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

In the present study, we have synthesized spherical silica particles covered with either layered V₂O₅ xerogel or V₂O₅/WO₃ mixed xerogel via an adapted Stöber 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 (0 0 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.