Transformation behavior of gibbsite to boehmite by steam-assisted synthesis

Conversion of gibbsite to boehmite as a precursor for many aluminum oxide materials was widely concerned. Herein, the steam-assisted crystallization (SAC) method was conducted to synthesis the boehmite from gibbsite. The transformation behavior of gibbsite to boehmite treated at 155, 165, 175, and 185 °C by SAC method was studied by XRD and SEM analysis. The treated temperature and time were the main factor determining the transformation of morphologies and crystal phase of gibbsite to boehmite. Boehmite was appeared at 165 °C and 12 h for the SAC method but at 175 °C and 12 h for the hydrothermal method. Lower temperature and less time were required for conversion of gibbsite to boehmite by SAC compared to hydrothermal method. The advantageous transformation of gibbsite to boehmite is ascribed to the steam activation. Thus, a novel and effective SAC method was presented to synthesis of boehmite from gibbsite.