直接甲醇燃料電池應用三元觸媒Pt-Ru-Ni之甲醇電氧化性能

Performance of Methanol Electro-Oxidation on a Ternary Pt–Ru–Ni Catalyst in DMFC

周弦篁(Hsien-Huang Chou)

指導教授 ： 邱青煌

國立虎尾科技大學/工程學院/機械與機電工程研究所/碩士(2011年)

摘要

本篇論文探討的是以含浸法還原Pt、Ru、Ni前驅物分別為H2PtCl6、RuCl3、NiCl2，並用MWCNT做為金屬離子之載體。實驗中所使用的還原劑分別為乙二醇、甲酸、NaBH4。
在本實驗中，使用三種還原劑合成Pt-Ru/CNT，並利用循環伏安法(Cyclic Voltammetry,CV)測試評估二元各項數據最好之還原劑為甲酸和乙二醇，再成功使用此兩種還原劑合成Pt-Ru-Ni/CNT，先以循環伏安法各別測試出最佳還原比例之電極觸媒，再將測試結果進行CO毒化指標、峰值電位與峰值電流之判定，兩者還原劑在三元合金Pt：Ru：Ni比例都為4：2：4為最佳，塗佈於Nafion上之陽極觸媒Pt-Ru-Ni/CNT觸媒劑量約為0.387mg/cm2，而陰極以相同還原劑製成之觸媒Pt/CNT塗佈，最終製成MEA進行單電池測試。
單電池測試中，使用甲酸及乙二醇還原之觸媒，雖開路電壓低，但甲酸電流密度卻比乙二醇來的佳，測試結果分別為甲酸1.71mA/cm2與乙二醇1.39mA/cm2，推測原因為甲酸製備之觸媒氧化電位比乙二醇製備之觸媒來的低，致使甲酸還原之觸媒擁有較佳之活性。
熱壓溫度、壓力及時間都會對製備出的MEA效能有所影響。因此，有效控制上述變因，將是提升膜電極（MEA）效能的重要條件。

關鍵字

燃料電池 ； 膜電極組（MEA） ； 含浸還原法 ； 熱壓壓製

並列摘要

This study was to prepare the Pt-Ru-Ni alloy electrocatalyst for direct methanol fuel cells using Impregnation-reduction with three different reductants. The process of this work was divided into two steps. The first step was to use Enhylene glycol, Formic acid, NaBH4 ehthylene glycol as the reductants respectively to reduce hexachlorplatinic acid into Pt-Ru-Ni nanoparticles. Dispersion stability of the electrocatalyst nanoparticles on multi-walled carbon nanotube was examined respectively by changing the volumetric ratio of Pt-Ru-Ni and evaluated the catalytic activity of the catalysts by cyclic voltammetry (CV).
　　The second was to prepare Membrane and Electrode Assembly(MEA) with the best catalytic activity of the Pt:Ru:Ni(40:20:40) electrocatalyst under I-V characteristic curve for cyclic voltammetry. The catalysts used at the anode and cathode were applied on the membrane by a spraying method, sandwiched with carbon cloth, and hot pressed by changing temperature and pressure. The loading of the alloy electrocatalyst on electodes was 0.387mg/cm2. MEA performance was evaluated using a DMFC single cell with a 12.25 cm2 cross-section area and measured with a potentiometer which recorded the cell potential from the circuit voltage under constant current condition. The result indicated that the performance of MEA prepared by using Formic acid as the reductants was better than using the Enhylene glycol.

並列關鍵字

Fuel cell ； MEA ； Hot-pressuring ； impregnation-reduction

參考文獻

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