Through the method of solvent-free confined encapsulation,dibromo-p-diphenyl and 4,4'-bipyridine were adsorbed into the UiO-67 material,and then in situ polymerized into the polymer ionic liquid PBpy-Br.The com-posite PBpy-Br@UiO-67 contains three kinds of active centers:Br-,Zr-OH/Zr-OH2 and N heterocyclic.The structure was characterized by X-ray diffraction(XRD),Fourier transform infrared(FTIR)spectroscopy,scanning electron microscopy(SEM),13C nuclear magnetic resonance spectrometry(13C NMR),Brunauer-Emmett-Teller(BET)analysis and thermogravimetric analysis(TGA).The composite was applied to catalyze the cycloaddition reaction of CO2 and epichlorohydrin.On the basis of single factor experiments,the optimal reaction conditions determined by response surface optimization were 100 ℃,pCO2=0.1 MPa,PBpy-Br@UiO-67 mass fraction of 0.22％and 22 h.Under the optimum reaction conditions,the yield of cyclochlorocarbonate reached 99.6％,and the conversion decreased by only 2.3％after 5 cycles.When the composite was used to catalyze other epoxides,a conversion of over 50％was obtained.PBpy-Br@UiO-67 has milder reaction conditions and higher catalytic efficiency,which provides a new catalytic system for CO2 fixation and conversion.
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