發(fā)布時間：2018-02-04 23:49

  本文關(guān)鍵詞： 陰離子膜燃料電池 非貴金屬陰極催化劑 氧還原反應(yīng)　出處：《大連海事大學(xué)》2016年碩士論文　論文類型：學(xué)位論文

【摘要】：以堿性陰離子膜為電解質(zhì)的陰離子膜燃料電池(AEMFC)不僅能提高氧還原反應(yīng)(oxygen reduction reaction,ORR)動力學(xué),而且可以使用非貴金屬陰極催化劑,從而大大降低制造成本,在燃料電池的商業(yè)化進程中更具有競爭力。作為關(guān)鍵部件之一的ORR催化劑,其性能優(yōu)劣直接關(guān)系電池輸出性能的好壞,開發(fā)新型、低成本的ORR催化劑,對推動AEMFC的發(fā)展具有重要的理論和實際意義。本文以淀粉為碳源,納米氧化鐵和氧化鎳為活性中心,通過高熱解法制備了Fe/C、Ni/C、FeNi/C催化劑。高分辨率的透射電鏡證實,三種催化劑均具有核殼結(jié)構(gòu),殼為片層石墨層,核為金屬納米顆粒。Fe納米顆粒的粒徑約為25 nm,而Ni顆粒與合金顆粒直徑分別為幾十納米到幾百納米不等,三種催化劑均對02表現(xiàn)出催化活性。當(dāng)熱解溫度為800℃、保溫時間4 h時,控制淀粉與鐵、鎳的質(zhì)量比分別為:100:5(淀粉/鐵)、50:1(淀粉/鎳)和100:2:3(淀粉/鐵/鎳)可分別制備出具有最優(yōu)催化活性的Fe/C、Ni/C、FeNi/C催化劑。催化劑的最大比表面積為:373 m2·g-1。在最優(yōu)條件下制備的三種催化劑在-0.6V時氧還原反應(yīng)的極化電流密度分別達到0.799 mA,cm-2、0.89 mA·cm-2、1.266 mA·cm-2,對ORR的催化活性順序為:FeNi/CNi/CFe/C。與Fe/C與Ni/C相比,FeNi/C的ORR催化活性分別提高了58.4%、42.2%。在三種催化劑上,ORR的電子轉(zhuǎn)移數(shù)分別為:2.29、2.83、3.26,表明氧還原反應(yīng)同時存在2電子和4電子過程。三種催化劑經(jīng)過500次的循環(huán)伏安測試后,性能未出現(xiàn)衰減,均表現(xiàn)出良好的穩(wěn)定性。
[Abstract]:The anion membrane fuel cell with alkaline anion membrane as electrolyte can not only increase oxygen reduction reaction, but also improve oxygen reduction reaction. ORR) kinetics, and the use of non-noble metal cathode catalysts can greatly reduce manufacturing costs and become more competitive in the commercialization process of fuel cells. As one of the key components, ORR catalyst. Its performance is directly related to the output performance of the battery. The development of new low-cost ORR catalyst has important theoretical and practical significance to promote the development of AEMFC. In this paper, starch is used as carbon source. Fe / C / Ni / Ni / Fe / Ni / C catalysts were prepared by high pyrolysis of nano-ferric oxide and nickel oxide as active centers. The results of high resolution transmission electron microscopy show that the three catalysts have core-shell structure. The shell is a lamellar graphite layer, the core is metal nanoparticles. Fe nanoparticles are about 25 nm in diameter, while Ni particles and alloy particles have diameters ranging from tens to hundreds of nanometers. When the pyrolysis temperature is 800 鈩，

本文編號：1491505