Research Of Structure And Catalytic Performance In Multivariate Metal-organic Frameworks(MTV-MOFs)

The structural analysis and property research of Multivariate Metal-Organic Frameworks(MTV-MOFs)has become a hot topic in recent years.It has effectively enhanced the performance of MOFs,through the introduction of multi-component,including multi-metals and multi-functional groups of linkers and their synergies.The existing research is mainly focused on the construction and performance study of MTV-MOFs,lacking the establishment of the relationship between structure and property.In the aspect of performance,almost research is focused on gas adsorption,luminescence,magnetic and electrochemical properties,and there is no research about catalysis.In addition,for the special type of MOFs,Zeoletic Imidazolate Frameworks(ZIFs),there is no analysis of the whole system and the summary of structural construction.In this thesis,the researchs are mainly focused on the arrangement of components in MTV-MOFs and structural deconstruction analysis in ZIFs.And the relationship between the arrangement of MTV-MOFs and catalysis performance and the construction of large-pore ZIFs are initially established.The main contents and innovations including:1.Synthesis of tetrakis(4-carboxyphenyl)porphyrin,tetracarboxyphenyl porphyrin(TCPP-M)for short,with different metals.High purity TCPP-M linkers were synthesized by three-step reaction using pyrrole,methyl p-formylbenzoate and metal chloride as raw materials.2.Design and characterization of series of iso-reticular MOFs with stp topology.Firstly,starting from the topology,concrete structure was used to replace the node in the topology and design the MOF structures by changing the metal types.Secondly,36 kinds of iso-reticular MOFs were synthesized,including 27 kinds of single SBU metal MOFs and 9 kinds of mixed metal MTV-MOFs,by research the synthetic conditions.Finally,a series of test methods,including single crystal X-ray diffraction(SXRD),powder X-ray diffraction(PXRD),nitrogen adsorption test,thermogravimetric analysis(TGA),infrared absorption spectroscopy(IR)and X-ray absorption spectroscopy(XAS)were used to characterize the structures of the series of MOFs.3.Study on catalytic performance of the iso-reticular MOF series.Based on the quasi-first order reaction of 1,5-dihydroxynaphthalene(DHN),the catalytic activity of MOFs,the influence of metal species on the catalytic performance of MOFs was studied and the effects of MTV-MOFs on the catalytic reaction the quasi-first order reaction of 1,5-dihydroxynaphthalene(DHN),the catalytic activity of MOFs was studied,and the influence of metal species on the catalytic performance of MOFs was studied.The effects of MTV-MOFs on the catalytic reaction were researched.4.Study on the arrangement of metal components in MTV-MOFs and the photocatalytic mechanism.It shows two kinds of behavior in the photocatalytic performance of MTV-MOFs:first is that the catalytic properties of MTV-MOFs obtained by some combinations of metals(Mn/Fe,Mn/Co and Mn/Mg)were only between two kinds of single SBU metal MOFs.And the other one is that the catalytic activity of some mixed SBU metal MTV-MOFs(Mn/Ni and Ni/Fe)exceeds their single SBU-metal counterparts.Uv-vis diffuse reflection spetrum(UV-vis DRS)and X-ray photoelectron spectroscopy(XPS)were used to study the presence of two metal arrangement patterns in mixed SBU metal MTV-MOFs,which is domain and well-mixed.Base.d on the catalytic behavior analysis of MTV-MOFs,the relationship between the metal arrangement pattern and the catalytic performance in MTV-MOFs was established.5.Structural analysis and synthesis of MTV-ZIFs.This part is mainly devoted to the analysis of the structure of multivariate zeoletic imidazolate frameworks(MTV-ZIFs),focusing on the conditions and regularity of large ring and pore formation in ZIFs.The feasibility of using multi-linker strategy to synthesize macroporous ZIF was verified.The steric hindrance of large imidazole linkers could induce the formation of large rings which 4,5-position of imidazole linkers point into the ring;large ring is easier to form large pores,but it needs small ring to adjust the angle between the large ring;linkers with various sizes build ZIFs with large pores.At the same time,the synthesis and structural characterization of two kinds of large pore MTV-ZIFs were completed.