| The traditional crystalline materials are facing the loss of performance due to shaped process and low mass transfer efficiency at micron scale in the process of removing volatile organic compounds（VOCs）.In order to realize efficient VOCs removal,an in-situ phase inversion method was developed to achieve the preparation of shaped metal organic frameworks（MOFs）.Especially,ascribed to the solubility difference between solvent and non-solvent,ligand of MIL-101 was loaded in polyethersulfone（PES）matrix via phase inversion process.Followed by hydrothermal process,nanosized MIL-101 with developed hierarchical porous structure was prepared in confined space.Then,benzene and n-hexane this two typical VOCs of benzene-containing oil-and-gas in coal chemical industry were used to evaluate the absorption performance of MIL-101@PES Beads.Furthermore,Mn BDC PAN composite were prepared by solvothermal-phase inversion method in a high viscosity system with polyacrylonitrile（PAN）as carrier.The derived Mn Ox was obtained by pyrolysis,and the silver species were introduced simultaneously.Then the catalytic oxidation performance for formaldehyde was investigated.In this process,the physical and chemical properties were analyzed by scanning electron microscope,X-ray diffraction,nitrogen adsorption-desorption,thermogravimetric analysis and fourier transform infrared spectrometer.The main findings are as follows:（1）MIL-101@PES Beads with high sphericity,good thermal stability and abundant porous structure were prepared by in-situ phase inversion-hydrothermal method with PES as matrix.Beads-3 obtained under moderate feeding ratio exhibited higher specific surface area and larger pore volume（776.3 m2/g and 0.45 cm3/g）with a micropore-mesoporous distribution.The mass loading rate of nanosized MIL-101（60-100 nm）was 33.21%.Consequently,the adsorption capacity of Beads-3 was 245.56 mg/g for benzene and 228.82mg/g for n-hexane in mono-component adsorption.When it comes to multi-component,a slight decrease of 10.6%and 14.3%were displayed,demonstrating the simultaneous removal for VOCs and good reuse performance of adsorbents.While the adsorption capacity of Beads-E prepared by traditional embedding technology with same loading rate decreased by37.5%and 48.0%respectively when compared with Beads-3.The adsorption rate constant of Beads-E was smaller indicating the larger mass transfer resistance for VOCs molecules to access active sites.In brief,the results showed the superiority of phase inversion-hydrothermal method.（2）The shaped Mn BDC-PAN composites were synthesized by solvothermal-phase inversion method in a high viscosity system using PAN as support,and the loading rate of Mn BDC was increased to 45.43%.After pyrolysis under different gas flow,Mn Ox composites were obtained.Above all,phase inversion method was extended to the shaping of nonaqueous MOFs with a more convenient preparation strategy.Compared with the embedded sample Mn Ox-E,the carbonized derived catalyst Mn Ox-S presented better dispersion and more oxygen vacancies,which had a positive effect on the catalytic oxidation of formaldehyde.In catalytic oxidation test,90%of HCHO can be completely converted into CO2 at 90.3 oC on Mn Ox-S.As a carrier for further loading of silver species,catalysts could realize the conjunct improvement of Ag and manganese oxide catalytic activity.At 75 oC,the HCHO conversion can reach 90%,the feasibility of Mn Ox-S as catalyst and carrier was demonstrated. |
