Synthesis,Characterization And Catalytic Properties Of Porous Materials Based On Metalloporphyrin Gels

In the past few decades,functional porous materials have been attracting great attention by many researchers due to their outstanding performance and wide-range application in many areas.Porphyrinand its derivatives bear many unique physical and chemical properties:the central four N atoms can.coordinate with the metal ions,with peripheral groupsbeing readily modified,rendering them an exceptionalstructural building block.In addition,the approach to synthesizingmetal-organic gels based onporphyrinsis ofgreatsimplicity and efficiency.Further,the addition of metallic gel materials makessuch porous materialhave the combined characteristics ofporphyrin with metal organic gel,such propertiespotentiate its use in catalysis,gas adsorption separation,drug delivery release,dye sensitization and many other areas.In my thesis,we primarily focused on the design and synthesis oftwo free porphyrins:5,10,15,20-tetra(4-(3-formateethyl)phenoxy)phenyl porphyrin(H2MePp)and 5,10,15,20-tetra(4-(3-carboxyl)phenoxy)-phenyl porphyrin(H2CPp),and their corresponding metalloporphyrins:FeMePpCl,CoMePp,CuMePp,ZnMePp,MnMePp(OAc);FeCPpCl,CoCPp,CuCPp,ZnCPp,MnCPp(OAc).In resolving the structure of the synthesized porphyrin molecules,allaforementioned porphyrinic compounds have been characterized by elemental analyses,FI-IR,1H NMR,MS and UV-vis.Subsequently,as-prepared porphyrin(H2CPp,FeCPpCl,CoCPp,CuCPp,ZnCPp,MnCPp(OAc))served as building blocks were reacted with Fe(NO3)3·9H2O,Al(NO3)3·9H2O and SiO2 sol,respectively,in the solvothermal condition to form metalloporphyrin gels and dried by supercritical CO2 extraction to produce 18 porous porphyrin materials with partially pored structure.We studied the as-prepared metal porphyrin gels using FT-IR,UV-vis-DRS,X-ray powder diffraction(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM),thermogravimetric analysis(TGA)and N2 adsorption-desorption,and analyzed the formation procedure of such porous porphyrin materials.The results indicated that the as-prepared porous porphyrin materials were possibly due to the accumulation of mesoporous materials with long-range disordered,comparatively large surface area and better thermal stability.In the last step,the adsorption properties(dye adsorption,solvent adsorption)and the activity of the catalytic oxidation of alkylbenzene to aromatic ketone were studied and theirrational catalytic mechanism was discussed correspondingly.The catalysis results suggested that(1)The catalytic activity center in three types of porphyrin porous materials based on metal organic gels is porphyrinswith catalysis capability;among them,the porous materials constructed with MnCPpserve as structural unitsto exhibit the excellent catalytic activity and high selectivity(>99%)in the study of catalytic oxidation toalkylbenzene.(2)After 5 cycles of the experiment,the porous metalloporphyrin materials could remain a relatively high-level catalytic activity in alkylbenzene catalysis.(3)The conversion rate of catalytic oxidation of alkylbenzene to aromatic ketone for porous porphyrin materials was associated with the porphyrins of the peripheral metal ions.The adsorption for dye adsorption and solvent adsorption tests revealed that(1)The porous porphyrinsmaterials formed by Al(NO3)3·9H2O,Fe(NO3)3·9H2O,SiO2 sol dye adsorption have the ability to show some level of adsorption of solvent molecules and dye molecular removal rate;Therefore,the porphyrin porous materials based on metalloporphyrin gels we synthesized using laboratory approachis indeed a novel type of material with larger surface area,superior catalytic activity,controllable morphology and better chemical stability.