Synthesis, characterization and reactivity of vanadium-containing mesoporous molecular sieves

Under the alkaline condition, vanadium-substituted mesoporous molecular sieves with different Si/V ratio were successfully formed in a hydrothermal system. Using the techniques of XRD, IR, TG, et al., the relationship between the vanadium content and the structure was intensively studied. With the increase of the vanadium content, the structure of V-MCM-41 became disorder while the value of d100 and the intensity of IR peak at 960 cm-1 were increased. The result of DrTGA showed that the temperature of the decomposition of surfactant was reduced by the incorporation of vanadium. V-MCM-41 was found to be catalytically active in the oxidation of styrene with H2O2 (30%) as oxidant and acetonitrile as solvent. The main product were benzaldehyde and benzene carbonic acid. With the increase of vanadium content, the conversion of styrene was increased. As for V-MCM-41 (Si/V=25), the styrene conversion can be as high as 95%, and the selectivity of the main products is not less than 90%.