Tungsten/titania oxidation catalyst

Patent metadata

Field	Value
Publication number	US-9943830-B2
Application number	US-201414341890-A
Country	US
Kind code	B2
Filing date	Jul 28, 2014
Priority date	Jul 26, 2013
Publication date	Apr 17, 2018
Grant date	Apr 17, 2018

Abstract

A catalyst article for treating an emission gas is provided comprising (a) an oxidation catalyst comprising at least one noble metal on a WO 3 —TiO 2 support, wherein the support contains about 1 to about 20 weight percent WO 3 based on the combined weight of the WO 3 and TiO 2 ; and (b) a substrate, wherein the first and second catalyst layers are on and/or within the substrate.

First claim

What is claimed is:

1. A method for regenerating a catalytic article used to treat exhaust gas comprising:
a. flowing an exhaust gas through a substrate having an oxidation catalyst, wherein the exhaust gas contains SO x prior to entering the substrate, and wherein the oxidation catalyst comprises a noble metal on a WO 3 —TiO 2 composite oxide support, wherein the support contains about 1 to about 20 weight percent WO 3 based on the combined weight of the WO 3 and TiO 2 ;
b. absorbing at least a portion of the SO x in the catalyst layer; and
c. regenerating the catalyst after the catalyst layer adsorbs at least 5 g/L of the SO x .

2. A method for regenerating a catalytic article used to treat exhaust gas comprising:
a. flowing an exhaust gas through a substrate having an oxidation catalyst, wherein the exhaust gas contains SO x prior to entering the substrate, and wherein the oxidation catalyst comprises a noble metal on a WO 3 —TiO 2 composite oxide support, wherein the support contains about 1 to about 20 weight percent WO 3 based on the combined weight of the WO 3 and TiO 2 ;
b. absorbing at least a portion of the SO x in the catalyst layer; and
c. regenerating the catalyst at a temperature of not greater than 350° C.

3. The method of claim 1 , wherein the support contains about 2 to about 10 weight percent WO 3 based on the combined weight of the WO 3 and TiO 2 .

4. The method of claim 1 , wherein the oxidation catalyst is essentially free of V, Ce, Zr, Al, Si, and Mo.

5. The method of claim 1 , wherein the noble metal is Au, Ag, Pt, Pd, Rh, or combination thereof.

6. The method of claim 1 , wherein the noble metal is Pt, Pd, or a combination thereof.

7. The method of claim 1 , wherein the substrate further comprises a washcoat, wherein the washcoat contains the oxidation catalyst.

8. The method of claim 1 , wherein the substrate further comprises a second catalyst for selectively reducing NO x in the presence of oxygen and/or for storing NH 3 , wherein the second catalyst is disposed on or within substrate, but is physically separate from the oxidation catalyst.

9. The method of claim 8 , wherein the oxidation catalyst is disposed on the substrate as a first washcoat layer and the second catalyst is disposed on the substrate as a second washcoat layer, wherein the first washcoat layer completely covers, but is separate from, the second layer.

10. The method of claim 9 , wherein the second catalyst layer comprises a high surface area metal oxide selected from the group consisting of Al 2 O 3 , TiO 2 , CeO 2 , SiO 2 , and ZrO 2 , or an aluminosilicate or silicoaluminophosphate molecular sieve, wherein the metal oxide or molecular sieve optionally supports a promoter metal selected from the group consisting of V, Cr, Co, Cu, Fe, Hf, La, Ce, In, V, Mn, Ni, Zn, and Ga.

11. The method of claim 10 , wherein the second catalyst layer comprises a promoter metal selected from Cu and Fe supported on a molecular sieve having a framework selected from the group consisting of AEI, AFX, CHA, KFI, LEV, ERI, DDR, UEI, RHO, EAB, PAU, MER, GOO, YUG, GIS, UFI, VIN, AEI/CHA intergrowths, BEA, MOR, and FER.

12. The method of claim 2 , wherein the support contains about 2 to about 10 weight percent WO 3 based on the combined weight of the WO 3 and TiO 2 .

13. The method of claim 2 , wherein the oxidation catalyst is essentially free of V, Ce, Zr, Al, Si, and Mo.

14. The method of claim 2 , wherein the noble metal is Au, Ag, Pt, Pd, Rh, or combination thereof.

15. The method of claim 2 , wherein the noble metal is Pt, Pd, or a combination thereof.

16. The method of claim 2 , wherein the substrate further comprises a washcoat, wherein the washcoat contains the oxidation catalyst.

17. The method of claim 2 , wherein the substrate further comprises a second catalyst for selectively reducing NO x in the presence of oxygen and/or for storing NH 3 , wherein the second catalyst is disposed on or within substrate, but is physically separate from the oxidation catalyst.

18. The method of claim 17 , wherein the oxidation catalyst is disposed on the substrate as a first washcoat layer and the second catalyst is disposed on the substrate as a second washcoat layer, wherein the first washcoat layer completely covers, but is separate from, the second layer.

19. The method of claim 18 , wherein the second catalyst layer comprises a high surface area metal oxide selected from the group consisting of Al 2 O 3 , TiO 2 , CeO 2 , SiO 2 , and ZrO 2 , or an aluminosilicate or silicoaluminophosphate molecular sieve, wherein the metal oxide or molecular sieve optionally supports a promoter metal selected from the group consisting of V, Cr, Co, Cu, Fe, Hf, La, Ce, In, V, Mn, Ni, Zn, and Ga.

20. The method of claim 19 , wherein the second catalyst layer comprises a promoter metal selected from Cu and Fe supported on a molecular sieve having a framework selected from the group consisting of AEI, AFX, CHA, KFI, LEV, ERI, DDR, UEI, RHO, EAB, PAU, MER, GOO, YUG, GIS, UFI, VIN, AEI/CHA intergrowths, BEA, MOR, and FER.

Assignees

• Johnson Matthey Plc

Inventors

• Micallef David
• Parsons Alex

Classifications

• B01J38/02 Primary

  Heat treatment · CPC title

• B01D2255/106

  Gold · CPC title

• B01D2258/01

  Engine exhaust gases · CPC title

• B01J23/42

  Platinum · CPC title

• B01D2255/1025

  Rhodium · CPC title