Diesel exhaust article and catalyst compositions therefor

Abstract

A self-cleaning diesel exhaust particulate filter system is disclosed wherein burn-off of collected particulate matter is accomplished at normal exhaust gas temperatures, the filter system being provided with a catalyst mixture of a co-formed ceria-zirconia composite and, optionally, a base metal oxide, the presence of which allows regeneration of filters at temperatures that are readily achieved in diesel exhaust systems, including operating conditions that are at low load where lower exhaust temperatures exist.

Description

Diesel engine exhaust and catalyst composition accordingly Cross References to Related Applications This application claims priority to US Provisional Application No. 60 / 705,823, filed August 5, 2005, and entitled "Diesel Engine Exhausts and Catalyst Compositions Accordingly." field of invention The present invention relates to an apparatus and catalyst composition for reducing harmful emissions from diesel engines, and more particularly to an apparatus for increasing the efficiency of oxidation of particulate components in the emissions. Background of the invention Diesel engine exhaust is a heterogeneous mixture containing not only gaseous emissions such as carbon monoxide ("CO"), unburned hydrocarbons ("HC") and nitrogen oxides ("NOx"), but also condensed phase substances (liquids and solids), the condensed phase material consists of so-called particles or particulate matter. Total particulate matter ("TPM") emissions contain three main components. One component is...

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Problems solved by technology

For example, lower diesel exhaust temperatures were observed under low load and start-up conditions. At lower diesel exhaust temperatures, the catalyst located on the filter was less efficient at catalyzing the combustion of particulate matter collected on the filter, Increased back pressure in the exhaust system

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