Synthesis Of MFI Zeolites And Disordered Mesoporous Materials With Polyether Compounds

The syntheses of molecular sieves often use quaternary ammonium, quaternary ammonium salts and amines as templates. These nitrogenous organic templates cause the high cost and environmental pollution problems in the synthesis of molecular sieve and their industrial applications. Polyether compounds containing carbon, hydrogen and oxygen are eco-friendly, highly hydrophilic, and of abundant configurations, and thus can satisfy the requirement of the synthesis of molecular sieve and other nanoporous material. This thesis mainly focuses on the effect of polyether compounds on the synthesis of MFI molecular sieves and disordered mesoporous materials, including three parts.Part one discusses the effect of polyether compounds on the synthesis of Al-containing ZSM-5zeolites. The synthetic parameters including different templates, Na2O/SiO2ratio, H2O/SiO2ratio, SiO2/Al2O3ratio, silica source, polyether amount and polyether molecular weight were investigated in detail. Secondly, the mechanism of the growth of the molecular sieve with polyethylene glycol (PEG) is suggested. Finally, the polyether is applied to the synthesis of ferrierite zeolite.Part two focuses on the synthesis and catalytic performance of Ti-containing TS-1molecular sieves and the effect of polyether compounds. The highly active TS-1molecular sieves are synthesized using sodium-containing inorganic silicon source and inorganic titanium source, where the cost of synthesis is greatly reduced. In the synthesis of Al-containing zeolite, the complexation polyether and Na+favor the crystallization of zeolite. In the synthesis of Ti-containing molecular sieves, the complexation of polyethylene glycol and sodium ions may inhibit the formation of TiOx species, and favor the incorporation of Ti into the framework. It is well known that sodium ions have a great influence on the activity of titanium silicalite molecular sieve. In this part, the synthetic parameters, including the preparation and pretreatment of filter cake, H2O/SiO2ratio, Na2O/SiO2ratio, SiO2/TiO2ratio, NH4OH/SiO2ratio and TPAOH/SiO2ratio were investigate. Especially, the effect of TPAOH/SiO2ratios is deeply explored. Finally, the effect of polyether compounds on the synthesis of TS-1and their catalytic performance are discussed. Part three investigated the synthesis of disordered mesoporous materials using hydrophilic polyethylene glycol. The synthesis is based on the interaction between hydrophilic polyethylene glycol and hydrophobic silica species, which leads to disordered mesoporous silicas that show diffraction peaks in the low angle XRD pattern. The synthesis conditions, including the different kinds of acid, molecular weight of polyethylene glycol, temperature and aging process, concentration of acid and the carboxylic of the end hydroxy of polyethylene glycol are discussesed.