Study On The Process Of Direct Generation Of 2,2'-bipyridine By Continuous Method

As a chemical intermediate,2,2'-bipyridine is widely used in organic synthesis,paints,dyes,spices,coatings,pharmaceuticals,pesticides and other aspects of life.Because of its unique chelation,2,2'-bipyridine can be used as indicator,photosensitizer,ligand for metal catalyst,etc.In recent years,domestic and foreign demand for 2,2'-bipyridine is increasing.But up to now,no effective green synthesis route has been developed in China.In addition,people are calling for more and more environmental protection.In addition,people are calling for more and more environmental protection.In order to build a green ecological environment,our research group has developed a new technology to replace the existing production mode with huge pollution.In this paper,based on the previous research of our group,the fixed bed reactor was used as the reaction device,and the process conditions were changed by the control variable method,so as to explore the influence of the change of each process condition on the yield of 2,2'-bipyridine synthesis.The M₁-M₂/AC bimetal nanometer alloy catalyst was prepared by excessive impregnation.When M₁ loading is 5%and M₁:M₂=1:4,the catalyst shows the best activity in the fixed bed.We hope to establish the relationship between the yields of 2,2'-bipyridine through a series of characterization methods.For M₁-M₂/AC catalyst,we used bet,XRD,XPS,TEM,SEM and other methods to test and characterize.According to the analysis of the images,both M₁ and M₂ particles were uniformly loaded on the carrier activated carbon,and M₁-M₂ nano alloy particles were also generated on M₁-M₂/AC catalyst.The chemical structure of bipyridine was detected by superconducting nuclear magnetic resonance spectrometer.Finally,whether the synthesized bipyridine was2,2'-bipyridine was determined.For example,we optimize and select the catalyst proportion,catalyst dosage,solvent,catalyst activation temperature,catalyst activation time,fixed bed reactor preheating temperature,reaction temperature,reaction pressure,heating rate,carrier gas type,carrier gas flow rate,sample injection rate,reaction time,etc.Finally,we get the best work of M₁-M₂/AC catalytic synthesis of 2,2'-bipyridine Technical conditions:catalyst dosage:30g,pyridine flow rate:6 ml/min,heating rate:14?/min,preheating temperature:175?,reaction temperature:400?,carrier gas type:hydrogen,carrier gas flow rate:100ml/min,reaction pressure:3.5 Mpa,reaction time:12 h.The results show that under the optimum conditions,the highest content of 2,2'-bipyridine in the reaction solution is 21.8%.