CATALYSED PARTICULATE FILTER AND METHODS FOR COATING PARTICULATE FILTER Russian patent published in 2017 - IPC B01J35/04 B01J37/02 F01N3/35 B01D53/94 

FIELD: chemistry.

SUBSTANCE: invention relates to a wall flow particulate filter and a method for preparation thereof. Catalysed wall flow filter consists of a plurality longitudinal inlet flow channels and outlet flow channels separated by gas permeable porous partition walls, each inlet flow channel having an open inlet end and a closed outlet end, and each outlet flow channel having a closed inlet end and an open outlet end, wherein each inlet flow channel comprises a first catalyst being active in reaction of nitrogen oxides with carbon monoxide and hydrogen to ammonia; each outlet channel comprises a second catalyst being active in selective reduction of nitrogen oxides by reaction with ammonia to nitrogen; and wherein mode particle size of either first or second catalyst is less than mean pore size of gas permeable porous partition walls, and mode particle size of catalyst having not less mode particle size is larger than mean pore size of gas permeable partition walls, wherein catalyst, which is active during conversion of nitrogen oxides to ammonia, includes palladium, platinum, mixture of palladium and rhodium and mixture of palladium, platinum and rhodium, and catalyst, which is active during selective reduction of nitrogen oxides, includes at least one of zeolite, silicon dioxide and aluminium phosphate, ion-exchange zeolite, silicon dioxide and aluminium phosphate, promoted with iron and/or copper, one or more oxides of a base metal.

EFFECT: invention enables one of catalysts to efficiently diffuse in partition walls and prevent another catalyst to diffuse into channels.

8 cl, 1 ex