The Functionalization Of MIL-101 And The Feasibility Study Of Its Potential Application Fields

Metal Organic Framework（MOFs）materials have received people’s attention and attention due to their unique chemistry in recent years.MOFs is a metal ion and organic ligand to connect to a new type of crystalline microporous material through a coordination bond.In recent years,it has attracted the interest of researchers in the fields of ion conductors and catalytic fields.This paper prepares the functionalized MIL-101 crystal material and applies it to a fuel cell alkaline anion exchange membrane and a new type of catalytic material.The specific research content is as follows:1.By using the affinity of F-and Al3+ to be greater than the affinity of F-to Cr3+,the anion stripping method is used to strip the F in the metal organic framework material MIL-101,directly transforming the neutral framework into a cation framework,making it attractive and The ability to conduct OH-.Using quaternized chitosan（QCS）as a polymer matrix,introducing a cationic metal-organic framework MOF material,and using glutaraldehyde as a crosslinking agent,a series of QCS/MOFs with ordered conductive channels of cationic active sites are prepared.Anion exchange membrane（QCS-X-MIL）.The structure of the composite membrane was characterized by infrared spectroscopy,X-ray diffraction,TGA and transmission electron microscopy to confirm the existence of the structure.The moisture content,swelling property,mechanical properties,ion exchange capacity,electrical conductivity,alkali resistance stability,methanol permeability and single cell performance of the composite membrane are also analyzed and discussed.The experimental results show that the introduction of the rigid MOF structure reduces the water absorption and swelling rate of the composite membrane by 27%and 37%,respectively.At 80℃,the OH-conductivity of the MIL-9-QCS film（composite film doped with 9 wt%Cr-MIL-101 crystal）reached 2.30×10-2 S·cm-1,and the power density reached the maximum（90.2 mW·cm-2）,the tensile strength reaches 20.12 MPa,which is higher than the 18.7 MPa of Nafion-115 membrane.Compared with pure QCS membrane,the spatial network structure of MOF reduces the methanol permeability of MIL-9-QCS membrane by 24%.In addition,the MIL-9-QCS composite membrane exhibits excellent alkali stability.After being immersed in a 2 mol·L-1 NaOH solution at 80℃ for 240 h,its OH-conductivity still reaches 77%of the initial value.2.Firstly,the anion is phosphotungstate ionic liquid heteropoly acid salt（[C3SO3Hnhm]3PW12O40）was synthesized by a two-step method.Then,a one-pot method was used to add ionic liquid phosphotungstate with different contents during the MIL-l0lcrystal synthesis process,and the composite catalyst X%[C3S]PW@MIL-101 was obtained after washing and drying.The structure,composition and thermal stability of the composite catalyst were determined by infrared spectroscopy,X-ray diffraction,nitrogen adsorption,TGA and scanning electron microscopy.At the same time,the catalytic activity of the process of catalyzing the oxidation of cyclohexene to adipic acid,the optimal reaction conditions,and the recovery rate of the catalyst were investigated.The results showed that at 95℃,the molar ratio of H2O2 to cyclohexene was 4.4,and 1g 35%[C3S]PW@MIL-101 catalyst was used to catalyze the reaction for 10 h,and the yield of adipic acid reached 81.2%.The results of the catalyst recovery and utilization rate showed that the catalyst activity was not significantly reduced after being recycled,vacuum-dried,and recycled for 6 times.