Synthesis and characterization of ordered mesoporous zeolite LTA with high ion exchange ability

Abstract

An ordered mesoporous zeolite LTA is prepared by using organofunctionalized silica as Si-source. The mesoporous zeolite LTA has nano-cages of 3 nm interconnected to each other through 0.8–1.2 nm channels. A Jacobsen salen complex can be encapsulated successfully in the supercages of the zeolite. ²⁹Si, ²⁷Al-MAS NMR and in situFT-IR spectra reveal a new crystallization mechanism. The mesostructure and nano-supercages in the zeolite result from the bond-blocking action during the crystal growth. The zeolite has connatural micropore and ordered mesopore systems within the zeolite particles. The mesoporosity of the mesoporous zeolite can be rationally controlled by the degree of silanizing. The diffusion rate of hydrated Mg²⁺ in the synthesized submesoporous zeolite is 170 times higher than in a traditional zeolite at 308 K.