Abstract
The direct synthesis of three-dimensional (3-D) cubic V-KIT-6 was prepared using a Pluronic P123 triblock copolymer as the structure directing agent and n-butanol as the co-surfactant. The material obtained therein showed a very high specific surface area similar to 1000 m(2)/g With pore diameters that could be tuned within a narrow size distribution of 5.7-6.0 nm. After calcination, Raman and UV-vis analysis revealed the presence of V5+ Species in a highly dispersed state with much less crystalline V2O5 formation. V-51-NMR analysis showed that the vanadium species interacted directly with the silica framework in an almost symmetrical tetrahedral environment. NH3-TPD analysis for V-KIT-6 showed a wide distribution of acid sites at temperatures ranging from 200 to 800 degrees C. The calcined V-KIT-6 materials showed excellent catalytic activity in the direct oxidation of cyclohexane using dilute aqueous H2O2 as the oxidant. (c) 2008 Elsevier Inc. All rights reserved.