Non-hydrolytic sol-gel routes based on alkyl halide elimination:: toward better mixed oxide catalysts and new supports -: Application to the preparation of a SiO2-TiO2 epoxidation catalyst

The first part of this article is a concise review on non-hydrolytic sol-gel routes based on alkyl halide elimination. The molecular chemistry founding these routes is presented, as well as examples of applications to the synthesis of oxides and mixed oxides that may be of interest as catalysts or supports. In the second part, the straightforward non-hydrolytic preparation of a SiO2-TiO2 catalyst (not involving supercritical drying) is reported. The resulting SiO2-TiO2 calcined xerogel was highly homogeneous and displayed a high BET surface area located mainly in the mesopore region. Preliminary tests in the epoxidation of cyclohexene by cumene by hydroperoxide indicated good selectivity and activity. (C) 2002 Elsevier Science B.V. All rights reserved.