Oxygen Storage Capacity and Thermal Stability of Synergized PGM Catalyst Systems

• US 20150148224A1
• 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:
  US14/090,887
• Publication Number:
  US 20150148224A1
• Time in Patent Office: Days
• US Class Current: 502/324
• CPC Class Codes: B01D 2255/1023 Palladium
• CPC Class Codes: B01D 2255/207 Transition 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 2255/40 Mixed oxides
• CPC Class Codes: B01D 2255/405 Spinels
• CPC Class Codes: B01D 2255/9022 Two layers
• CPC Class Codes: B01D 2255/9025 Three layers
• 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 2523/48 Zirconium
• 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 37/035 : Precipitation on carriers
• CPC Class Codes: B01J 37/038 : to form slurries or suspensions, e.g. a washcoat
• CPC Class Codes: B01J 37/10 : in the presence of water, e.g. steam
• CPC Class Codes: Y02T 10/12 : Improving ICE efficiencies

Abstract

Synergized PGM (SPGM) catalyst systems including ZPGM material compositions and formulations are disclosed. Variations of catalyst systems are tested to determine the synergistic effect of adding ZPGM material to PGM catalysts. The synergistic effect is determined under isothermal oscillating condition from which enhanced OSC property indicates enhanced catalytic behavior of disclosed SPGM catalyst systems as compared with commercial PGM catalysts with OSM for TWC applications. Disclosed SPGM catalyst systems is free of rare earth metals and especially Ce and may have an optimal OSC property and optimal thermal stability that increases with the temperature, showing acceptable level of O₂ storage even at low temperatures.

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 platinum group metal catalyst and Al₂O₃;

wherein the O₂ storage capacity of the at least one oxygen storage material increases with temperature.

2. The catalyst system of claim 1, wherein the at least one oxygen storage material is hydrothermally aged at about 900°

C.

3. The catalyst system of claim 1, wherein the hydrothermal aging is for about 4 hours.

4. The catalyst system of claim 1, wherein the at least one oxygen storage material is hydrothermally aged at about 1,000°

C.

5. The catalyst system of claim 1, wherein the hydrothermal aging is for about 4 hours.

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

Mn spinel comprises CuMn₂O₄.

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

Mn spinel is stoichiometric.

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

ZrO₂.

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

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

11. A catalyst system, comprising:

at least one substrate;

at least one washcoat comprising at least one platinum group metal catalyst and Al₂O₃; 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 O₂ storage capacity of the at least one oxygen storage material increases with temperature.

12. The catalyst system of claim 12, wherein the at least one oxygen storage material is hydrothermally aged at about 900°

C.

13. The catalyst system of claim 12, wherein the hydrothermal aging is for about 4 hours.

14. The catalyst system of claim 12, wherein the at least one oxygen storage material is hydrothermally aged at about 1,000°

C.

15. The catalyst system of claim 12, wherein the hydrothermal aging is for about 4 hours.

16. The catalyst system of claim 12, wherein the Cu—

Mn spinel comprises CuMn₂O₄.

17. The catalyst system of claim 12, wherein the Cu—

Mn spinel is stoichiometric.

18. The catalyst system of claim 12, wherein the niobium-zirconia support oxide comprises Nb₂O₅—

ZrO₂.

19. The catalyst system of claim 12, further comprising at least one impregnation layer.

20. 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 O₂ storage capacity of the at least one oxygen storage material increases with temperature.