- 學位論文
奈米複合電極觸媒材料的製備與鑑定
Preparation and characterization of nanocomposite electrode catalysts
摘要
本論文目的在製備奈米複合電極觸媒並鑑定其活性，我們以SBA-15為模板合成中孔洞碳材：CMK-3，接著以CMK-3為支架形成複合高分子/CMK-3材料，利用不同的複合高分子/CMK-3為載體，以膠體法及乙二醇還原法合成甲醇燃料電池陽極觸媒。另外為了增進催化活性，也添加TiO2或是CeO2於複合高分子碳材再以乙二醇還原製備陽極觸媒。上述的材料以X光粉末繞射儀、氮氣物理吸脫附儀、熱分析儀做結構鑑定。陽極觸媒的活性則以循環伏安法分析甲醇氧化及一氧化碳剝除實驗來判斷。結果顯示以複合親水性的高分子CMK-3為載體可提高觸媒活性，但在0.8V運作大約30分鐘電流強度下降約40% ~ 50%。而添加TiO2或是CeO2後催化電流強度與觸媒的穩定性相較於未添加前都有明顯的提升。
並列摘要
In this thesis we have aimed at the preparation and characterization of nanocomposite electrocatalysts for direct methanol fuel cell (DMFC). We applied mesoporous SBA-15 silica as a hard template to prepare mesoporous CMK-3 carbon, which were then used to prepared polymer/CMK-3 nanocomposites. Pt nanoparticles were then reduced and deposited on the nanocomposites by the colloidal method or alcohol reduction method. Alternatively, metal oxides including TiO2 and CeO2 were added into the nanocomposites, with the attempt to enhance the electroactivity of Pt nanoparticles. The thus prepared nanocomposite materials were characterized by X-ray diffraction, nitrogen physisorption analysis, and thermal analysis. Besides, the electrochemical activities of the Pt-containing nanocomposite catalysts were analyzed by cyclic voltammetry and CO-stripping experiments. The results showed that the catalytic activity got better when using polymer/CMK-3 nanocomposites containing hydrophilic polymers. However, these nanocomposite catalysts also exhibited 40-50% decrease in current density of methanol oxidation at 0.8 V after running the half cells for around 30 min. On the other hand, the addition of TiO2 or CeO2 indeed enhance the performance of the Pt-containing nanocomposites, which exhibited higher current density and better stability.