The Synthesis Of Organic Porous Polymers Based On Imidazole Framework And Their Application In Chemical Conversion Of Carbon Dioxide

The rapid increase of CO₂ concentration in the atmosphere is the main cause of the greenhouse effect.Therefore,reducing the concentration of CO₂ in the atmosphere and reducing CO₂ emissions has become a global consensus.As a greenhouse gas,CO₂ is also a kind of green C1 resource with rich reserves,cheap and readily available,and extremely promising application potential.The chemical conversion of CO₂ is one of the research hotspots in this century,a large number of catalysts have been developed to catalyze the conversion of CO₂.Due to the stability of the CO₂ structure,the development of highly active catalysts is still a challenge.The heterogeneous catalyst has the characteristics of easy separation,recyclability,and continuous production.It has very important application value in industrial production.In this paper,three kinds of organic porous polymers based on imidazole were synthesized and applied to the chemical conversion of CO₂.The main contents are as follows:?1?The porous organic polymer?PoPs-FR-IM?was prepared by cross-linking polymerization of benzyl-imidazolium ionic liquid with an alkenyl functionalized group and DVB.The material was characterized by TEM,SEM,TGA and other testing techniques.The results show that the catalyst has large specific surface area and hierarchical pores.With the increase of the DVB,the specific surface area and pore volume of the POPs increase.The frameworks have good thermal stability.The catalyst can efficiently catalyze the N-Formylation of Amines reaction with CO₂under room temperature and pressure.After 5 times cycles,the catalytic activity does not decrease significantly.?2?A highly crosslinked organic porous polymer?PoPs-FC-IM?was prepared by subjecting the benzyl-imidazolium ionic liquid through Friedel-Crafts reaction.The material was characterized by SEM,nitrogen adsorption desorption,TGA and other testing techniques.The results show that the polymer contains a hierarchical structure consisting of stacked beads and network structure.The frameworks have good thermal stability.The catalyst shows good catalytic effect in the cycloaddition reaction between CO₂ and epoxides,and it can give good yield under mild conditions.After 5 times cycles,the catalytic activity does not decrease significantly.?3?The alkenyl-functionalized benzyl imidazolium ionic liquid was used as ligand to synthesize nitrogen-heterocyclic carbene gold complexes,and then cross-linked with DVB to synthesize organic porous polymer Poly-NHC-Au.The material was characterized by SEM,nitrogen adsorption desorption,TGA,ICP,XPS and other testing techniques.The results show that a new type of Au?I?polymer catalyst has been synthesized.The results show that the catalyst has a large specific surface area and hierarchical pores,showing a layered structure.There is no change in the Au?I?valence state before and after polymerization,and its skeleton has good thermal stability.The catalyst can efficiently catalyze the cyclization of CO₂ with1-Benzylamino-2-butyne under mild conditions and the catalyst can be reused five times.