Reduction-catalyst-coated diesel particle filter having improved characteristics

摘要

An SCR-catalytically active diesel particle filter having a ceramic wall flow filter substrate with inflow channels, outflow channels, walls separating the inflow and outflow channels, and two coatings. The first coating is applied in inflow channels, is composed of high-melting point materials, and closes the inflow sides of pores in walls connecting the inflow channels and outflow channels to soot particles without preventing passage of gaseous exhaust gas constituents. The second coating is within the walls between inflow channels and outflow channels, and effectively catalyzes the selective reduction of nitrogen oxides when in the presence of a reducing agent. The particle filter displays excellent banking-up pressure properties combined with high filtration efficiency and good regeneration properties; and displays good aging stability of NOx conversion activity.

主权项

1. A diesel particle filter, comprising:
a ceramic wall flow filter substrate comprising inflow channels open at a first end of the wall flow filter substrate, outflow channels open at a second end of the wall flow filter substrate, and channel walls extending between the inflow channels and the outflow channels, the channel walls comprising pores that extend from openings at an inflow side to openings at an outflow side; a first coating in the inflow channels, the first coating forming closures at pore openings at the inflow sides of the channel walls that inhibit soot particles from entering the pores at the inflow sides without preventing passage of gaseous exhaust gas constituents through the pores; and a second coating inside the channel walls, the second coating being one that effectively catalyzes selective reduction of nitrogen oxides when in the presence of a reducing agent.