NOx adsorber catalyst

Patent metadata

Field	Value
Publication number	US-11358127-B2
Application number	US-201715586491-A
Country	US
Kind code	B2
Filing date	May 4, 2017
Priority date	May 5, 2016
Publication date	Jun 14, 2022
Grant date	Jun 14, 2022

Abstract

A NOx adsorber catalyst and its use in an emission treatment system for internal combustion engines, is disclosed. The NOx adsorber catalyst composition comprises a support material, one or more platinum group metals disposed on the support material, and a NOx storage material.

First claim

The invention claimed is:

1. An emissions treatment system for treating a flow of a combustion exhaust gas that comprises a NO x adsorber catalyst in fluid communication with a lean burn engine, wherein the lean-burn engine is a diesel engine, and wherein the NO x adsorber catalyst has a first layer comprising:
a mixture or alloy of platinum and palladium on a support containing alumina or a composite or mixed oxide containing alumina; and
a NO x storage material consisting of neodymium-doped ceria; and
wherein the NO x adsorber catalyst is deposited directly on a metal or ceramic substrate.

2. The emissions treatment system as claimed in claim 1 , wherein the neodymium-doped ceria comprises about 0.5-18 mol % neodymium.

3. The emissions treatment system as claimed in claim 1 , wherein the support material is alumina, or a magnesia/alumina composite oxide or mixed oxide.

4. The emissions treatment system of claim 1 , wherein the first layer is substantially free of rhodium.

5. The emissions treatment system of claim 1 , wherein the first layer is substantially free of alkali metals.

6. The emissions treatment system of claim 1 , wherein the substrate is a flow-through monolith or a filter monolith.

7. The emissions treatment system of claim 4 , wherein the first layer contains no rhodium.

8. The emissions treatment system of claim 1 , further comprising an emissions control device downstream of the NO x adsorber catalyst.

9. The emissions treatment system of claim 8 , wherein the emissions control device is selected from a diesel particulate filter (DPF), a lean NOx trap (LNT), a lean NOx catalyst (LNC), a selective catalytic reduction (SCR) catalyst, a diesel oxidation catalyst (DOC), a catalysed soot filter (CSF), a selective catalytic reduction filter (SCRF™) catalyst, or an ammonia slip catalyst (ASC).

10. The emissions treatment system of claim 8 , wherein the emissions control device is a selective catalytic reduction (SCR) catalyst or a selective catalytic reduction filter (SCRF™) catalyst.

11. The emissions treatment system of claim 10 , further comprising an injector for injecting a nitrogenous reductant into exhaust gas downstream of the NOx adsorber catalyst and upstream of the SCR catalyst or the selective catalytic reduction filter (SCRF™) catalyst.

Assignees

• Johnson Matthey Plc

Inventors

• Armitage Andrew Paul
• Duran-Martin Desiree
• Millington Paul James
• Phillips Paul Richard
• Rajaram Raj Rao
• Reid Stuart David
• Swallow Daniel

Classifications

• B01J35/56

  Foraminous structures having flow-through passages or channels, e.g. grids or three-dimensional [3D] monoliths · CPC title

• B01D53/94 Primary

  by catalytic processes · CPC title

• B01D2255/1023

  Palladium · CPC title

• B01D2255/1021

  Platinum · CPC title

• B01D53/9468

  in different layers · CPC title