论文部分内容阅读
SBA-15介孔分子筛内填充蔗糖并炭化后,分别在碱性和弱酸性条件下,用含铝源及TPABr的溶液浸渍,将SBA-15分子筛孔壁的无定形结构转化成ZSM-5分子筛的晶体结构,除碳后得到含介孔的ZSM-5分子筛.用X射线衍射、N2吸附-脱附、27Al MAS NMR、NH3-TPD、TEM、SEM等对样品进行了表征,考察了晶化时间等参数对样品的影响.结果表明,碱性条件下合成的ZSM-5分子筛晶体中含有少量孔径约3.2～4.2nm的介孔孔道,其酸强度接近与常规ZSM-5分子筛的酸强度;弱酸性条件下合成的ZSM-5分子筛晶体中含有大量孔径约1.4～1.6nm的孔道,其酸强度明显低于常规ZSM-5分子筛的酸强度.
SBA-15 mesoporous molecular sieve filled with sucrose and carbonized, respectively, under alkaline and weakly acidic conditions, with aluminum source and TPABr solution impregnated SBA-15 molecular sieve pore wall amorphous structure into ZSM-5 molecular sieve The mesoporous ZSM-5 molecular sieve was obtained after carbon removal.The samples were characterized by X-ray diffraction, N2 adsorption-desorption, 27Al MAS NMR, NH3-TPD, TEM and SEM etc. The effects of crystallization Time and other parameters.The results show that the mesoporous ZSM-5 molecular sieve crystals synthesized under basic conditions contain a small amount of mesopores with a pore size of about 3.2-4.2 nm, and the acid strength is close to that of the conventional ZSM-5 zeolite. ZSM-5 molecular sieve crystals synthesized under weakly acidic conditions contain a large number of pores with a diameter of about 1.4-1.6 nm, and the acid strength of the synthesized ZSM-5 zeolite crystals is obviously lower than that of the conventional ZSM-5 zeolite.