A NEW STEP TOWARD TRANSITION-METAL INCORPORATION IN CUBIC MESOPOROUS MATERIALS - PREPARATION AND CHARACTERIZATION OF TI-MCM-48

A mesoporous material containing Ti and Si atoms in the walls, which i s isomorphous to the cubic MCM-48 silicate structure has been synthesi zed by using a gemini surfactant. Characterization (XRD, BET, UV-Visib le, IR and Raman) shows that the titanium atoms are well dispersed, pr obably substituting silicon atoms in the mesoporous walls. Spectral fe atures within the range 980-970 cm(-1), observed by Raman and photoaco ustic FT-IR spectroscopies, indicate the presence of silanol groups in side the mesoporous channels in both the blank and the Ti containing s amples whereas an IR absorption near 960 cm(-1), observed only for Ti- MCM-48 samples, is associated with the Ti incorporation.