MCM-41Immobilized Acidic Functional Ionic Liquid And Its Catalytic For Esterification Reaction

At present, the widely used catalyst in the esterification reaction is still acidiccatalys. Concentrated sulfuric acid catalytic was used for synthesis of ester inindustry,wich was soon restricted because of its not easy separation, equipmentcorrosion and environmental pollution,etc. green catalysis and other environmentalfriendly new esterification catalyst appeared under the guidance of the concept in recentyears, Among them, the ionic liquid with its unique performance mostly showed astrong catalytic activity, was immobilized in ordered mesoporous molecular sieveMCM-41, the solid material applied in esterification,etc, organic reactions. Not onlyeffectively improve the reaction selectivity and the conversion rate, but also greatlyimprove whole catalyst reusing, and the repeated using only need a simple filter withoutthe need for many complicated procedure.This thesis used the multiple step synthetic method to immobilize acidfunctionalized ionic liquids into the ordered mesoporous materials MCM-41molecularsieves. using X-ray diffractometer （XRD）, infrared spectrum （IR）, nitrogen adsorption-desorption analyzer and scanning electron microscopy （SEM） to characterize thenanometer microspheres. And then use it to catalyse esterification, and study theinfluence of the mole ratio of reactants, reaction temperature, time, dosage of catalyst,etc. on the esterification rate.Use1-vinyl imidazole as the basis, introduce1,3-propane sultone to get1-vinyl-3-（3-sulfonic acid propyl） imidazole salt intermediate, and the sulfuric acid wasused as acid functionalized material, get acid functionalized ionic liquid[（CH₂）₃SO₃HVIm]HSO₄. Use tetraethoxysilane （TEOS） and cetyltrimethylammoniumbromide （CTAB） which were used as silica source and template respectively and themethod of microwave radiation to prepare MCM-41mesoporous materials. Useheterogeneous-phase to make the acid functionalized ionic liquid [（CH₂）₃SO₃HVIm]HSO₄go into the carrier of MCM-41. Using X-ray diffraction （XRD）, infraredspectrum （IR）, nitrogen adsorption-desorption analyzer and scanning electronmicroscopy （SEM） to characterize the homemade catalyst. The results showed thatMCM-41-[（CH₂）₃SO₃HVIm] HSO₄have the mesoporous feature, the introduction ofionic liquid reduce the orderliness of MCM-41carrier channel.The MCM-41-[（CH₂）₃SO₃HVIm] HSO₄was applied to the esterification reaction with benzyl alcohol and acetic acid as template, investigate the influence of the differentmole ratio of reactants, reaction temperature, catalyst, the amount of ionic liquid load,dosage of catalyst, etc. on the esterification rate. Results show that the best mole ratio ofreactants is1:1.5; the optimum reaction temperature is140℃, in examining the catalystactive site. Use respectively MCM-41,[（CH₂）₃SO₃HVIm] HSO₄, MCM-41-[（CH₂）₃SO₃HVIm] HSO₄catalysing esterification reaction as catalyst, find that thecatalytic production rate of MCM-41is close to blank contrast group, ionic liquid ispart of the catalytic effect. The ionic liquid load was investigated for the esterificationrate impact: when the mass radio of MCM-41: IL is1:1.40, the benzyl acetateproduction rate can be as high as96.88%. The esterification rate will increase with theincrease of the catalyst’s dosage. After the catalyst reused four times, the esterificationrate could still be reached82.23%.According to the properties of the ionic liquid structure and can be designed, thethird part immobilize a kind of new acid functionalized ionic liquid. Based on the1-vinyl imidazole, introduce benzyl chloride to get the intermediates, and join thesulphate to access sulfonic group, then get the functionalized ionic liquids （IL²）. Usingmultiple steps synthesized MCM-41-IL². Use X-ray diffraction （XRD）, infraredspectrum （IR）, scanning electron microscope （SEM） charactering. The results showedthat MCM-41-IL²still has a mesoporous feature. Useing MCM-41-IL²in esterificationreaction of benzyl alcohol and acetic acid, esterification reaction of benzyl alcohol andacetic anhydride, the catalyst has a certain catalytic effect. These studies of thefunctional immobilization ionic liquid materials’ applying in organic reactions ascatalyst provide the experimental basis, improving further the catalytic activity ofcatalyst and rusability, etc.needs to further investigate.