臺灣博碩士論文加值系統

使用清淨能源可以減輕大量空氣污染物及CO2之排放，而燃料電池是清淨能源的載具，但因其有壽命及效能的限制，仍會成為需要處理之廢棄物，其廢電極中含有貴稀金屬，值得回收再利用。因此本研究乃以燃料電池廢電極貴金屬回收為標的，使用人工回收液進行初步試驗，探討不同鉑塩、濃度、pH及陰離子等條件下回收液之電化學特性及電解結果，以做為應用於實際程序之參考。
結果顯示：1~10 mM Pt濃度樣品之H2PtCl6溶液中，以CV掃瞄時，其Pt錯離子氧化及還原峰峰電流及電沉積Pt電化學活性面積隨Pt濃度之增加而增加，而在相同Pt濃度之K2PtCl6溶液中，其掃瞄結果相似。以LSV掃瞄時，10 mM Pt之H2PtCl6溶液於-0.4 V~-0.3 V (vs. Ag/AgCl)電位間達極限電流，而相同Pt濃度之K2PtCl6溶液則於-0.5 V~-0.2 V (vs. Ag/AgCl)電位間達極限電流；H2PtCl6溶液中CV掃瞄之Pt錯離子氧化及還原峰峰電流及電沉積Pt電化學活性面積隨添加Cl-濃度之增加而減少，而添加NO3-時，則無此現象。於LSV掃瞄時，其Pt錯離子還原峰電位位移則隨添加Cl-濃度之增加而減少，而添加NO3-時，則無此現象；10 mM Pt之H2PtCl6與K2PtCl6溶液於定電位-0.5 V下電解180 min後，其Pt濃度(C)分別降至原濃度(Co)之0.47及0.64； 10 mM Pt之H2PtCl6與K2PtCl6溶液於定電流(0.1 A)下電解180 min後，Pt之C/Co均約降至0.09，而其穩定之系統電位均約為5 V。

關鍵字：燃料電池、廢電極、鉑貴稀金屬、電化學特性

The use of cleaner energy may allivate the considerable emission of air pollutants and CO2. The cleaner energy can be used as fuels for fuel cells. However, the fuel cells, due to aging/decay after use, will become wastes that need to be treated. The spent fuel cell electrodes contain precious metals deserved to be recycled/reused.
In this study, therefore, preliminary tests were conducted to recover the precious metals in spent fuel cell electrodes. Electrochemical analyses and electrolytic experiments were performed for the platinum chloride solutions with different Pt salts, Pt concentrations, pHs, and anions.
Results show that the redox peak currents of Pt chloride complexes and the electroactive areas of electro-deposited Pt increased with the increase of Pt concentrations (1–10 mM) in H2PtCl6 solutions after cyclic voltammetry (CV) scans. Similar results were found for the K2PtCl6 solutions with similar Pt concentrations. The 10 mM-Pt H2PtCl6 and K2PtCl6 solutions exhibited limiting currents around the potentials of -0.4 – -0.3 V and -0.5 – -0.2 V, respectively. The redox peak currents of Pt chloride complexes and the electroactive areas of deposited Pt decreased with increasing Cl- addition in H2PtCl6 solutions but this phenomenon was not found for the similar solutions with NO3- addition; moreover, similar results were found for the peak potential shift of Pt complex redox peaks for the Pt chloride solutions with the Cl- and NO3- addition in linear scan voltammetry (LSV) tests. For the constant potential (-0.5 V) electrolysis, the 10 mM H2PtCl6 and K2PtCl6 solutions displayed C/Co (Pt concentration with time/initial Pt concentration) values of 0.47 and 0.64, respectively at 180 min whereas for the constsnt current (0.1 A) electrolysis, the C/Co values of both the solutions reached about 0.09 with similar stable cell potentials around 5 V.

Keywords: Fuel cells , Spent electrodes , Noble/precious metals ,
Electrochemical characteristics

