Synthesis Of Organic - Inorganic Hybrid Microporous Materials And MFI - Type Metal Heterogeneous Molecular Sieve

Super-microporous materials bridge the gap of microporous zeolites and mesoporous materials with pore diameters in the range of 1–2 nm. The synthesis of super-microporous materials with preferable diffusion of large-molecule and the shape catalytic capability is an interesting topic in industry. In this paper, the super-microporous organic hybrid silicas were prepared by using Tetraethyl orthosilicate(TEOS) and γ-Chloropropyl Trimethoxysilane(CPTMS) s silica source. Cetyltrimethylammonium bromide(CTAB) and β-cyclodextrin(CD) were used as co-template to direct the synthesis of super-microporous organic hybrid silicas. CTAB molecules would enter the cavities of β-CD molecules and thus formed inclusion complexes, and this complexes could alter the self-assembly of CTAB which direct the synthesis of super-microporous organic hybrid silicas. The mixed surfactants were removed by extraction with 0.5mol/L HCl ethanol solution. The obtained super-microporous organic hybrid silicas were characterized by XRD、FTIR、SEM-EDS、TEM、BET etc. The TEM and BET results show that the pore diameter of products is in the range of 1.2-1.5nm. The adsorption capacity of the resulted materials achieved 340 mg/g to Rhodamine B and the adsorption equilibrium time was 10 min. Especially, this material exhibited 95% adsorption capacity of the initial adsorption capacity even in the third adsorption cycle, which suggest that the sample may be useful for practical applications.Transition metal doped zeolites with MFI-type structure have been widely explored due to their good selective oxidation or redox properties under mild conditions. In the second part of this paper, the shaped transition metal doped zeolites with MFI-type structure(Metal = Ti, Fe, Cr, Ni) were prepared by using zeolites seed sol containing transition metal as director with dry gel conversion(DGC) method. In this strategy, the usage of Tetrapropylammonium hydroxide(TPAOH) and solvent has been reduced to close the theoretically demand, which not only cuts costs and but also reduces environmental pollution. The preparation of seed sol was the key step in this strategy. Triethanolamine(TEA) was used as complexing agent to make the well dispersion of transition metal in the seed sol. The metal doped MFI-type zeolites were characterized by XRD、FTIR、ESR、UV-vis、SEM、BET etc. The XRD and FTIR results show the successful synthesis of transition metal doped zeolites with MFI-type structure. The ESR and UV-vis results show that transition metal species have occupied site-isolated positions in the zeolite framework. The influence of TEA and water content to the size and crystallinity of zeolites were studied: the crystal particle size increased with increasing addition of the TEA; and the 10 wt% mass percent of water was needed for the zeolites with well relative crystallinity. In conclusion, the shaped metal(Ti, Fe, Cr, Ni) doped zeolites with MFI structure were prepared under low usage of TPAOH and minimal-solvent by one-step DGC method.