Synthesis of Core-shell ZSM-5@ Ordered Mesoporous Silica by Tetradecylamine Surfactant

A core-shell composite consisting of ZSM-5 zeolite as the core and ordered mesoporous silica as the shell was prepared by a surfactant-controlled sol-gel process and using tetradecylamine (TDA) as the template and Tetraethylorthosilicate (TEOS) as the silica precursor. The pores of the silica shell were found to be ordered and perpendicular to the crystal faces of the zeolite core. The thickness of the shell in the core-shell structured composite can be adjusted in the range of 20–90 nm, while the surface morphology and the pore size distribution were modified by changing the mass ratio of TEOS to zeolite. The composite molecular sieves have higher surface area for capturing molecules than ZSM-5, and with the increase of mesoporous shell layer, the ZSM-5@SiO2-x composites show stronger adsorption capacity of butyraldehyde. However, when the shell thickness exceeds 90 nm, the adsorption capacity of butyraldehyde decreases instead. The composites have a huge potential for environmental applications.