Study On Preparation And Catalytic Performance Of Graphite-phase Carbon Nitride Non-covalently Supported Salen Metal Complex Catalysts

g-C₃N₄is a two-dimensional monolayer material composed of sp²hybrid carbon atoms.It has a large specific surface area,a large number of conjugate structures and excellent mechanical and thermodynamic properties.Because of its special structure,other catalysts can be supported on the g-C₃N₄framework to catalyze different reactions and realize the recycling of catalysts.Metal Salen catalysts,also known as double Schiff alkali metal complexes,are a class of chelating catalysts commonly used in coordination chemistry and homogeneous catalysis.Different Salen ligands are combined with different metals to form catalysts with different catalytic efficiency and uses.Salen metal complexes have been widely used in catalytic organic reactions,but most of them occur in homogeneous catalytic systems,so it is difficult to realize the recovery and reuse of catalysts.In this thesis,two kinds of SalenCo complex catalysts were designed and synthesized,which were loaded onto the surface of g-C₃N₄in a non-covalent bond functionalization mode,and were applied to catalyze the cycloaddition reaction of carbon dioxide and epoxy compounds.The main research contents are as follows:Part one:We designed and synthesized a diethylamino axial pyrene functionalized SalenCo complex,which was loaded onto the surface of graphite carbon nitride by?-?conjugation,and applied to catalyze the coupling reaction of carbon dioxide and epoxy compound.The effects of the amount of catalyst,reaction temperature and reaction time on the reaction were investigated.The results show that carbon dioxide can be coupled with epoxy compounds without adding any solvent at80?and atmospheric pressure,and cyclocarbonate can be obtained with high yield.Part two:We designed and synthesized a dual-function polymerization SalenCo-OAc catalyst,which was recombined with g-C₃N₄by non-covalent bond,and applied to catalyze the coupling reaction of carbon dioxide and epoxy compounds.The results show that cyclocarbonate can be obtained from different epoxides in high yield under the optimum reaction conditions without adding solvent and cocatalyst.In addition,the catalytic material can still maintain good catalytic effect after five times of recycling,which has industrial application value.