Design,synthesis And Catalytic Evolution Properties Of Zr-Metal Organic Framworks Materials Nanoreactor

Nanoreactors are nano-functional material in which substrate and product can be selectively transported,consisting of a site where micro-reactions can occur and internal environment.The most critical aspect of constructing nanoreactors is its shell layer material.Metal-Organic Frameworks（MOFs）are porous crystalline materials composed of metal ions and organic ligands.The combination of different inorganic and organic structural units gives MOFs adjustable pore sizes,so that the controlled transport of substances can be achieved by constructing nanoreactors with MOFs.Among the various MOFs with different properties,Zr-MOFs not only have diverse structures,but also have high hydrothermal stability and large specific surface area.In this paper,metal-loaded Zr-MOFs are used as the target for structural modulation and post-modification strategies to construct a series of Zr-MOFs nanoreactors with core-shell,hollow and ortho-octahedral configurations.Their application in chemical catalysis was also investigated.The main researches are as follows:1.Research and application of Mn（Ⅱ）-doped functionalized magnetic core-shell structured Zr-MOFs nanoreactors in wastewater treatment.Fe₃O₄ nanoparticles are selected as the magnetic core,and Mn（Ⅱ）-doped layered porous NH₂-Ui O-66 is designed as the shell.Ionic liquid[BMIM][PF₆]post-modified core-shell nanoreactor（MFC@Mn-NH₂-Ui O-66@IL）for bifunctional adsorption and Fenton degradation of methylene blue.The chemical composition,structure,morphology,and their catalytic properties of MFC@Mn-NH₂-Ui O-66@IL were analysed using a series of characterisation and tests.The characterisation of the composites showed that the magnetic Zr-MOFs nanoreactors we synthesised were graded porous materials,which facilitated the adsorption process and Fenton catalysis.The presence of electrostatic interactions,hydrogen bonding andπ-πinteractions between[BMIM][PF₆]and methylene blue greatly enhance the adsorption performance.Subsequently,H₂O₂ is rapidly decomposed in the Zr-MOF and Fe₃O₄ system to produce·OH for the oxidative decomposition of methylene blue.Zr⁴⁺played a role in the catalytic reaction in terms of electron transfer.The results show that the MFC@Mn-NH₂-Ui O-66@IL material has a high adsorption capacity for aqueous methylene blue solutions.In combination with the Fenton catalysis process,a removal efficiency of 98%is achieved within 90 min.The nanoreactors can be rapidly recycled in the presence of a magnetic field,and after three cycles,the removal efficiency still reach 88.2%.2.Design and tuning of hollow structured Zr-MOFs nanoreactors doped with Ce（Ⅲ）.Environmentally friendly and safe colloidal carbon is chosen as the template.By varying the molar ratio of Ce and Zr,bimetallic hollow Zr/Ce-MOFs nanoreactors with controllable internal space were designed and synthesised.The structure of the nanospheres differ for different ratios of modulation.The chemical composition,structure,morphology and catalytic performance of the hollow Zr/Ce-MOFs were analysed using a series of characterisation.The characterisation results show the formation of hollow structures and the successful doping of Ce（III）into the Ui O-66 backbone with good crystalline morphology.The bimetallic hollow Ce/Zr-Ui O-66 nanoreactors was then investigated for catalytic conversion of furfural to furfuryl alcohol in the absence of exogenous hydrogen.The catalytic results show that the hollow structure and the modulation of the bimetallic Ui O-66 were beneficial to the catalytic reaction.The hollow Ce/Zr-Ui O-66 1:4 showed 95%conversion of furfural and 94%yield of furfuryl alcohol with good catalytic activity.3.Application of Zr-MOFs composites dope with noble metal nanoparticles Ag for the catalysis of nitroaromatics.Ui O-66@Ag and NH₂-Ui O-66@Ag composites are constructed by impregnating Ag nanoparticles loaded on Zr-MOFs and use for the catalytic degradation of three nitroaromatic pollutants,p-nitrophenol,o-nitrophenol and p-nitroaniline.The chemical composition,structure,morphology,and their catalytic properties of Ui O-66@Ag and NH₂-Ui O-66@Ag were analysed using a series of characterisation.Ag nanoparticles are dispersed on the surface of MOFs with loading rates of 28.82 wt%and 36.59 wt%,respectively.The catalytic results show that the catalytic activity of NH₂-Ui O-66@Ag is superior.The apparent rate constants of NH₂-Ui O-66@Ag are 4.5×10^-3s^-1,8.3×10^-3s^-1and 5.4×10^-3s^-1 for p-nitrophenol,o-nitrophenol and p-nitroaniline when 1 mg of catalyst is added.The catalytic performance only lost by 3%after three cycles of reuse of the catalyst.