Systems and Methods Using Cu-Mn Spinel Catalyst on Varying Carrier Material Oxides for TWC Applications

• US 20140357475A1
• Filed: 05/29/2013
• Published: 12/04/2014
• Est. Priority Date: 05/29/2013
• Status: Abandoned Application

• Current Assignee: Clean Diesel Technologies, Inc.
• Original Assignee: CDTI
• Inventors: Nazarpoor, Zahra, Golden, Stephen J.
• Application Number:
  US13/904,255
• Publication Number:
  US 20140357475A1
• Time in Patent Office: Days
• US Class Current: 502/73
• CPC Class Codes: B01D 2255/2073 Manganese
• CPC Class Codes: B01D 2255/20761 Copper
• CPC Class Codes: B01D 2255/405 Spinels
• CPC Class Codes: B01D 2255/65 Catalysts not containing noble metals
• CPC Class Codes: B01D 2255/9022 Two layers
• CPC Class Codes: B01D 2258/014 Stoichiometric gasoline engines
• CPC Class Codes: B01D 53/945 characterised by a specific catalyst
• CPC Class Codes: B01J 23/005 Spinels
• CPC Class Codes: B01J 23/8892 Manganese
• CPC Class Codes: B01J 2523/00 Constitutive chemical elements of heterogeneous catalysts
• CPC Class Codes: B01J 2523/3712 Cerium
• CPC Class Codes: B01J 2523/48 Zirconium
• CPC Class Codes: B01J 2523/56 Niobium
• CPC Class Codes: B01J 35/30 characterised by their physical properties
• CPC Class Codes: B01J 37/0215 Coating
• CPC Class Codes: B01J 37/035 Precipitation on carriers
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

Disclosed here are variations of carrier material oxide formulations to create Cu—Mn spinel, where the formulations may include Ti_1-xNb_xO₂, TiO₂, SiO₂, Doped alumina, Nb₂O₅—ZrO₂, Nb₂O₅—ZrO₂—CeO₂, Doped ZrO₂ and combinations thereof. The formation of type of Cu—Mn oxide phase depends on type of carrier material oxide. The crystallite size of Cu—Mn spinel, NO and CO conversion rate of Cu—Mn Spinel may vary according to the carrier material oxide and condition treatment used to form the spinel during co-precipitation method.

Claims

1. A zero platinum group metals (ZPGM) catalyst system, comprising:

a substrate;

a washcoat suitable for deposition on the substrate, comprising at least one oxide solid selected from the group consisting of at least one of a carrier material oxide, and a first ZPGM catalyst; and

an overcoat suitable for deposition on the substrate, comprising at least one overcoat oxide solid selected from the group consisting of at least one of a carrier material oxide, and a second ZPGM catalyst;

wherein at least one of the first catalyst and the second catalyst comprises at least one spinel structured compound having the formula AB₂O₄, wherein each of A and B is selected from the group consisting of at least one of copper and manganese; and

wherein one of the at least one carrier material oxide in selected from the group consisting of TiO₂, doped TiO₂, Ti1-xNbxO₂, SiO₂, alumina, doped alumina, ZrO₂, doped ZrO₂, Nb₂O₅—

ZrO₂, Nb₂O₅—

ZrO₂—

CeO₂, and combinations thereof.

2. The ZPGM catalyst system of claim 1, wherein the substrate comprises cordierite.

3. The ZPGM catalyst system of claim 1, wherein the spinel structured compound is prepared by co-precipitation.

4. The ZPGM catalyst system of claim 3, wherein a metal salt solution is used in the co-precipitation process and is selected from the group consisting of copper nitrate, copper acetate, manganese nitrate, manganese acetate, and combinations thereof.

5. The ZPGM catalyst system of claim 1, wherein the crystallite size of the spinel structured compound is dependent on the carrier material oxide.

6. The ZPGM catalyst system of claim 5, wherein the crystallite size of the spinel structured compound is about 18 nm.

7. The ZPGM catalyst system of claim 5, wherein the crystallite size of the spinel structured compound is about 8 nm.

8. The ZPGM catalyst system of claim 1, wherein the spinel structured compound is aged.

9. The ZPGM catalyst system of claim 8, wherein the spinel structured compound is stable.

10. The ZPGM catalyst system of claim 1, wherein the phase of the spinel structured compound is dependent on the carrier material oxide.

11. The ZPGM catalyst system of claim 1, wherein an NO conversion rate corresponds to the carrier material oxide.

12. The ZPGM catalyst system of claim 1, wherein a T50 conversion temperature for carbon monoxide is less than about 200 degrees Celsius.

13. The ZPGM catalyst system of claim 1, wherein a T50 conversion temperature for carbon monoxide is less than about 175 degrees Celsius.

14. The ZPGM catalyst system of claim 1, wherein the at least one carrier material oxide comprises Nb₂O₅—

ZrO₂.

15. The ZPGM catalyst system of claim 14, wherein the ZrO₂ is about 60% to about 80% by weight of the at least one carrier material oxide.

16. The ZPGM catalyst system of claim 14, wherein the ZrO₂ is about 75% by weight of the at least one carrier material oxide.

17. The ZPGM catalyst system of claim 1, wherein the at least one carrier material oxide is heated to about 900°

C. for about 4 hours.

18. The ZPGM catalyst system of claim 1, wherein the doped ZrO₂comprises praseodymium.

19. The ZPGM catalyst system of claim 18, wherein the ZrO₂ is about 80% to about 95% by weight of the at least one carrier material oxide.

20. The ZPGM catalyst system of claim 18, wherein the ZrO is about 90% by weight of the at least one carrier material oxide.