| abstract |
FIELD: chemical or physical processes.SUBSTANCE: invention relates to a method for synthesis of zeolite for NOxreduction and/or NH3oxidation, having a CHA framework structure. Catalyst composition contains a synthetic zeolite having a CHA framework structure and a molar ratio of silicon dioxide to aluminum oxide (SAR) of 45 to 85, and an atomic ratio of copper to aluminum of at least 1.25. Method includes: forming a reaction mixture containing a silicon dioxide source, an aluminum oxide source, a first organic template reagent for CHA in the form of a copper metal-amine complex (Cu-TEPA), a second organic template reagent for CHA (DMECHA) and seed crystals; heating the reaction mixture to facilitate crystallisation and precipitation of crystals of the catalyst composition; and collecting, washing and drying crystals. Reaction mixture is free from fluorine.EFFECT: technical result is obtaining zeolites as a catalyst, which is less susceptible to high-temperature hydrothermal degradation, thereby reducing loss of activity.3 cl |