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

•K-F (EDI topology) nanozeolites are prepared in SDA-free system.•The nanocrystals are prepared at 100 °C for 3 h.•The nucleation and crystallization of nanozeolites are monitored and studied.•The nanocrystals have flattened cuboid shape morphology and sized of ca. 27 nm.•The resulting nanocrystals have Si/Al ratio = 1.10 and 79% crystalline solid yield.

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.

Graphical abstractDownload high-res image (255KB)Download full-size image