ZPGM Catalyst Systems and Methods of Making Same

• US 20140271390A1
• Filed: 03/22/2013
• 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
• Application Number:
  US13/849,185
• Publication Number:
  US 20140271390A1
• Time in Patent Office: Days
• US Class Current: 422/177
• CPC Class Codes: B01D 2255/2063 Lanthanum
• CPC Class Codes: B01D 2255/2066 Praseodymium
• CPC Class Codes: B01D 2255/2068 Neodymium
• 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 2255/30 Silica
• CPC Class Codes: B01D 2255/40 Mixed oxides
• CPC Class Codes: B01D 2255/407 Zr-Ce mixed oxides
• 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 23/002 Mixed oxides other than spinels, e.g. perovskite
• CPC Class Codes: B01J 23/005 Spinels
• 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 23/894 with rare earths or actinides
• 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 2523/18 : Silver
• CPC Class Codes: B01J 2523/31 : Aluminium
• CPC Class Codes: B01J 2523/3706 : Lanthanum
• CPC Class Codes: B01J 2523/3712 : Cerium
• CPC Class Codes: B01J 2523/3718 : Praseodymium
• CPC Class Codes: B01J 2523/3725 : Neodymium
• CPC Class Codes: B01J 2523/48 : Zirconium
• CPC Class Codes: B01J 2523/72 : Manganese
• CPC Class Codes: B01J 37/0036 : Grinding
• CPC Class Codes: B01J 37/0219 : the coating containing organic compounds
• CPC Class Codes: B01J 37/0242 : Coating followed by impregnation
• CPC Class Codes: B01J 37/0244 : Coatings comprising several layers
• CPC Class Codes: B01J 37/0248 : Coatings comprising impregnated particles
• CPC Class Codes: B01J 37/038 : to form slurries or suspensions, e.g. a washcoat
• 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

Abstract

Described are ZPGM catalyst systems which are free of any platinum group metals for reducing emissions of carbon monoxide, nitrogen oxides, and hydrocarbons in exhaust streams. ZPGM catalyst systems may include a substrate, a washcoat, and an overcoat. Both manganese and copper may be provided as catalysts, with copper in the overcoat and manganese preferably in the washcoat. The manganese can also be provided in the overcoat, but when in the overcoat should be stabilized for greatest effectiveness. A carrier material oxide may be included in both washcoat and overcoat. It has been discovered that the ZPGM catalyst systems are effective even without OSM in washcoat and the ZPGM catalysts within washcoat and overcoat may be best prepared by co-milling an aqueous slurry that includes manganese with alumina for the washcoat and copper and cerium salts with alumina and an OSM, for overcoat prior to overcoating and heat treating. Disclosed ZPGM TWC systems in catalytic converters may be employed to decrease the pollution caused by exhaust from various sources, such as automobiles, utility plants, processing and manufacturing plants, airplanes, trains, all-terrain vehicles, boats, mining equipment, and other engine-equipped machines.

Claims

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

at least one source of exhaust comprising hydrocarbons and carbon monoxide; and

a catalyst system, comprising;

a substrate;

a catalyst;

a washcoat suitable for deposition on the substrate; and

an overcoat suitable for deposition on the substrate or the washcoat;

wherein the catalyst comprises about 10% to about 16% by weight of copper, about 12% to about 20% by weight of cerium, and about 5% to about 10% by weight of manganese; and

wherein the catalyst is suitable for deposition on a coat selected from the group consisting of at least one of the washcoat and the overcoat.

2. The apparatus of claim 1, wherein the washcoat further comprises at least one oxide solid selected from the group consisting of at least one of a carrier metal oxide, and a catalyst.

3. The apparatus of claim 1, wherein the overcoat further comprises at least one overcoat oxide solid selected from the group consisting of a carrier metal oxide, and a catalyst, and at least one oxygen storage material, wherein the carrier metal oxide comprises at least one selected from the group consisting of alumina, lanthanum-doped alumina, and SiO₂-doped alumina.

4. The apparatus of claim 1, wherein the catalyst is prepared by a method selected from the group consisting of co-milling, co-precipitation, impregnation, and stabilization.

5. The apparatus of claim 1, wherein the catalyst comprises about 10% by weight of copper and 12% by weight of cerium.

6. The apparatus of claim 1, wherein the catalyst system oxidizes a plurality of the hydrocarbons and the carbon monoxide.

7. The apparatus of claim 1, wherein the T50 conversion temperature for the hydrocarbons is less than 450 degrees Celsius.

8. The apparatus of claim 1, wherein the T50 conversion temperature for nitrogen oxide is about 350 degrees Celsius.

9. The apparatus of claim 1, wherein the T50 conversion temperature for the carbon monoxide is less than about 200 degrees Celsius.

10. The apparatus of claim 1, wherein at least one of the washcoat and the overcoat comprises a carrier metal oxide, and wherein the carrier metal oxide is selected from the group consisting of at least one of Al₂O₃, CeO₂, ZrO₂, and TiO₂.

11. The apparatus of claim 10, wherein the catalyst is deposited on the carrier metal oxide.

12. The apparatus of claim 1, wherein at least one of the washcoat and the overcoat further comprises an oxygen storage material, and wherein the oxygen storage material is selected from the group consisting of at least one of cerium, zirconium, neodymium, and praseodymium.

