REDUCTION-CATALYST-COATED DIESEL PARTICLE FILTER HAVING IMPROVED CHARACTERISTICS

摘要

A diesel particle filter which comprises a ceramic wall flow filter substrate and two coatings is described. The first coating which is applied in the inflow channels and is composed of high-melting materials has such a nature that it closes the inflow channels and pores in the wall connecting the inflow channels and outflow channels to soot particles on the inflow side without preventing passage of the gaseous exhaust gas constituents. The second coating is introduced into the wall between inflow channels and outflow channels and is of such a nature that it can effectively catalyze the selective reduction of nitrogen oxides by means of a reducing agent. The resulting component is an SCR-catalytically active particle filter and displays excellent banking-up pressure properties combined with high filtration efficiency and good regeneration properties. Furthermore, the component displays good aging stability of the NOx conversion activity.