Preparation And Catalytic Performance Of Zirconium-based Metal Organic Frameworks Material

Metal organic frameworks?MOFs?are new porous materials composed of metal nodes and organic linkers.Due to their permanent porosity,adjustability and versatility,MOFs have gained wide attention in a variety of fields,including gas storage,separation,drug delivery,luminescence and catalysis.MOFs can become the ideally tunable platforms through the wise design of metal nodes and organic linkers.The ability to control the structure and rel evant properties of MOFs at the molecular level has led to great advances in basic science,particularly in supramolecular chemistry.The pursuit of advanced capabilities in MOFs often requires more complex structures and pore environments,accompanied with higher challenges to their design of geometry.Multifunctional metal organic frameworks?MTV-MOFs?are constructed from many different or identical components.In recent years,relevant researchers have accelerated the exploration of MTV-MOFs,expanded the complexity and diversity of known porous materials.The main contents of this article include three parts as follows:?1?In view of the critical role of 1,3,5-triazine ligands in catalyzing cycloaddition of CO₂ and the successful synthesis of Zr-BTB MOLs?MOLs=metal organic layers?of?3,6?connected kdg layers,we synthesized Zr-TATB MOLs?H₃TATB=2,4,6-tris?4-carboxyphenyl?-1,3,5-triazine?with the same configuration as Zr-BTB MOLs.The catalytic effect of Zr-TATB MOLs for CO₂cycloaddition were investigated under 50°C and 1 bar CO₂.The yield of propylene oxide to epoxy carbonate was found to be as high as 90%.Finally,we recovered the catalyst and found that the structure of Zr-TATB MOLs was still stable,and the yield of the substrate propylene oxide was still 87%after three catalytic cycles.?2?The highly stable PCN-224 was used as parent MOF to embed Fe³⁺to form PCN-224?Fe?guided by the kinetics.Then,we introduces the two-linked hydrophobic group 2,2'-bis?trifluoromethyl?-4,4'-biphenyldicarboxylic acid?H₂L¹?to the PCN-224?Fe?to synthesize the material PCN-224?Fe?-H₂L¹ by post-modification.The catalytic oxidation of cyclohexane by PCN-224?Fe?-H₂L¹was also investigated.It was found that when 8 uL TBHP was added to the reaction system,the selectivity of PCN-224?Fe?-H₂L¹ to KA oil was 89%,the conversion rate was 41.3%,and the yield of KA was 36.7%.The catalyst is stable after the reaction.?3?Based on the high catalytic conversion performance of bimetallic Zn/Co-ZIF to convent epoxide to epoxy carbonate.PCN-224 was used as parent MOFs to embed different proportions of Zn/Co to form PCN-224-ZnCo_x?x=0.5,1,2?by post-synthetic modification.We also explored the effect of PCN-224-ZnCo_x on catalyzing CO₂ cycloaddition reaction under mild conditions.It was found that the yield of propylene oxide catalyzed by PCN-224-ZnCo₂ was as high as 97%,also higher than that of PCN-224,PCN-224-ZnCo_0.5 and PCN-224-ZnCo₁.The structure of PCN-224-ZnCo₂ remained stable after three cycles and the yield of epoxy carbonate maintained above 95%.