研究生: |
江政鉉 Chiang, Cheng-Hsuan |
---|---|
論文名稱: |
利用電化學沉積法直接於微孔層上製備商用尺寸質子交換膜燃料電池之奈米鉑觸媒 Preparation of Platinum Nanostructures Directly Grown on Microporous Layer by an Electrodeposition Technique for a Commercial-Scale PEMFC |
指導教授: |
葉宗洸
Yeh, Tsung-Kuang |
口試委員: |
曾繁根
Tseng, Fan-Gang 王本誠 Wang, Pen-Cheng |
學位類別: |
碩士 Master |
系所名稱: |
原子科學院 - 工程與系統科學系 Department of Engineering and System Science |
論文出版年: | 2019 |
畢業學年度: | 108 |
語文別: | 中文 |
論文頁數: | 111 |
中文關鍵詞: | 燃料電池 、質子交換膜 、電沈積 |
相關次數: | 點閱:2 下載:0 |
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本研究嘗試利用電化學沉積製程於商業尺寸電極之微孔層上製備奈米鉑(Pt)觸媒並應用於質子交換膜燃料電池中。電極基材使用塗佈微孔層之碳布(GDL-CT, Fuelcells etc),為使碳材試片之微孔層增加親水性以利電沉積反應進行,試片先經醇類進行表面親水化處理,使-OH官能基吸附碳材表面增加其與電鍍液的接觸性。試片經親水處理後,先以恆定電位電鍍法於碳材上產生成核點,接著再以電化學方式進行沉積,直接於碳材表面製備一層薄觸媒層。而為了解使用商用尺寸電極進行電沉積製程對觸媒成長的影響,本實驗採用3種不同基材尺寸做為對照,分別為1、4、25cm2之相同碳材。
測試方面,利用循環伏安法於0.5 M硫酸溶液中進行循環伏安法(CV, Cyclic Voltammetry),並利用掃描式電子顯微鏡(SEM)、與電感耦合等離子體質譜(ICP-MS)進行觸媒形貌及金屬組成定量分析。經由SEM觀察發現在小面積電極上使用脈衝電鍍可生長出具立體結構之枝晶狀鉑觸媒;而在大面積下,由於電場分布及鉑前驅物擴散場的限制,脈衝式電鍍僅能生長出立方塊形貌的鉑觸媒,在鉑觸媒結晶度上較差。故本實驗為尋得在高面積下製備立體枝晶結構鉑觸媒,進行一連串電鍍參數改善,最終在使用較高濃度前驅物及恆電流沉積法下製備成功。使用本研究之電沉積方式製備的立體結構鉑觸媒,具有3~5 μm的主幹長度及150~400 nm的分枝寬度。兩極皆使用此方式製備之觸媒層,可在1cm2單電池下達到656 mW的功率;4 cm2單電池下達到1.621 W;25 cm2單電池立方體觸媒達到6.675 W;枝晶狀觸媒可達6.21 W。而透過ICP-MS對工作面積25cm2的電極鉑金屬沉積量進行測定,確認其沉載量約為0.628mg/cm2。
為瞭解為何具較好催化性質的枝晶狀結構觸媒,無法在全電池測試中獲得優異的功率結果,我們對組合過的膜電極組進行剖面分析。從結果發現枝晶狀觸媒的機械性質較差,無法承受熱壓的壓力,因而電池效率較為低落。
最後在實驗C,我們對立方形觸媒進行熱壓壓力的最佳化,並於實驗D中以相同載量商用觸媒進行對比,並發現電沈積觸媒在全電池組裝下的缺陷。
In this study, platinum (Pt) catalysts supported on carbon based micro porous layer(Pt/MPL) were developed to enhance efficiency of proton exchange membrane fuel cell (PEMFC) . The MPL were directly roll coating on carbon cloths with polytetrafluoroethylene (PTFE) to enhance the hydrophobic property of gas diffusion layer(GDL) and then the MPL was treated with hydrophilic process to make conduction with plating solution. The Pt nano- catalysts were deposited on MPL by pulse electroplating. Then we attempted to used three different substrate with different surface area (1,4,25 cm¬2) to figure out the efficiency, morphology and dispersibility difference between. After confirming electrochemical efficiency of Pt catalysts, the commercial Pt/C specimens were also prepared by using roll coating procedure for comparison.
Electrochemical characteristics of the Pt/MPL catalyst were investigated via cyclic
voltammetry analysis and rotating disk electrode test in 0.5 M sulfuric acid. Structure
and platinum loading were measured by SEM and ICP-MS analysis.
After measurement, the electrodeposited 25cm2 single cell shows that its peak power is 7.45 W/cm2 and ICP-MS result shows that the Pt loading on the 25cm2 electrode is 0.628mg/cm2.
