Multifunctional filters for diesel emission control

Patent metadata

Field	Value
Publication number	US-10188987-B2
Application number	US-201615562621-A
Country	US
Kind code	B2
Filing date	Mar 30, 2016
Priority date	Mar 30, 2015
Publication date	Jan 29, 2019
Grant date	Jan 29, 2019

Abstract

Provided are multi-zone catalyst articles, methods of manufacturing multi-zone catalyst articles, and methods for controlling emissions in diesel engine exhaust streams with multi-zone catalyst articles, where the emission treatment system of various embodiments effectively treats diesel engine exhaust with a single multi-zone catalyst article.

First claim

What is claimed is:

1. A catalyzed particulate filter comprising:
a plurality of porous walls extending longitudinally to form a plurality of parallel passages extending from an inlet end to an outlet end, wherein a quantity of the passages are inlet passages that are open at the inlet end and closed at the outlet end, and a quantity of passages are outlet passages that are closed at the inlet end and open at the outlet end;
at least three coatings creating at least two zones axially along the plurality of porous walls, wherein a first coating is a first SCR catalyst coating, a second coating is a second SCR catalyst coating, and a third coating is a platinum group metal coating.

2. The catalyzed particulate filter of claim 1 , wherein the at least three coatings create at least three zones axially along the plurality of porous walls, and wherein:
a first zone extends axially from the inlet end of the porous walls a distance less than the full length of the porous walls and consists essentially of the first SCR catalyst coating; and
a second zone extends axially from the first zone a distance less than the distance to the outlet end of the porous walls and comprises the platinum group metal coating and the first SCR catalyst coating.

3. The catalyzed particulate filter of claim 2 , wherein:
a third zone extends axially from the second zone to the outlet end of the porous wall and comprises the platinum group metal coating and the second SCR catalyst coating.

4. The catalyzed particulate filter of claim 2 , which further comprises a third zone and a fourth zone axially along the plurality of porous walls, wherein:
the third zone extends axially from the second zone a distance less than the distance to the outlet end of the porous wall and consists essentially of the first SCR catalyst coating, the second SCR catalyst coating, and the platinum group metal coating; and
the fourth zone extends axially from the third zone to the outlet end of the porous walls and comprises the platinum group metal coating and the second SCR catalyst coating.

5. The catalyzed particulate filter of claim 4 , wherein the first SCR catalyst coating and the second SCR catalyst coating each independently comprise a molecular sieve with a zeolitic framework material selected from AEI, CHA, and AFX, and wherein the molecular sieves of the first and second SCR catalyst coatings are independently promoted with a metal selected from Cu, Fe, Co, Ni, La, V, Mo, W, Mn, Ce, and combinations thereof; and
wherein the platinum group metal is present in the third and fourth zones at a loading in the range of about 1 g/ft 3 to about 50 g/ft 3 .

6. The catalyzed particulate filter of claim 5 , wherein the platinum group metal coating in the second zone is on the surface of the porous walls; and the platinum group metal coating in the third zone is sandwiched between the first SCR catalyst coating and the second SCR catalyst coating.

7. The catalyzed particulate filter of claim 1 , wherein the at least three coatings create at least three zones axially along the plurality of porous walls, and wherein:
a first zone extends axially from the inlet end of the porous walls a distance less than the full length of the porous wall and consists essentially of the first SCR catalyst coating; and
a second zone extends axially from the first zone a distance less than the distance to the outlet end of the porous walls comprises the first SCR catalyst coating and the second SCR catalyst coating.

8. The catalyzed particulate filter of claim 7 , which further comprises a third zone axially along the plurality of porous walls, wherein:
the third zone extends axially from the second zone to the outlet end of the porous walls and comprises the platinum group metal coating and the second SCR catalyst coating.

9. The catalyzed particulate filter of claim 7 , which further comprises a third zone and a fourth zone axially along the plurality of porous walls, wherein:
the third zone extends axially from the second zone a distance less than the distance to the outlet end of the porous walls and consists essentially of the first SCR catalyst coating, the second SCR catalyst coating, and the platinum group metal coating; and
the fourth zone extends axially from the third zone to the outlet end of the porous walls and comprises the platinum group metal coating and the second SCR catalyst coating.

10. The catalyzed particulate filter of claim 9 , wherein the platinum group metal coating in the third zone is sandwiched between the first SCR catalyst coating and the second SCR catalyst coating; and the platinum group metal coating is intermingled with the second SCR catalyst coating in the fourth zone, wherein the first SCR catalyst coating and the second SCR catalyst coatings in the first, second, third, and fourth zones each comprise a molecular sieve with a zeolitic framework material selected from AEI, CHA, and AFX, and wherein the molecular sieves are independently promoted with a metal selected from Cu, Fe, Co, Ni, La, V, Mo, W, Mn, Ce, and combinations thereof.

11. The catalyzed particulate filter of claim 1 , wherein the at least three coatings create at least three zones axially along the plurality of porous walls, and wherein:
a first zone extends axially from the inlet end of the porous walls a distance less than the full length of the porous walls and consists essentially of the first SCR catalyst coating;
a second zone extends axially from the first zone a distance less than the distance to the outlet end of the porous wall and comprises the first SCR catalyst coating, the second SCR catalyst coating, and the platinum group metal coating; and
a third zone extends axially from the second zone to the outlet end of the porous walls and comprises the platinum group metal coating and the second SCR catalyst coating.

12. The catalyzed particulate filter of claim 1 , wherein the at least three coatings create at least three zones axially along the plurality of porous walls, and wherein:
a first zone extends axially from the inlet end of the porous walls a distance less than the full length of the porous wall and comprises the first SCR catalyst coating and the platinum group metal coating; and
a second zone extends axially from the first zone a distance less than the distance to the outlet end of the porous wall and consists essentially of the first SCR catalyst coating, the second SCR catalyst coating, and the platinum group metal coating.

13. The catalyzed particulate filter of claim 12 , wherein:
a third zone extends axially from the second zone to the outlet end of the porous wall and consists essentially of the second SCR catalyst coating.

14. The catalyzed particulate filter of claim 12 , which further comprises a third zone and a fourth zone axially along the plurality of porous walls, wherein:
the third zone extends axially from the second zone a distance less than the distance to the outlet end of the porous wall and consists essentially of the second SCR catalyst coating, and the platinum group metal coating; and
the fourth zone extends axially from the third zone to the outlet end of the porous wall and consists essentially of the second SCR catalyst coating,
wherein the platinum group metal coating in the first zone is on the surface of the porous walls;
the platinum group metal coating in the second zone is sandwiched between the first SCR catalyst coating and the second SCR catalyst coating, and the platinum group metal coating is intermingled with the second SCR catalyst coating in the third zone.

15. The catalyzed particulate filter of clai

Assignees

• Basf Corp

Inventors

• Li Yuejin
• Roth Stanley A

Classifications

• B01J23/42

  Platinum · CPC title

• B01D53/9418

  for removing nitrogen oxides by selective catalytic reduction [SCR] using a reducing agent in a lean exhaust gas · CPC title

• B01D2255/20723

  Vanadium · CPC title

• B01J37/0244

  Coatings comprising several layers · CPC title

• B01D2255/50

  Zeolites · CPC title