Co slip catalyst and method of using

Patent metadata

Field	Value
Publication number	US-2017284262-A1
Application number	US-201715631812-A
Country	US
Kind code	A1
Filing date	Jun 23, 2017
Priority date	Aug 28, 2013
Publication date	Oct 5, 2017
Grant date	—

Abstract

A CO slip catalyst, for treating an exhaust gas from a lean burn internal combustion engine, is disclosed. The CO slip catalyst comprises palladium and a ceria-containing material. The invention also includes a method for oxidizing excess CO in an exhaust gas, wherein the excess CO results from the periodic contact of an upstream catalyst under rich exhaust conditions. The method comprises contacting the excess CO in the exhaust gas with a CO slip catalyst at a temperature in the range of 100 to 700° C.

First claim

We claim:

1 . An exhaust system for treating an exhaust gas from a lean burn internal combustion engine, said exhaust system comprising an upstream catalyst and a CO slip catalyst, where the CO slip catalyst comprises palladium and a ceria-containing material, and wherein the CO slip catalyst is located downstream of the upstream catalyst.

2 . The system of claim 1 , wherein the ceria-containing material comprises ceria, ceria-zirconia, ceria-zirconia-alumina, and mixtures thereof.

3 . The system of claim 1 or claim 2 , wherein the upstream catalyst comprises a three-way catalyst or a selective catalytic reduction catalyst.

4 . The system of claim 1 , wherein the CO slip catalyst comprises 0.5 to 5 weight percent palladium.

5 . The system of claim 1 , wherein the CO slip catalyst further comprises one or more alkali or alkaline earth metals.

6 . The system of claim 1 , wherein the CO slip catalyst further comprises one or more inorganic oxide binders selected from the group consisting of alumina, silica, titania, zirconia, magnesia, niobia, tantalum oxide, molybdenum oxide, tungsten oxide, and mixed oxides of any two or more thereof.

7 . The system of claim 1 , wherein the CO slip catalyst is coated on a substrate.

8 . The system of claim 7 , wherein the substrate is a ceramic substrate or a metallic substrate.

Assignees

• Johnson Matthey Plc

Inventors

• Ballinger Todd Howard
• Chen Hai-Ying
• Cox Julian Peter
• Mulla Shadab Sharif
• Rieck Jeffrey Scott
• Weigert Erich Conlan

Classifications

• Y02A50/20

  Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters · CPC title

• F01N2510/06

  for exhaust purification, e.g. catalytic reaction · CPC title

• F01N2370/02

  used in catalytic reactors · CPC title

• B01D2255/904

  Multiple catalysts · CPC title

• B01D2255/20715

  Zirconium · CPC title