目錄
摘要....................................................................................................................I
Abstract...........................................................................................................III
誌謝..................................................................................................................V
目錄.................................................................................................................VI
表目錄.............................................................................................................XI
圖目錄...........................................................................................................XII
第1章 前言.....................................................................................................1
1.1 研究縁起..............................................................................................1
1.2 研究目的..............................................................................................1
第2章 文獻回顧.............................................................................................3
2.1 燃料電池的特性與介紹......................................................................3
2.2 貴金屬回收再生..................................................................................4
2.3 貴金屬之定義及特性..........................................................................4
2.4 回收貴重金屬之技術..........................................................................5
2.4.1 冶煉方法.......................................................................................5
2.4.1.1 結晶法..................................................................................5
2.4.1.2 電解回收法..........................................................................5
2.5 Pt還原的可能電化學反應................................................................5
2.6 循環伏安法掃瞄(Cyclic Voltammetry , CV)介紹.............................6
2.7 Pt錯離子化合物................................................................................6
第3章 材料與方法.........................................................................................7
3.1 實驗原理..............................................................................................7
3.2 實驗流程..............................................................................................8
3.3 實驗設備與實驗設置圖......................................................................9
3.3.1 實驗設備.......................................................................................9
3.3.2 電化學分析儀之實驗示意圖.......................................................9
3.4 實驗藥品............................................................................................10
3.5 溶液之製備........................................................................................11
3.5.1 H2PtCl6溶液….............................................................................11
3.5.1.1 曝氮氣與未曝氮氣..........................................................11
3.5.1.2 濃度..................................................................................11
3.5.1.3 pH.....................................................................................11
3.5.1.4 添加陰離子之溶液..........................................................11
3.5.1.4.1 陰離子Cl- 添加.......................................................11
3.5.1.4.2 陰離子NO3- 添加...................................................11
3.5.2 K2PtCl6溶液(濃度).......................................................................11
3.6 實驗條件............................................................................................12
3.7 實驗步驟............................................................................................12
3.7.1 CV掃描…....................................................................................12
3.7.2 LSV掃描......................................................................................12
3.7.3 電化學分析儀定電位電解.........................................................12
3.7.4 電化學分析儀定電流電解.........................................................13
3.7.5 電源供應器(DC Power Supply)定電流電解…….....................13
第4章 結果與討論.......................................................................................14
4.1 曝氮氣與未曝氮氣對CV之影響.....................................................14
4.2 不同鉑塩溶液之CV掃描.................................................................18
4.2.1 H2PtCl6溶液.................................................................................18
4.2.1.1 Pt濃度對PtCl62-於石墨電極上電化學
特性之影響(CV掃描)........................................................18
4.2.1.2 Pt濃度對PtCl62-於石墨電極上電化學
特性之影響(LSV掃描)......................................................20
4.2.1.3 pH對PtCl62-於石墨電極上電化學
特性之影響(CV掃描)........................................................22
4.2.1.4 pH對PtCl62-於石墨電極上電化學
特性之影響(LSV掃描)......................................................24
4.2.1.5 陰離子對PtCl62-於石墨電極上電化學
特性之影響…….................................................................26
4.2.1.5.1 Cl-對PtCl62-於石墨電極上電化學
特性之影響(CV掃描)..............................................26
4.2.1.5.2 Cl-對PtCl62-於石墨電極上電化學
特性之影響(LSV掃描)…........................................29
4.2.1.5.3 NO3-對PtCl62-於石墨電極上電化學
特性之影響(CV掃描)..............................................31
4.2.1.5.4 NO3-對PtCl62-於石墨電極上電化學
特性之影響(LSV掃描)............................................33
4.2.2 K2PtCl6溶液.................................................................................35
4.2.2.1 Pt濃度對PtCl62-於石墨電極上電化學
特性之影響(CV掃描)........................................................35
4.2.2.2 Pt濃度對PtCl62-於石墨電極上電化學
特性之影響(LSV掃描)......................................................37
4.3 不同鉑塩溶液於定電位下之電解曲線............................................39
4.3.1 H2PtCl6溶液.................................................................................39
4.3.1.1定電位圖..............................................................................39
4.3.1.2溶液中Pt濃度下降曲線....................................................40
4.3.2 K2PtCl6溶液.................................................................................40
4.3.2.1定電位圖..............................................................................40
4.3.2.2溶液中Pt濃度下降曲線.....................................................41
4.4 不同鉑塩溶液於定電流下之電解曲線............................................42
4.4.1 H2PtCl6溶液.................................................................................42
4.4.1.1溶液中Pt濃度下降曲線.....................................................42
4.4.1.2系統與陰陽極電位變化......................................................43
4.4.2 K2PtCl6溶液.................................................................................44
4.4.2.1溶液中Pt濃度下降曲線.....................................................44
4.4.2.2系統與陰陽極電位變化......................................................44
第5章 結論與建議.......................................................................................46
5.1 結論....................................................................................................46
5.2 建議....................................................................................................47
參考文獻.........................................................................................................48
作者簡介.........................................................................................................51



