Research On The Anodic Catalyst In DAFC

Compared with other traditional fuel cells, the direct alcohol fuel cell (DAFC) is of the wide application prospect as the powerful source in the portable electronic devices and vehicle etc. DAFC has a lot of merits such as the easy transportation and storage of the fuel, light weight and small volume, inherent simplicity of the structure, the high energy efficiency and low pollution. It, however, has two key technique issues: the poor kinetics of the anodic reaction of the commonly used fuel and methanol crossover, which hindered the commercial applications of DAFCs. With regard to the above two problems this dissertation focused on highly efficient catalysts and the substitutes for methanol. It also discussed the effects of the several factors on the catalyst performance.My main research contained: 1) the study on the relationship between the electroactivity and composition in the catalyst, especially the catalyst performance, which is influenced by Nafion loading; 2) the preparation of the anodic Pt/C, PtRu/C and PtRuMo/C catalysts using the infuse reduction method and the electrocatalytic activity of the catalysts investigated by CV and XRD; (3) Study on the methods to deal with the supporting of C black powder.The main results obtained are as follows:(1) The electrocatalytic activity of the catalyst with different Nafion loading in three solution: vitriol, methanol and ethanol solution, was compared. It was found that the catalysts with different Nafion loading performed quit differently in the three solutions. In vitriol solution, the best Nafion loading is from 30% to 40%, as same as the result range of 33% to 36% in the literatures. In methanol solution, the best Nafion loading is between 10% and 20%. In ethanol solution, the best Nafion loading is between 5% and 10%. The influence of Pt loading and temperature to the electrocatalytic activity of the catalysts was also compared. It was found that the catalysts with different Pt loading performed quit differently but the catalyst performed nearly the same from the room temperature to the boiling point of the solutions.(2) The electrocatalytic activity of the catalyst before and after heat treatment was compared. It was found that the electrocatalytic activity of the catalyst performed a distinct increase after heat treatment.(3) The preparation of the anodic Pt/C, PtRu/C and PtRuMo/C catalyst using the infuse reduction method with different reducing agents was compared. It was found that the electrocatalytic activity of the catalysts were much better than the commercial catalyst with the same Pt loading when the reducing agents were formaldehyde and glycol in the preparation of Pt/Cå’ŒPtRu/C catalyst. But in the preparation of PtRuMo/C catalyst, formaldehyde and glycol didn't perform distinct preponderant than the tradition reducing agent NaBH 4. And It was also found that the reaction temperature was an important factor in the preparation of the anodic catalysts using the infuse reduction method.