Synthesis of nano crystalline sized gamma-alumina with high thermal stability by sol-gel method

γ -Al2O3 is widely used as a support in heterogeneous catalysis because it is thermally stable and allows the dispersion of active phases due to its high surface area. In this work nanocrystalline gamma-Al2O3 has been synthesized by a three step (hydrolysis, condensation and calcination) sol–gel procedure in nitric acid medium with cationic surfactant (hexadecyltrimethyl ammonium bromide). The synthesized samples were characterized by thermogravimetric analysis, Fourier transform infrared spectroscopy, nitrogen adsorption–desorption and X-ray diffraction techniques. The results showed BET surface areas larger than 370 m2/gr with pore volumes higher than 1.5cc/gr. The samples also showed a high thermal stability up to 750°C. Thermal treatment in two steps (firstly under nitrogen and subsequently under air) led to obtain a higher surface area and pore volume for the prepared sample

کلیدواژه ها:

γ -Al2O3 ، Nano crystalline ، Thermal stability ، Cationic Surfactant