Influence of Support Oxide Materials on Coating Processes of ZPGM Catalyst Materials for TWC Applications

• US 20140274674A1
• Filed: 02/18/2014
• Published: 09/18/2014
• Est. Priority Date: 03/15/2013
• Status: Abandoned Application

• Current Assignee: Clean Diesel Technologies, Inc.
• Original Assignee: CDTI
• Inventors: Nazarpoor, Zahra, Golden, Stephen J.
• Application Number:
  US14/183,081
• Publication Number:
  US 20140274674A1
• Time in Patent Office: Days
• US Class Current: 502/302
• CPC Class Codes: B01D 2255/2066 Praseodymium
• CPC Class Codes: B01D 2255/2068 Neodymium
• 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 2255/405 Spinels
• CPC Class Codes: B01D 2255/65 Catalysts not containing noble metals
• CPC Class Codes: B01D 2255/9025 Three 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 21/066 Zirconium or hafnium; Oxides or hydroxides thereof
• CPC Class Codes: B01J 23/005 Spinels
• CPC Class Codes: B01J 23/8892 Manganese
• 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

The influence of a plurality of support oxides on coating process for ZPGM catalysts is disclosed. ZPGM catalyst samples with washcoat on suitable ceramic substrate and overcoat including a plurality of support oxides are prepared including an impregnation layer of Cu—Mn spinel or overcoat may be prepared from powder of Cu—Mn spinel with support oxide. Testing of fresh and aged ZPGM catalyst samples is developed under isothermal steady state sweep test condition. Catalyst testing allows to determine effect of a plurality of support oxides on coating processes, TWC performance, and stability of ZPGM catalysts for a plurality of TWC applications. Stability of ZPGM-TWC systems may be improved by promotion of the activity of ZPGM materials incorporating support oxides. Improvements that may be provided by the combination of support oxides with ZPGM materials in the catalyst may lead to a most effective utilization of ZPGM materials in TWC converters.

Claims

1. A catalytic system, comprising:

a substrate;

a washcoat applied to said substrate comprising alumina;

at least one support oxide applied to said washcoat; and

at least on catalyst applied to the at least one support oxide;

wherein the at least one catalyst is substantially free of platinum group metals and wherein the at least one support oxide is selected from the group consisting of Nd₂O₅—

ZrO₂, Pr₆O₁₁—

ZrO₂, Pr—

ZrO₂, and mixtures thereof.

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

3. The catalyst system of claim 1, wherein the at least one catalyst comprises comprises Cu and Mn.

4. The catalyst system of claim 1, wherein the at least one catalyst comprises a spinel structured compound.

5. The catalyst system of claim 1, wherein the at least one catalyst has a general formula of Cu_xMn_3-xO₄.

6. The catalyst system of claim 5, wherein x is at least 0.5.

7. The catalyst system of claim 1, wherein at least one catalyst is applied as an overcoat.

8. The catalyst system of claim 1, wherein the conversion of CO is greater than 98%.

9. The catalyst system of claim 1, wherein the conversion of NO, is greater than 70%.

10. The catalyst system of claim 1, wherein the conversion of NO, is greater than 98%.

11. The catalyst system of claim 1, wherein the at least one support oxide layer is calcinated at about 600°

C. for about 5 hours.

12. The catalyst system of claim 1, wherein the washcoat comprises alumina at about 120 g/L.

13. A catalytic composition, comprising:

at least one catalyst substantially free of platinum group metals; and

at least one support oxide selected from the group consisting of Nd₂O₅—

ZrO₂, Pr₆O₁₁—

ZrO₂, Pr—

ZrO₂, and mixtures thereof.

wherein the at least one catalyst comprises comprises Cu and Mn.

14. The catalyst composition of claim 13, wherein the at least one catalyst comprises a spinel structured compound.

15. The catalyst composition of claim 13, wherein the at least one catalyst has a general formula of Cu_xMn_3-xO₄.

16. The catalyst composition of claim 15, wherein x is at least 0.5.

17. The catalyst composition of claim 13, wherein the at least one catalyst catalyzes CO at greater than 98%.

18. The catalyst composition of claim 13, wherein the at least one catalyst catalyzes NO_x at greater than 70%.

19. The catalyst composition of claim 13, wherein the at least one catalyst catalyzes NO_x at greater than 98%.

20. The catalyst composition of claim 13, wherein the at least one catalyst and at least one support oxide are combined by the incipient wetness method.