Direct synthesis of sulfonic acid-functionalized periodic mesoporous benzene–silicas with large pores

Periodic mesoporous benzene–silicas containing sulfonic acid groups were directly synthesized by the co-condensation of 1,4-bis (triethoxysilyl) benzene organosilica precursor and 3-mercaptopropyltrimethoxysilane (MeO)3Si(CH2)3SH in the presence of H2O2 using non-ionic block copolymer templates such as a Pluronic P123 (EO20PO70EO20) and poly(ethylene oxide)–poly(dl-lactic acid-co-glycolic acid)–poly(ethylene oxide) (EO16(L29G7)EO16) under low acidic conditions. The sulfonic acid functional groups (–SO3H) were generated in situ by the oxidation of the propylthiol using H2O2 as an oxidant during the sol–gel synthetic process, which was observed by FT-IR and solid-state 13C NMR spectroscopy. Well-defined 2D hexagonal (p6mm) mesostructures were also observed using BET, TEM, and SAXS measurements. The sulfonated mesoporous benzene–silicas prepared in this study also exhibit spherical macrostructures with diameters of 2–5 μm.