Study On Ionothermal Synthesis Of Inorganic Porous Material

Ionic liquids(ILs) is a kind of novel solvent which developed rapidly in20thcentury.They show more superiority compared with traditional inorganic and organicsolvents.Ionothermal synthesis is a new material synthetic method which has manyunique capabilities such as reacting in normal pressure or preparation of materials withnew structures or with particular morphologies,or the technologies of in-situ can trackthe synthesis process of molecular sieve which provides an opportunity to synthesismechanism of molecular sieve.The rsearch of ionothermal synthesis of zeolite is mostly focus on phosphate type,only a few are Si-Al zeolites.In this paper,we researched the stability of FAU zeolitesin ionic liquids and the dealuminization of zeolite for the purpose of getting more datasfor the ionothermal synthesis of Si-Al zeolite.The results showed that FAU zeoliteswere stable in ionic liquids,but when a little water or HF existed,the crystal structurewould damaged quickly.The research of FAU zeolites in ionic liquids showed that thepreparation of rich silicon zeolite in ionic liquids did not need high temperature andhigh pressure environment as in hydrothermal synthesis.Also silicon-aluminum ratioscan be changed in a short time,but crystal structure damaged seriously.For the first time,we used ionothermal synthesis method,NaX/HY zeolites as thesilicon source and aluminum source,successfully prepared mischcrystal of NaX/HYand AEL zeolites with no destroyed FAU crystal structure.Also it realized that thecoexistence of acidic zeolite and alkaline zeolite.We studied the effects ofcrystallization time、crystallization temperature、water contents etc.The results showedthat the best crystallization temperature was160℃;With the increase of water contents,the framework of molecular sieve materials collapsed as the result of volatile.Reactionproducts were dense materials instead of FAU and AEL mischcrystal.In the synthesis,HY zeolite was more stable than NaX zeolite.