Synthesis And Heterogeneous Catalysis Properties Of Cationic Hierarchical Porous Organic Frameworks

Porous ionic polymers（PIPs）are a new class of non-neutral porous organic polymers（POPs）with advantages of high BET surface area,high charge density,excellent porosity,and various synthesis methods,and these materials have promising applications in heterogeneous catalysis,proton conduction,sewage treatment,antibacterial treatment,and so on.Hierarchical porous frameworks have advantages that can’t be matched by microporous materials,such as large specific surface area,diversity of pore size,and rapid mass transfer of guest molecule.So far,the research on hierarchical porous materials mainly focused on silica,zeolites,MOFs,and thus hierarchical PIPs has been relatively reported less.We firstly reported on two cationic porous organic frameworks,then we chose polystyrene spheres and silica nanospheres as templates to synthesize a series of hierarchical cationic porous organic frameworks,and investigate their heterogeneous catalysis performance.The main results of them are discussed and analyzed as follows:1.1,3,5-triformylphloroglucinol（TP）and3,8-diamino-5-ethyl-6-phenylphenan-thridinium bromide（EB）were selected to obtain cationic covalent organic framework TP-EB-COF under solvothermal conditions.Then,polystyrene nanospheres with diffenert particle sizes as templates were used to synthesize two hierarchical cationic porous materials Mc-TP-EB-COF-160/320.Due to cationic frameworks,anion exchange and Na BH₄ reduction was used to synthesize Pd@TP-EB-COF,Pd@Mc-TP-EB-COF-160,Pd@Mc-TP-EB-COF-320.The resulting materials could serve as heterogeneous catalysts to catalyze the one pot tandem reaction of benzyl alcohol and aniline/benzylamine to form imine compounds.The catalysts exhibited good catalytic activity,good substrate suitability,and reusability.2.Imidazolium-based nitrile monomer bpim was used to synthesize the cationic covalent triazine framework bpim-CTF-400/500 under ionothermal conditions.Then,we used silica nanospheres with diffenert particle sizes as templates to synthesize two hierarchical cationic porous materials CTF-500-Mc-250/500.After strong alkali treatment,the cationic imidazole group in the frameworks were converted to N-heterocyclic carbene structure.Ag NO₃complexation and Na BH₄ reduction was used to synthesize Ag@NHC-CTF-500 and Ag@NHC-CTF-500-Mc-250/500.The resulting materials served as heterogeneous catalysts to catalyze the reaction of terminal alkynes and CO₂ to form carboxylic compounds.The catalysts were characteristics of mild reaction conditions,high catalytic efficiency,good reusability and wide substrate suitability.