The resulting
powders were calcined at about 540 C for 10 h in air to obtain
mesoporous Al-SBA-15 samples and were donated as Al-SBA-15 (x), where x is Si/Al ratio in the synthesis gel. The preparation routes of mesoporous pure-silica SBA-15 was prepared by the above procedure, but without the ‘‘pH-adjusting’’ step and the addition of Al2(SO4)318H2O. That is, the preformed mesoporous solid was recovered by filtration after the completion of the first hydrothermal treatment, and washed, dried and calcined under the same conditions as above