Preparation Of Superacidic Ionic Materials And Their Catalytic Activities In Acid Catalyzed Reactions

Acid catalysis is a very important field in the chemical industrials.However,traditional sulfuric acid catalyst can not entirely meet the requirements of green chemistry and chemical process.Then it is imperative to design and prepare highly efficient green catalysts to replace the traditional acid catalysts.As a representative of green chemistry,acidic ionic liquids are expected to become one of the alternatives of traditional acid catalysts owing to their unique physical and chemical properties.However,acidic ionic liquids still have some inherent drawbacks such as less acid sites,lower catalytic activity in specific reactions,and tedious procedure for separation and recycle.To this end,the study on preparation of ionic liquids with multiple acid sites,solid super acid ionic hybrid materials,and solid superacid catalysts with high acid values was listed in this thesis.The catalytic activities of these three types of acid catalysts were also studied systematically in acid catalyzed reactions.The main contents are as follows:?1?16 kinds of acidic ionic liquids with multiple acid sites were synthesized and employed to catalyze the esterification of cyclopentene and acetic acid.It was found that the ionic liquid catalyst[Ps₂BPy][HSO₄]₂ with 4 mol/mol acid sites showed the best catalytic activity.The effect of reaction time,temperature,catalyst dosage,and molar ratio of reactants on the esterification results were systematicallystudied.Therecyclingtestfurtherdemonstratedthat[Ps₂BPy][HSO₄]₂ had good stability to reuse without obvious decrease.?2?The superacid ionic hybrid catalyst[BPy-SO₃H-OTf]PW was prepared by making use of the precipitation of heteropoly anions and the electrophilicity of electronic-withdrawing group.Several techniques of solid ³¹P MAS NMR,FT-IR,XRD,and SEM characterized the structure and acid properties of such ionic hybrids.In addition,the catalytic properties and recycle stability of[BPy-SO₃H-OTf]PW in indirect hydration of olefins to alcohols were studied in detail.The results showed that the yield of alcohols by indirect hydration was more than 80%,which is superior to that by direct hydration.?3?By modification and functionalization of h-BN,a 2D solid superacid BN-OSO₃H with high acid value was designed and prepared successfully.The structure and properties of BN-OSO₃H were characterized by FT-IR?XRD?SEM?TEM.Moreover,the catalytic tests showed that the catalyst BN-OSO₃H exhibited very good catalytic performance in the Friedel-Crafts alkylation and turpenes isomerization,in which both of the conversion of aromatics and the conversion of?-pinene are higher than 90%.