【作者】 孙耀；

【导师】 李涛；

【作者基本信息】 华中科技大学 ， 物理化学， 2007， 硕士

【摘要】 均相催化剂虽然有较高的活性,但存在催化剂与产物分离困难及对反应容器腐蚀严重等缺点;而多相催化剂则易于与产物分离、回收重复使用。为使液相氧化羰化催化剂兼具均相与多相催化剂的优点,本文首次将离子液体与均相催化剂同时固载在有机-无机杂化材料上,并用于苯酚氧化羰化法合成碳酸二苯酯（DPC）反应,主要内容如下:以2-吡啶甲醛作为有机配体,与γ-胺丙基三乙氧基硅烷反应合成席夫碱,再经NaBH4还原成仲胺,然后与正硅酸乙酯（TEOS）通过溶胶-凝胶过程合成有机-无机杂化材料（OIH）,并与Pd（PhCN）₂Cl₂配位制备多相化PdCl₂/OIH催化剂。在此基础上,将合成好的四氟硼酸和六氟磷酸咪唑离子液体通过物理吸附或化学嫁接的方法固载到OIH上,制备新型固载型催化剂PdCl₂/OIH/BF₄-C、PdCl₂/OIH/BF₄-P、PdCl₂/OIH/PF₆-C、PdCl₂/OIH/PF₆-P。采用傅立叶红外光谱（FT-IR）、X-射线衍射（XRD）、固体核磁共振(²⁹SiNMR)、火焰原子吸收光谱（AA）等表征手段对载体及固载型催化剂的结构进行了表征。考察所合成的催化剂在苯酚氧化羰化反应中的催化性能,以PdCl₂作主催化剂,Cu₂O和苯醌为助催化剂,3A分子筛作脱水剂。分别考察了均相PdCl₂、多相PdCl₂/OIH以及固载离子液体后的多相催化体系,结果表明固载离子液体后的多相PdCl₂/OIH催化剂具有更好的活性,其中PdCl₂/OIH/PF₆-C催化剂具有最好的活性,DPC产率和TON分别达到为10.5%和52.1。还考察了固载不同类型的离子液体及固载方式对催化性能的影响,结果表明采用化学嫁接固载六氟磷酸离子液体的催化剂催化性能最好。更多还原

【Abstract】 Homogeneous catalysts show high catalytic activity, but it is usually difficult to separate the catalyst from the products and recycle the catalyst. Heterogeneous catalysts have attractive advantages over homogeneous ones, including easy removal of catalysts from reaction mixtures and recycling of the catalysts. In order to combine the advantages of both the homogeneous and heterogeneous catalysts, ionic liquids and PdCl₂ catalyst was supported on the organic-inorganic hybrid materials, and the catalytic performance of the supported catalysts in liquid phase oxidative carbonylation of phenol to diphenyl carbonate （DPC） was investigated.PdCl₂/OIH were prepared as follows: 1) synthesis of the Schiff-bases fromγ-aminopropyltriethoxysilane and 2-pyridine-carboxaldehyde; 2) reduction of the Schiff-bases by NaBH₄ in methanol; 3) cogelification with tetraetyl orthosilicate to produce OIH; 4) Pd（PhCN）₂Cl₂ reacing with OIH materials. Synthesize [Bmim]BF₄ and [Bmim]PF₆ ionic liqueds, then support them on OIH materials by physical adsorption or chemical grafting to produce PdCl₂/OIH/BF₄-C、PdCl₂/OIH/BF₄-P、PdCl₂/OIH/PF₆-C、PdCl₂/OIH/PF₆-P catalysts. The strucure of the support and the heterogeneous catalysts were characterized by FT-IR, XRD, ²⁹SiNMR and AA.The resultant catalysts were used in the reaction of liquid phase oxidative carbonylation of phenol to diphenyl carbonate with PdCl₂ as main catalyst, Cu₂O and tetrahydrofuran as additives, 3A molecular sieves as dehydrating agent. It was found that the heterogeneous PdCl₂/OIH catalyst showed similar catalytic activity to the homogeneous PdCl₂ catalyst. The OIH supported ionic liquids catalysts showed higher catalytic activity than the heterogeneous PdCl₂/OIH catalyst, and PdCl₂/OIH/PF₆-C catalyst revealed good catalytic activity with DPC yield and TON of 10.5% and 52.1, respectively. The catalytic activity of different ionic liquids was also studied, and PdCl₂/OIH supported [Bmim]PF₆ catalyst prepared by chemical grafting showed the best catalytic activity更多还原