Preparation of α-alumina nanoparticles via vapor-phase hydrolysis of AlCl3

A novel alumina precursor, represented as AlOxCly(OH)(z), was prepared in a batch reactor through a vapor-phase hydrolysis of AlCl3 at 200 degrees C for I 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 degrees C for 6 h to obtain alpha-alumina nearly 100% in alpha-transformation degree. The weight loss upon calcination was 40%, comparable to 35% of Al(OH)(3). The surface-area equivalent diameter of the obtained alpha-alumina particles was calculated to be 35 nm. (C) 2009 Elsevier B.V. All rights reserved.