| abstract |
The present invention relates to an organotemplate-free synthetic process for the production of a zeoiitic material having a CHA-type framework structure comprising YO2, X2O3, and optionally comprising Z2O5, wherein said process comprises the steps of: (1 ) providing a mixture comprising one or more sources for YO2, one or more sources for X2O3, and seed crystals having a CHA framework structure, wherein the CHA framework structure of the seed crystals comprises YO2, X2O3, and optionally comprises Z2O5; and (2) crystallizing the mixture obtained in step (1 ); wherein Y is a tetravaient element, X is a trivalent element, and Z is a pentavalent element, wherein optionally one or more sources for Z2O5 are further provided in step (1 ), and wherein if the CHA framework of the seed crystals does not contain Z2O5, the seed crystals then have a Y02 : X2O3 molar ratio of 5 or greater than 5. |