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以含有咪唑阳离子的周期性介孔有机硅(PMO-ILs)材料为载体,制备了一类固载化磷钼酸(PMA)多相催化材料(PMA@PMO-ILs),并采用N2吸附-脱附实验、X射线衍射、原子吸收光谱、差热-热重分析、红外光谱、紫外光谱及固体核磁共振技术研究了材料的结构及物理化学性质.结果表明,磷钼酸通过静电相互作用被成功固载到PMO-ILs载体表面和孔道中,且在制备过程中磷钼酸及载体基本结构均未发生变化.反应结果表明,PMA@PMO-ILs材料在以叔丁基过氧化氢为氧化剂的环辛烯环氧化反应中表现出一定的催化活性和很高的选择性.中断实验结果表明,催化剂的主要活性中心在反应过程中未发生明显流失,且催化剂经多次循环使用后活性及选择性基本保持不变.PMO-ILs中大量的咪唑阳离子能有效稳定磷钼酸阴离子,使该催化材料表现出良好的稳定性.
A series of PMA @ PMO-ILs were prepared with periodic mesoporous silica (PMO-ILs) containing imidazolium as support. Desorption experiments, X-ray diffraction, atomic absorption spectroscopy, differential thermal-thermogravimetric analysis, infrared spectroscopy, ultraviolet spectroscopy and solid state nuclear magnetic resonance were used to study the structure and physico-chemical properties of the materials. The results showed that the phosphomolybdic acid Successfully immobilized on the surface of PMO-ILs carrier and the channel, and the basic structure of phosphomolybdic acid and carrier did not change during the preparation process.The results showed that PMA @ PMO-ILs material in tert-butyl hydroperoxide as oxidant Of cyclooctene epoxidation showed some catalytic activity and high selectivity.Experimental results show that the main active center of the catalyst did not significantly loss during the reaction, and the catalyst after repeated cycles of activity And the selectivity remained basically unchanged.Many imidazolium cations in PMO-ILs could effectively stabilize phosphomolybdic acid anions and make the catalytic material show good stability.