Hydrothermal synthesis of hierarchical zeolite T aggregates using tetramethylammonium hydroxide as single template

Abstract

In this paper, the hierarchical zeolite T aggregates with different sizes have been successfully synthesized by hydrothermal method with the aid of single template (tetramethylammonium hydroxide, TMAOH). The products have been studied in detail by XRD, SEM, TEM and N2 adsorption–desorption techniques. The influences of the preparation parameters including the amounts of TMAOH and water, crystallization temperature, pre-crystallization, seeding and aging on the synthesis of zeolite T aggregates have been investigated thoroughly. The synthesized samples typically display the column-like aggregates consisted of tightly packed primary nanocrystal grains. The additional mesopores of samples are attributed to the interstitial voids existing between the nanocrystals. The decreased crystallization temperature, pre-crystallization, seeding and aging disposals can reduce the particle sizes and improve the mesoporous properties of zeolite T aggregates. Among all the prepared samples, zeolite T sample which first statically aged at room temperature for 48h and then synthesized at 373K for 48h had the highest BET surface area (SBET) of 461m2/g and mesopore volume (Vmeso) of 0.231cm3/g. This paper provides an efficient and facile route to prepare hierarchical zeolite T aggregates.