Ti/HMS mesoporous sieve catalysts were prepared by a chemical vapor deposition method (CVD) and modified by methyl-grafting. The catalysts were characterized by XRD, N2-adsorption, ICP-AES, IR, UV-Vis and 29Si CP/MAS NMR, respectively, and evaluated by the epoxidation of propylene. It was revealed that both the mesopore size and surface area of HMS were decreased after the incorporation of titanium and methyl-grafting treatment, but the mesoporous characteristic was still maintained. Both the titanium content and epoxidation performance were increased with the deposition time (0.5～2 h), and all kept invariable after further deposition. The cumene hydroperoxide (CHP) conversion and the selectivity were all enhanced after the methyl-grafting treatment. Ti/HMS prepared by CVD displays better catalytic activity to epoxidation than Ti-HMS prepared hydrothermally.

Key words: Ti/HMS catalyst, chemical vapor deposition, methyl-grafting, epoxidation of propylene