Rhodium-iron catalysts

• US 9,475,004 B2
• Filed: 06/05/2015
• Issued: 10/25/2016
• 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., Golden, Stephen J., Ngo, Johnny T.
• Primary Examiner(s): Nguyen, Cam N.
• Application Number:
  US14/732,307
• Publication Number:
  US 20150352531A1
• Time in Patent Office: 508 Days
• Field of Search: 502302-304, 502326-327, 502/336, 502/338, 502/349, 502/355, 502/439, 502/527.12, 502/527.13
• 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 rhodium iron catalysts of use in catalyst systems. Disclosed here are TWCs configured to include a substrate and one or more of a washcoat layer, an impregnation layer, and/or an overcoat layer. Disclosed herein are one or more of a washcoat layer and/or an overcoat layer formed using a slurry that includes one or more of an oxygen storage material, a refractory support oxide, iron, and rhodium. Disclosed herein are methods of preparing catalysts wherein a washcoat layer is deposited onto the substrate, one or more impregnation layers may be deposited onto the washcoat layer, one or more overcoat layers may be deposited onto the impregnation washcoat layer, and one or more additional impregnation layers may be deposited onto the one or more washcoat layers.

Claims

1. A catalyst system, comprising:

a substrate;

a washcoat deposited on the substrate;

at least one impregnation layer; and

an overcoat;

wherein the washcoat comprises at least one of the group consisting of about 10 wt % to about 75 wt % cerium oxide, about 25 wt % to about 90 wt % zirconium-hafnium oxide, about 0 wt % to about 15 wt % lanthanum oxide, about 0 wt % to about 15 wt % neodymium oxide, about 0 wt % to about 15 wt % yttrium oxide, and about 0 wt % to about 15 wt % praseodymium oxide;

wherein the at least one impregnation layer comprises one or more of the group consisting of rhodium, iron nitrate, cerium, and combinations thereof; and

wherein the overcoat comprises at least one of the group consisting of an oxygen storage material, a refractory support oxide, iron, rhodium, and combinations thereof.

2. The catalyst system of claim 1, wherein the washcoat further comprises at least one of the group consisting of a refractory support oxide, iron, rhodium, and combinations thereof.

3. The catalyst system of claim 1, wherein the at least one impregnation layer is loaded with about 2.9 g/ft³ to about 9.8 g/ft³ of rhodium.

4. The catalyst system of claim 3, wherein the at least one impregnation layer is loaded in the washcoat and wherein the washcoat further comprises a second impregnation layer of about 1 wt % to about 4 wt % iron.

5. The catalyst system of claim 3, wherein the at least one impregnation layer is loaded with about 60 g/ft³ to about 630 g/ft³ of iron.

6. The catalyst system of claim 5, wherein the at least one impregnation layer is loaded with about 150 g/ft³ to about 630 g/ft³ of iron.

7. The catalyst system of claim 3, wherein the washcoat comprises at least one of the group consisting of a fluorite phase Cerium Zirconium-Hafnium Lanthanum (CZL) OSM, a Cerium Zirconium-Hafnium Neodymium (CZN) OSM, a Cerium Zirconium-Hafnium Yttrium (CZY) OSM, a Cerium Zirconium-Hafnium Lanthanum Praseodymium (CZLP) OSM, a Cerium Zirconium (CZ) OSM, and a Cerium Zirconium-Hafnium Neodymium Yttrium (CZNY) OSM.

8. The catalyst system of claim 7, wherein said CZL OSM includes 30 wt % Cerium Oxide, 60 wt % Zirconium-Hafnium Oxide, and 10 wt % Lanthanum Oxide;

said CZN OSM includes 30 wt % Cerium Oxide, 60 wt % Zirconium-Hafnium Oxide, and 10 wt % Neodymium Oxide;

said CZY OSM includes 30 wt % Cerium Oxide, 60 wt % Zirconium-Hafnium Oxide, and 10 wt % Yttrium Oxide;

said CZLP OSM includes 30 wt % Cerium Oxide, 60 wt % Zirconium-Hafnium Oxide, 5 wt % Lanthanum Oxide, and 5 wt % Praseodymium Oxide;

said CZ OSM includes 75 wt % Cerium Oxide and 30% Zirconium-Hafnium Oxide; and

said CZNY OSM includes 31 wt % Cerium, 58.3 wt % Zirconium-Hafnium, 5.5 wt % Neodymium, and 5.2 wt % Yttrium Oxide.

9. The catalyst system of claim 3, wherein the washcoat comprises at least one of the group consisting of a CZL, a CZN, a CZY, a CZLP, and a CZNY.

10. The catalyst system of claim 9, wherein said CZL OSM includes 30 wt % Cerium Oxide, 60 wt % Zirconium-Hafnium Oxide, and 10 wt % Lanthanum Oxide;

said CZN OSM includes 30 wt % Cerium Oxide, wt % Zirconium-Hafnium Oxide, and 10 wt % Neodymium Oxide;

said CZY OSM includes 30 wt % Cerium Oxide, 60 wt % Zirconium-Hafnium Oxide, and 10 wt % Yttrium Oxide;

said CZLP OSM includes 30 wt % Cerium Oxide, 60 wt % Zirconium-Hafnium Oxide, 5 wt % Lanthanum Oxide, and 5 wt % Praseodymium Oxide; and

said CZNY OSM includes 31 wt % Cerium, 58.3 wt % Zirconium-Hafnium, 5.5 wt % Neodymium, and 5.2 wt % Yttrium Oxide.

11. The catalyst system of claim 3, wherein the at least one impregnation layer is further loaded with about 150 g/ft³ to about 630 g/ft³ of iron;

about 499 g/ft³ to about 1497 g/ft³ Cerium; and

0 g/ft³ to about 317 g/ft³ yttrium.

12. The catalyst system of claim 3, wherein the at least one impregnation layer is further loaded with about 150 g/ft³ to about 630 g/ft³ of iron;

0 g/ft³ to about 1497 g/ft³ Cerium; and

about 31.7 g/ft³ to about 317 g/ft³ yttrium.

13. The catalyst system of claim 3, wherein the washcoat comprises about 7.36 wt % iron.

14. The catalyst system of claim 1, wherein the at least one impregnation layer is loaded with about 60 g/ft³ to about 630 g/ft³ of iron.

15. The catalyst system of claim 1, wherein the at least one impregnation layer is loaded with about 499 g/ft³ to about 1497 g/ft³ of cerium.

16. The catalyst system of claim 1, wherein the washcoat comprises iron, rhodium, and CZNY OSM.

17. The catalyst system of claim 16, wherein the washcoat comprises 7.36 wt % iron, rhodium, and CZNY OSM, and wherein the CZNY OSM comprises 31 wt % Cerium, 58.3 wt % Zirconium-Hafnium, 5.5 wt % Neodymium, and 5.2 wt % Yttrium Oxide.

18. The catalyst system of claim 1, wherein the washcoat comprises about 4 wt % to about 20 wt % iron.

19. The catalyst system of claim 1, wherein rhodium is loaded in the washcoat at about 0.1 g/ft³ to about 20 g/ft³.

20. The catalyst system of claim 19, wherein rhodium is loaded in the washcoat at about 4.8 g/ft³.