Three-way Catalyst Systems Including Nb-Zr-Al-Mixed Oxide Supports, Ba-Pd, and Rh-Fe Material Compositions

• US 20150352494A1
• Filed: 06/05/2015
• Published: 12/10/2015
• Est. Priority Date: 06/06/2014
• Status: Active Grant

• Current Assignee: Clean Diesel Technologies, Inc.
• Original Assignee: Clean Diesel Technologies, Inc.
• Inventors: Hatfield, Randal L., Nazarpoor, Zahra, Ngo, Johnny T., Lee, Edward J., Golden, Stephen J.
• Granted Patent: US 9,604,175 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B01D 2255/1023 Palladium
• CPC Class Codes: B01D 2255/1025 Rhodium
• CPC Class Codes: B01D 2255/2042 Barium
• CPC Class Codes: B01D 2255/2061 Yttrium
• CPC Class Codes: B01D 2255/2063 Lanthanum
• CPC Class Codes: B01D 2255/2065 Cerium
• CPC Class Codes: B01D 2255/2066 Praseodymium
• CPC Class Codes: B01D 2255/2068 Neodymium
• CPC Class Codes: B01D 2255/207 Transition metals
• CPC Class Codes: B01D 2255/20715 Zirconium
• CPC Class Codes: B01D 2255/20738 Iron
• CPC Class Codes: B01D 2255/209 Other metals
• CPC Class Codes: B01D 2255/2092 Aluminium
• CPC Class Codes: B01D 2255/40 Mixed oxides
• CPC Class Codes: B01D 2255/902 Multilayered catalyst
• CPC Class Codes: B01D 2255/908 O2-storage component incorporated in the catalyst
• CPC Class Codes: B01D 53/945 characterised by a specific catalyst
• CPC Class Codes: B01D 53/9454 characterised by a specific device
• CPC Class Codes: B01D 53/9472 in different zones
• CPC Class Codes: B01J 21/04 Alumina
• CPC Class Codes: B01J 23/002 : Mixed oxides other than spinels, e.g. perovskite
• CPC Class Codes: B01J 23/10 : of rare earths
• CPC Class Codes: B01J 23/20 : Vanadium, niobium or tantalum
• CPC Class Codes: B01J 23/63 : with rare earths or actinides
• CPC Class Codes: B01J 23/83 : with rare earths or actinides
• CPC Class Codes: B01J 23/8906 : Iron and noble metals
• CPC Class Codes: B01J 23/894 : with rare earths or actinides
• CPC Class Codes: B01J 2523/00 : Constitutive chemical elements of heterogeneous catalysts
• CPC Class Codes: B01J 27/232 : Carbonates
• CPC Class Codes: B01J 35/19 : Catalysts containing parts with different compositions
• CPC Class Codes: B01J 35/56 : Foraminous structures having flow-through passages or channels, e.g. grids or three-dimensional monoliths
• CPC Class Codes: B01J 37/0244 : Coatings comprising several layers
• CPC Class Codes: Y02A 50/20 : Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters
• CPC Class Codes: Y02T 10/12 : Improving ICE efficiencies

Abstract

The present disclosure describes zoned three way catalyst (TWC) systems including Rhodium-iron overcoat layers and Nb—Zr—Al Oxide overcoat layers. Disclosed herein are TWC sample systems that are configured to include a substrate and one or more of a washcoat layer, an impregnation layer, and/or an overcoat layer. In catalyst systems disclosed herein, closed-coupled catalysts include a first catalyst zone with an overcoat layer formed using a slurry that includes an oxide mixture and an Oxygen Storage Material (OSM). In catalyst systems disclosed herein, oxide mixtures include niobium oxide (Nb₂O₅), zirconia, and alumina. Further, catalyst systems disclosed herein include a second catalyst zone with an overcoat layer formed to include a rhodium-iron catalyst. Yet further, catalyst systems disclosed herein include impregnation layers that include one or more of Palladium, Barium, Cerium, Neodymium, and Rhodium.

Claims

1. A close-coupled converter system, comprising:

a first catalyst zone; and

a second catalyst zone;

wherein the first catalyst zone is configured to receive exhaust gases, process the received exhaust gases into first treated gases, and expel the first treated gases into the second catalyst zone;

wherein the second catalyst zone is configured to receive the first treated cases from the first catalyst zone, process the received first treated gases into second treated gases, and expel the second treated gases;

wherein the first catalyst zone comprises;

a first catalyst zone substrate;

a first catalyst zone washcoat deposited on the first catalyst zone substrate;

at least one first catalyst zone impregnation layer; and

a first catalyst zone overcoat;

wherein the first catalyst zone washcoat comprises a first catalyst zone first oxygen storage material including Cerium, Zirconium-Hafnium, Neodymium, and Yttrium, and a first catalyst zone support oxide;

