Synthesis And Application Of Shaped Binderless ZSM-11 Zeolite

Zeolite is a kind of important chemical raw material with ordered microporous,large specific surface area and pore volume,good thermal and hydrothermal stability,and excellent ion exchange capacity,making it widely used in chemical industry.Zeolite powder is inconvenient in practical applicationand its mechanical strength can not meet the requirements of practical application.However,the binderless zeolite can solve these problems abovementioned effectively therefore,this material has attracted widespread attention.The binderless zeolite refers to the zeolite particles contain noor only a small amount of inert binder,which mainly rely on the interaction between the zeolite crystal particles to achieve a certain shape,size and mechanical strength.The content of zeolite in the binderless zeolite is high,and its effective surface area is large,leading to the excellent performance in the ion exchange and industrial catalysis.This paper studied the effect of the synthetic conditions on the physicochemical and catalytic performance of binder/binderless ZSM-11 zeolite catalyst,using a variety of characterization methods such as XRD,XRF,SEM,TEM,MAS NMR and TG-TGA.Combined with the characterization results above,the structure of the preparation of zeolite catalyst samples were investigated in dry-gel conversion method,and the macroscopic,microscopic morphology were also observed.In addition,the possible crystallization mechanism of binder/binderless zeolite was proposed.The alkylation of benzene is an important reaction in chemical industry process.Although ethylene,propylene,methanol and ethanol are the most used alkylating agents,however,dimethyl ether?DME?has also caused a wide range of public attention in recent years.The alkylation of benzene with DME is a typical acid catalytic process,and the catalyst with moderate acidity is necessary for an excellent reaction performance.On this basis,the diffusion performance and acidity of binder/binderless ZSM-11zeolite synthesized with different time were further investigated using N₂ adsorption stripping,IGA,NH₃-TPD and Py-IR characterization methods.Meanwhile,the obtained samples were applied in the alkylation of benzene with DME,to explore the relationship between the physicochemical properties and reaction performances of these catalysts,which laid the foundation for their application.Besides,the reaction performance of DME and benzene on the micro/mesoporous ZSM-11 zeolite synthesized through hydrothermal method was investigated,and the reaction performance of micro/mesoporous ZSM-11 zeolite samples was associated with acidity.