Catalysts for lean burn engines

• US 8,323,601 B2
• Filed: 05/20/2010
• Issued: 12/04/2012
• Est. Priority Date: 05/20/2009
• Status: Active Grant

• Current Assignee: Clean Diesel Technologies, Inc.
• Original Assignee: ECS Holdings Limited, Catalyst Health Solutions Incorporated (UnitedHealth Group Incorporated)
• Inventors: Malyala, Rajashekharam, Iretskaya, Svetlana, Trandal, Dylan, To, Dien, Pless, Jason, Golden, Stephen, Yoo, Jiho, Justice, Rachelle
• Primary Examiner(s): Silverman, Stanley
• Assistant Examiner(s): Zimmer, Anthony J
• Application Number:
  US12/784,140
• Publication Number:
  US 20100316547A1
• Time in Patent Office: 929 Days
• Field of Search: 423/213.2, 423/213.5, 423/247, 423/598, 423/594.9, 423/594.12, 502349-352, 502/339, 502/325
• US Class Current: 423/213.5
• CPC Class Codes: B01D 2255/1021 Platinum
• CPC Class Codes: B01D 2255/1023 Palladium
• CPC Class Codes: B01D 2255/206 Rare earth metals
• 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 2255/2092 Aluminium
• CPC Class Codes: B01D 2255/50 Zeolites
• CPC Class Codes: B01D 2258/012 Diesel engines and lean burn gasoline engines
• 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 21/063 Titanium; Oxides or hydroxides thereof
• CPC Class Codes: B01J 21/066 Zirconium or hafnium; Oxides or hydroxides thereof
• 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 23/14 of germanium, tin or lead
• CPC Class Codes: B01J 23/626 with tin
• CPC Class Codes: B01J 23/83 with rare earths or actinides
• CPC Class Codes: B01J 23/835 with germanium, tin or lead
• CPC Class Codes: B01J 23/8892 Manganese
• CPC Class Codes: B01J 2523/00 Constitutive chemical elements of heterogeneous catalysts
• CPC Class Codes: B01J 2523/17 : Copper
• 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 2523/43 : Tin
• CPC Class Codes: B01J 2523/47 : Titanium
• CPC Class Codes: B01J 2523/48 : Zirconium
• CPC Class Codes: B01J 29/061 : containing metallic elements added to the zeolite
• CPC Class Codes: B01J 29/072 : Iron group metals or copper
• CPC Class Codes: B01J 29/46 : Iron group metals or copper
• CPC Class Codes: B01J 37/0246 : Coatings comprising a zeolite
• CPC Class Codes: F01N 2370/02 : used in catalytic reactors
• CPC Class Codes: F01N 2370/04 : Zeolitic material
• CPC Class Codes: F01N 3/035 : with catalytic reactors , e.g. catalysed diesel particulate filters
• CPC Class Codes: F01N 3/103 : Oxidation catalysts for HC and CO only

Abstract

Embodiments of the present disclosure include a catalyst for the conversion of CO and/or hydrocarbons in an exhaust stream including a Sn compound selected from the group consisting of a binary composition comprising Sn and Ti, a ternary composition comprising Sn, Ti and Zr, and mixtures of any thereof. In those embodiments, the binary composition may include Sn_(X)Ti_(y)O₂, wherein x+y=1, 0.85>y>0. In other embodiments of the present disclosure, the Sn compound includes a ternary composition including Sn_(a)Ti_(b)Zr_(c)O₂, wherein a is 0.25, b is 0.25 and c is 0.5. Certain embodiments of this disclosure include a method for the conversion of CO in an exhaust stream, including contacting an exhaust stream containing CO with the catalyst described above containing a Sn compound. In other embodiments, the exhaust stream includes hydrocarbons.

Claims

1. A method for the conversion of CO in an exhaust stream, comprising:

contacting an exhaust stream containing CO with a catalyst, the catalyst made from the addition of a Sn compound is a ternary composition comprising Sn, Ti and Zr, wherein the ternary composition comprises Sn_(a)Ti_(b)Zr_(c)O₂, wherein a is 0.25, b is 0.25 and c is 0.5.

