Crystallization and morphology of mordenite zeolite influenced by various parameters in organic-free synthesis

A series of mordenite zeolites with different morphologies were synthesized via a facile organic-free hydrothermal route, and characterized by X-ray diffraction, scanning electron microscopy, X-ray fluorescence spectrometer and N2 adsorption–desorption techniques. Influences of synthetic parameters, including seed crystal, silicon precursor, SiO2/Al2O3, Na2O/SiO2 and H2O/SiO2, on mordenite crystallization were investigated systematically. It was found that mordenite zeolites with various morphologies, such as fiber-like, rod-like, prism-like and needle-like ones could be synthesized in control. Especially, novel nano fiber-like MOR crystals with high c/b aspect ratio were prepared from low silica concentration system, which was manipulated by using small initial SiO2/Al2O3 ratio, large H2O/SiO2 and silicon source with slow dissolution rate. Moreover, mordenite samples with various morphologies exhibited different mesopore property and thermal stability.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideResearch highlights► Seed, gel composition and silicon source affect the crystallization process of MOR. ► Seed, gel composition and silicon source influence the morphology of MOR. ► Low silica concentration results in MOR with high c/b aspect ratio. ► Novel nano fiber-like MOR with c/b aspect ratio of 89 was organic-free synthesized. ► The morphology of MOR influences its mesopore property and thermal stability.