Abstract:

V-MCM-41 mesoporous materials were synthesized by the hydrothermal method, and characterized by powder X-ray diffraction, ICP-AES, FTIR, diffuse reflectance UV-Vis and N₂ adsorption-desorption.The results showed that a part of vanadium ions were incorporated into the MCM-41 framework and all synthesized samples exhibited a high crystallinity that increased with increasing molar ratio of V/Si in the synthesis gels.The results of cyclohexene oxidation catalyzed by V-MCM-41 indicated that its catalytic activity decreased in cyclohexene selective oxidation when the V content was larger than 1.10% due to the presence of V-O-V species.And at the same time, acetonitrile was also found to be the best solvent for the V-MCM-41 catalyzed cyclohexene oxidation with H₂O₂, and the optimum reaction temperature was 70℃.The reaction results showed that cyclohexene conversion and H₂O₂ utilization could reach 23.91%(mol) and 95.4%(mol) under the optimum reaction conditions, respectively.

Key words:

V-MCM-41, 水热合成, 环己烯, 催化选择性氧化

摘要：

采用水热法合成了V-MCM-41，并用ICP-AES、FTIR、DRS-UV-Vis、XRD、BET等技术对其进行了表征，发现只有部分V进入分子筛，所合成的V-MCM-41具有较高的结晶度，并且其结晶度随晶化液中V/Si摩尔比的增大而升高。V-MCM-41催化环己烯/H₂O₂氧化反应结果表明，当V-MCM-41中V含量大于1.10%（摩尔分数）时，骨架V-O-V物种在催化环己烯氧化反应的同时，也可加速H₂O₂的分解;乙腈是该反应体系的最佳溶剂，最佳反应温度为70℃。最佳反应结果表明，环己烯的单程转化率和H₂O₂有效利用率可分别达到23.91%和95.4%。

关键词:

V-MCM-41, 水热合成, 环己烯, 催化选择性氧化