Study On Electrochemistry And Raman Spectrum Of Picoline Electro-Oxidation Beavior In Non-aqueous System

With the progress of society and the development of medicine, food and feed industry, the need of 2-picolinic acid and 4- picolinic acid was yearly increased both in China and abroad,but the productions of 2-picolinic acid and 4- picolinic acid were very deficiency. The study of new synthesis methods were very active. The electrochemical synthesis of 2-picolinic acid and 4- picolinic acid which called as "Green Technology" was characterized by mild reaction conditions, high product purity and reduced waste compared with other synthesis methods, so it has become the main direction of synthesis study of 2-picolinic acid and isonicotinic acid。Using 2-picoline and 4-methylpyridine as raw materials the method of direct electrooxidation synthesis of 2-picolinic acid and isonicotinic acid has a very important industrial application. The choice of electrode material, the methods of improving synthesisand the optimization of electrolytic process conditions were studied by a lot of people and have made great progress, but the studies almost were carried out in water system, the mechanism study of eletro-oxidation of 2-picoline and 4-picoline is very few.In this paper, the oxidation processes of 2-picoline and 4-picoline were studied by the conventional electrochemical method and spectroscopic electrochemical method in non- aqueous system,and expect to explain the electro-oxidation processes of 2-picoline and 4-picoline on molecular level, so to provide experimental and theoretical basis for further understand the electro-oxidation mechanism of 2-picoline and 4-picoline.In this paper, Pt nanoparticles modified glass carbon electrode(Ptnano/GC) and Aucore@Ptshell nanoparticles modified glass carbon electrode (Aucore@Ptshell/GC) were prepared.Direct electro-oxidation behaviors of the 2-picoline and 4-picoline on the two electrodes were carried out by conventional electrochemical method in non-aqueous system.The experimental results showed that 2-picoline and 4-picoline could be electro-catalytic oxidated both on the Ptnano/GC electrode and Aucore@Ptshell/GC electrode. The initial oxidation potential of 2-picoline on the two electrodes were about 0.6V, but the initial oxidation potential of 4- picoline on the two electrodes were 1.0V, which showed that 2-picoline was more easily electro-oxidatated on the two electrodes. In order to better understand the mechanism of the electro-oxidation processes of 2-picoline and 4-picoline, In-situ surface-enhanced Raman spectroscopy studies of 2-picoline and 4-picoline at Ptnano/ GC electrode and Aucore @ Ptshell/GC electrode were first carried out in non-aqueous system.It confirm the initial oxidation potential of 2-picoline and 4-picoline on the two electrodes were about 0.6V andl.OV respectively and can provide relevant molecular informatios for further investigating electro-process of the two kinds of picoline expand the application of the Raman spectra in the electrical catalytic reaction system, so it has certain theoretical significance and potential practical application value..