Single Current Pulse Plating Platinum on Carbon Nanotubes/C for Electrochemical Oxidation

• Main Authors: Ren-Jian Hou, 侯仁健
• Other Authors: J-Y Hwang
• Format: Others
• Language: zh-TW
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/83s7j3

碩士 === 國立臺北科技大學 === 化學工程所 === 94 === The proton exchange membrane (PEM) fuel cell both of its cathode and anode half reaction must use the platinum catalyst to reduce the activation energy. The principle of catalyst design depends on the enhancement of contacting probability of the active material, the increasing of electricity catalysis performance, reduction of catalyst amount. In this way we can get a lower cost of the electrode. In order to enhance the platinum catalyst exposed ratio, we usually choose small particle with good electric conductivity, and choose the catalyst support with the character of anticorrosion. We use carbon nanotubes as the support with the more compacting coating layer single current pulse plating way in the experimental because of it’s better conductivity and surface area. By controlling the pulse current density, pulse frequency and the catalyst loading capacity, the nanostructured platinum catalyst can be obtained. In 0.01M H2PtCl6, 1M HCl, 1.25M CH3OH solution, controlling the different single current pulse parameters can make the platinum catalyst. The pulse current density ip is in the range of 20 to 200 mA/cm2. The pulse frequency ton/toff is in the range of 0.05s、0.1s、0.15s、0.2s/0.1s、0.3s、0.5s、0.7s、0.9s. The catalyst loading capacity is in the range of 2 to 8 C/cm2. We use the CV method for analysis with different electrode plates obtained within various combination of parameters in 0.5M sulfuric acid and 1M methanol. In this way, we can get the optimum parameters which are ip = 100mA/cm2, ton/toff = 0.1s/0.5s, and loading capacity 6C/cm2. This result is suitable for both the hydrogen adsorption and the methanol oxidation. By SEM, we can observe the uniform structure and the size of the platinum catalyst. The particle size is about 50~80nm.