分子氧环氧化烯烃多相催化剂PCuMo11/富氮类共价有机骨架材料的制备及应用

Preparation and application of heterogeneous catalyst PCuMo11/ nitrogen rich covalent organic framework material for olefin epoxidation with molecular oxygen oxidant

  • 摘要: 环氧化合物是一类重要的有机合成中间体和化工原料,主要通过烯烃环氧化反应获得。制备在分子氧环境下高效、稳定、可重复使用的烯烃环氧化反应新型催化剂是一项十分有意义的工作。以富氮类共价有机骨架材料(PC)为载体,多金属氧酸盐PCuMo11为活性物质,制备了复合材料PCuMo11/PC。通过FT-IR、N2吸附脱附、XPS、TEM及EDS等测试对材料进行了表征,并将PCuMo11/PC应用于多相催化分子氧气氛下的烯烃(苯乙烯、1-辛烯、环辛烯和环十二烯)环氧化反应中,取得了较高的催化活性和选择性,循环使用5次以上催化活性没有明显下降。实验结果显示,二维层状富氮类共价有机骨架材料的高表面积及骨架中丰富的氮元素含量,有利于均匀地分散催化活性物质多金属氧酸盐,并与其建立相对稳定的化学链接,提高复合材料的催化活性及稳定性。

     

    Abstract: Epoxide is an important organic synthesis intermediate and chemical raw material that is mainly prepared from the olefin epoxidation. It is a very interesting work to prepare efficient catalysts with stability and recyclability for aerobic olefins epoxidation. Composite PCuMo11/PC was prepared by using the nitrogen rich covalent organic framework material (PC) as support and the polyoxometalate PCuMo11 as active substance. The materials were characterized by FT-IR, N2 adsorption and desorption, XPS, TEM and EDS. The application of PCuMo11/PC for heterogeneous catalytic epoxidation of olefins (styrene, 1-octene, cyclooctene, cyclododecene) with molecular oxygen oxidant has obtained high catalytic activity and selectivity. There is no significant decrease in catalytic activity after recycling over five times. The experimental results show that large surface area and rich nitrogen content in the skeleton of the two-dimensional layered nitrogen rich covalent organic framework material are benefit to disperse the catalytic active substance polyoxometalate uniformly and establish a relatively stable chemical link, so as to improve the catalytic activity and stability of the composite.

     

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