本研究透過濕式化學還原法，以硼氫化鈉當作還原劑，依序將鈷(Co)、鈀(Pd)與鉑(Pt)金屬離子還原至酸化奈米碳管(CNT)上，形成鈷核鈀殼層疊結構，表面修飾三角形排列鉑原子團的三元金屬奈米顆粒，作為鹼性燃料電池陰極觸媒材料。與20wt%商業用鉑奈米觸媒相比，本研究製備的觸媒貴金屬含量低，鉑金屬負載量降低至1.2~13wt%；具有高氧氣還原反應活性，氧氣還原反應電流強度提高10倍，質量電流密度提高了30倍；以及高穩定性與絕佳耐久度，可以連續工作8個月，超過32萬次的電壓循環壽命，效率沒有衰退，也無發生降解現象。
　　本研究分為三個部分，探究不同的觸媒製備方法對於其結構與活性之關聯：第一為改變鉑的使用量，探討不同的鉑含量團簇的分散性與顆粒大小對於奈米晶體成長方式以及氧氣還原反應的活性影響；第二為調整鉑還原的時間，探討鉑在鈷核鈀殼粒子表面或內部對於氧氣還原反應的活性與觸媒結構影響，並了解鉑在其粒子上的成長模式；第三為控制鉑還原的溫度，探討反應動力學對於奈米粒子成長的影響，分析還原溫度對於氧氣還原反應活性與穩定性的影響。
　　本研究製備出的鉑原子團修飾鈷核鈀殼結構三元金屬奈米觸媒，藉由調整鉑含量、鉑還原時間、鉑還原溫度，確定不同鉑金屬結構的變化與觸媒氧氣還原反應活性的關聯性，有效增加催化電流、提高穩定性與耐久度、降低鉑使用量與成本，為鹼性燃料電池奠立新的里程碑。

Nanocatalysts with cobalt-palladium core-shell structures and surface decoration of atomic scale platinum-trimer clusters are synthesized by using a self-aligned wet chemical reduction method in carbon nanotube supports for the use in alkaline fuel cell cathodes. The CoPdPt nanocatalyst contains a low platinum loading of only 2.4 wt% while a commercial platinum catalyst contains a platinum loading of 20 wt%. The mass activity of CoPdPt nanocatalyst has been increased to 30 times as compared to that of a commercial platinum catalyst. It shows an extraordinary stability and an outstanding durability in the accelerated degradation test (ADT) for over 320k potential cycles in an alkaline electrolyte without degradation, which is attributed to the decoration of atomic scale platinum-trimer clusters.
This study is divided into 3 parts. The structural characterizations and electrochemical analyses are compared with (1) different platinum loadings, (2) different platinum reduction time and (3) different platinum reduction temperature.
The results reveal that the high current density with substantial stability in the oxygen reduction reaction (ORR) is attributed to a strong electronic coupling and interface lattice that extract electrons from cobalt and palladium atoms in the presence of atomic platinum clusters in the palladium shell. These findings are expected to be useful for surface engineering and design of advanced fuel cell catalysts with atomic-scale platinum decoration.

摘要　　i
Abstract　　ii
誌謝　　iii
目錄　　iv
表目錄　　viii
圖目錄　　ix
第一章 緒論　　1
1.1 前言　　1
1.2 燃料電池歷史與簡介　　2
1.3 燃料電池種類與應用　　3
1.4 鹼性燃料電池簡介與原理　　5
1.5 燃料電池發展概況　　6
1.6 氧氣還原反應 (Oxygen Reduction Reaction, ORR)　　8
1.7 研究動機　　9
第二章 文獻回顧　　10
2.1 氧氣還原反應觸媒　　10
2.2 觸媒開發方向　　10
2.3 不同金屬觸媒對氧吸附能與氧氣還原反應的影響　　11
2.4 觸媒大小與形貌對於氧氣還原反應的影響　　12
2.5 配體效應 (Ligand Effect)　　14
2.6 晶格應變 (Lattice Strain)　　15
2.7 雙功能機制 (Bifunctional Mechanism)　　16
2.8 文獻回顧總結　　17
第三章 實驗方法　　18
3.1 實驗設計　　18
3.2 實驗流程　　19
3.2.1 觸媒製備　　20
3.2.2 電化學分析　　22
3.2.3 材料結構分析　　23
3.3 分析方法　　24
3.3.1 循環伏安法 (Cyclic Voltammetry, CV)　　24
3.3.2 線性掃描伏安法 (Linear Sweep Voltammetry, LSV)　　26
3.3.3 加速劣化測試 (Accelerated Degradation Test, ADT)　　28
3.3.4 高解析穿透式電子顯微鏡 (High Resolution Transmission Electron Microscope, HRTEM)　　29
3.3.5 X光繞射 (X-ray Diffraction, XRD)　　31
3.3.6 X光光電子能譜 (X-ray Photoelectron Spectroscopy, XPS)　　32
3.3.7 X光吸收光譜 (X-ray Absorption Spectroscopy, XAS)　　34
3.4 實驗分項　　37
第四章 結果與討論　　38
4.1 不同鉑金屬含量觸媒對氧氣還原活性的影響　　38
4.1.1 電化學分析　　39
4.1.2 高解析穿透式電子顯微鏡　　46
4.1.3 X光繞射　　47
4.1.4 X光光電子能譜　　49
4.1.5 X光吸收光譜　　51
4.1.6 總結　　52
4.2 不同鉑金屬還原時間觸媒對氧氣還原活性的影響　　53
4.2.1 電化學分析　　53
4.2.2 高解析穿透式電子顯微鏡　　55
4.2.3 X光繞射　　56
4.2.4 X光光電子能譜　　57
4.2.5 X光吸收光譜　　58
4.2.6 總結　　60
4.3 不同鉑金屬還原溫度觸媒對氧氣還原活性的影響　　61
4.3.1 電化學分析　　61
4.3.2 高解析穿透式電子顯微鏡　　63
4.3.3 X光繞射　　63
4.3.4 X光光電子能譜　　65
4.3.5 X光吸收光譜　　65
4.3.6 總結　　67
第五章 結論　　68
參考文獻　　69
附錄　　71

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