Alkene and thioether oxidations with H2O2 over Ti-containing mesoporous mesophase catalysts

Well-organized Ti-containing mesoporous mesophase materials (Ti-MMM) have b een synthesized by hydrothermal synthesis using C16H33N(CH3)(3)Br and chara cterized by elemental analysis, IR, DRS-UV, XRD, and N-2 adsorption. Cataly tic properties of these materials in alkene and thioether oxidations with a queous H2O2 in CH3CN have been studied and compared with those of the Ti-co ntaining hexagonal mesoporous silica (Ti-HMS). The Ti-MMM catalysts with th e Si/Ti atomic ratio varying in the range of 49-124 showed the highest cata lytic activities in alkene oxidation. Both the structure of a silicate matr ix and a degree of isolation of titanium ions in it are crucial factors det ermining catalytic activity of Ti-MMM. For thioether oxidation, the structu ral perfection of Ti-MMM catalysts is less important. No leaching of titani um ions occurs during both reactions. The oxidation process proved to be tr uly heterogeneous. (C) 2000 Elsevier Science B.V. All rights reserved.