SYNTHESIS AND CHARACTERIZATION OF 18-CROWN-6 ETHER-CONTAINING KFI-TYPE ZEOLITE

Pure high silica KFI-type zeolite samples with a framework Si/AI molar ratio as high as 4.0 were prepared by using 18-crown-6 ether as an or ganic template from a starting aluminosilicate gel containing potassiu m and strontium cations, The solids were characterized by elemental an alysis, SEM, XRD, thermal analysis, solid state n.m.r. spectroscopy, a nd n-hexane adsorption. The 18-crown-6 ether is occluded in the struct ure (one molecule/unit cell), its presence allows reproducible prepara tions of highly crystalline materials with high Si/Al ratios.