MIXED TEMPLATE SYNTHESIS OF Cu-CHA WITH HIGH CONTENT OF SILICON DIOXIDE Russian patent published in 2019 - IPC B01J29/76 C01B39/48 B01D53/94 

FIELD: chemistry.

SUBSTANCE: invention relates to a catalyst composition for treating exhaust gas, a method of synthesis of a zeolite having a CHA framework structure, to catalytic products for treating exhaust gas and a method of treating exhaust gas. Catalyst composition contains a synthetic zeolite having a carcass structure CHA and molar ratio of silicon dioxide and aluminium oxide (SAR) of 25 to 150, containing copper in the form of extra-framework copper, uniformly dispersed in the volume of cavities and channels of the zeolite, and free copper oxide, wherein the weight ratio of the free copper oxide to the in-frame copper is less than 1. Method for synthesis of said zeolite comprises: preparing a reaction mixture comprising (a) at least one aluminium oxide source, (b) at least one silicon dioxide source, (c) an amine organic templating agent containing a transition metal, (d) germ crystals and (e) a different organic templating agent other than the first, wherein each of the first and second templating agents is suitable for forming a carcass structure of CHA, wherein the reaction mixture contains substantially no fluorine; heating the reaction mixture in crystallisation conditions for a time sufficient to form said zeolite. Exhaust gas treatment method includes contacting exhaust gas after combustion, comprising NO_x and/or NH₃, with catalytic product for selective reduction of at least part of NO_x up to N₂ and H₂O and/or oxidation of at least part of NH₃.

EFFECT: technical result is high hydrothermal stability of catalyst composition.

21 cl, 1 dwg, 2 tbl, 2 ex