Effect of temperature on the synthesis of active alumina by flash calcination of gibbsite

In this paper, activated aluminas were synthesized directly using cheap precursor via a simple thermal process and short time using no sacrificial templates. The dehydration of gibbsite has been studied at different temperatures (350-1150 degrees C) by flash calcination. The synthesized materials were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and N-2 adsorption measurements. According to the obtained results, the temperature appeared to be the key parameter at activation process. The changes of the specific surface area affected on the average pore size because the amounts of pore volume were nearly constant. The powders prepared by the flash calcination method had a monomodal pore distribution with mesopores. FE-SEM images showed particle growth in nanodimensional. The optimum temperature for powder synthesized by flash calcination was 650 degrees C, which the surface area, pore volume, and average pore size were 262 m(2)/g, 0.22 cm(3)/g, and 33 (A) over circle, respectively. The synthesized powder had smaller nanoparticles for 650 degrees C in comparison of other temperatures.