13. The apparatus of claim 1, wherein the washcoat further comprises at least one oxygen storage material.

14. The apparatus of claim 1, wherein the catalyst converts at least the hydrocarbons, nitrogen oxide, and the carbon monoxide

15. The apparatus of claim 1, wherein the catalyst system oxidizes at least one of the hydrocarbons and the carbon monoxide

16. A zero platinum group metal (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 metal oxide, and a 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 metal oxide, and a ZPGM catalyst;

wherein at least one of the ZPGM catalysts comprises at least one perovskite structured compound having a formula ABO₃, wherein A is selected from the group consisting of at least one of, magnesium, calcium, barium, strontium, and mixtures thereof, and wherein B comprises at least one transition metal.

17. The catalyst system of claim 16, wherein the transition metal is selected from the group consisting of at least one of iron, manganese, copper, nickel, and cobalt.

18. The catalyst system of claim 16, wherein the at least one perovskite structured compound has the formula AMn₁-xCu_xO₃, wherein A is selected from the group consisting of at least one of lanthanum, cerium, barium, strontium, a lanthanide, and an actinide, and wherein x is 0 to 1.

19. The catalyst system of claim 16, wherein the at least one perovskite structured compound having the formula ABO₃ is ACe₁-xCu_xO₃, wherein A is manganese, and wherein x is 0 to 1.

20. The catalyst system of claim 16, wherein the concentration of the at least one perovskite structured compound is about 10 g/L to about 180 g/L.

21. The catalyst system of claim 16, wherein the concentration of the at least one perovskite structured compound is about 5% to about 50% by weight.

22. The catalyst of claim 16, wherein the at least one perovskite structured compound having the formula ABO₃ is AB₁-xM_xO₃, wherein x is 0 to 1.

23. A zero platinum group metal (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 at least one of a carrier metal oxide, and a ZPGM catalyst; and

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

wherein at least one of the ZPGM catalysts comprises at least one spinel structured compound having the formula AB₂O₄, wherein each of A and B is selected from the group consisting at least one of aluminum, magnesium, manganese, gallium, nickel, copper, cobalt, molybdenum, vanadium, iron, chromium, titanium, and tin.

24. The catalyst system of claim 23, wherein the at least one spinel structured compound having the formula AB₂O₄ is CuMn₂O₄.

25. The catalyst system of claim 23, wherein at least one of the ZPGM catalysts further comprises at least one carrier material oxide.

26. The catalyst system of claim 23, wherein the spinel is present in about 5% to about 50% by weight.

27. The catalyst system of claim 23, wherein a conversion temperature for hydrocarbon is about 165°

C.

28. The catalyst system of claim 23, wherein a conversion temperature for nitrogen oxide is about 80°

C.

29. A method of making a zero platinum group metal (ZPGM) catalyst system, comprising:

depositing at least one washcoat and at least one transition metal salt on to a substrate;

heat treating the washcoat for about 2 to about 6 hours at about 300°

C. to about 700°

C.;

depositing at least one overcoat comprising an overcoat oxide solid selected from the group consisting at least one of a carrier metal oxide, and a ZPGM catalyst;

wherein the ZPGM 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 aluminum, magnesium, manganese, gallium, nickel, copper, cobalt, molybdenum, vanadium, iron, chromium, titanium and tin.

30. The method of claim 29, wherein the at least one spinel structured compound is CuMn₂O₄.

31. The method of claim 29, wherein the catalyst further comprises at least one carrier material oxide.

32. The method of claim 29, wherein the spinel is present in about 5% to about 50% by weight.

33. The method of claim 29, wherein a conversion temperature for hydrocarbon is about 165°

C.

34. The method of claim 29, wherein a conversion temperature for nitrogen oxide is about 80°

C.

35. The method of claim 29, wherein the transition metal salt is precipitated.

36. The method of claim 29, wherein the heat treating of the washcoat is at about 550°

C. for about 4 hours.

37. An apparatus for reducing emissions from an engine having associated therewith an exhaust system, the apparatus providing a reaction effective for selective catalytic reduction, comprising:

at least one source of exhaust comprising hydrocarbons and carbon monoxide; and

a catalyst system, comprising;

a substrate;

a catalyst;

a washcoat suitable for deposition on the substrate; and

an overcoat suitable for deposition on the substrate or the washcoat;

wherein the catalyst is selected from the group consisting at least one of copper, cerium, manganese, and silver; and

wherein the catalyst is suitable for deposition on a coat selected from the group consisting of at least one of the washcoat and the overcoat.

38. The apparatus of claim 37, wherein the catalyst is prepared by a method selected from the group consisting of co-milling, co-precipitation, impregnation, and stabilization.

39. The apparatus of claim 37, wherein the catalyst comprises about 4% to about 10% by weight of silver.

40. The apparatus of claim 37, wherein the catalyst comprises about 10% to 16% by weight of copper.

41. The apparatus of claim 37, wherein the catalyst comprises about 12% to 20% by weight of cerium.

42. A zero platinum group metal (ZPGM) catalyst system, comprising:

a substrate;

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

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

wherein at least one of the ZPGM catalysts comprises either a perovskite structured compound or a spinel structured compound.