Methods for Oxidation and Two-way and Three-way ZPGM Catalyst Systems and Apparatus Comprising Same

• US 20140271425A1
• Filed: 03/22/2013
• Published: 09/18/2014
• Est. Priority Date: 03/15/2013
• Status: Active Grant

• Current Assignee: Clean Diesel Technologies, Inc.
• Original Assignee: CDTI
• Inventors: Nazarpoor, Zahra
• Granted Patent: US 8,858,903 B2
• Time in Patent Office: Days
• US Class Current: 423/213.2
• CPC Class Codes: B01D 2255/104 Silver
• CPC Class Codes: B01D 2255/206 Rare earth metals
• CPC Class Codes: B01D 2255/2061 Yttrium
• CPC Class Codes: B01D 2255/2063 Lanthanum
• CPC Class Codes: B01D 2255/2065 Cerium
• 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 2255/20761 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: B01D 53/945 characterised by a specific catalyst
• CPC Class Codes: B01J 23/002 Mixed oxides other than spinels, e.g. perovskite
• CPC Class Codes: B01J 23/005 Spinels
• CPC Class Codes: B01J 23/66 Silver or gold
• CPC Class Codes: B01J 23/688 with manganese, technetium or rhenium
• CPC Class Codes: B01J 23/83 with rare earths or actinides
• CPC Class Codes: B01J 23/8892 Manganese
• CPC Class Codes: B01J 37/0244 : Coatings comprising several layers
• CPC Class Codes: B01J 37/0246 : Coatings comprising a zeolite
• CPC Class Codes: Y02A 50/20 : Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters
• CPC Class Codes: Y02T 10/12 : Improving ICE efficiencies
• CPC Class Codes: Y10S 502/52712 : Plural layers on a support, each layer having a distinct function

Abstract

Oxidation ZPGM catalyst systems and three way ZPGM catalyst systems are disclosed. ZPGM catalyst systems may oxidize toxic gases, such as carbon monoxide and hydrocarbons, optionally some ZPGM catalyst systems may as well reduce nitrogen oxides that may be included in exhaust gases. ZPGM catalyst systems may include: a substrate, a washcoat, and an overcoat. The washcoat may include at least one ZPGM catalyst and carrier material oxides. Similarly, overcoat may include at least one ZPGM catalyst, carrier material oxides and OSMs. Suitable known in the art chemical techniques, deposition methods and treatment systems may be employed in order to form the disclosed ZPGM catalyst systems.

Claims

1. A method for reducing emissions from an engine having associated therewith an exhaust system, the method providing a catalyst system for a reaction effective for selective catalytic reduction, comprising:

providing a substrate;

depositing on said substrate a washcoat suitable for deposition on the substrate, comprising at least one oxide solid, silver, or mixtures thereof; and

depositing an overcoat suitable for deposition on the substrate, comprising copper oxide, cerium, or mixtures thereof.

2. The method of claim 1, wherein the ratio of the oxide solid and an oxygen storage material in the washcoat is about 60:

40 by weight.

3. The method of claim 2, wherein the oxide solid is alumina.

4. The method of claim 1, wherein the silver is about 1% to about 20% by weight of the washcoat.

5. The method of claim 1, wherein the silver is about 4% to about 10% by weight of the washcoat.

6. The method of claim 1, wherein the silver and the at least one oxide solid are milled together.

7. The method of claim 1, further comprising heating said substrate and said washcoat to between about 300°

Celsius and about 700°

Celsius.

8. The method of claim 7, wherein the heating duration is from about 2 hours to about 6 hours.

9. The method of claim 1, further comprising heating said substrate and said washcoat to about 550°

Celsius.

10. The method of claim 9, wherein the heating duration is about 4 hours.

11. The method of claim 1, wherein the T50 conversion temperature for carbon monoxide is less than 250 degrees Celsius.

12. The method of claim 1, wherein the T50 conversion temperature for hydrocarbons is about 400 degrees Celsius.

13. The method of claim 1, wherein the overcoat further comprises silver.

14. The method of claim 1, wherein the washcoat further comprises an oxygen storage material.

15. The method of claim 1, wherein the washcoat further comprises at least one element selected from the group consisting of calcium, tin, niobium, zirconium, lanthanum, iron, and cobalt.

16. A catalytic apparatus, comprising:

a catalyst system, comprising;

a substrate comprising cordierite;

a washcoat suitable for deposition on the substrate, comprising at least one oxygen storage material and alumina; and

an overcoat suitable for deposition on the substrate, comprising copper oxide, cerium, alumina, and at least one oxygen storage material,

wherein the ratio of the alumina and the oxygen storage material in the washcoat is about 60;

40 by weight and the ratio of the alumina and the oxygen storage material in the overcoat is about 40;

60 by weight.

17. The apparatus of claim 16, wherein the at least one oxygen storage material of the washcoat comprises at least one element selected from the group consisting of cerium, zirconium, samarium, lanthanum, and yttrium.

18. The apparatus of claim 16, wherein the at least one oxygen storage material of the overcoat comprises at least one element selected from the group consisting of cerium, zirconium, neodymium, and praseodymium.

19. The apparatus of claim 16, wherein the copper oxide of the overcoat is about 10% to about 16% by weight of the overcoat.

20. The apparatus of claim 16, wherein the cerium of the overcoat is about 12% to about 20% by weight of the overcoat.

21. The apparatus of claim 16, wherein the catalyst system is heated to about 550°

Celsius for about 4 hours.

22. The apparatus of claim 16, wherein the T50 conversion temperature for carbon monoxide is less than 250 degrees Celsius.

23. The apparatus of claim 16, wherein the T50 conversion temperature for hydrocarbons is less than about 400 degrees Celsius.