DBHFC阴极Pt-Ag-Co合金纳米催化剂的制备及电催化性能研究

发布时间：2018-02-13 08:45

  本文关键词： Pt-Ag-Co合金 阴极催化剂 双氧水 电化学还原 燃料电池　出处：《上海应用技术学院》2015年硕士论文　论文类型：学位论文

【摘要】：直接NaBH4/H2O2燃料电池(DBHFC)作为碱性燃料电池研究新方向,因其具有转换效率高、清洁无污染、高的质量比能量以及原料易于储存和运输,能应用于水下、太空等一些特殊环境等优点而备受关注。目前,在阳极催化剂研究相对成熟的条件下,科学研究者们主要致力于其阴极催化剂的研究。贵金属Pt作为阴极主要的催化剂因其资源有限,价格昂贵而在一定程度上限制了这类燃料电池在商业上的应用。因此,制备出能代替贵金属Pt又能对H2O2保持高催化活性的催化剂已经成为了最近研究的热点。本文主要采用浸渍-还原的方法制备了以碳粉VulcanXC-72为载体,不同还原反应时间(2h,3.5h,5h)和不同比例的Pt-Ag/C, Pt-Ag-Co/C催化剂,通过TEM.XRD对上述催化剂进行了表征。利用CHI660d电化学工作站分别在酸性(H2SO4)、碱性(NaOH)条件下对它们进行了不同温度(20℃,25℃,30℃,40℃),不同电解质浓度M (NaOH) =0.5M,1M,2M,3M以及不同反应物浓度M(H2O2)=0.03M,0.1M,0.15M,0.2M下的电化学性能测试。XRD,TEM结果表明：所制备的催化剂材料均为面心立方结构,催化剂颗粒能很好的分布在碳载体上,二元催化剂粒径在10nm左右,三元催化剂的粒径大小为2-4nm.。CV结果表明：在Pt/C催化剂中引入单金属Ag制备成Pt-Ag/C催化剂,在一定程度上提高了催化剂的催化活性,而在Pt-Ag/C催化剂引入Co制成Pt-Ag-Co/C催化剂,其催化效果要优于Pt-Ag/C催化剂。测定了Pt-Ag-Co比例分别为5-10-15,10-10-15时的交流阻抗,在25℃时,分别以Pt-Ag-Co (5-10-15, (10-10-15)为阴极催化剂,商业Pt/C(40%)为阳极催化剂制成了直接NaBH4/H2O2燃料电池(DBHFC),并测定了这两种电池分别在H2O2浓度分别0.06mol/L,0.2mol/L时的恒电流放电曲线,由此计算出两种电池的功率密。计算结果表明以Pt-Ag-Co (10-10-15)为阴极催化剂的DBHFC在H2O2浓度为0.2mol/L时拥有良好的电池性能,常温下的最大功率密度为110.7m W/cm2。
[Abstract]:Direct NaBH4/H2O2 fuel cell (DBHFC) is a new research direction of alkaline fuel cell, because of its high conversion efficiency, clean and pollution-free, high mass specific energy and easy storage and transportation of raw materials, it can be used under water. Space and other special environmental advantages have attracted much attention. At present, under the condition of relatively mature anode catalyst research, Scientific researchers focus on their cathodic catalysts. The use of precious metal Pt as cathode catalyst is limited to some extent because of its limited resources and high cost. The preparation of catalysts that can replace precious metal Pt and maintain high catalytic activity for H2O2 has become a hot topic in recent years. In this paper, carbon powder VulcanXC-72 was prepared by impregnation and reduction. Different reduction reaction time was 2 h ~ 3.5 h ~ 5 h) and Pt-Ag / C / C / Pt-Ag-Co/C catalyst was used as catalyst. The catalysts were characterized by TEM.XRD. Under the conditions of acidic H _ 2SO _ 4 and alkaline NaOH, the catalysts were prepared at different temperatures of 20 鈩，

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