質子交換膜燃料電池的觸媒層合成組裝與特性

Catalyst synthesis, assembly and characterization of proton-exchange-membrane fuel cells

張益哲(Yi-Che Chang)

指導教授 ： 汪治平

共同指導教授 ： 陳賜原(Szu-Yuan Chen)

國立臺灣大學/理學院/物理研究所/碩士(2013年)

https://doi.org/10.6342/NTU.2013.02201

摘要

隨著石化能源的大量開採，衍生出能源短缺與環境污染的隱憂，因此能源工程及環境保護關係著二十一世紀人類文明的發展。是否能由現行以石化燃料為基礎的碳能循環，逐步朝向氫能循環發展，燃料電池扮演著關鍵角色，且可能成為二十一世紀的重要能源裝置。在這論文裡，主要是在記錄如何製作燃料電池以及建立電池效能的檢測系統；其中還包括製作過程中可能遭遇的問題，以及如何對其檢測與找出可能的解決方法。
首先我們建立了一套負載為75 W的全電池測試系統，並建立了一套燃料電池封裝與測試的標準作業程序。我們所製作的燃料電池，乃以氫氣與氧氣為反應氣體的質子交換膜燃料電池組，主要的發電機制來自於常被稱為是燃料電池心臟的膜電極組（Membrane Electrode Assembly，MEA）。膜電極組為五層結構，其中心是傳導氫離子的質子交換膜，兩旁各為陽極觸媒層及陰極觸媒層，最外層是燃料氣體擴散層及氧氣擴散層。因觸媒層需考慮其高穩定度以及高活性，所以最常見的材料是使用鉑（Pt），並以奈米顆粒的形式附著於碳載體上（Pt/C）。Pt/C與Nafion溶液以及去離子水混合配製成漿料，塗佈於氣體擴散層上，與氣體擴散層及交換膜熱壓製成膜電極組。實驗中所使用觸媒包含商用Pt/C以及自製合成的Pt/C。實驗結果顯示，由自製的觸媒層所製成的燃料電池，其單位觸媒重量所產生的功率（5.4 mW/μg），與使用商用觸媒層的結果相近。由此可證明，自製的觸媒層效能可媲美商用觸媒層。然而，在這些製作與分析的過程中，我們同時也遭遇到許多問題，其中最主要問題是觸媒（鉑）的含量過低。在接下來的論文裡，我們會針對這些問題做詳細的分析與討論。

關鍵字

燃料電池 ； 質子交換膜 ； 觸媒層 ； 鉑 ； 膜電極組 ； 濕化學 ； Nafion溶液

並列摘要

Owing to the bulk mining of fossil fuel, worries about the shortage of energy and environmental pollution has gradually revealed since energy engineering and environment protection are closely related to the development of human civilization in the 21st century. From the carbon cycle that mainly depends on fossil fuels, we are devoted to develop hydrogen cycle now. While developing hydrogen cycle, fuel cell plays a significant role and may become one of the most important energy installation in the 21st century. In this thesis, the main contents focus on recording how to manufacture fuel cells and establishing a detection system that could monitor the efficacy of the fuel cell. The problems that may encounter in the manufacturing processes as well as how to detect the fuel cells and find possible solutions to problems are also parts of the contents in this thesis.
First, we build up a set of the whole fuel cell detection system with load of 75 W and set up standard operation procedures (SOP) for assembling and examination of fuel cells. We manufacture fuel cells that use hydrogen and oxygen as reaction gases to serve as a proton exchange membrane fuel cell. The mechanism for generating electricity mainly depends on the membrane electrode assembly (MEA), which is also called the heart of fuel cell. The MEA itself is a 5-layered structure that with membrane that could conduct protons in the center position and anode catalyst layer and cathode catalyst layer on the two sides. The outermost layer is the layer for gas diffusion (GDL). Considering the high stability and activity requirement, platinum is the most common material for catalyst and usually is attached to the carbon supplier with the form of nanoparticles (Pt/C). We mix Pt/C, Nafion solution, and water to produce the slurry to coat on the surface of gas diffusion layer and heat press the coated gas diffusion layer (GDL) and membrane together to produce MEA. The
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catalysts used in the experiments include commercial Pt/C and Pt/C produced and synthesized by ourselves. The experiment results indicate that the fuel cell that uses catalysts produced by ourselves yields similar output power per unit weight of catalyst while comparing with commercial catalyst layer. This result shows that the catalysts produced by ourselves are as efficient as commercial catalysts. Nevertheless, while undergoing manufactures and analyses, we also simultaneously encountered many problems. The main problem is that the content of platinum is too low in the catalyst. In the thesis, we would provide detailed analysis and discussion about these problems.

並列關鍵字

fuel cell ； proton exchange membrane ； catalyst layer ； platinum ； membrane electrode assembly ； wet chemistry ； Nafion solution

參考文獻

[4] 衣寶蓮, “燃料電池－原理與應用”, 2007.

[8] 蔡秉蒼, “應用金屬 發泡材為流道之質子交換膜燃料電池之研究”, 中央機械, (2012)

[25] 郭清癸, 黃俊傑, 牟中原, “金屬奈米粒子的製造”, 物理雙月刊（廿三卷六期）2001年12月.

[5] Yun Wang et al., “A review of polymer electrolyte membrane fuel cells: Technology, applications, and needs on fundamental research” , Applied Energy 88 (2011) 981–1007.

[6] Yunfeng Zhai, “The stability of Pt/C catalyst in H3PO4/PBI PEMFC during high temperature life test”, J. Power Sources (2007) 164, 126–133.