Light-duty diesel engine and a particulate filter therefor

摘要

A diesel engine includes an exhaust system having a particulate filter made from a porous material having a mean pore diameter of from 5 m to 40 m, a porosity of at least 40% and a bulk volumetric heat capacity of at least 0.50 J cm3 K1 at 500° C. The filter includes a diesel oxidation catalyst (DOC) located in a first catalyst zone on the front end of the filter and at least one catalyst zone located downstream thereof, for oxidizing carbon monoxide, hydrocarbons and nitrogen monoxide. The engine includes engine management means, in use, to provide continuously or intermittently an exhaust gas having sufficient nitrogen oxides or hydrocarbon and/or an exhaust gas of sufficiently high temperature to combust particulate matter. The platinum group metal (PGM) loading in the first catalyst zone is greater than the total PGM loading in the at least one downstream catalyst zone.