EXHAUST GAS TREATMENT CATALYSTS Russian patent published in 2018 - IPC B01J23/63 B01J23/83 B01J23/847 B01J23/648 B01J23/44 B01J35/10 B01J37/02 B01D53/94 F01N3/20 F01N3/35 

FIELD: technological processes.

SUBSTANCE: invention relates to a catalyst for treating an exhaust gas from a diesel engine comprising: (a) 0.1 to 10 wt.% of a group 8 to 11 transition metal; and (b) 90 to 99.9 wt.% of a support. Wherein the support comprises at least 90 wt.% of cerium dioxide and 0.1 to 10 wt.% of a dopant doped on the cerium dioxide, wherein the dopant comprises niobium (Nb) or tantalum (Ta). Invention also relates to a process for preparing said catalyst comprising: (a) impregnating cerium dioxide with an aqueous solution comprising a water-soluble niobium (Nb) or tantalum (Ta) salt; (b) calcining the impregnated cerium at a temperature within the range of 600 °C to 1,000 °C to obtain a support; (c) impregnating the support with a solution comprising a platinum group transition metal. Invention also relates to an exhaust gas after-treatment system comprising a catalyst and optionally a SCR catalyst, a diesel particulate filter, a catalyzed soot filter, an ammonia slip catalyst, or a combination thereof, and to a method for oxidizing a gaseous flow of diesel exhaust gas comprising carbon monoxide, unsaturated hydrocarbons, or both, in the presence of said catalyst.

EFFECT: improved ability to oxidize NO, CO and a reduced tendency to oxidize ammonia, improved resistance to sulfur poisoning.

20 cl, 12 dwg, 6 ex