氯鉑釕酸廢液之貴金屬電解回收研究

Electrolytic recovery of noble metals from acidic platinum and ruthenium chlorides wasteliquid

邱建文(Chien-Wen Chiu)

指導教授 ： 黃進益

國立臺北科技大學/工程學院/化學工程研究所/碩士(2008年)

摘要

在石化能源短缺的今日，直接甲醇燃料電池(DMFC)的研究與發展日形重要，然而所使用的鉑和釕(Pt-Ru)貴金屬觸媒，因鉑和釕價格昂貴，成為燃料電池的發展之關鍵。使用過後之電池觸媒與電鍍廢液，若能加以回收再利用，可節省電池成本。
本研究係以所內實驗室過去所使用的氯鉑釕酸電鍍廢液作為電解回收的來源，內含鉑濃度約為1900ppm，釕濃度約為1800ppm，其pH=0.7；廢液先以伏安法(voltammetric method)分析，分別以鉑和碳布為工作電極，使用銀/氯化銀為參考電極，鉑為輔助電極，掃描電位範圍為1.0至-0.1V，以掃描速率為0.05V/s進行掃描，發現在電位0.6~0.4V，有一鉑釕還原波峰，其反應分別為 、 ，在25℃下，通入氮氣的情況，波峰電流會上升，溫度上升到70℃時，其波峰電流最為顯著；在超音波震盪的情形下，波峰電流也會有提升；接著將電化學反應置於超音波震盪(46KHz)進行定電位電解回收，在室溫25℃下，定電位進行實驗，以AA記錄其廢液濃度變化，並以掃描式電子顯微鏡(SEM)和X光繞色分析儀(XRD)觀察分析其回收沉積表面型態及組成，在有震盪的情況下其回收率會比較好，電解5小時後，其鉑的回收率達91.1%，釕的回收率達67.5%。

關鍵字

鉑 ； 釕 ； 電解回收

並列摘要

In the situation of fossil fuel shortage, the direct methanol fuel cell (DMFC) was day after day more important. However the fuel cell is uses platinum and ruthenium metals catalyst as the cell core. Since the platinum and the ruthenium prices are expensive, therefore the DMFC is unable to be popular for use. If the used catalyst and wasteliquid of the fuel cell could be recovered, the cell cost might be reduced and could reach the recycling use.
In this study used the wasteliquid from our laboratory the platinum concentration was 1900ppm, the ruthenium concentration was 1800ppm, the pH value was 0.7. At first, use the voltammetric method was used to analyze the solutions. The Pt and Ag/AgCl electrode were used as the working, counter, and reference electrodes, respectively. The scan rate was 0.05V/s, the scan potential was 1.0~-0.1V. A reduction peak in the range of 0.4 to 0.6V was found. The reduction reaction of platinum and ruthenium was and . When temperature increased to 70℃, the reduction peak increased obviously. When the solution temperature was 25℃, using aeration and ultrasound agitation(46kHz) ,and the reduction peak would raise. Further using the platinum electrode to recover platinum and ruthenium from wasteliquid by potentiostat method, control potential and we measure the concentration by atomic absorption spectrometry (AA) and scan the surface of cladding material by scanning electronic microscope (SEM) and X-ray diffraction (XRD). It could recovery 91.1% platinum and 67.5% ruthenium in 300 min.

並列關鍵字

platinum ； ruthenium ； electrolytic recovery

參考文獻

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