Continuous synthesis of spherical beads of tungsten(VI)-containing materials

Monodispersed beads of tungstic acid (5% dispersivities), which are supported in a hydrophilic poly(acrylamide) matrix, have been prepared, The diameters of the beads may be modified within the range 0.5-2 mm by changing the experimental conditions. The specific surface areas of the materials are above 100 m(2) g(-1), with extensive mesoporous regions. On calcination, different successive crystalline phases have been identified. Calcination at high temperature in air yields rather brittle beads of tungsten(VI) oxide. The synthesized materials are suitable for catalyzed oxidation reactions of alkenes.