Synthesis and properties of mesoporous silica–alumina with narrow pore size distribution obtained without use of pore-regulating agents

The synthesis of a mesoporous silica–alumina (MSA) containing 50 wt.% alumina from simple inorganic salts (sodium metasilicate and aluminum nitrate) without the use of pore-regulating agents is described. The BET surface area of MSA was 491 m2/g and its pore structure almost exclusively formed by 3–5 nm mesopores. From X-ray diffraction, electron microscopy and 27Al MAS NMR it follows that the MSA is amorphous with the disordered pore arrangement, with the majority of the aluminum atoms in the octahedral coordination. Its pore size distribution is much narrower in comparison to the distributions of commercial silica–aluminas. The MSA showed a good hydrothermal stability and its textural properties were influenced only slightly by treatment in boiling water and calcination at temperatures up to 800 °C.