Generating Superbasic Sites on Mesoporous Silica SBA-15

Superbasic sites have been generated on the mesoporous silica materials for the first time, through a new strategy to prepare the MgO-modified SBA-15 in one-pot synthesis and then to disperse KNO 3, possessing the good textural structure of the host and the high basic strength ( H - ) of 27.0. The in situ coated Mg species passivated the silanol groups on the surface of siliceous SBA-15 so that the mesostructure of SBA-15 could be reserved after the composite was loaded with KNO 3 and activated at high temperature. Existence of the special protection layer of MgO on the surface of SBA-15 was also beneficial for decomposition of KNO 3 to form superbasic sites on the mesoporous silica. The influence of coating amount of MgO on the protection of the textural properties of SBA-15 is examined and discussed in terms of consuming surface silanol groups. Dispersion and decomposition of KNO 3 on the MgO layer is also explored. Other metal oxides such as CaO, ZnO, and Al 2 O 3 are in situ coated on the surface of SBA-15 through one-pot synthesis and their function of protecting SBA-15 is evaluated for comparison with MgO.