Co-N-C材料的制备及在芳烃侧链选择性氧化中的应用研究

发布时间：2018-03-23 11:05

本文选题：催化氧化　切入点：选择性氧化　出处：《南京航空航天大学》2017年硕士论文

【摘要】：近年来,随着材料技术的不断进步,一系列氮掺杂材料由于具备制备简单、性能优越等优点,成功进入到有机化学家的视线中,特别是负载了过渡金属的氮掺杂材料被广泛的运用在有机合成中。本文制备了一种Co-N-C材料,并将其运用在液相氧化上,结果表明,该催化剂在芳烃侧链的选择性氧化以及烯烃烯丙位的选择性氧化方面拥有突出的催化性能。首先,我们采用球磨的方法将前驱体三聚氰胺和六水合硝酸钴反应,制备了相应的Co-N-C材料。其次,对所制备的材料进行了SEM,BET,HRTEM,XRD,XPS和FTIR等表征,结果显示前驱体三聚氰胺和钴离子结合形成Co-N-C材料,该材料具有片层微孔结构,同时三聚氰胺可能自身发生聚合生成类似于g-C_3N_4的CN材料。最后,探索了Co-N-C催化剂在液相氧化方面的催化性能。结果表明,该催化剂在芳烃侧链的选择性氧化以及烯烃烯丙位的选择性氧化方面的性能突出。整个氧化过程的条件温和,仅仅需要千分之五的Co-N-C催化剂,氧化剂则为绿色氧源--氧气,在此条件下,可以十分高效的选择性氧化乙基苯,得到目标产物苯乙酮(92.8%的底物转化率以及95.5%的目标产物选择性),把该反应进行放大到200g级别的反应也获得了成功,得到了接近70%的单程收率,除此之外,我们将反应的催化剂进行了循环性能的测试,测试的结果十分优异,同一催化剂在循环5次之后,其氧化性能并没有出现下降,仍然保持高效。综上,本文通过新颖、廉价、简单的方法制得Co-N-C材料,绿色、高效的实现了芳烃侧链的选择性氧化以及烯烃烯丙位的选择性氧化,并具有良好的底物适应性和官能团容忍性。
[Abstract]:In recent years, with the development of material technology, a series of nitrogen-doped materials have successfully entered the view of organic chemists because of their advantages of simple preparation and superior performance. Especially, nitrogen-doped materials loaded with transition metals have been widely used in organic synthesis. In this paper, a kind of Co-N-C material was prepared and used in liquid phase oxidation. The catalyst has outstanding catalytic properties in selective oxidation of aromatics side chains and selective oxidation of olefin allylic sites. Firstly, the precursor melamine was reacted with cobalt nitrate hexahydrate by ball milling. The corresponding Co-N-C materials were prepared. Secondly, the prepared materials were characterized by SEMBETTEMTEMTEMT-XRDX and FTIR. The results showed that the precursor melamine combined with cobalt ions to form Co-N-C material, which had a lamellar microporous structure. At the same time, melamine may polymerize itself to produce CN material similar to g-C_3N_4. Finally, the catalytic performance of Co-N-C catalyst in liquid phase oxidation is explored. The catalyst has excellent performance in selective oxidation of aromatics side chain and selective oxidation of olefin allylic sites. The conditions of the whole oxidation process are mild, only 5/1000 Co-N-C catalyst is needed, and the oxidant is green oxygen source-oxygen. Under these conditions, ethyl benzene can be oxidized very efficiently, the target product acetophenone is 92.8% of the substrate conversion and the target product is 95.5% selective. The reaction is also successfully amplified to 200g level. Nearly 70% of the single pass yield was obtained. In addition, the cyclic performance of the catalyst was tested, and the results were excellent. After 5 cycles, the oxidation performance of the same catalyst did not decrease. In this paper, Co-N-C materials are prepared by novel, cheap and simple methods. Green, efficient and selective oxidation of aromatics side chains and allyl alkenes is achieved. And has good substrate adaptability and functional tolerance.
【学位授予单位】：南京航空航天大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O643.36;O621.3

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