Study On Organic Modification Of Boron Nitride Materials And Their Catalytic Application

Hexagonal boron nitride,as an emerging two-dimensional layered nanomaterial,has caused researchers to carry out related theoretical research and application exploration due to its unique two-dimensional structure and excellent physical and chemical properties.Boron nitride has stable chemical properties and excellent mass and heat transfer properties,it has great potential application value in the field of heterogeneous catalysis.Boron nitride can be loaded with active components after modification and functionalization,and is an excellent carrier for various active substances.Based on the organic modification of boron nitride,this paper innovatively proposes a series of hydroxylated boron nitride derivatives to prepare an efficient and recyclable supported catalyst,which expands its application in organic synthesis.In this paper,boron nitride nanosheets（BNNSs）prepared by ultrasonic-assisted liquid-phase exfoliation were used as carriers.An improved catalyst BNNSs@Schiff@Pd for microwave reaction was prepared by fuctionalization and coordination of hydroxyl group,amino group and Schiff base on the surface of BNNSs The structure and morphology of the catalyst were characterized by FT-IR,Raman,XRD,TGA,XPS,SEM,TEM,and EDS mapping.The prepared supported Pd（Ⅱ）catalyst was used to catalyze microwave Heck reaction,and compared with the self-made graphene-based palladium catalyst.Under the conditions of optimal microwave power,raw material ratio,catalyst dosage,microwave irradiation time,and acid binding agent and solvent types,the reaction yield reached 95.6%,and the catalytic performance of BNNSs@Schiff@Pd maintained a high level after 7 times of recycling.In this paper,BNNSs prepared by ultrasonic-assisted liquid-phase exfoliation were used as carriers.After introducing amino groups on the plane of the carriers,organic amine groups and Schiff base structure were introduced through the aldol condensation reaction of amino groups with 4-（diethylamino）salicylic aldehyde.Alkaloid is used to support the Pd（OAc）₂,and a Pd²⁺-organic amine group synergistic catalytic system is constructed.The structure and morphology of the catalyst were characterized by FT-IR,Raman,XRD,TGA,XPS,SEM,TEM,and EDS mapping.Take Tsuji-Trost allylation reaction as a model reaction to test the catalytic performance of the prepared synergistic catalytic system,and using the catalyst prepared in Chapter 2 as a reference catalyst to investigate the synergistic catalytic effect of organic amine groups and palladium complexes.Under the conditions,the conversion rate of the reactants was 93.81%,and the catalyst still had high catalytic activity after 7 times of recycling.In this paper,（3-chloropropyl）trimethoxysilane and N-methylimidazole were used as raw materials to prepare an functional ionic liquid（[Sm Im]OH）,whose silanol group was coupled with the hydroxyl group on the BNNSs@OH to realize the loading of[Sm Im]OH.The morphology and structure of the catalyst were characterized by XRD,TGA,XPS,and SEM.Based on the reaction of 1,2-phenylenediamine and benzaldehyde for the synthesis of benzimidazole derivatives,the optimal reaction conditions were explored from the reaction time,the type of solvent and the ratio of the reaction substrate,and the yields were obtained under the optimal conditions.It reached 93.2%and the catalyst was tested for recycling.