Pseudo-brookite Compositions as Active Zero-PGM Catalysts for Diesel Oxidation Applications

• US 20160023188A1
• Filed: 10/01/2015
• Published: 01/28/2016
• Est. Priority Date: 06/06/2013
• Status: Abandoned Application

• Current Assignee: Clean Diesel Technologies, Inc.
• Original Assignee: Clean Diesel Technologies, Inc.
• Inventors: Nazarpoor, Zahra, Golden, Stephen J.
• Application Number:
  US14/873,020
• Publication Number:
  US 20160023188A1
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B01D 2255/2061 Yttrium
• CPC Class Codes: B01D 2255/20715 Zirconium
• CPC Class Codes: B01D 2255/2073 Manganese
• CPC Class Codes: B01D 2255/65 Catalysts not containing noble metals
• 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 23/002 Mixed oxides other than spinels, e.g. perovskite
• CPC Class Codes: B01J 23/34 Manganese
• CPC Class Codes: B01J 23/688 with manganese, technetium or rhenium
• CPC Class Codes: B01J 2523/00 Constitutive chemical elements of heterogeneous catalysts
• CPC Class Codes: B01J 2523/18 Silver
• CPC Class Codes: B01J 2523/31 Aluminium
• CPC Class Codes: B01J 2523/36 Yttrium
• CPC Class Codes: B01J 2523/3706 Lanthanum
• CPC Class Codes: B01J 2523/48 Zirconium
• CPC Class Codes: B01J 2523/72 Manganese
• CPC Class Codes: B01J 29/06 Crystalline aluminosilicate zeolites; Isomorphous compounds thereof
• CPC Class Codes: B01J 35/30 characterised by their physical properties
• CPC Class Codes: B01J 37/0244 Coatings comprising several layers
• CPC Class Codes: B01J 37/03 Precipitation; Co-precipitation
• CPC Class Codes: C01G 45/1285 of the type [Mn2O5]n-
• CPC Class Codes: C01P 2002/34 : perovskite-type (ABO3)

Abstract

YMn₂O₅ pseudo-brookite compositions with improved thermal stability and catalytic activity as Zero-PGM (ZPGM) catalyst systems for DOC application are disclosed. Testing of YMn₂O₅ pseudo-brookite catalysts and YMnO₃ perovskite catalysts, including variations of calcination temperatures, are performed under DOC light-off (LO) tests at wide range of space velocity to evaluate catalytic performance, especially level of NO oxidation. The presence of YMn₂O₅ pseudo-brookite oxides in disclosed ZPGM catalyst compositions is analyzed by x-ray diffraction (XRD) analysis. XRD analyses and LO tests confirm that YMn₂O₅ pseudo-brookite catalysts exhibit higher catalytic activity and significant improved thermal stability when compared to conventional YMnO₃ perovskite catalysts.

Claims

1. A catalyst composition comprising a pseudo-brookite structured compound of general formula AB₂O₅, wherein A is a cation selected from the group consisting of silver (Ag), manganese (Mn), yttrium (Y), lanthanum (La), cerium (Ce), iron (Fe), praseodymium (Pr), neodymium (Nd), strontium (Sr), cadmium (Cd), cobalt (Co), scandium (Sc), copper (Cu), niobium (Nb), and tungsten (W), and wherein B is a cation selected from the group consisting of Ag, Mn, Y, La, Ce, Fe, Pr, Nd, Sr, Cd, Co, Sc, Cu, Nb, and W.

2. The catalyst composition of claim 1, wherein A is Y.

3. The catalyst composition of claim 2, wherein B is Mn.

4. The catalyst composition of claim 1, further comprising at least one support oxide selected from the group consisting of ZrO₂, doped ZrO₂, Al₂O₃, doped Al₂O₃, SiO₂, TiO₂, and Nb₂O₅.

5. The catalyst composition of claim 4, wherein the at least one support oxide includes Pr doped ZrO₂ of formula ZrO₂—

Pr₆O₁₁.

6. The catalyst composition of claim 5, wherein the Pr doped ZrO₂ comprises about 10% by weight Pr₆O₁₁.

7. The catalyst composition of claim 3, further comprising at least one support oxide selected from the group consisting of ZrO₂, doped ZrO₂, Al₂O₃, doped Al₂O₃, SiO₂, TiO₂, and Nb₂O₅.

8. The catalyst composition of claim 7, wherein the at least one support oxide includes Pr doped ZrO₂ of formula ZrO₂—

Pr₆O₁₁.

9. The catalyst composition of claim 8, wherein the Pr doped ZrO₂ comprises about 10% by weight Pr₆O₁₁.

10. The catalyst composition of claim 3, wherein the catalyst composition is calcined at a temperature from about 800°

C. to about 1000°

C.

11. A method of manufacturing a catalyst composition comprising, mixing a first solution including nitrate and a cation A, a second solution including nitrate and a cation B, and water to form a first mixture, wherein the molar ratio of cation B to cation A is about 2 moles of cation B to about 1 mole of cation A,

firing the first mixture at a nitrate combustion temperature to form a fired mixture, and

calcining at a calcining temperature for a calcining period,

wherein the catalyst composition is a pseudo-brookite structured compound of general formula AB₂O₅, wherein cation A is selected from the group consisting of Ag, Mn, Y, La, Ce, Fe, Pr, Nd, Sr, Cd, Co, Sc, Cu, Nb, and W, and wherein cation B is selected from the group consisting of Ag, Mn, Y, La, Ce, Fe, Pr, Nd, Sr, Cd, Co, Sc, Cu, Nb, and W.

12. The method of manufacturing the catalyst composition of claim 11, wherein the nitrate combustion temperature is about 300°

C. to about 400°

C.

13. The method of manufacturing the catalyst composition of claim 11, wherein the calcining temperature is about 800°

C. to about 1000°

C.

14. The method of manufacturing the catalyst composition of claim 11, wherein the calcining period is about 5 hours.

15. The method of manufacturing the catalyst composition of claim 11, further comprising drying the fired mixture at a drying temperature, wherein the drying temperature is about 120°

C.

16. The method of manufacturing the catalyst composition of claim 11, wherein cation A is Y.

17. The method of manufacturing the catalyst composition of claim 16, wherein cation B is Mn.

18. The method of manufacturing the catalyst composition of claim 11, further comprising grinding the fired mixture to form a first powder prior to calcining at the calcining temperature for the calcining period.

19. The method of manufacturing the catalyst composition of claim 11, further comprising adding the fired mixture drop-wise to a doped zirconia according to incipient wetness methodology to form a catalyst solution.

20. The method of manufacturing the catalyst composition of claim 19, further comprising drying the catalyst solution at a drying temperature, wherein the drying temperature is about 120°

C., prior to calcining at about 800°

C. to about 1000°

C.