Controllable Fabrication Of Hierarchical Nanocrystalline ZSM-5Zeolites And The Application Of Their Catalytic Performances In The Alkylation Bezene/Ethanol

The main study of the thesis was about the controllable preparation of hierachicalnano-ZSM-5zeolites and investigated the ideal conditions of the benzene/ethanolalkylation reaction and the performance of the hierarchical ZSM-5zeolite in thealkylation reaction of benzene ethanol.The main aim of the second chapter work is to fabricate hierarchicallynanostructured ZSM-5zeolites by using APTMS as an organic additive，and todiscuss the effects of Si/Al ratio on the morphologies, porous structures. The sampleswith different Si/Al ratio have similar crystal structure and crystallinity; When theSi/Al ratio is30、60、100，the samples constructed by many nanoparticles. Thesenanoparticles aggregate to form the supermicropores and mesopores with the poresize of1.4,1.8,2.8nm. As the Si/Al ratio arrives at300, the obtained ZSM-5Dbecomes monocrystals without the hierarchical nanostructure.In Chapter3，the synthesized ZSM-5zeolites with different Si/Al ratio wasdesilicated by alkaline treatment with the0.6mol/L Na2CO3solution.The time ofalkaline treatment which has a great influence on the morphology and structure of theZSM-5zeolites with different Si/Al ratio was studied. When alkaline treatment timewas0.5h, the external morphology of the ZSM-5zeolites was not damaged, and thecavity structure in the interior of the zeolites was obtained by the means of TEM.With the extension of alkaline treatment time, the Si/Al ratio of ZSM-5zeolites with40and60remained relatively complete external morphology. While the Si/Al ratioincreased to400, the more time of the alkaline treating, the more serious damage to itsmorphology.The fourth chapter investigated the catalytic performance of the ZSM-5zeolitescatalyzed the alkylation reaction of benzene/ethanol on the fixed bed reactor;Whenthe catalytic bed temperature is400, benzene/ethanol mole ratio of4, the Si/Al ratioof60,the benzene conversion can reach to42.35%. When using the ZSM-5zeoliteswith the Si/Al ratio of60as the catalyst, the optimal condition is the reaction temperature400℃and the benzene/ethanol mole ratio of4;The catalytic results ofthe ZSM-5zeolite after alkaline treatment was analyzed and try to wash with acidafter the alkaline treatment in the future work.