THREE-LAYER NOx CATALYST-ADSORBER Russian patent published in 2021 - IPC B01D53/94 B01J23/58 B01J23/63 F01N3/35 

FIELD: internal combustion engines.

SUBSTANCE: depleted NO_x trap catalyst and its use in an exhaust purification system for internal combustion engines are described. The trap catalyst contains the first layer, the second layer and the third layer, while the second layer is deposited on the first layer, and the third layer is deposited on the second layer. The first layer contains a mixture or alloy of platinum and palladium, the first material containing cerium dioxide, alkaline or alkaline earth metal and the first inorganic oxide. The second layer contains a mixture or alloy of platinum and palladium, the second material containing cerium dioxide, and the second inorganic oxide. The third layer contains a mixture or alloy of rhodium and platinum, which have reducing activity, and the third inorganic oxide.

EFFECT: improved characteristics of NO_x accumulation and conversion, as well as improved CO conversion in both active and deactivated states.

45 cl, 6 tbl, 6 ex