Preparation of macro-mesostructured pseudoboehmite and γ-Al2O3 with high surface area

As a very important catalyst support, adsorbent and separate material, the preparation of macromesostructured gamma-AI(2)O(3) is very important, especially for catalytic conversion of petroleum heavy cuts and residues. However, while increasing the pore volumes, the surface areas decrease for most conventional preparation methods of macro-mesostructured gamma-Al2O3. The methods and their mechanisms to prepare macro-mesostructured pseudoboehmite and gamma-Al2O3 with high surface areas are reviewed in this paper, including controlling the precipitation process of pseudoboehmite, the precipitation processing techniques of the precipitated pseudoboehmite and the introducing pore forming additives or sintering additives. These preparation ways include pH swing method, organic reagent as reaction media, surfactant assembly, microwave-assisted heating, hydrothermal processing of pseudoboehmite or gamma-Al2O3 directly, displacement water in wet precipitate by organic solvent, unconventional drying method and control of pore structure with pore forming additives or sintering additives. Finally, development trend for preparation techniques of macromesostructured pseudoboehmite and gamma-Al2O3 is also suggested.