Synthesis, Characterization, And Catalytic Application Of Covalent Organic Frameworks (COFs)

Since the seminal work of Yaghi on covalent organic frameworks (COFs) in2005, this subject of research has attracted extensive interest not only from chemists in materials science and organic synthesis, but also from various researchers in the fields of energy storage, separation, photoelectricity, and catalysis. So far, many new COFs with different structures and diverse functionalities have been synthesized. However, the synthetic methods of COFs are still limited. Since its discovery, most of the COFs were produced via solvothermal synthesis. This synthetic approach still has some drawbacks, such as harsh reaction conditions and difficult operating procedures, these may limit the synthesis of COF materials on large scales for further practical applications. Therefore, this thesis aims to explore new synthetic methods of COFs and then-potential applications in catalysis.In Chapter I, the recent development of COF materials, especially the synthesis, characterization, and its application in various areas, such as photoelectricity, gas storage and heterogeneous catalysis, was presented.In Chapter II, a method to synthesize the imine-based COFs at ambient conditions was reported. The production of COF-LZU1on large scale (approximately,2.0g) has been achieved via this method. Synthetic conditions including reaction time, temperature, pressure, and acid concentration for the formatioan of COF-LZU1have been examined. The formation mechanism of COF-LZU1was then discussed.In Chapter III, the synthesis of three acid-functionalized materials using2,5-diaminobenzoic acid,2,5-diaminobenzenesulfonic acid and2,5-diaminoterephthalic acid via the "bottom-up" approach was described. The acid-functionalized materials were characterized via FT-IR, solid-state NMR spectroscopy (SSNMR), powder X-ray diffraction (PXRD), and elemental analysis. The preliminary catalytic applications of COF-A1were also studied.