白金微粒/Ru錯合物/高分子薄磨修飾電極之製備及其電催化應用

孫禮成(Li-Chen Sun)

指導教授 ： 林如章博士

國立臺灣師範大學/理學院/化學系/碩士(1999年)

摘要

薄膜-金屬修飾電極常用於燃料電池、光電池…等薄膜電池，其中還原端的金屬部分多為鉑等對酸的氫析出有良好的催化效應的物種，基於此，本實驗嘗試在薄膜與金屬間再分別加入數種錯合物，利用它們優良的電子傳遞特性建立暢通的電子傳遞體系，期望能有優於雙金屬微粒電極的表現。
分別以不同種的Ru系列錯合物與Nafion混合後塗佈於玻璃化碳電極（GC）上製成薄膜，待乾燥後於H2PtCl6金屬鹽類水溶液，經脈衝電解（DPTB）後，可得數種不同的薄膜-金屬修飾電極，同時，當Ru系列錯合物混入Nafion的不同濃度，可以得到不同的鉑電析數量，利用此一特性可以找出用去較少的鉑，而能得到較高的真實面積。
利用掃瞄式電子顯微鏡（SEM）測量出金屬微粒的粒徑及分佈狀態以及鉑的電析位置，並利用能量發散光譜儀（EDS）測微粒之金屬成份，雷射半生儀、螢光儀測出Ru系列錯合物與鉑之間的通路確實良好，能夠有效率地將酸還原成氫，同時，在同樣製備過程未用Ru系列錯合物修飾的薄膜-金屬修飾電極之真實面積也不如使用Ru系列錯合物修飾的薄膜-金屬修飾電極來得大，同時此一修飾電極，有非常長的連續使用效果，連續一個月的穩定測試之後，效果依然穩定。

關鍵字

薄膜-金屬修飾電極 ； 氫析出 ； 電子傳遞 ； 釕錯合物

並列摘要

Membrane-metal modified cells are usually applied to the field of membrane cells, such as fuel cells, light cells… etc. Some hydrogen evolution catalysts, for example Pt metal, are used as the cathodes in these cells. Therefore, in this research, we try to dose a series of Ru complexes into the intervals between the cathode and the thin film electrode to improve the hydrogen evolution efficiency of the membrane-metal modified cells.
Ru complex (chosen from Ru(bpy)2phenNH2, Ru(dmb)2 phenNH2, Ru(tmb)2phenNH2, Ru(bpy)2Cl2, Ru(dmb)2Cl2, Ru(tmb)2Cl2) doped Nafion solution was drop-coated onto glassy carbon (GC) electrode and formed a thin film after drying. Then, the GC electrode was immersed into H2PtCl6 solution, and the Pt/Ru complex/polymer modified electrode was obtained by reducing Pt with a DPTB method. Different amount of Pt was electroplated on the GC electrode even at the same conditions (the same potential, the same time interval) when different consistency or kinds of Ru complexes were used, suggesting the influence of the ligands on the red-ox property of Ru complexes. The effective surface area (estimated by CV method) of Pt in the modified electrode is also varied with different species of Ru complexes, which in turn affect on the efficiency of hydrogen evolution.
Furthermore, from the information obtained by SEM and EDS, the alignment and the density of Pt particles growing on the GC electrode are figured out. From the fluorescence lifetime and luminescence spectra, a good electron-transfer is considered to have occurred between D series Ru complexes and Pt modified electrode that explained why a high hydrogen evolution efficiency has been obtained. The modified electrodes are still stable one month after fabricated and their hydrogen evolution efficiency was as good as a newly prepared one.

並列關鍵字

membrane-metal modified electrode ； hydrogen evolution ； electrotransfer ； Ru-complex

參考文獻

4. P.R.Moses, L.Wier, R.W.Murray, Anal. Chem., 1975, 47, 1882.

8. Q.Chini, J.Zhang, S.Dong, E.Wang, Electrochimica Acta. ,1994, 39, 2431.

13.J.Wang, H.Wu, J.Electroanal.Chem.,1995,395,287

17.Kiwi. J, “The effect of polymers on dispersion properties”; Tadros,Th.F.,Ed.,Academic Press: London,1982.

22.P.OCON ESTEBAN*, J.-M.LEGER, C.LAMY, JOURNAL OF APPLIED ELECTROCHEMISTRY, 1989, 19,462.