碱处理对ZSM-5沸石结构和形貌的影响

Influence of Alkali Treatment on the Structure and Shape of ZSM-5 Zeolite

本文在碱液中对ZSM-5沸石进行了处理.在一定温度下,制备了不同碱液浓度、不同时间和不同方式(静置、搅拌和加压)化学处理的样品,利用XRD、SEM和IR技术表征了各个样品,考察了碱液浓度、处理时间和处理方式对ZSM-5沸石结构和形貌的影响.结果表明:碱处理时间的长短对ZSM-5沸石结构和形貌均有影响,处理时间越长,破坏程度越严重.相对于碱处理时间的长短而言,碱处理浓度对ZSM-5沸石结构和形貌影响更大,浓度越高.其破坏程度越严重.搅拌和置于压力釜同样可以加速ZSM-5沸石结构和形貌的破坏.ZSM-5沸石经碱处理可选择性的脱除部分骨架硅物种,这些纳米级的硅铝物种可作为硅铝源合成复合结构的MCM-41、SBA-15等介孔分子筛.

At a given temperature, the ZSM-5 zeolite was prepared by chemical treatment in alkali liquid with different concentration, different time or different treatments （ standing, stirring and pressure）. The influence of alkali liquid treatment on the structure and shape of ZSM-5 zeolite was ivestigated by using X-ray diffraction （XRD） , Scanning Electron Microscope （SEM） and Infrared Spectra Analysis（IR）. The results showed that the structure and the shape of ZSM-5 zeolite were af- fected by the length of alkali treatment time, the longer the processing time was, the more serious the damage. Relative to the length of the alkali treatment time, the influence of alkali treatment concentration on the structure and the shape of ZSM-5 zeolite is bigger. The higher the concentration is, the more serious damage is. Mixing and under pressure treatments can also accelerate the destruction of the structure and the shape of ZSM-5 zeolite. Part of the skeleton silicon species in ZSM-5 zeolite can be selectively removed off by alkali treatment. These nanoscale silicon aluminum species can be used as silicon aluminum source to synthesize the compound structure of MCM-41, SBA-15 mesoporous molecular sieves.