Preparation And Properties Of ZSM-11 Magnetic Mesoporous Composite Materials

In recent years,there has been widespread interest in molecular sieve materials having mesoporous channels.Molecular sieves introduce a certain number of mesoporous channels in crystalline microporous molecular sieves.ZSM-11 belongs to this class of molecular sieves.The molecular sieve materials of composite pores not only have good thermal stability and strong catalytic activity of microporous molecular sieves,but also have a smooth mass transfer channel of mesoporous materials.Mesoporous molecular sieve has potential application value and is expected to be widely used in the fields of catalysis,medicine,environmental protection,adsorption and separation,chemical industry,petrochemical industry,and new materials.Can be used as ion exchange material,adsorbent,catalyst and so on.Because the ZSM-11 molecular sieve has a very similar structure to the ZSM-5molecular sieve,the ZSM-5 molecular sieve is prone to heterogeneity during the synthesis of the ZSM-11 molecular sieve.Therefore,it is difficult to synthesize a pure phase ZSM-11 molecular sieve.In addition,the extraction and separation of molecular sieves have become a problem.In view of the existing problems,through the improvement of the synthesis method of ZSM-11 molecular sieves,the magnetic composite Fe₃O₄@ZSM-11 with core-shell structure was prepared,and the ferrite was used as the core and ZSM-11 as the shell to further improve its performance.To expand the application area,the main work of this paper is as follows:1.The mesoporous material ZSM-11 was prepared by a one-step hydrothermal synthesis method.The crystallization temperature and time,the ratio of the template agent to the silicon source during the preparation process were respectively used to synthesize a series of samples,and the morphology of the synthesized ZSM-11molecular sieve was observed.Performancechanges.Accordingto the characterization results,there is no ZSM-5 heteromorphous peak in the synthesized molecular sieve ZSM-11,and the microstructure has a relatively uniform spherical morphology.The resulting sample does not have a ZSM-5 molecular sieve heterocrystal,and the specific surface area value is 256.7²98.6m²/g.2.Using hydrothermal synthesis method,a layer of ordered mesoporous material is coated on the surface of magnetic particle Fe₃O₄ to form a magnetic composite material Fe₃O₄@ZSM-11 with magnetic nanoparticle as the core.By changing the amount of Fe3O4 added,the morphology of the composite material is observed.With the change of properties,the microstructure of the obtained Fe₃O₄@ZSM-11composite has a relatively uniform spherical morphology.The molar ratio of the silicon source to the template agent is 100:17,the crystallization temperature is 135?,and the crystallization time is 6 In the experimental scheme of day,the synthesized sample has the best orderability when doped with 0.5g,and the hysteresis loop based on the N₂ adsorption and desorption isotherm curve is the most obvious to prove that the sample introduced has the largest mesoporous content and the largest specific surface area.The value is 318.6159 m²/g.