AbstractThe parallel flow drop solvothermal method was utilized to synthesize the crystal of MOF-5 by taking the molar ratio of the metal ions to the organic ligands of 2:1 at 140∘C, and the reaction time at 12 hours. Meanwhile, the structure and properties of MOF-5 were characterized by the X-ray diffraction (XRD), scanning electron microscope (SEM), thermogravimetric analysis (TGA) and fourier transform infrared spectroscopy (FTIR). SEM analysis shown that the crystal morphology of MOF-5 changed from sheet to cubic with increasing reaction temperature and molar ratio of the metal ions to the organic ligands, and its thermal stability was also gradually increased. TGA analysis shown that its thermal stability could live up to 489.36∘C. FTIR analysis shown that the terephthalic acid is completely protonated, and the Zn2+ and the carboxyl group are formed by the coordination of the multi-tooth bridge in the crystal of MOF-5. Then the structure activity relationship of the crystal MOF-5 synthesis, microstructural, thermal stability and N2 adsorption property were further studied.

In this study, the thermal stability and CO 2 adsorption property of ZIF-8 were effectively improved by using parallel flow-drop solvothermal method. -NH 2 was successfully introduced into the surface of ZIF-8 and their structures by pre-modification with polyaniline. XRD analysis shown that the intensity of ZIF-8 characteristic peak increased with the increase doped content of polyaniline, but the crystal structure of ZIF-8 remained unchanged. FTIR analysis shown that the two new peaks at 1609 and 690 cm −1 can be attributed to the -NH 2 bonding of ZIF-8. TGA analysis shown that the thermal stability of NH 2 -ZIF-8 was 632.71°C. SEM analysis shown that the increase of CO 2 adsorption property was due to the increase of NH 2 -ZIF-8 cubic crystal system. It was found that BET surface area was 789.7 m 2 g −1 , micropore volume was 0.55 cm 3 g −1 , pore size was 0.99 nm by taking the molar ratio of metal ions to ligands being 1:2, and the molar ratios of polyaniline to metal ions being 12%.

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