Abstract: The molecular sieve catalysis material of Si-MCM-41, Sn-MCM-41 were preparaed under the condition of low template concentration in weak base and the samples were characterized by XRD, N₂ adsorption-desorption, FT-IR, ICP-AES and TEM techniques. Effect of the synthesis methods on the Sn-containing MCM-41 were studied. The results showed that Sn species were mainly incorporated into the framework of MCM-41 molecular sieves prepared by direct hydrothermal synthesis method (DHT), while Sn species were mainly existed on the wall surface of Sn-MCM-41 molecular sieves prepared by template-ion exchange method (TIE). The catalytic properties of Sn containing MCM-41 molecular sieves in Baeyer-Villiger oxidation of cyclohexanone were investigated. Catalytic activity results show that under the reaction condition of n(H₂O₂):n(Cyclohexanone)＝3:1, 30 g dioxane, at 70℃ for 6 h, the conversion of cyclohexanone and the selectivity of ε-caprolactone reach 40.02% and 45.69%, respectively.

Key words: direct hydrothermal synthesis, template-ion exchange, Si-MCM-41, Sn-MCM-41, Baeyer-Villiger oxidation