Rapid Transformation of Amorphous Nanoparticles into Crystalline Y Nanozeolites Using Poly(vinyl alcohol) Layers Covered onto the Amorphous Nanoparticles

摘要

The Faujasite zeolite (Type-Y) is highly desired for many applications; nevertheless, these nanozeolites are challenging to synthesize via fast and low-cost pathways. This work provides a novel, simple, fast, and low-cost pathway to synthesize of Y nanocrystalline zeolite using poly(vinyl alcohol) as a growth inhibitor. Poly(vinyl alcohol) fasts the process transformation of amorphous particles into Y nanocrystalline zeolite through coating, protecting, and stabilizing of amorphous nanoparticles under high crystalline temperature. The structures and morphologies of Y nanozeolites were investigated with field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray (EDX) analysis, X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET), and transition electron microscopy (TEM). It was found that when poly(vinyl alcohol) is present during heating step, it can impact the size of the Y zeolite crystals. The pure Y nanozeolites with the size 30 nm and excellent textural properties (V-total = 0.73 cm(3)/g and S-BET = 816 m(2)/g) were obtained after an aging period of 24 h and a heating step at 100 degrees C during 5 h. This novel synthesis could contribute to overcoming the challenges of obtaining various nanozeolites under high-temperature synthesis for a short time instead of low-temperature synthesis for a long time.