STRUCTURAL-PROPERTIES OF SOME FERRIERITE-TYPE ZEOLITES

The zeolite ferrierite was synthesized from a sodium and tetramethylammonium (TMA) containing gel. Powder x-ray diffraction data show the basic framework for natural and synthetic ferrierite to be similar. X-ray diagrams of natural ferrierite are frequently burdened by effects from preferred orientation of the crystallites. The (110) reflection is generally of much less intensity than expected from pattern simulation based on published crystal structure data. The temperature-induced changes in the unit-cell dimensions of synthetic ferrierite (with TMA as template, in the calcined form, and in the H-form) are presented, and the contraction of the unit cell correlates with weight losses as determined thermogravimetrically. The thermally induced changes in the framework of H-ferrierite are discussed.