Several optimizations were applied to enhance the efficiency of our homemade electrodeposition catalyst MEA in this study. However, in the end we found out the commercial Pt/C MEA did have better conductivity between catalyst and electrolyte membrane.
[1] Subasri M. Ayyadurai, Yoon-Seok Choi, Prabhu Ganesan, “Novel PEMFC Cathodes Prepared by Pulse Deposition”, Journal of the Electrochemical Society, vol. 154, pp. 1063-1073,
[2] B. Wickman, “Nanostructured Model Electrodes for Studies of Fuel Cell Reactions”, Chalmers University of Technology, 2010
[3] W.R.Grove, ”On voltaic series and the combination of gases by platinum”, Phil. Mag., vol. 14, pp. 127-130, 1839
[4] 李依文,「應用於質子交換膜燃料電池陰極端之奈米碳管支撐鉑鎳二元觸媒對於氧氣還原之效能研究」,清華大學工程與系統科學系,碩士論文,中華民國一O四年
[5] M. S. Wilson, J. A. Valerio, and S. Gottesfeld, "Low Platinum Loading Electrodes for Polymer Electrolyte Fuel-Cells Fabricated Using Thermoplastic Ionomers," Electrochimica Acta, vol. 40, pp. 355-363, Feb 1995
[6] FuelCellsEtc, httpss://fuelcellsetc.com/store/DS/nafion-comparison-chart.pdf
[7] Allen Hermanna, Tapas Chaudhuria, Priscila Spagnolb, “Bipolar plates for PEM fuel cells: A review”, International Journal of Hydrogen Energy vol. 30, pp. 1297 – 1302, 2005
[8] Frano Barbir, "PEM Fuel Cells: Theory and Practice,"Elsevier. 46, pp. 117-135, Jul 2002.
[9] Jitendra N. Tiwari, Rajanish N. Tiwari, Gyan Singh, Kwang S. Kim, "Recent progress in the development of anode and cathode catalysts for direct methanol fuel cells", Nano Energy, vol. 2, pp.553–578, 2013
[10] M. Naraghi, Carbon Nanotubes - Growth and Applications, InTech, 2011
[11] J. Larminie and A. Dicks, Fuel cell systems explained, 2nd ed. Chichester, West Sussex: J. Wiley, 2003
[12] M. C. Tsai, T. K. Yeh, and C. H. Tsai, "An improved electrodeposition technique for preparing platinum and platinum-ruthenium nanoparticles on carbon nanotubes directly grown on carbon cloth for methanol oxidation", Electrochemistry Communications, vol. 8, pp. 1445-1452, Sep 2006.
[13] Irene J.Hsu, Daniel V.Esposito, Elizabeth G.Mahoney, “Particle shape control using pulse electrodeposition: Methanol oxidation as a probe reaction on Pt dendrites and cubes”, Journal of Power Sources, vol. 196, pp.8307-8312, Oct 2011.
[14] J. Lee, "Morphological features of electrodeposited Pt nanoparticles and its application as anode catalysts in polymer electrolyte formic acid fuel cells", Journal of Power Sources, vol. 195, pp. 5929–5933, Sep 15 2010.
[15] Wang J., Analytical Electrochemistry, 2nd Edition, New York, 2000.
[16] 郭豔如,「可拋棄式奈米白金碳墨修飾電極電化學偵測之研究」, 國立交通大學應用化學系, 碩士論文, 2009
[17] Department of Chemical Engineering and Biotechnology, University of Cambridge, http://www.ceb.cam.ac.uk/research/groups/rg-eme/teaching-notes/linear-sweep-and-cyclic-voltametry-the-principles
[18] 陳柏璋,「脈衝式電鍍法製備之新穎奈米結構鉑觸媒應用於高效能質子交換膜燃料電池」,清華大學工程與系統科學系,碩士論文,中華民國一O五年
[19] 莊宸綱,「利用邁衝式電鍍法製備高燃料氧化效能及抗一氧化碳毒化之新穎奈米結構鉑觸媒」,清大工程與系統科學系,碩士論文,中華民國一○三年
[20] Geochemical Instrumentation and Analysis, http://serc.carleton.edu/research_education/geochemsheets/BraggsLaw.html
[21] 李珠,「感應耦合電漿質譜儀技術及其在材料分析上的應用」,工業材料雜誌 181 期,2002
[22] H. I. Lee, C. H. Lee, T. Y. Oh, S. G. Choi, I. W. Park, and K. K. Baek, "Development of 1 kW class polymer electrolyte membrane fuel cell power generation system," Journal of Power Sources, vol. 107, pp. 110-119, Apr 20 2002
[23] Florida Solar Energy Center, Procedure for Performing PEM Single Cell Testing, 2009.