Multi-layer catalyst composition for internal combustion engines

Patent metadata

Field	Value
Publication number	US-2018333677-A1
Application number	US-201716074215-A
Country	US
Kind code	A1
Filing date	Feb 1, 2017
Priority date	Feb 3, 2016
Publication date	Nov 22, 2018
Grant date	—

Abstract

The invention provides a catalyst article including a substrate underlying a multi-layer catalyst composition and a multi-layer catalyst composition comprising a first layer and a second layer, the first layer positioned between the substrate and the second layer, wherein the first layer comprises a first porous refractory oxide material impregnated with at least one base metal component and the second layer comprises a second porous refractory oxide material impregnated with at least one platinum group metal. Either the second porous refractory oxide material is a porous refractory oxide material other than alumina or the catalyst composition further comprises an intermediate layer between the first layer and the second layer, the intermediate layer comprising a refractory oxide material other than alumina. Methods of making and using the catalyst article are also provided, as well as emission treatment systems comprising the catalyst article.

First claim

1 . A catalyst article comprising a multi-layer catalyst composition adapted for oxidation of gaseous HC and CO emissions and conversion of NOx to N 2 , the catalyst article comprising:
a substrate in adherence to a multi-layer catalyst composition; the multi-layer catalyst composition comprising a first layer, a second layer and optionally an intermediate layer between the first and second layers; the first layer positioned between the substrate and the second layer and comprising a first porous refractory oxide material impregnated with at least one base metal component; the second layer comprising a second porous refractory oxide material impregnated with at least one platinum group metal; and the intermediate layer comprising a refractory oxide material, wherein the second layer is substantially free of alumina and/or the intermediate layer is present and is substantially free of alumina.

2 . The catalyst article of claim 1 , wherein the first porous refractory oxide material is selected from the group consisting of alumina, silica, zirconia, ceria, and combinations thereof; and wherein the second porous refractory oxide material is selected from the group consisting of silica, zirconia, titania, ceria, and combinations thereof.

3 . The catalyst article of claim 1 , wherein the base metal oxide is selected from oxides of copper, manganese, iron, nickel, cerium, praseodymium, and combinations thereof.

4 . The catalyst article of claim 1 , wherein multi-layer catalyst composition includes an intermediate layer comprising a refractory oxide material selected from the group consisting of silica, zirconia, titania, ceria, and combinations thereof.

5 . The catalyst article of claim 1 , wherein one or both of the first and second layers further comprise an oxygen storage component.

6 . The catalyst article of claim 5 , wherein the oxygen storage component is ceria.

7 . The catalyst article of claim 1 , wherein the first layer comprises alumina impregnated with at least one base metal component and optionally ceria, and the second layer comprises zirconia impregnated with at least one platinum group metal and optionally ceria, and wherein the second layer is substantially free of alumina.

8 . The catalyst article of claim 7 , wherein the at least one base metal component comprises at least one of copper oxide and manganese oxide and the at least one platinum group metal comprises rhodium.

9 . The catalyst article of claim 1 , wherein the substrate has a plurality of channels adapted for gas flow, each channel having a wall surface upon which the multi-layer catalyst composition is coated.

10 . The catalyst article of claim 1 , wherein the catalyst article, upon aging at 950° C. for eight hours, is characterized by less than about 15% by weight of the total base metal content being present in the second layer.

11 . A method of treating an exhaust stream, comprising passing the exhaust stream through a catalyst article according to claim 1 such that carbon monoxide and hydrocarbon gases within the exhaust stream are oxidized and NOx is converted to N 2 within the catalyst article.

12 . An emission treatment system for treatment of an exhaust gas stream, the emission treatment system comprising:
i) An internal combustion engine producing an exhaust gas stream; and ii) a catalyst article according to claim 1 positioned in fluid communication with the exhaust gas stream and adapted for oxidation of carbon monoxide and hydrocarbon gases and conversion of NOx to N 2 within the exhaust stream to form a treated exhaust gas stream.

13 . A method for preparing a catalyst article comprising a multi-layer catalyst composition adapted for oxidation of gaseous HC and CO emissions and conversion of NOx to NO 2 , the method comprising:
forming a first washcoat slurry comprising a first porous refractory oxide material impregnated with at least one base metal component; exposing a catalyst substrate having a plurality of channels adapted for gas flow to the first washcoat slurry to coat the channels with the first washcoat slurry; calcining the catalyst substrate to form a first layer on the catalyst substrate; optionally, forming an intermediate washcoat slurry comprising a porous refractory oxide material other than alumina; optionally, exposing the catalyst substrate to the intermediate washcoat slurry to coat the channels with the intermediate washcoat slurry; optionally, calcining the catalyst substrate to form an intermediate layer on the catalyst substrate; forming a second washcoat slurry comprising a second porous refractory oxide material impregnated with at least one platinum group metal; exposing the catalyst substrate to the second washcoat slurry to coat the channels with the second washcoat slurry; and calcining the catalyst substrate to form a second layer on the catalyst substrate, wherein, if the optional intermediate layer is not present on the catalyst article, the second porous refractory oxide material is a refractory oxide material other than alumina.

14 . The method of claim 13 , wherein the first porous refractory oxide material is selected from the group consisting of alumina, silica, zirconia, ceria, and combinations thereof; and wherein the second porous refractory oxide material is selected from the group consisting of silica, zirconia, titania, ceria, and combinations thereof.

15 . The method of claim 13 , wherein the base metal component is selected from oxides of copper, manganese, iron, nickel, cerium, praseodymium, and combinations thereof.

16 . The method of claim 13 , wherein the intermediate layer comprises a refractory oxide material selected from the group consisting of silica, zirconia, titania, ceria, and combinations thereof.

17 . The method of claim 13 , wherein the second layer is substantially free of alumina and wherein the intermediate layer, when present, is substantially free of alumina.

18 . The method of claim 13 , wherein one or both of the first and second layers further comprise an oxygen storage component.

19 . The method of claim 18 , wherein the oxygen storage component is ceria.

20 . The method of claim 13 , wherein the first layer comprises alumina impregnated with at least one base metal component and optionally ceria, and the second layer comprises zirconia impregnated with at least one platinum group metal and optionally ceria, and wherein the second layer is substantially free of alumina.

21 . The method of claim 20 , wherein the at least one base metal component comprises at least one of copper oxide and manganese oxide and the at least one platinum group metal comprises rhodium.

Assignees

• Basf Corp

Inventors

• Shacklady-Mcatee Danielle Maria
• Liu Ye
• Tran Pascaline Harrison

Classifications

• B01J37/0201

  Impregnation · CPC title

• B01J23/8892

  Manganese · CPC title

• B01J21/066

  Zirconium or hafnium; Oxides or hydroxides thereof · CPC title

• B01D2255/20715

  Zirconium · CPC title

• B01J35/0006

  Operations & Transport · mapped topic