Synthesis And Application Of Two-dimensional Covalent Organic Framework Materials

This thesis mainly consists of three chapters. The first chapter is the introduction,in this chapter, the formation and development of covalent organic frameworks was discussed. The second chapter studies the synthesis of pyrene covalent organic frameworks and their application in the field of CO₂ storage. The third chapter mainly introduces the synthesis of porphyry-pyrene covalent organic frameworks and their application in CO₂ adsorption-conversion.Chapter I. IntroductionThis chapter mainly introduces the development of covalent organic frameworks.In this chapter, the brief introduction, the design, the synthesis and characterization,the application, of the covalent organic frameworks and the research significance of this thesis were discussed respectively. Yaghi and his co-workers initially put forward the concept of covalent organic frameworks. The application of covalent organic frameworks is led by Jiang Donglin, Banerjee, Ditchtel, etc. There is no doubt that they are also pioneers of this field. Solverthermal synthesis is the most popular method, and XRD, FT IR, SEM, TEM and ICP are the most used characterization methods.Chapter II. The Synthesis of Pyrene COF and its Application in CO₂ StorageThis chapter discusses the synthesis of the two kinds of pyrene monomers: four benzaldehyde 1,3,6,8-tetrakis?p-formylphenyl? pyrene?TFPPy? and4,4',4'',4'''-?pyrene-1,3,6,8-tetrayl? tetra aniline?PyTTA?. The pyrene COF is synthesized from these two monomers, which is stable about the thermal and chemical surroundings.?1? The TF-Py COF we synthesized is a noval covalent organic frameworks. The structure was studied by various of methods. The thermal and chemical stability of the pyrene COF was also discussed by TGA and different chemical solvents.?2? To study the characterizations of gas capacity, physical adsorption of CO₂, CH₄ and H₂ are measured respectively. The study result showed that the chemical and thermal stability of pyrene COF are very good, and the gas capacity of pyrene COF is acceptable compared with other materials. The protonconductivity of Im @ TF-PyCOF is up to 1.8×10-5 Scm-1, this result is comparable to other organic proton conductive materials.Chapter III. The synthesis of Cobalt?II?@TF-TA COF and its adsorption and conversion for CO₂.?1? We synthesized the monomer and COF firstly and conducted characterization for them, respectively. Then we did some researches to characterization the thermal and chemical stability of the Porphyrin-Pyrene COF,including Co?II?@TF-TA COF and TF-TF COF.?2? The CO₂ capacity of Co?II?@TF-TA COF is up to 167mg/g at 273 K. The Co?II?@TF-TA COF has a higher CO₂ adsorption quantity compared with TF-TA COF. As a heterogeneous catalyst,Co?II?@TF-TA COF shows high catalytic activity in the cycloaddition of CO₂ and epoxide.?3? To study the size selectivity of Co?II?@TF-TA COF, an approach about estimation of epoxide molecular dimensions was developed and FT IR and Raman spectra also give strong evidence for size selectivity of Co?II?@TF-TA COF in the cycloaddition of CO₂ and epoxide. This study result shows that the COFs we synthesized is very stable when they are exposed to extreme chemical and thermal surroundings. The CO₂ capacity is up to 81 cc/g. The cyclic carbonate conversion rate of epichlorohydrin and CO₂ is up to 92% at 313 K, 1atm. And further study found that this Co?II?@TF-TA COF showed different catalytic activity when epoxides molecular size were different.