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

摘要

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 N_2 adsorption-desorption techniques. Influences of synthetic parameters, including seed crystal, silicon precursor, SiO_2/Al_2O_3, Na_2O/SiO_2 and H_2O/SiO_2, 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 cfb aspect ratio were prepared from low silica concentration system, which was manipulated by using small initial SiO_2/Al_2O_3 ratio, large H_2O/SiO_2 and silicon source with slow dissolution rate. Moreover, mordenite samples with various morphologies exhibited different mesopore property and thermal stability.