Combined Alkyl and Sulfonic Acid Functionalization of MCM-41-Type Silica: Part 1. Synthesis and Characterization

Single-step synthesis of well-ordered MCM-41 materials containing simultaneously alkyl (methyl or propyl) and 3-mercaptopropyl groups has been carried out by hydrothermal treatment of gels containing a mixture of dodecyl and hexadecyltrimethylammonium surfactants. A wide range of synthesis conditions has been studied in order to optimize the pore arrangement and to vary the alkyl/mercaptopropyl ratio of the product. A number of characterization techniques suggest that the anchored organic fragments lined the wall channels of the MCM-41 in a close-packed configuration. The mercaptopropyl groups can be oxidized with hydrogen peroxide to sulfonic acid with a high retention of sulfur and no loss of methyl groups.