Synthesis And Characteristic Of Zeolite Beta-ZIF-8 Composite Beads

At present,the world is facing serious energy and environment problems.The questions that academic and applied scientism should answer today are: how to transform more efficiently the petroleum into valuable products,how to storage hydrogen,how to absorb the carbon dioxide greenhouse gas,and how to absorb heavy metal ions are hot topics in today's world.Nowadays we should also answer of the question what would be the renewable hydrocarbon sources that we will use when the fossil hydrocarbons will be exhausted.The effort of the researcher to adapt well know porous materials as zeolites for the current needs;but also to create new and better performing porous solids as MOFs and COFs,bring hope in solving these problems.These three families of materials all have unique structure and properties,they all keep high expectations in different uses in petroleum industry,environmental protection and in biological and medicine fields.Zeolite are relatively strong acids,they have porous structure and high thermal stability.Among them,zeolite beta have 12 membered ring channel system.MOFs have porous structure too,they always have high specific surface area,their channels are very diverse and can be modified.Among them,ZIF-8 has unique structure and wonderful performance.The motivation for this work is based on:1.Due to fact that zeolite materials have many pores and acid catalytic sites,they are widely used in industrial catalysis field.But they only have micropores,which brings carbon deposition effect,and this may decrease zeolite's catalytic lifetime and catalytic performance.So scientists introduce hierarchical porous structure into zeolite to optimize the catalytic performance.In addition,spherical shape is easier to operate in practical applications.In this paper,I use ion exchange resin as hard template,the reaction is treated at 120 ? for 9 days,and successfully obtain hierarchical porous zeolite beta beads.The hierarchical porous zeolite beta beads have high specific surface area and good mechanical strength.The zeolite beta beads adsorb 7 times higher CO₂ than N₂;The zeolite beta beads' CO₂ adsorption amount is 4 times higher than CH₄ adsorption amount.They can be used as good gas adsorption and separation materials;In order to optimize the synthesis of zeolite beta beads,two other reactions were prepared in this paper,and obtain zeolite beta beads which only have micropores.2.Zeolite and MOFs materials have their own advantages and disadvantages.In this part,the purpose is to obtain zeolite and MOFs composite material,this material may has some new or better properties,which can broaden the scope of their application.In this paper,one host guest composite material of hierarchical zeolite beta beads and ZIF-8 were synthesized by using heating method.I do TG analysis of the composite beads,and find they have very good thermal stability,but their specific surface area decreased.Overall,this composite has potential application in catalytic field.3.In order to combine two materials which have different catalytic and separation performance,core-shell configuration is the most appropriate,because the existence of shell can control the species which go into the core,this means that the core-shell structure materials are very important in selective catalysis,gas adsorption and gas separation fields.In this study,the hierarchical zeolite beta beads were pre-treated with HCOONa in order to facilitate the growth of ZIF-8,and further subjected to hydrothermal treatment in order to obtain core-shell composite beads.The analysis of the TG and adsorption properties,showed that the composite beads have high specific surface area and good thermal stability.The composite adsorb 6 times higher CO₂ than N₂;The composite's CO₂ adsorption amount is 5 times higher than CH₄ adsorption amount.That means the core-shell composite beads can be used as a highly selective gas adsorption and separation materials,that might be interesting for industrial uses.