Synthesis of γ-alumina via precipitation in ethanol

Nanosized gamma-alumina powder was prepared via sol-gel precipitation in ethanol followed by a washing-drying treatment and calcination. The reactant concentration, the molar ratio of reactants and the calcination temperature were inspected by homogenous design. BET, TEM, XRD and IR were used to characterize the products. The experimental results showed that ethanol can avoid hard agglomerate during precipitation and that calcination temperature was the major factor to determine the surface area, the diameter and the phase composition of the final product. When the calcination temperatures were controlled between 686-1029 degrees C, the agglomerate-free nano-sized gamma-alumina particles with a size range of 5-9 nm were obtained. (C) 2008 Elsevier B.V. All rights reserved.