Optimization of the preparation method of HSO3-functionalized MCM-41 solid catalysts

In this work, a systematic study of the acid extraction of the surfactant present in MCM-41 mesoporous materials was carried out. Two organic solvent/acid mixtures were used at various temperatures and for different periods of time. Propylthiol groups were subsequently grafted onto the surface by reacting the mesoporous silica with 3-mercaptopropyltrimethoxysilane. The resulting organic matter loading is compared with the one yielded by grafting of calcined samples. Acid catalysts were obtained by oxidation of the single bondSH groups to the single bondSO3H form. The catalysts were tested for alkylation of benzene with 1-dodecene. These materials were characterized by means of XRD, themogravimetric analysis, N2 adsorption–desorption isotherms, organic elemental analysis and acid titration. The acid extraction of the surfactant allowed the preparation of catalysts with a high concentration of active centers.