表目錄
表2-1可能的電化學反應及標準電極電位(E0)..............................................6
表3-1本研究所使用之儀器設備及出廠廠商.................................................9
表3-2本研究所使用之藥品規格及供應商...................................................10






























圖目錄
圖 3-1 工作電極為Pt電極時的標準電流電位圖..........................................7
圖 3-2 實驗流程圖..........................................................................................8
圖 3-3 電化學分析儀之實驗示意圖............................................................10
圖 4-1 未曝氣(0.5 M H2SO4中, Pt工作電極)..............................................14
圖 4-2 未曝氣(Pt工作電極)..........................................................................15
圖 4-3 未曝氣與曝氣CV之比較(1 mM Pt in H2SO4, Pt工作電極)….......16
圖 4-4 未曝氣與曝氣CV之比較(2 mM Pt in H2SO4, Pt工作電極)….......17
圖 4-5 0.5 M H2SO4中(石墨工作電極)........................................................18
圖 4-6 不同H2PtCl6濃度溶液之CV圖(石墨工作電極)…………………..19
圖 4-7 圖4-6 CV掃描後，相同石墨電極於0.5 M H2SO4中
之CV圖…………………………...…………...………………...….20
圖 4-8 不同H2PtCl6濃度溶液之LSV圖(石墨工作電極)……..………......21
圖 4-9 圖4-8 LSV掃描後，相同石墨電極於0.5 M H2SO4中
之CV圖..............................................................................................22
圖 4-10 不同pH溶液之CV圖(6.4 mM Pt,石墨工作電極)………………...23
圖 4-11 圖4-10 CV掃描後，相同石墨電極於0.5 M H2SO4中
之CV圖..............................................................................................24
圖 4-12 不同pH溶液之LSV圖(6.4 mM Pt,石墨工作電極)……...….....….25
圖 4-13 圖4-12 LSV掃描後，相同石墨電極於0.5 M H2SO4中
之CV圖..............................................................................................26
圖 4-14 添加不同Cl-濃度溶液之CV圖
(4.825 mM Pt,石墨工作電極)………..…………………...………...27
圖 4-15 圖4-14局部放大圖............................................................................28
圖 4-16 圖4-14 CV掃描後，相同石墨電極於0.5 M H2SO4中
之CV 圖............................................................................................29
圖 4-17 添加不同Cl-濃度溶液之LSV圖
(4.825 mM Pt,石墨工作電極)............................................................30
圖 4-18 圖4-17 LSV掃描後，相同石墨電極於0.5 M H2SO4中
之CV圖..............................................................................................31
圖 4-19 添加不同NO3- 濃度溶液之CV圖
(4.825 mM Pt,石墨工作電極)............................................................32
圖 4-20 圖4-19 CV掃描後，相同石墨電極於0.5 M H2SO4中
之CV圖..............................................................................................33
圖 4-21 添加不同NO3- 濃度溶液之LSV圖
(4.825 mM Pt,石墨工作電極)............................................................34
圖 4-22 圖4-21 LSV掃描後，相同石墨電極於0.5 M H2SO4中
之CV圖..............................................................................................35
圖 4-23 不同K2PtCl6濃度溶液之CV圖(石墨工作電極)..............................36
圖 4-24 圖4-23 CV掃描後，相同石墨電極於0.5 M H2SO4中
之CV圖..............................................................................................37
圖 4-25 不同K2PtCl6濃度溶液之LSV圖(石墨工作電極)…………...….....38
圖 4-26 圖4-25 LSV掃描後，相同石墨電極於0.5 M H2SO4中
之CV圖..............................................................................................39
圖 4-27 H2PtCl6溶液之定電位圖(石墨工作電極).........................................40
圖 4-28 K2PtCl6溶液之定電位圖(石墨工作電極).........................................41
圖 4-29 10 mM H2PtCl6與K2PtCl6溶液之電解曲線
(定電位 -0.5 V vs. Ag/AgCl，石墨工作電極)………………..…....42
圖 4-30 10 mM H2PtCl6與K2PtCl6溶液之電解曲線
(定電流 0.1 A vs. Ag/AgCl，石墨工作電極)....................................43
圖 4-31 10 mM H2PtCl6溶液之系統與陰陽極電位變化圖
(定電位 0.1 A vs. Ag/AgCl，石墨工作電極)....................................44
圖 4-32 10 mM K2PtCl6溶液之系統與陰陽極電位變化圖
(定電位 0.1 A vs. Ag/AgCl，石墨工作電極)………………...….…45

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