Three-way Catalyst Systems Including Fe-activated Rh and Ba-Pd Material Compositions

• US 20150352532A1
• 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., Ngo, Johnny T., Golden, Stephen J., Lee, Edward J.
• Granted Patent: US 9,475,005 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

Three way catalysts (TWCs) for catalyst systems are disclosed. The disclosed TWC systems include Iron (Fe)-activated Rhodium (Rh) and Barium (Ba)-Palladium (Pd) layers capable of interacting with conventional and/or non-conventional catalyst supports and additives. Variations of TWC system samples are produced including Fe-activated Rh layers deposited onto a washcoat (WC) layer having one or more of an oxygen storage material (OSM). Other TWC system samples are produced including an impregnation (IMPG) layer having loading variations of Ba within a Pd, Ce, and Nd applied onto an OSM WC layer, and a further overcoat layer including Fe-activated Rh is applied onto the IMPG layer. The catalytic performance of disclosed TWC catalysts is evaluated by performing a series of light-off tests, wide pulse perturbation tests, and standard isothermal oxygen storage capacity oscillating tests. Disclosed TWC catalysts exhibit high catalytic performance and significant oxygen storage capacity.

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 (w/w) to about 75 (w/w) cerium oxide, about 25 (w/w) to about 90 (w/w) zirconium-hafnium oxide, about 0 (w/w) to about 15 (w/w) lanthanum oxide, about 0 (w/w) to about 15 (w/w) neodymium oxide, about 0 (w/w) to about 15 (w/w) yttrium oxide, and about 0 (w/w) to about 15 (w/w) praseodymium oxide;

wherein the at least one impregnation layer comprises rhodium at about 1 g/ft3 to about 20 g/ft3 and iron at about 60 g/ft3 to about 630 g/ft3; and

wherein the overcoat comprises at least one of the group consisting of a second oxygen storage material, support oxides, barium carbonate, doped Alumina, strontium carbonate, and combinations thereof.

2. The catalyst system of claim 1, wherein the overcoat is platinum group metal free.

3. The catalyst system of claim 1, wherein the washcoat comprises a first oxygen storage material including about 31 (w/w) Cerium, about 58 (w/w) Zirconium-Hafnium, about 5.5 (w/w) Neodymium, and about 5 (w/w) Yttrium Oxide.

4. The catalyst system of claim 1, wherein the at least one impregnation layer comprises about 3 g/ft3 rhodium.

5. The catalyst system of claim 1, wherein the at least one impregnation layer comprises about 140 g/ft3 iron.

6. The catalyst system of claim 1, wherein the overcoat comprises the second oxygen storage material and wherein the second oxygen storage material includes about 30 (w/w) Ce, about 60 (w/w) Zr—

Hf, about 5 (w/w) Nd, and about 5 (w/w) praseodymium (Pr) oxides.

7. The catalyst system of claim 1, wherein the overcoat comprises the second oxygen storage material and wherein the second oxygen storage material includes about 30 (w/w) Ce, about 58(w/w) Zr—

Hf, about 5.5 (w/w) Nd, and about 5 (w/w) yttrium oxides and wherein the second oxygen storage material is loaded at about 42 g/L.

8. The catalyst system of claim 1, wherein the overcoat comprises high surface area alumina stabilized with La2O3.

9. The catalyst system of claim 8, wherein the overcoat is loaded with 40 g/L of the high surface area alumina stabilized with La₂O₃.

10. A catalyst system, comprising:

a substrate;

a washcoat deposited on the substrate;

at least one impregnation layer impregnated in the washcoat; and

an overcoat;

wherein the at least one impregnation layer comprises Pd nitrate, Ce nitrate, Nd nitrate, and a Ba salt;

wherein the Ba salt is loaded from about 50 g/ft3 to about 700 g/ft3.

11. The catalyst system of claim 10, wherein the overcoat comprises a second oxygen storage material including Ce, Zr, Nd, and Y;

wherein the oxygen storage material is impregnated with Fe nitrate; and

wherein the overcoat is further impregnated with Rh nitrate.

12. The catalyst system of claim 11, wherein the overcoat is loaded with about 9 g/ft3 Rh.

13. The catalyst system of claim 12, wherein the overcoat is loaded with about 210 g/ft3.

14. The catalyst system of claim 10, wherein the at least one impregnation layer is loaded with about 92 g/ft3 Pd, about 105 g/ft3 Ce, and about 12 g/ft3 Nd.

15. The catalyst system of claim 10, wherein the at least one impregnation layer is loaded with about 22 g/ft3 Pd, about 115 g/ft3 Ba, about 105 g/ft3 Ce, and about 12 g/ft3 Nd.

16. The catalyst system of claim 11, wherein the at least one impregnation layer is loaded with about 22 g/ft3 Pd, about 115 g/ft3 Ba, about 105 g/ft3 Ce, and about 12 g/ft3 Nd.

17. The catalyst of claim 10, wherein the at least one impregnation layer is loaded with about 50 g/ft3 to about 230 g/ft3 of the Ba salt.

18. The catalyst system of claim 14, wherein the at least one impregnation layer is loaded with about 140 g/ft3 iron.