Studies On Electrochemical Oxidation Of Methanol-FTIR Spectroelectrochemistry Cyclic Voltabsorptometry And Derivative Cyclic Voltabsorptometry

The development of fuel cell and reaction mechanism were summarized firstly in this article. The advantages, the reaction principle and application prospects of direct methanol fuel cell are also pointed out. At the same time, the shortcomings of fuel cell were also reviewed. Then, infrared spectroscopy combining with in-situ electrochemical technique was used to investigate the oxidized reaction mechanism and products under acid and alkaline media. Finally, cyclic voltabsorptometry and derivative cyclic voltabsorptometry spectroelectrochemical technique were used to derive possible reaction mechanism of methanol oxidative.1.Using cyclic voltammetry technique, in-situ FTIR spectroelectrochemical and CVA technique to study methanol oxidation in H2SO4 solution. The electrochemical results sguuest that oxidation of CH3OH in H2SO4 on the scanning process of cyclic voltammetry exist oxidation peaks but no reduction peak. Poisoned intermediate CO is observed from infrared difference spectra and the intermediate of HCHO are also observed by the technology of 3D in-situ FTIR.The CVA and DCVA technique shows that the possible reaction mechanism is that CH3OH adsorbed on the electrode surface in H2SO4 solution firstly, then gradually deprotonation, build carbon-oxygen,HCOH or HCOOH finally.2.Methanol oxidation in NaOH solution was investigated by using CV and in-situ FTIR spectroelectrochemical technique. The results suggested that different oxidation mechanism occurred in NaOH solution compared to in sulfuric acid solution. The oxidation begin at much lower potential in NaOH solution than in acid solution. Although HCOO" can be observed in oxidation process, the poisoned intermediate product, CO, was not found. We got the information of the formation and transformation of intermediate, HCOO-, by CVA and DCVA techniques. Based on the study of different concentration ratio of NaOH/CH3OH, we find that the bigger the concentration of the NaOH, the more positive the oxidation peak is shifted and the CVA and DCVA curve deformated heavily.3.It is found easily that high signal to noise ratio IR spectra can be obtained when methanol oxidation in the heavy water (deuterium oxide) system.Hence,methanol oxidation in the heavy water was also studied by using infrared CVA (Cyclic Voltabsorptometry) and DCVA (Derivative Cyclic Voltabsorptometry). The results can help us to understand the generated sequence and the maximum production rate of the intermediate during oxidation process. It also suggested that the intermediate formation of the methanol oxidation is HCOO-, and subsequent further oxidation of HCOO- to the final products:CO2, CO32- and HCO3-.