應用於質子交換膜燃料電池陰極端之奈米碳管支撐鉑鎳二元觸媒對於氧氣還原之效能研究

Efficiency of Carbon-Nanotube-Supported Pt-Ni Binary Catalysts on Oxygen Reduction Reaction at the Cathode of a Proton Exchange Membrane Fuel Cell

李依文(Lee, Yi Wen)

指導教授 ： 葉宗洸

國立清華大學/原子科學院/工程與系統科學系/碩士(2015年)

摘要

本研究於奈米碳管上製備PtNi二元觸媒並應用於質子交換膜燃料電池中之陰極。奈米碳管是藉由化學氣相沉積法直接成長於碳布上以增加電極表面積，經由親水處理後，先以脈衝式電鍍法於奈米碳管上沉積金屬鎳顆粒，而後將試片浸於攝氏80度含有氯鉑酸及乙二醇之溶液中沉積鉑奈米顆粒；純鉑之單元觸媒亦會製備做為對照組。
測試方面，經由循環伏安法於0.1 M過氯酸溶液中進行電化學測試，並利用X光粉末繞射儀(XRD)、掃描式電子顯微鏡(SEM)、穿透式電子顯微鏡(TEM)以及電感耦合等離子體質譜(ICP-MS)對試片做進一步的分析。經由TEM觀測發現觸媒形貌為5 nm之Pt顆粒包覆在50 nm之Ni顆粒上。透過電化學結果顯示，PtNi二元觸媒較Pt單元觸媒活性高，並反應在CV及LSV之測試曲線中，包含CV氫氧吸脫附區域及LSV測得的反應起始電位及電流密度大小，都顯示Ni的存在確實優化觸媒之催化效果。
半電池立體化成全電池時三相介面為重要考量，於自製陰極電極噴塗0.8 mg/cm2 Nafion與商用觸媒作組裝再經由氫氣單電池測試，此效率表現最佳，功率密度可達611 mW/cm2，比商用觸媒之329 mW/cm2高出許多，顯示出透過本研究手法製備之PtNi電極其催化效果優良。

關鍵字

鉑 ； 鎳 ； 二元觸媒 ； 氧氣還原反應 ； 質子交換膜燃料電池

並列摘要

In this study, Pt-Ni binary alloy catalysts supported on carbon nanotubes (PtNi/CNTs) were developed for enhancing the oxygen reduction reaction (ORR) efficiency for proton exchange membrane fuel cell (PEMFC) application. The CNTs were directly grown on carbon cloths by chemical vapor deposition method and then treated with hydrophilic process. The nickel nanoparticles were deposited on CNTs by pulse electro-planting, and then the platinum particles were reduced on them in a chloroplatinic acid solution containing platinum precursor and ethylene glycol at 80 ℃ for different hours. The sample with Pt/CNTs was also prepared for comparison. Electrochemical characteristics of the PtNi/CNTs catalyst were investigated via cyclic voltammetry analysis and rotating disk electrode test in 0.1 M perchloric acid. Structure and elementary composition were measured by SEM, EDX and ICP-MS. In ORR test, it was found that the limiting current density and onset potential of PtNi/CNTs specimen were better than those of Pt/CNTs specimen. The outcome signified better PtNi binary catalysts in adsorption and desorption behavior of oxygen to increase the ORR rate.

並列關鍵字

Platinum ； Nickel ； Binary Catalyst ； ORR ； PEMFC

參考文獻

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