2. The method of claim 1, wherein the ternary composition comprises a srilankite crystal phase.

3. A method for the conversion of CO in an exhaust stream, comprising:

contacting an exhaust stream containing CO with a catalyst, the catalyst comprising a Sn compound selected from the group consisting of a binary composition comprising Sn and Ti, and a ternary composition comprising Sn, Ti and Zr, and mixtures of any thereof, wherein the Sn compound comprises a composition defined by a region of a phase diagram between Zr_0.5Sn_0.25Ti_0.25O₂ and, Sn_1-xTi_xO₂, where x is greater than or equal to 0 and less than 0.85;

the catalyst further comprising a catalyst component selected from the group consisting of Pt, Pd, one or more base metals, and combinations of any thereof, wherein the base metal is selected from the group consisting of Cu, Fe, Ni, W, V, Cr, Mn, Co, and mixtures of any thereof.

4. A method for the conversion of CO in an exhaust stream according to claim 3, wherein the binary composition comprises Sn_(x)Ti_(y)O₂, wherein x+y=1, 0.85>

y>

0.

5. The method of claim 4, wherein 0.5>

y>

0.05.

6. The method of claim 4, wherein the binary composition comprises a rutile crystal phase.

7. The method of claim 3, wherein x is greater than or equal to 0.05 and less than 0.85.

8. The method of claim 3, wherein the Sn compound comprises a composition defined by a region of a phase diagram between Zr_0.5Sn_0.25T_0.25O₂ and rutile Sn_1-x,Ti_xO₂ where 0.05<

x<

0.85, comprising;

Zr_aSn_bTi_c, where a, b and c comprise;

a=0.5, b=0.25, c=0.25;

a=0.4, 0.23<

b<

0.39, 0.21<

c<

0.37;

where b+c=0.6;

a=0.3, 0 21<

b<

0.53, 0.17<

c<

0.49;

where b+c=0.7;

a=0.2, 0.19<

b<

0.67, 0.13<

c<

0.61;

where b+c=0.8;

a=0.1, 0.17<

b<

0.81, 0.09<

c<

0.73;

where b+c=0.9;

a=0, 0.15<

b<

0.95, 0.05<

c<

0.85;

where b+c=1.0;

and all intermediate regions between a=0 and a=0.5.

9. A method for the conversion of CO in an exhaust stream according to claim 3, wherein the catalyst is on a substrate.

10. The method of claim 9, wherein the substrate comprises a ceramic support.

11. The method of claim 10, wherein the ceramic support comprises a material selected from the group consisting of cordierite and silicon carbide.

12. The method of claim 11, wherein the substrate comprises a particulate filter.

13. The method of claim 12, wherein the particulate filter comprises a wall flow filter.

14. The method of claim 13, wherein the particulate filter comprises a diesel particulate filter.

15. A method for the conversion of CO in an exhaust stream, comprising:

contacting an exhaust stream containing CO with a catalyst, the catalyst comprising a Sn compound selected from the group consisting of a binary composition comprising Sn and Ti, and a ternary composition comprising Sn, Ti and Zr, and mixtures of any thereof, the catalyst further comprising a component selected from the group consisting of Pt, Pd, one or more base metals, and combinations of any thereof, wherein the base metal is selected from the group consisting of Cu, Fe, Ni, W, V, Cr, Mn, Co, and mixtures of any thereof.

16. The method of claim 15, wherein the catalyst comprises Pd.

17. The method of claim 16, wherein Sn compound comprises the binary compound comprising Sn_1-xTi_xO₂, wherein 0.5>

x>

0.05.

18. A method for the conversion of CO in an exhaust stream, comprising:

contacting an exhaust stream containing CO with a catalyst, the catalyst comprising a Sn compound selected from the group consisting of a binary composition comprising Sn and Ti, and a ternary composition comprising Sn, Ti and Zr, and mixtures of any thereof, wherein the catalyst further comprises a zeolite.

19. The method of claim 18, wherein the zeolite is selected from the group consisting of ZSM-5, ZSM-11, ZSM-12, ZSM-18, ZSM-23, MCM-zeolites, mordenite, faujasite, ferrierite, zeolite beta, and mixtures thereof.