The Synthesis of Mesoporous Pseudoboehmite by A Route Mineral and its Transformation into Alumina-γ

This work reports the synthesis of a mesoporous pseudoboehmite without the use of organic agents. Precipitation at pH=7 and at atmospheric pressure of a temperature solution of 60°C, alkaline melting of a bauxite, gave a mesoporous pseudoboehmite with a specific surface area of 317 m2/g. The Hydrochloric acid (HCl) is used as a precipitating agent. In contrast, the same procedure repeated this time to the same solution, but at a different temperature of 25°C, provided an amorphous gel low specific surface. The temperature of the synthesis solution therefore has a considerable effect on the textural properties of products made particularly on the volume and the pore diameter. Thus, the amorphous gel has a low pore volume and a high average pore diameter than pseudoboehmite. Moreover, the transformation of this pseudoboehmite obtained by this simple method gave a nano spinel lattice alumina-γ with a specific surface area of 272 m2/g. And the textural study of alumina-γ obtained almost kept the topotactic properties of pseudoboehmite. The analytical methods used during this work to characterize the synthesized products are EDX, XRD, FTIR, SEM and BET.