Sun Qiao, Liu Min, Li Keyan, Han Yitong, Zuo Yi, Wang Junhu, Song Chunshan, Zhang Guoliang, Guo Xinwen
State Key Laboratory of Fine Chemicals, PSU-DUT Joint Center for Energy Research, School of Chemical Engineering, Dalian University of Technology, Dalian 116024, People's Republic of China.
Mössbauer Effect Data Center, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, People's Republic of China.
Dalton Trans. 2016 May 10;45(19):7952-9. doi: 10.1039/c5dt05002b.
A series of MIL-53(Fe)-type materials, Fe(BDC)(DMF,F), were prepared by using different ratios of n(FeCl3)/n(FeCl2), which have varied amounts of Fe(2+) in their frameworks. From FeCl3 to FeCl2, the structures of the synthesized samples transform from MIL-53(Fe) to Fe(BDC)(DMF,F). Along with this structure transformation, the crystal morphology goes through a striking change from a small irregular shape to a big triangular prism. This phenomenon indicates that the addition of FeCl2 is beneficial for the formation of a Fe(BDC)(DMF,F) structure. The catalytic activity of these iron-containing MOFs was tested in phenol degradation with hydrogen peroxide as an oxidant at near neutral pH and 35 °C. The degradation efficiency of these samples increases gradually from MIL-53(Fe) to Fe(BDC)(DMF,F). (57)Fe Mössbauer spectra reveal that Fe(2+) and Fe(3+) coexist in the Fe(BDC)(DMF,F) framework, and the highest amount of Fe(2+) in the sample prepared with mixed FeCl3 and FeCl2 is 26.0%. The result illustrates that the amount of Fe(2+) in the samples can be controlled using varied n(FeCl3)/n(FeCl2) in the feed. The diverse amount of Fe(2+) in this series of FeMOF materials exactly explains the distinction of reaction efficiency. The iron leaching tests, structures of the fresh and used catalysts, and the data of the recycling runs show that the Fe-containing MOFs are stable in this liquid-phase reaction.
通过使用不同比例的n(FeCl3)/n(FeCl2)制备了一系列MIL-53(Fe)型材料Fe(BDC)(DMF,F)，其骨架中含有不同量的Fe(2+)。从FeCl3到FeCl2，合成样品的结构从MIL-53(Fe)转变为Fe(BDC)(DMF,F)。随着这种结构转变，晶体形态经历了从小的不规则形状到大三棱柱的显著变化。这一现象表明添加FeCl2有利于Fe(BDC)(DMF,F)结构的形成。在接近中性pH值和35°C的条件下，以过氧化氢为氧化剂，测试了这些含铁金属有机框架材料在苯酚降解中的催化活性。这些样品的降解效率从MIL-53(Fe)到Fe(BDC)(DMF,F)逐渐增加。(57)Fe穆斯堡尔谱表明Fe(2+)和Fe(3+)共存于Fe(BDC)(DMF,F)骨架中，用混合FeCl3和FeCl2制备的样品中Fe(2+)的最高含量为26.0%。结果表明，通过在进料中使用不同的n(FeCl3)/n(FeCl2)可以控制样品中Fe(2+)的含量。这一系列铁基金属有机框架材料中不同量的Fe(2+)恰好解释了反应效率的差异。铁浸出试验、新鲜和使用过的催化剂的结构以及循环运行数据表明，含铁金属有机框架材料在该液相反应中是稳定的。
