Green synthesis of nanocrystalline faujasite zeolite

In this work, the synthesis of 28 and 38 nm Na-Y zeolite nanocrystals is reported. The process was performed via green synthesis without any organic structure directing agents (SDAs), at low temperature and applying ultrasound-assisted aging. The zeolite nanoparticles obtained were characterized by X ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and N₂ adsorption - desorption isotherm at 77 K. A simple, fast, efficient and environmentally friendly procedure to synthetize nanocrystalline FAU zeolite is described in the present study. The sonochemical pretreatment was found to directly affect the Na-Y zeolite properties. The final product obtained via ultrasound pretreatment shows high phase purity and crystallinity degree with crystal size smaller than 38 nm and elevated surface area (S_BET ∼ 950 m² g^-1). The hierarchical micro- and mesoporous FAU zeolites exhibit a pore volume of ∼0.4 cm³ g^-1.