Synthesis of MOR Zeolite/Magnetite Composite via Seed Assisted Method.

Abstract

MOR zeolite is an effective adsorbent for separating organic molecules from various solutions owing to its large windows of 0)65 × 0)70 nm and its relatively high silica-alumina ratio which provides higher hydrophobicity. Fine powdery MOR zeolite is desirable for adsorption of organic molecules considering its larger surface area; however, fine particles are difficult to remove from solutions after treatment. Intensification of magnetic susceptibility through combination with magnetic particles ensure quick and easy removal of fine adsorbents by magnetic force. Meanwhile, seed assisted method is a powerful technique to direct and accelerate zeolite synthesis by adding seed crystals into the precursor sol prior to hydrothermal synthesis. In this work, we selected magnetite as the magnetic particle and propose the hydrothermal synthesis of MOR zeolite/magnetite composite via seed assisted method for the first time. MOR zeolite/magnetite composite with high MOR zeolite crystallinity was obtained by synthesizing for only 6 hours at 463 K when adding seed crystals, while no sign of crystallization was observed even after 24 hours in their absence. In addition, pre-milling of seed crystals together with magnetite was found to be effective to incorporate magnetite into MOR zeolite during crystallization and to decrease the primary crystal size of the crystallized MOR zeolite.