An efficient solid acid catalyst: Poly-p-styrenesulfonic acid supported on SBA-15 via surface-initiated ATRP

The sulfonic acid-functionalized mesoporous organic–inorganic hybrid materials were synthesized via atom transfer radical polymerization (ATRP) method. SBA-15 material was first grafted with 4-(chloromethyl)phenyltrimethoxysilane. The surface-initiated polymerization of sodium p-styrenesulfonate inside the pore wall of functionalized SBA-15 results in p-styrenesulfonic acid functionalized SBA-15 (PSS-SBA-15). The results of FT-IR, nitrogen sorption isotherm, XRD, TEM and thermal gravimetric analyses (TGA) confirm that the PSS-SBA-15 materials have ordered mesoporous structure, open channels and styrenesulfonic acid functionalities. The catalytic activity of PSS-SBA-15 was higher than commercial Nafion resin in the esterification of lauric acid with ethanol. The unique catalytic performance of PSS-SBA-15 is probably attributed to the increased accessibility of the active sites to the reactants because of the existence of styrenesulfonic acid on the pore surface of SBA-15.