Novel Preparation Method of Nano-Sized Zeolite Using Pulverization Technology and Its Application

Abstract

When zeolites are used as catalysts or adsorbents, diffusion in micropores affects the catalyst/adsorption phenomenon itself. Therefore, the development of technology that enables the preparation of fine particles is important. However, it is not easy to directly synthesize nano-sized crystals (~100 nm) by the bottom-up method in zeolite synthesis, that is, by controlling nucleation and crystal growth. Normally, zeolites often grow to a size of about several microns under hydrothermal conditions, and there is also a method for pulverizing the zeolite to size-regulate it. However, zeolite, which is a porous material, is more susceptible to damage from mechanical impact than dense metal oxides. In recent years, the authors have developed a new method for preparing nanosized zeolites by combining a bead milling method with low mechanical load and a recrystallization method using an aluminosilicate aqueous solution (Wakihara et al., Cryst. Growth Des. 2011, 11, 4, 955–958). At present, the target is expanded from the initial LTA-type zeolite to various zeolite systems.