초록 ▼

An emission control system especially for light duty diesel engines has a first catalyst, 2, positioned upstream of a second catalyst, 3. The first catalyst converts NO to NO.sub.2 and the second catalyst oxidises HC, CO and VOF. The tendency of the second catalyst to collect soot particles is reduc

An emission control system especially for light duty diesel engines has a first catalyst, 2, positioned upstream of a second catalyst, 3. The first catalyst converts NO to NO.sub.2 and the second catalyst oxidises HC, CO and VOF. The tendency of the second catalyst to collect soot particles is reduced by combustion of the soot particles by NO.sub.2 from the first catalyst.

대표청구항 ▼

[ What is claimed is:] [1.]1. An emission control system for internal combustion engines which emit carbonaceous soot particles, which system comprising a first catalyst effective to oxidize NOx to NO.sub.2 and a second catalyst effective to oxidize hydrocarbons, carbon monoxide and volatile organic

[ What is claimed is:] [1.]1. An emission control system for internal combustion engines which emit carbonaceous soot particles, which system comprising a first catalyst effective to oxidize NOx to NO.sub.2 and a second catalyst effective to oxidize hydrocarbons, carbon monoxide and volatile organic fractions, each catalyst being supported on a honeycomb flow-through monolith, whereby soot particles trapped on or within said second catalyst are combusted in the NO.sub.2 containing gas from said first catalyst, and wherein the first catalyst is supported on a flexible metal monolith of up to 31 cells/cm.sup.2, whereby soot particle collection on the first catalyst support is minimized.