CATALYST FOR EXHAUST GAS TREATMENT Russian patent published in 2020 - IPC B01J29/76 B01D53/56 B01J21/04 B01J21/06 F01N3/20 

FIELD: chemistry.

SUBSTANCE: described is a catalyst composition suitable for use as a selective catalytic reduction catalyst, a catalytic article containing said composition, method of selective reduction of nitrogen oxides, exhaust gas treatment system containing catalytic article, method of producing catalyst composition and method of producing catalytic product. Catalytic composition suitable for use as selective catalytic reduction catalyst contains: fine-pore molecular sieve particles, having a porous structure and a maximum ring size of eight tetrahedral atoms and impregnated with a promoter metal, and metal oxide particles, dispersed in the particles of the fine-pore molecular sieve and outside the porous structure of the fine-pore molecular sieve particles, where the metal oxide particles are selected from a group consisting of zirconium dioxide, aluminum oxide, cerium oxide, yttrium oxide, hafnium oxide, and combinations thereof. Method of producing a catalyst composition comprises: dissolving a salt of at least one promoter metal in a water-based metal oxide sol, where the salt of at least one promoter metal dissociates in the water-based metal oxide sol to form a metal salt / metal oxide sol mixture on a water base, where the metal oxide is selected from a group, consisting of zirconium dioxide, aluminum oxide, cerium oxide, hafnium oxide, yttrium oxide, and combinations thereof; treatment of particles of ammonium- or proton-exchanged fine-pored molecular sieve, having a porous structure and a maximum ring size of eight tetrahedral atoms, a metal salt / metal oxide sol on a water base, to enable impregnation of the promoter metal into the porous structure of the fine-pore molecular sieve; and drying and calcining the treated fine-pore molecular sieve particles to form a catalyst composition, where the catalyst composition contains fine-pore molecular sieve particles impregnated with a promoter metal and metal oxide particles, fine-porous molecular sieve dispersed in the particles and outside the porous structure of fine-pore molecular sieve particles.

EFFECT: catalyst composition has improved efficiency of converting NO_x and less amount of N₂O and effectively promotes reaction of ammonia with nitrogen oxides with formation of nitrogen and H₂O selectively in temperature range from 200 to 600 °C.

31 cl, 16 dwg, 5 tbl, 7 ex