Preparation Of M₁-M₂@C Bimetallic Nanomaterials And Synthesis Of 2,2 '-Bipyridine

As an important chemical raw material and pharmaceutical intermediates,2,2 '-bipyridine has been widely used in medicine,pesticide and electronic chemistry.At present,most of the industrial production of 2,2 '-bipyridine at home and abroad adopts the Ullmann coupling method.Using Cul,NiC12 as catalyst,metal Zn as reducing agent,2-Chloropyridine or other 2-halogenated pyridine as raw materials,2,2'-bipyridine was produced at high temperature.The industrial production of Ullmann coupling method is limited by 2,2'-bipyridine technology,such as difficult source of raw material,large amount of metal catalyst and reducing agent,and large pollution in the production process.The production cost of 2,2'-bipyridine is relatively high.Therefore,it is of great economic value and important social significance to carry out the research and application of the green production technology of 2,2 '-bipyridine.In this paper,2,2-bipyridine was synthesized from pyridine by supported bimetallic nanometallic catalyst.The preparation methods,carrier selection,active components and reaction conditions of the catalyst were optimized.The main contents and results are as follows:The impregnation method and precipitation method were selected for the preparation of the catalyst.The experiments show that the catalyst prepared by the impregnation method has a higher catalytic activity.Using M1,M2,M3,M4 and other metals as active components and activated carbon as carriers,bimetallic nanocrystalline alloy catalysts were prepared by stirring,dissolution,loading,drying,calcination and reduction.The catalysts with high activity and good stability were prepared by optimizing the content of precious metals,the proportion of active components and the types of active components.The catalyst morphology with X-ray diffraction(XRD),transmission electron microscopy(TEM)and scanning electron microscopy(SEM)characterization methods were analyzed,the results show that the M1 and M2 in two kinds of metal as the active component of the catalyst,activated carbon as the carrier,active component ratio M1:M2=1:6 and M1 content is 7%,the highest catalytic activity of catalyst.After the preparation of the catalyst,2,2'-bipyridine was synthesized with pyridine catalyst,and the catalytic activity of the catalyst was verified.The content of 2,2'-bipyridine was determined by Gas chromatograph.The optimum reaction conditions for the synthesis of 2,2'-bipyridine were optimized by optimizing the reaction temperature,reaction time,reaction pressure and the ratio of catalyst to raw material.In the autoclave as to optimize the reaction conditions,reaction vessels,experiments show that the reaction temperature is 350?,reaction pressure 1.5MPa,reaction time 25h,400r/min speed and the amount of catalyst for total quality of raw materials of the 10%reaction conditions,2,2 '-bipyridine yield up to 34.2%.The reaction equation is as follows:(?)Experiments show that usingM1-M2@C as catalyst,2,2 '-bipyridine synthesis,not only has the advantages of simple operation,no pollution,and has the advantages of high yield,stable catalyst,and has broad application prospect in the industrial laid a solid foundation for the synthesis of 2,2'-bipyridine.