Particle filter and method for producing a particle filter

A particle filter (1) for an exhaust gas system (2), the particle filter (1) comprising:

• a first end face (6);
• a second end face (7);
• a plurality of porous channel walls (8);
• and
• a plurality of Sow channels (5) extending from the first end face (6), at which an exhaust gas (10) enters, through to the second end face (7), the flow channels (5) being separated from one another by respective ones of the porous channel walls (8), the flow channels (5) each having a closure (9) arranged alternately at the first and second end laces (6, 7) so that the exhaust gas (10) entering a flow channel (5) that is open at the first end face (6) flows through the channel wall (8) and flows out from the particle filter (1) through an adjacent flow channel (5) that is open at the second end face (7), each channel wall (8) having at least the following layers in succession in a flow direction (11):
• a particle filter layer (13) having a porosity of from 5 to 50% and an average pore size, of from 5 to 15 μm on the exhaust gas entry side (12);
• an intermediate layer (14) having a porosity of from 55 to 95% and an average pore size of from 15 to 100 μm, the intermediate layer (14) comprising a first selective catalytic reduction (SCR) coating (15) having a first catalytic activity (16);
• and
• a second SCR coating (18) having a second catalytic activity (19), different from the first catalytic activity (16), arranged on an exhaust gas exit side (17).

A process for producing a particle filter (1), the process comprising:

• providing a plurality of flow channels (5) each extending from a first end face (6) to a second end face (7) and being separated from one another by porous channel walls (8);
• alternately arranging closures (9) in the flow channels (5) at the first and second end faces (6, 7);
• coating the porous channel wall (8) with a first selective catalytic reduction (SCR) coating (15) having a first catalytic activity (16);
• coating the channel walls (8) of the flow channels (5) that are open at the second end face (7) with a second SCR coating (18) having a second catalytic activity (19), the second catalytic activity (19) being different from the first catalytic activity (16);
• arranging a particle filter layer (13) on channel walls (8) of the flow channels (5) that are open at the first end face (6), the particle filter layer (13) having a porosity of from 5 to 50% and an average pore size of from 5 to 15 μm.