Systems and Methods for Managing a Synergistic Relationship Between PGM and Copper-Manganese in a Three Way Catalyst Systems

• US 20150148225A1
• Filed: 11/26/2013
• Published: 05/28/2015
• Est. Priority Date: 11/26/2013
• Status: Abandoned Application

• Current Assignee: Clean Diesel Technologies, Inc.
• Original Assignee: Clean Diesel Technologies, Inc.
• Inventors: Nazarpoor, Zahra, Golden, Stephen J.
• Application Number:
  US14/090,938
• Publication Number:
  US 20150148225A1
• Time in Patent Office: Days
• US Class Current: 502/324
• CPC Class Codes: B01D 2255/102 Platinum group metals
• CPC Class Codes: B01D 2255/20715 Zirconium
• CPC Class Codes: B01D 2255/2073 Manganese
• CPC Class Codes: B01D 2255/20761 Copper
• CPC Class Codes: B01D 2255/2092 Aluminium
• 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: B01J 23/005 Spinels
• CPC Class Codes: B01J 23/8986 with manganese, technetium or rhenium
• CPC Class Codes: B01J 2523/00 Constitutive chemical elements of heterogeneous catalysts
• CPC Class Codes: B01J 2523/17 Copper
• CPC Class Codes: B01J 2523/31 Aluminium
• CPC Class Codes: B01J 2523/56 Niobium
• CPC Class Codes: B01J 2523/72 Manganese
• CPC Class Codes: B01J 2523/824 Palladium
• CPC Class Codes: B01J 37/0244 Coatings comprising several layers
• CPC Class Codes: B01J 37/038 to form slurries or suspensions, e.g. a washcoat
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

Synergized Platinum Group Metals (SPGM) catalyst systems for TWC application are disclosed. Disclosed SPGM catalyst systems may include a washcoat with a Cu—Mn spinel structure, Cu_1.0Mn_2.0O₄, supported on Nb₂O₅—ZrO₂ and an overcoat that includes PGM supported on carrier material oxides, such as alumina. SPGM catalyst system that includes the spinel structure of Cu_1.0Mn_2.0O₄ show significant improvement in nitrogen oxide reduction performance under stoichiometric operating conditions and especially under lean operating conditions, which allows a reduced consumption of fuel. Additionally, disclosed SPGM catalyst system with spinel structure of Cu_1.0Mn_2.0O₄ also enhances the reduction of carbon monoxide and hydrocarbon within catalytic converters. Furthermore, disclosed SPGM catalyst systems are found to have enhanced catalyst activity compared to same catalyst system that do not include Cu—Mn spinel catalysts, showing that there is a synergistic effect among PGM catalyst and Cu—Mn stoichiometric spinel structure within the disclosed SPGM catalyst system.

Claims

1. A catalyst system, comprising:

at least one substrate;

at least one washcoat comprising at least one oxygen storage material further comprising Cu—

Mn spinel having a niobium-zirconia support oxide; and

at least one overcoat comprising at least one selected from the group comprising platinum group metal catalyst, Al₂O₃, and mixtures thereof;

wherein the catalyst system has a T50 value of less than 300°

C.

2. The catalyst system of claim 1, wherein the Cu—

Mn spinel comprises CuMn₂O₄.

3. The catalyst system of claim 1, wherein the Cu—

Mn spinel is stoichiometric.

4. The catalyst system of claim 1, wherein the niobium-zirconia support oxide comprises Nb₂O₅—

ZrO₂.

5. The catalyst system of claim 1, further comprising at least one impregnation layer.

6. The catalyst of claim 1, wherein the at least one substrate comprises a ceramic.

7. The catalyst of claim 1, wherein the conversion of NO is substantially complete under lean exhaust conditions.

8. The catalyst of claim 1, wherein the conversion of CO is substantially complete under lean exhaust conditions.

9. The catalyst of claim 1, wherein the conversion of NO is near 95% under lean exhaust conditions.

10. The catalyst of claim 1, wherein the conversion of NO is improved over a catalyst system comprising at least one platinum group metal catalyst and substantially no Cu—

Mn spinel.

11. The catalyst of claim 1, wherein the NO cross over R-value is about 0.950.

12. The catalyst of claim 1, wherein the CO cross over R-value is about 0.965.

13. A catalyst system, comprising:

at least one substrate;

at least one washcoat comprising at least one selected from the group comprising platinum group metal catalyst, Al₂O₃, and mixtures thereof; and

at least one overcoat comprising at least one oxygen storage material further comprising Cu—

Mn spinel having a niobium-zirconia support oxide;

wherein the catalyst system has a T50 value of less than 300°

C.

14. The catalyst system of claim 13, wherein the Cu—

Mn spinel comprises CuMn₂O₄.

15. The catalyst system of claim 13, wherein the Cu—

Mn spinel is stoichiometric.

16. The catalyst system of claim 13, wherein the niobium-zirconia support oxide comprises Nb₂O₅—

ZrO₂.

17. The catalyst system of claim 13, further comprising at least one impregnation layer.

18. The catalyst of claim 13, wherein the at least one substrate comprises a ceramic.

19. The catalyst of claim 13, wherein the conversion of NO is substantially complete under lean exhaust conditions.

20. The catalyst of claim 13, wherein the conversion of CO is substantially complete under lean exhaust conditions.

21. The catalyst of claim 13, wherein the conversion of NO is improved over a catalyst system comprising at least one platinum group metal catalyst and substantially no Cu—

Mn spinel.

22. A catalyst system, comprising:

at least one substrate comprising ceramics;

at least one washcoat comprising Al₂O₃;

at least one overcoat comprising at least one oxygen storage material further comprising Cu—

Mn spinel having a niobium-zirconia support oxide; and

at least one impregnation layer comprising at least one platinum group metal catalyst;

wherein the at least one platinum group metal catalyst comprises palladium; and

wherein the catalyst system has a T50 value of less than 300°

C.