| 초록 |
The direct incorporation of vanadium into the three-dimensional (3-D) cubic Ia3d mesostructure designated as V-KIT-6 was prepared and the material obtained therein showed a very high specific surface area 1000 m2/g with tunable pore diameters in narrow distribution of sizes 6.0 nm. The extent of mesopore structural ordering was confirmed from X-ray diffraction, N2 physisorption, SEM, and TEM analysis. The coordination and nature of V sites in V-KIT-6 are characterized by FT-Raman, UV-visible diffuse reflectance, 51V-spin-echo NMR and NH3-TPD analysis. It shows that after calcination, the V4+ species are totally oxidized to V5+ state with 4- and 6- coordinated V-O environments in a highly dispersed state with very less crystalline V2O5 formation. The calcined V-KIT-6 materials showed excellent catalytic activity in the direct oxidation of styrene using tert-butyl hydroperoxide (TBHP) as an oxidant. |
