Synthesis and Characterization of Sulfonic Acid Catalysts Supported on Mesoporous Molecular Sieves

摘要

Catalysts containing benzenesulfonic acid (BSA), trifluoromethanesulfonic acid (TFA) or tetrafluoroethanesulfonic acid (TFESA) groups supported on ordered mesoporous materials were synthesized. The 9.32 wt % BSA/MCM-41, 9.52 wt % TFA/MCM-41, 8.36 wt % TFESA/MCM-41, 9.55 wt % BSA/SBA-15, 9.31 wt % TFA/SBA-15 and 8.83 wt % TFESA/SBA-15 catalysts were obtained by the pore volume impregnation methodusing aqueous solutions of acids. The nitrogen adsorption/desorption isotherms confirmed the type TV characteristic for the well-ordered hexagonal structure silicas and allowed determining the pore size distribution before and after impregnation. XRD measurements proved the amorphous hexagonal structure of the silica supports MCM-41 and SBA-15. The FT-IR spectra gave evidence for the presence of sulfonic acid groups in the structure of the catalysts. The synthesized 8.36 wt % TFESA/MCM-41 and 8.83 wt % TFESA/ SBA-15 catalysts were tested in glycerol etherification with isobutene and proved good activity leading to high conversions for both reagents (95.0 % for glycerol and 100.0 % for isobutene).