Ordered mesoporous sulfated silica-zirconia materials with high zirconium contents in the structure
Du, YC × Sun, YY Di, Yan Zhao, L Liu, S Xiao, FS #
Kluwer Academic Publishers
Journal of Porous Materials vol:13 issue:2 pages:163-171
A series of mesoporous sulfated silica-zirconia materials with various Si/Zr molar ratios (2.0-5.0) have been prepared using tri-block copolymer as a template, which were characterized by X-ray diffraction, TEM, nitrogen adsorption, UV-Vis diffuse reflectance spectroscopy, infrared spectroscopy, thermal gravimetric analysis, and catalytic reactions. XRD patterns displayed that ordered mesoporous sulfated silica-zirconia materials were obtained when the molar ratio of Si/Zr was not less than 4.0 (ZrSiS-4 and ZrSiS-5). When the molar ratio of Si/Zr was less than 4.0, the samples had a separated phase of amorphous sulfated zirconia (ZrSiS-2 and ZrSiS-3). Furthermore, TEM images (ZrSiS-4 and ZrSiS-5) revealed that the mesostructure of these materials were highly ordered. N-2 adsorption (ZrSiS-4 and ZrSiS-5) exhibited typical IV adsorption isotherms and uniform pore distribution. UV-Vis reflectance and IR spectra suggested (ZrSiS-4 and ZrSiS-5) that Zr atoms were incorporated into the walls of mesoporous silica. Cracking reactions of cumene and 1,3,5-triisopropylbenzene (TIPB) showed that, the ordered mesoporous sulfated silica-zirconia materials were very active in acidic catalytic reactions, especially for the cracking of large molecules.