wherein the at least one first catalyst zone impregnation layer comprises Pd, Ba, Ce, and Nd;

wherein the first catalyst zone overcoat comprises a first catalyst zone second oxygen storage material comprising Cerium, Zirconium-Hafnium, Neodymium, and Yttrium, and a first catalyst zone oxide mixture comprising Niobium, Zirconium-Hafnium, Alumina and Rhodium;

wherein the second catalyst zone comprises;

a second catalyst zone substrate;

a second catalyst zone washcoat deposited on the second catalyst zone substrate;

at least one second catalyst zone impregnation layer; and

a second catalyst zone overcoat;

wherein at the second catalyst zone overcoat comprises rhodium and iron.

2. The close-coupled converter system of claim 1, wherein the second catalyst zone overcoat comprises a second catalyst zone oxygen storage material, Fe, and Rh.

3. The close-coupled converter system of claim 1, wherein the at least one second catalyst zone impregnation layer comprises Pd, Ba, Ce, and Nd.

4. The close-coupled converter system of claim 1, wherein a first layer of the at least one first catalyst zone impregnation layer comprises about 22 g/ft³ to about 90 g/ft³ of palladium and about 115 g/ft³ to about 690 g/ft³ of barium.

6. The close-coupled converter system of claim 1, wherein a second layer of the at least one first catalyst zone impregnation layer includes 0 g/ft³ to about 147 g/ft³ of loaded palladium.

7. The close-coupled converter system of claim 6, wherein a second layer of the at least one first catalyst zone impregnation layer includes 70 g/ft³ to about 147 g/ft³ of loaded palladium.

8. The close-coupled converter system of claim 1, wherein a first layer of the at least one second catalyst zone impregnation layer comprises 25 g/ft³ of loaded palladium;

about 115 g/ft³ of loaded barium;

about 105.8 g/ft³ of loaded cerium; and

about 12 g/ft³ of loaded neodymium.

9. The close-coupled converter system of claim 4, wherein a first layer of the at least one second catalyst zone impregnation layer comprises 25 g/ft³ of loaded palladium;

about 115 g/ft³ of loaded barium;

about 105 g/ft³ of loaded cerium; and

about 12 g/ft³ of loaded neodymium.

10. The close-coupled converter system of claim 6, wherein a first layer of the at least one second catalyst zone impregnation layer comprises 25 g/ft³ of loaded palladium;

about 115 g/ft³ of loaded barium;

about 105 g/ft³ of loaded cerium; and

about 12 g/ft³ of loaded neodymium.

11. The close-coupled converter system of claim 1, wherein the first catalyst zone oxide mixture comprises about 10 wt % niobium oxide and about 20 wt % zirconia.

12. The close-coupled converter system of claim 1, wherein the first catalyst zone overcoat is loaded with about 3 g/ft³ to about 3 g/ft³ rhodium.

13. The close-coupled converter system of claim 1, wherein the first catalyst zone overcoat is loaded with about 15.1 g/ft³ to about 24 g/ft³ rhodium.

14. The close-coupled converter system of claim 1, wherein the second catalyst zone overcoat is loaded with about 3 g/ft³ to about 3 g/ft³ rhodium.

15. The close-coupled converter system of claim 1, wherein the second catalyst zone overcoat is loaded with about 210 g/ft³ iron.

16. The close-coupled converter system of claim 1, wherein the second catalyst zone second oxygen storage material comprises 31 wt % Cerium, about 58 wt % Zirconium-Hafnium, about 5 wt % Neodymium, and about 5 wt % Yttrium Oxide.

17. The close-coupled converter system of claim 1, wherein the first catalyst zone first oxygen storage material comprises 31 wt % Cerium, about 58 wt % Zirconium-Hafnium, about 5 wt % Neodymium, and about 5 wt % Yttrium Oxide.

18. The close-coupled converter system of claim 1, wherein the first catalyst zone washcoat comprises about 40 wt % of the first catalyst zone first oxygen storage material and about 60 wt % of the first catalyst zone support oxide and wherein the first catalyst zone support oxide is doped alumina.

19. The close-coupled converter system of claim 1, wherein, excluding the Rhodium, the first catalyst zone overcoat comprises about 40 wt % of the first catalyst zone second oxygen storage material and about 60 wt % of the catalyst zone oxide mixture.

20. The close-coupled converter system of claim 1, wherein the second catalyst zone washcoat comprises about 40 wt % of a second catalyst zone first oxygen storage material and about 60 wt % of a doped alumina.

5. The close-coupled converter system of claim 5, wherein the first layer of the at least one first catalyst zone impregnation layer further comprises about 105 g/ft³ of loaded cerium and about 12 g/ft³ of loaded neodymium.