Facile synthesis of nano-sized NH4-ZSM-5 zeolites

High crystalline nano-sized NH4-ZSM-5 zeolites with a wide SiO2/Al2O3 ratio range were directly synthesized through seed-induced approach. The products were characterized using X-ray powder diffraction (XRPD), scanning electron microscopy (SEM), Fourier transform infrared (FT-IR), N-2-sorption experiment, thermal gravimetry (TC.) analysis, ammonium temperature programmed desorption (NH3-TPD), inductively coupled plasma atomic emission spectroscopy (ICP-AES) and Al-27 and Si-29 MAS NMR. The crystal sizes could be controlled by simply adjusting the amount of seeding suspension. The as-prepared NH4-ZSM-5 can be converted the acid H-form by a single calcination. (C) 2012 Elsevier Inc. All rights reserved.