Preparation of silica microspheres coated with V2O5 xerogel and V2O5/WO3 composite xerogel via adapted Stober process

摘要

In the present study, we have synthesized spherical silica particles covered with either layered V2O5 xerogel or V2O5/WO3 mixed xerogel via an adapted Stober method using an ammonia solution of methyltriethoxysilane (MTES). The SEM images revealed the presence of a lamellar V2O5 xerogel layer coating the silica particles, as evidenced by the (00 1) diffraction lines. Both materials have voltammetric behavior that is quite similar to that of the V2O5 xerogel. The catalytic activity of the silica particles coated with the V2O5/WO3 mixed xerogel was evaluated in the epoxidation of styrene using iodosylbenzene as an oxidant. (C) 2008 Elsevier B.V. All rights reserved.