Preparation of α-alumina nanoparticles via vapor-phase hydrolysis of AlCl_3

摘要

A novel alumina precursor, represented as AlO_xCl_y(OH)_2. was prepared in a batch reactor through a vapor-phase hydrolysis of AlCl_3 at 200 ℃ for 1 min. The precursor particles were spherical and distributed in the size range of 30 to 200 nm, giving a number-average diameter of 70 nm. The precursor particles were calcined at 1200 ℃ for 6 h to obtain α-alumina nearly 100% in α-transformation degree. The weight loss upon calcination was 40%, comparable to 35% of Al(OH)_3. The surface-area equivalent diameter of the obtained α-alumina particles was calculated to be 35 nm.