Synthesis of mesoporous magnesium aluminate (MgAl_2O_4) nanopowder with high surface area with a novel and simple sol-gel method

摘要

Mesoporous MgAl_2O_4 nanopowders with high surface area and particle size smaller than 10 nm were synthesized by a very simple and quick sol-gel method using propylene oxide as gelation agent. The samples were characterized by X-ray diffraction, thermogravimetric/dif-ferential thermal analysis, N_2 adsorption-desorption, transmission electron microscopy and scanning electron microscopy techniques. The obtained results showed that the samples have mesoporous structure with high surface area and nanocrystalline structure with crystals in the range of 3-6 nm. Moreover, the effects of calcination temperature on the structural properties of the samples were investigated. The sample calcined at 500 ℃ showed the highest surface area (340.1 m~2/g) and pore volume (0.56 cm~3/g). With further increasing in calcination temperature the surface area decreased due to sintering and destruction and coalescence of the pores.