Structure and catalysis of mesoporous titania-supported vanadium oxide

摘要

We successfully prepare vanadium catalysts supported on mesoporous titania with the mesostructural order and extremely high surface area. Vanadium was incorporated into mesoporous titania by co-condensation (direct incorporation, V-meso TiO_2) and by post synthesis impregnation (impregnation, V/meso TiO_2). The peak in X-ray diffraction remained until the loading reached 5 wt percent as V metal for V-meso TiO_2, while no diffraction was observed in 6 wt percent V/meso TiO_2. The position and intensity of pre-edge absorption in V K edge spectra revealed that the valence of V is 4 +in V-meso TiO_2 under atmospheric conditions. Both V-meso TiO_2 and V/meso TiO_2 were highly active in a propene oxidation reaction producing carbon monoxide and dioxide. The oxidation rates per unit V were enhanced by a factor of 3.9 and 18 for V-meso TiO_2 and V/meso TiO_2, respectively, from the activity of V/JRC-TIO-4.