钒硅中孔分子筛的合成、表征及其催化性能研究

Synthesis, Characterization and Reactivity of Vanadium-Containing Mesoporous Molecular Sieves

在碱性环境中,采用水热合成法制备得到了不同硅钒比的钒硅中孔分子筛V-MCM-41,利用XRD,IR, TG等表征方法考察了钒的搀杂量与其结构和性能之间的关系。该催化剂对苯乙烯氧化反应具有较好的催化活性, 在一定的反应条件下,以H2O2溶液(30%)为氧化剂,以乙腈为溶剂,V-MCM-41(Si/V=25)能使苯乙烯的转化率达到95%以上,产物(苯甲醛+苯甲酸)的选择性不低于90%。

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%.