Preparation,characterization,and catalytic performance of a novel methyl-rich Ti-HMS mesoporous molecular sieve with high hydrophobicity

摘要

A novel methyl-rich Ti-containing hexagonal mesoporous silica (Ti-HMS) molecular sieve with high hydrophobicity has been prepared by a two-step method involving co-condensation followed by vapor-phase methyl grafting.The sample was characterized by XRD,N2 adsorption,FTIR,UV-visible and 29Si NMR spectroscopies,TG,ICP-AES,and hydrophilicity measurements,and its catalytic performance was evaluated using the epoxidation of cyclohexene as a probe reaction.The Ti-HMS material retains a typical mesoporous structure and compared with a co-condensed Ti-HMS prepared in a one-step method possesses more methyl groups and higher hydrophobicity,and also exhibits better catalytic activity and selectivity.