Mesoporous titanosilicates by templated non-hydrolytic sol–gel reactions

Abstract

A novel templated non-hydrolytic sol–gel synthesis of titanosilicate xerogels is reported. Acetamide elimination from silicon acetate and titanium diethylamide allows obtaining titanosilicates with a high content of Si–O–Ti bonds but low surface areas. These xerogels lose porosity on calcination. However, with addition of Pluronic P123 as a structure-directing agent, we synthesized mesoporous titanosilicate materials with large surface areas (up to 615 m2 g−1) and well dispersed tetrahedral Ti that are stable at temperatures up to 500 °C. These potential catalysts were characterized by variety of physico-chemical methods (IR, GC–MS, XRD, 29Si and 13C CPMAS NMR, DRUV-Vis, and N2 porosimetry) and tested in cyclohexene epoxidation with cumyl hydroperoxide in toluene. They display catalytic activity with the 100 % selectivity to cyclohexene oxide and high catalytic yields up to 96 % which is comparable to previously reported titanosilicate catalysts.