US 12,270,326 B2
Filter for the aftertreatment of exhaust gases of internal combustion engines
Massimo Colombo, Frankfurt am Main (DE); Jan Schoenhaber, Darmstadt (DE); Meike Antonia Gotthardt, Frankfurt (DE); and Carolin Braun, Langen (DE)
Assigned to UMICORE AG & CO. KG, Hanau-Wolfgang (DE)
Appl. No. 18/547,856
Filed by UMICORE AG & CO. KG, Hanau-Wolfgang (DE)
PCT Filed Mar. 22, 2022, PCT No. PCT/EP2022/057425
§ 371(c)(1), (2) Date Aug. 24, 2023,
PCT Pub. No. WO2022/200310, PCT Pub. Date Sep. 29, 2022.
Claims priority of application No. 21164198 (EP), filed on Mar. 23, 2021.
Prior Publication US 2024/0141812 A1, May 2, 2024
Int. Cl. F01N 3/035 (2006.01); B01J 29/74 (2006.01); B01J 35/56 (2024.01); B01J 37/02 (2006.01); F01N 3/02 (2006.01); F01N 3/021 (2006.01); F01N 3/022 (2006.01); F01N 3/20 (2006.01)
CPC F01N 3/035 (2013.01) [B01J 35/56 (2024.01); B01J 37/0232 (2013.01); F01N 3/021 (2013.01); F01N 3/0222 (2013.01); F01N 3/0224 (2013.01); F01N 3/2066 (2013.01); B01D 2255/1023 (2013.01); B01D 2255/1025 (2013.01); B01D 2255/407 (2013.01); B01D 2255/9155 (2013.01); B01J 29/743 (2013.01); F01N 2330/14 (2013.01); F01N 2510/068 (2013.01)] 21 Claims
OG exemplary drawing
 
1. Wall-flow filter for removing particles from the exhaust gas of an internal combustion engine, which comprises a wall-flow filter substrate of length L and coating F, wherein the wall-flow filter substrate has channels E and A extending in parallel between a first and a second end of the wall-flow filter substrate, which are separated by porous walls and form surfaces OE and OA, and wherein the channels E are closed at the second end and the channels A are closed at the first end, and wherein coating F is located on the surfaces OE, optionally in the porous walls but not on the surfaces OA,
characterized in that coating F comprises a sintered material S, wherein material S comprises kaolin, gypsum, bentonite, montmorillonite or a mixture comprising two or more of these materials, wherein
coating F is applied onto the surfaces OE by depositing material S in powder form onto the channels E, followed by a thermal treatment to cause sintering of material S, and the thermal treatment comprises heating the wall-flow filter substrate which carries material S on its surfaces OE to a temperature T and maintaining this temperature for a period of time M, and the wall-flow filter substrate is heated with a heating rate of 100 to 1000 K/h to a temperature T of 100 to 1350° C. and maintained at that temperature for a period of time M of 1 second to twelve hours;
and said wall-flow filter further comprising coating Z, which is coated on the surfaces OA and comprises palladium and/or rhodium and at least one cerium/zirconium mixed oxide, with the at least one cerium/zirconium mixed oxide comprising yttria and lanthana or praseodymia and lanthana; and wherein coating Z extends from the second end of the wall flow filter substrate to 40 to 97% of the length L of the wall-flow filter.