title: Controlled synthesis of mixed-valent Fe-containing metal organic frameworks for the degradation of phenol under mild conditions.
abstract: 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.
authors: 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. guoxw@dlut.edu.cn.
authors: Qiao
authors: Q
authors: Sun
authors: 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. guoxw@dlut.edu.cn.
authors: Min
authors: M
authors: Liu
authors: 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. guoxw@dlut.edu.cn.
authors: Keyan
authors: K
authors: Li
authors: 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. guoxw@dlut.edu.cn.
authors: Yitong
authors: Y
authors: Han
authors: 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. guoxw@dlut.edu.cn.
authors: Yi
authors: Y
authors: Zuo
authors: Mössbauer Effect Data Center, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, People's Republic of China.
authors: Junhu
authors: J
authors: Wang
authors: 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. guoxw@dlut.edu.cn and EMS Energy Institute, PSU-DUT Joint Center for Energy Research and Department of Energy & Mineral Engineering, Pennsylvania State University, University Park, Pennsylvania 16802, USA. csong@psu.edu.
authors: Chunshan
authors: C
authors: Song
authors: College of Biological and Environmental Engineering, Zhejiang University of Technology, Hangzhou 310014, People's Republic of China.
authors: Guoliang
authors: G
authors: Zhang
authors: 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. guoxw@dlut.edu.cn.
authors: Xinwen
authors: X
authors: Guo