Optimization of Zero-PGM Washcoat and Overcoat Loadings on Metallic Substrate

• US 20150018203A1
• Filed: 07/12/2013
• Published: 01/15/2015
• Est. Priority Date: 07/12/2013
• Status: Active Grant

• Current Assignee: Clean Diesel Technologies, Inc.
• Original Assignee: CDTI
• Inventors: Nazarpoor, Zahra, Kitazumi, Sen, Ngo, Johnny T.
• Granted Patent: US 9,545,626 B2
• Time in Patent Office: Days
• US Class Current: 502/304
• CPC Class Codes: B01D 2255/104 Silver
• CPC Class Codes: B01D 2255/2065 Cerium
• CPC Class Codes: B01D 2255/20707 Titanium
• CPC Class Codes: B01D 2255/20715 Zirconium
• CPC Class Codes: B01D 2255/20761 Copper
• CPC Class Codes: B01D 2255/65 Catalysts not containing noble metals
• CPC Class Codes: B01D 2255/9022 Two layers
• CPC Class Codes: B01D 2255/908 O2-storage component incorporated in the catalyst
• CPC Class Codes: B01D 53/944 Simultaneously removing carbon monoxide, hydrocarbons or carbon making use of oxidation catalysts three-way-catalysts [TWC] B01D53/9445
• CPC Class Codes: B01J 23/50 Silver
• CPC Class Codes: B01J 23/72 Copper
• CPC Class Codes: B01J 23/83 with rare earths or actinides
• CPC Class Codes: B01J 37/0244 Coatings comprising several layers

Abstract

The present disclosure refers to a plurality of process employed for optimization of Zero-PGM washcoat and overcoat loadings on metallic substrates. According to an embodiment a substantial increase in conversion of HC and CO may be achieved by optimizing the total washcoat and overcoat loadings of the catalyst. According to another embodiment, the present disclosure may provide solutions to determine the optimum total washcoat and overcoat loadings for minimizing washcoat adhesion loss. As a result, may increase the conversion of HC and CO from discharge of exhaust gases from internal combustion engines, optimizing performance of Zero-PGM catalyst systems.

Claims

1. A method for optimizing a catalytic system, comprising:

providing a catalyst system, comprising;

a substrate;

a washcoat suitable for deposition on the substrate, comprising at least one first oxide solid comprising alumina and at least one first zero platinum group catalyst comprising silver; and

an overcoat suitable for deposition on the substrate, comprising at least one second oxide solid selected from the group consisting of a carrier material oxide, at least one second zero platinum group catalyst comprising one selected from the group consisting of copper oxide, ceria, and combinations thereof, and a mixture thereof;

adjusting an amount of loading of the washcoat and the overcoat in accordance with washcoat adhesion loss.

2. The method according to claim 1, wherein the silver is present at about 5.5 g/L.

3. The method according to claim 1, wherein the copper is present at about 6.5 g/L.

4. The method according to claim 1, wherein the amount of washcoat loading is about 80 g/L and the amount of overcoat loading is about 60 g/L.

5. The method according to claim 4, wherein the washcoat adhesion loss is less than 4.0%.

6. The method according to claim 1, wherein the amount of washcoat loading is about 100 g/L and the amount of overcoat loading is about 800 g/L.

7. The method according to claim 6, wherein the washcoat adhesion loss is less than 2.0%.

8. The method according to claim 1, wherein the amount of washcoat loading is about 100 g/L and the amount of overcoat loading is about 60 g/L.

9. The method according to claim 8, wherein the washcoat adhesion loss is less than 2.0%.

10. The method according to claim 1, wherein the amount of washcoat loading is about 120 g/L and the amount of overcoat loading is about 100 g/L.

11. The method according to claim 10, wherein the washcoat adhesion loss is less than 1.0%.

12. The method according to claim 1, wherein the substrate is metallic.

13. The method according to claim 1, wherein the overcoat further comprises at least one oxygen storage material.

14. The method according to claim 1, wherein the carrier material oxide is selected from the group consisting of CeO₂, ZrO₂, TiO₂, and combinations thereof.

15. A method for optimizing a catalytic system, comprising:

providing a catalyst system, comprising;

a substrate;

a washcoat suitable for deposition on the substrate, comprising at least one first oxide solid comprising alumina, at least one first zero platinum group catalyst comprising silver, and a mixture thereof; and

an overcoat suitable for deposition on the substrate, comprising at least one second oxide solid selected from the group consisting of a carrier material oxide, at least one second zero platinum group catalyst comprising one selected from the group consisting of copper oxide, ceria, and combinations thereof, and a mixture thereof;

adjusting a ratio of washcoat loading to overcoat loading in accordance with the conversion of hydrocarbons and carbon monoxide.

16. The method according to claim 15, wherein the silver in present at about 5.5 g/L.

17. The method according to claim 15, wherein the copper in present at about 6.5 g/L.

18. The method according to claim 15, wherein the amount of washcoat loading is about 120 g/L and the amount of overcoat loading is about 100 g/L.

19. The method according to claim 18, wherein the T50 temperature for hydrocarbons is about 331°

C.

20. The method according to claim 15, wherein the substrate is metallic.

21. The method according to claim 15, wherein the overcoat further comprises at least one oxygen storage material.

22. The method according to claim 15, wherein the carrier material oxide is selected from the group consisting of CeO₂, ZrO₂, TiO₂, and combinations thereof.