K-F zeolite nanocrystals synthesized from organic-template-free precursor mixture

Abstract

K-F zeolite nanocrystals (structure code EDI) are synthesized from a template-free Al2O3–SiO2–K2O–H2O precursor system. The use of a very reactive organic-template-free gel system (4SiO2: 1Al2O3: 16K2O: 160H2O) enables the crystallization of EDI-type nanosized zeolite to accomplish within 3 h at 100 °C. The K-F zeolite crystals have flattened cuboid shape morphology (ca. 27 nm) and they tend to agglomerate and form secondary spherical particles (ca. 310 nm). The K-F zeolite nanocrystals have high alumina content (Si/Al ratio = 1.10) and high crystalline solid yield (79%) offering a promising route for large-scale production of hydrophilic zeolite nanoparticles.