Preparation and characterization of thermally stable high surface area mesoporous vanadium oxides

摘要

Vanadium oxides with high surface areas are desirable for the applications in catalysis and lithium batteries. A new method has been developed in this work for the preparation of mesoporous VO2 with the surface area of about 180 m~2/g and slit-shaped mesopores. In this simple method, V2O5 was first dissolved in aqueous solution of H2O2 and the solution was evaporated at 353 K to form a gel with layered structures. After being dried in n-butanol at 353 K, the layered gel intercalated with n-butanol was evacuated at 673 K to form the mesoporous VO2. Characterizations showed that the prepared mesoporous VO2 possessed much stronger surface acidity and redox ability than the traditional V2O5. Accordingly, it exhibited much higher activity than V2O5 for the conversion of isopropanol in air and the selective oxidation of toluene to benzaldehyde and benzoic acid. In addition, the mesoporous VO2 displayed high thermal stability. It possessed the surface area of 130 m~2/g even after the reaction of selective oxidation of toluene at 633 K.