Synthesis And Modification Of Metal-Organic Framework MIL-101 For Their Catalytic Properties

Metal-organic frameworks(MOFs)are a class of crystalline porous hybrid materials formed by the coordination of metal ions or metal clusters with organic molecules to form a one-dimensional,two-dimensional,or three-dimensional framework.Because of its excellent properties,such as large specific surface area,adjustable structure,easily modified surface and high permanent porosity,etc.It has attracted great attention in recent decades,making these materials show great potential in gas storage,adsorption,separation,drug loading,sensors and catalytic applications.These materials have shown great potential in gas storage,adsorption,separation,drug loading,sensor,and catalytic applications.In particular,MOFs have crystalline porous solids similar to zeolites,capable of building the largest surface area using the least amount of metal ions and organic ligands.This inherent structural property makes MOFs a new interface between heterogeneous catalysis and supramolecular chemistry.Thus,it is expected to be a promising candidate for heterogeneous supramolecular catalysis.The surface properties of MOFs that are easy to modify provide more structural controllability and design means for the multi-functionality of materials.In this paper,MIL-101,a MOFs material with excellent chemical stability,was selected as the carrier,and functional groups were further introduced to disperse metal Pt nanoparticles on the carrier to prepare heterogeneous catalysts.Catalytic performance in the reaction.The specific work is as follows:MIL-101 having a large specific surface area and an unsaturated metal coordination point was synthesized by the hydrothermal method,and Pt NPs were introduced onto MIL-101 by a simple impregnation method.Pt/MIL-101 was successfully synthesized by XRD,SEM,TEM,BET,XPS,and other characterization methods,and the basic skeleton structure and thermal stability of the material during the impregnation process were unchanged.The conditions of the catalytic reaction(catalyst dosage,molar ratio,reaction temperature and time,etc.)were optimized byusing allyl alcohol polyoxyethylene ether and heptamethyltrisiloxane as reaction substrates.The results show that the catalyst can effectively catalyze the hydrosilylation reaction,the amount of catalyst is small,and the product and catalyst are easy to separate.However,the lack of anchor functional groups in the reaction leads to the escape of Pt NPs.The catalyst is inactive after repeated use for 3 times.The MIL-101 material was hydrothermally synthesized using a high-pressure reactor.Subsequently,the synthesized MIL-101 was modified with silane coupling agent KH791 by heating under reflux with toluene as a solvent to obtain modified MIL-101(MIL-101-791),and Pt NPs were loaded onto the carrier by heat-assisted impregnation.On MIL-101-791.The modified and pre-loaded MIL-101 materials were characterized by XRD,TEM,FT-IR,BET,TGA,and XPS.The results showed that the MIL-101 product was successfully synthesized in this study.The specific surface area and pore volume of MIL-101-791 are reduced,but the crystal form and the frame structure remain intact.To test the catalytic activity of the material after loading Pt NPs,the allyl alcohol polyol alkyl ether and heptamethyltrisiloxane were used as a model reaction,and the catalyst was optimized by single factor process.The results show that the amount of the catalyst is small,the product and the catalyst are easy to separate,the color is pure,and the hydroxyl and amino functional groups in the material can limit the anchoring of Pt NPs to prevent escape.The catalyst still has good catalysis after repeated use for 5 times.active.A porous material MIL-101 modified with amino acetic acid(IDA)was used,in which toluene was used as a refluxing solvent.Although the modified IDA-MIL-101 has a reduced specific surface area and pore volume,the material not only maintains a good crystal structure but also creates new mesopores.It is believed that the addition of IDA causes MIL-101 to expand.The pore effect,using allyl alcohol polyoxyethylene ether and heptamethyltrisiloxane as reaction substrates,the conditions of the catalytic reaction(catalyst dosage,molar ratio,reaction temperature and time)were optimized,and the results showed that the catalyst was synthesized.The catalytic product and catalyst are easy to separate,the color is pure,and the product has low surface properties.The catalyst still has a good catalytic effect after repeated use 5 times,which shows that the catalyst has excellent catalytic activity andcatalytic stability.