One-step synthesis of hierarchical porous γ-alumina with high surface area

Hierarchical porous gamma-alumina is successfully fabricated from a precursor solution consisting of surfactants, polystyrene (PS) spheres, inorganic salts and solvents. After calcinations, uniform macropores are closely packed. The macropore size coincides with the original PS sphere size. These macropores are connected by small windows. In addition, the macropore walls have mesoporous structures, as confirmed by SAXS measurement and TEM observation. After calcination at 900 A degrees C, the amorphous alumina frameworks are converted to the crystallized gamma-alumina phase. Even after crystallization, the existence of uniform mesopores and high surface are well retained, though the mesoporous ordering is lower.