二氧化硅微球负载钌催化剂的制备及其在苯乙酮不对称氢转移反应中的应用

发布时间：2018-03-25 17:36

  本文选题：催化剂　切入点：载体　出处：《化工学报》2016年06期

【摘要】：采用一步原位聚合诱导沉淀法制得了形貌多样、结构复杂的二氧化硅介孔微球,将其与Noyori配体Ru Cl(p-cymene)[(R,R)-Ts-DPEN]络合制得负载型钌催化剂并应用于苯乙酮不对称氢转移反应。利用场发射扫描电镜和氮气等温吸脱附手段证明了二氧化硅微球和负载型钌催化剂的微球型介孔结构,结合透射电镜表明了钌元素均匀分布在二氧化硅微球上;通过红外光谱显示该催化剂与反应底物之间存在氢键作用;在此基础上考察了载体孔结构,反应条件等因素对催化性能的影响。研究结果表明,钌配体负载到具有小孔径、高比表面积的二氧化硅微球上有利于苯乙酮的不对称氢转移反应,由此引出介孔氧化硅微球的孔道限域效应对不对称催化反应的活性和光学选择性存在明显的促进作用。在40℃、0.2 ml苯乙酮的条件下反应16 h,负载型钌催化剂用于苯乙酮不对称转移加氢反应其转化率和对映选择性最高可分别达到64.1%和93.4%。
[Abstract]:Silica mesoporous microspheres with various morphologies and complex structures were prepared by one-step in-situ polymerization induced precipitation method. The supported ruthenium catalyst was prepared by complexing with the Noyori ligands Ru Cl-p-cymene [Ru / Ru Ts-DPEN] and used in asymmetric hydrogen transfer reaction of acetophenone. The results of field emission scanning electron microscopy and nitrogen isothermal adsorption and desorption showed that silica microspheres and supported ruthenium catalysts were used. The microsphere mesoporous structure of the agent, The results of TEM show that ruthenium is uniformly distributed on silica microspheres, the hydrogen bond between the catalyst and the substrate is observed by infrared spectroscopy, and the pore structure of the support is investigated. The effect of reaction conditions on the catalytic performance. The results showed that the asymmetric hydrogen transfer reaction of acetophenone was facilitated by ruthenium ligands loaded on silica microspheres with small pore size and high specific surface area. The pore limiting effect of mesoporous silica microspheres can obviously promote the activity and optical selectivity of asymmetric catalytic reaction. The supported ruthenium catalyst was used in the reaction for 16 h at 40 鈩，

本文编号：1664182