepburn Jeffrey Scott
• Thanasiu Eva
• Cavataio Giovanni
• Jen Hungwen
• Jagner Mark John
• Harrington Rachael Jean
• Shane Michael Daniel

Classifications

• B01D2255/407

  Zr-Ce mixed oxides · CPC title

• B01J23/10

  of rare earths · CPC title

• B01D53/945

  characterised by a specific catalyst · CPC title

• B01D2255/20715

  Zirconium · CPC title

• B01D2255/102

  Platinum group metals · CPC title