Synthesis and study of acid catalyst 30% WO3/SnO2

Solid acid catalyst 30% WO3/SnO2 was synthesized and studied by IR, X-ray p owder diffraction, solid state Sn-117 NMR and adsorbed pyridine thermodesor ption. The catalyst consists of SnO2 grains covered with W(VI) octahedra or ganized as in heteropolyacids. Its acidity is lower than the acidity of het eropolyacids but higher than that of the analogous catalyst WO3/ZrO2. The c atalyst exhibits a high activity when used in the liquid phase acid-catalyz ed reactions, but a part of it is washed out by polar solvents or substrate s. (C) 2000 Elsevier Science B.V. All rights reserved.