Abstract: MCM-41 molecular sieve was synthesized by the sol-gel method and functionalized with benzyl sulphonic acid and trimethylchlorosilane using a post-synthetic procedure. The organic groups were covalently bonded to the surface of MCM-41 by etherification ofSi-OHand thus a new S-B-MCM-41 catalyst was prepared. The structure and Brnsted acid amount of S-B-MCM-41 catalyst were characterized by XRD, N2 adsorption-desorption, and acid-base titration. The results showed that the mesoporous structure of MCM-41 was maintained in the S-B-MCM-41 catalyst with a BET surface area of 798 m2/g and acid capacity of 4.0 mmol/g. The synthesis of iso-amyl acetate from acetic acid and iso-amyl alcohol over S-B-MCM-41 catalyst and its catalytic performance were investigated. Under the optimum conditions of acetic acid 0.1 mol, iso-amyl alcohol 0.15 mol, catalyst0.2 g, water-entrainer toluene 15 ml, reaction temperature 110-125 ℃, and reaction time2 h, the esterification fraction was over 99%. By comparison, the MCM-41 molecular sieve only had an esterification fraction of 54% under the same conditions. After three times of repeated use, the esterification fraction above 90% still maintained over S-B-MCM-41. The reaction mechanism for the esterification was discussed.

Key words: MCM-41 molecular sieve, surface modification, benzoic alcohol, trimethylchlorosilane, chlorosulphonic acid, acetic acid, iso-amyl alcohol, iso-amyl acetate