Synthesis And Catalytical Performance Of Porous Quaternary Phosphonium Salts And Porous Solid Superacid

In recent years,environmental issues are increasing affecting people's daily lives.The massive emissions of CO2 exacerbate global climate anomalies,resulting in high household electricity consumption,and the burning of fossil fuels in power plants has further brought more CO2 emissions,creating a vicious circle.Besides,the discharge of waste water,waste gas and waste residue in industrial acid catalytic production process not only pollutes the atmosphere,and increases the frequency and duration of smog,but also causes irreparable pollution to water and soil.Therefore,how to transform CO2 on a large scale and how to reduce the waste discharge in industrial acid catalytic production has become two major problems that need to be solved urgently.The porous organic polymers,with its tough and easily modified skeleton structure,have become a better platform for catalyzing CO2 conversion and replacing traditional industrial acid catalysts.For porous organic polymers used for catalyzing CO2 conversion,although MOFs and COFs have very large BET surface area,their stability needs to be improved,while porous ionic liquid polymers,with high stability and modifiability,can be used as a good platform for studying the role of active centers in heterogeneous catalysis,and have broad prospects.Here,we synthesized a class of bifunctionalized porous ionic liquid polymers by vinyl radical polymerization based on vinyl triphenylphosphine,and applied them to cycloaddition reactions of epoxides and CO2.Hierarchical pores inside polymers which could enrich substrate and CO2,and introduction of hydrogen group,benefit cycloaddition reactions.By intramolecular fine adjusting the spatial position of hydroxyl group,we find that hydroxyl group in the meta position could achieve the best synergistic catalysis with bromide ion,which provided a new idea for the design of multi-active center synergistic catalyst.For solid acids that replace traditional industrial liquid acid catalysts,the current main research focuses on sulfated zirconia,while there are few studies on porous organic polymers with superacid strength.We synthesized a diphenyl porous organic polymer by vinyl radical polymerization,and obtained a new porous superacid solid after sulfated.Its large BET surface area,high acidic sites density and superacid strength make it excellent in esterification reactions,superior to other organic solid acids,and have a lower water sensitivity.