高等学校化学学报 ›› 2012, Vol. 33 ›› Issue (08): 1782.doi: 10.3969/j.issn.0251-0790.2012.08.027

• 物理化学 • 上一篇    下一篇

Fe-Nx/C电催化剂的氧还原性能及配体结构对催化活性的影响

李赏, 朱广文, 陈锐鑫, 王家堂, 赵伟, 潘牧   

  1. 武汉理工大学材料复合新技术国家重点实验室, 燃料电池湖北省重点实验室, 武汉 430070
  • 收稿日期:2011-12-08 出版日期:2012-08-10 发布日期:2012-08-10
  • 通讯作者: 李 赏, 女, 副研究员, 主要从事质子交换膜燃料电池研究. E-mail: lishang@whut.edu.cn E-mail:lishang@whut.edu.cn
  • 基金资助:

    中央高校基本科研业务费专项资金(批准号: 2011-IV-026)和国家"九七三"计划项目(批准号: 2012CB215504)资助.

Performance of Fe-Nx/C Electrocatalysts for Oxygen Reduction Reaction and the Effect of Ligand Stucture on the Catalytic Activity

LI Shang, ZHU Guang-Wen, CHEN Rui-Xin, WANG Jia-Tang, ZHAO Wei, PAN Mu   

  1. State Key Laboratory of Advanced Technology for Materials Synthesis and Progressing, Hubei Fuel Cell Key Laboratory, Wuhan University of Technology, Wuhan 430070, China
  • Received:2011-12-08 Online:2012-08-10 Published:2012-08-10

摘要: 以2,6-二氨基嘌呤(Hdap)为配体合成了Fe-Nx/C氧还原催化剂, 并优化了热处理温度和Fe含量. 对催化剂组成和结构进行了表征, 分析了配体Hdap在热处理过程中随温度的变化情况, 通过循环伏安法和线性扫描伏安法测试了催化剂的氧还原催化性能. 结果表明, 热处理温度为800℃, Fe质量分数为5%时, 催化剂活性最高. 吡啶N含量较高的配体有利于提高催化剂的活性, 配体中含S元素会增加催化剂的活性.

关键词: 质子交换膜燃料电池, 2,6-二氨基嘌呤, Fe-Nx/C电催化剂, 氧还原活性

Abstract: 2,6-Diaminopurine was used as a ligand to prepare Fe-Hdap complexes for the development of a new oxygen reduction reaction(ORR) catalyst. The prepared Fe-Hdap complexes were heat-treated at 600, 700, 800 and 900℃ to optimize their activity for ORR. It was found that the 800℃ heat-treatment yielded the most active Fe-Nx/C catalyst. Fe-Nx/C catalyst with several Fe loadings(3%, 4%, 5%, 6%, 7%, mass fraction) were also synthesized and a 5% Fe loading yielded the best catalytic ORR activity. XRD, TG, TEM, XPS and line-scan voltammograms techniques were used to characterize the structural changes in these catalyst after heat-treatment, including the catalyst composition, structure, morphologe and the electrochemical activity. As observed by XRD, when the heat-treatment temperature or Fe content was too high, Fe3O4 could be produced. This would lead to a decrease in ORR activity. XPS analysis revealed that the catalyst surface consisted of 0.61%(mass fraction) N(largely pyrrolic-like). The ORR activities of catalysts synthesized using ligands with different structures were studied. The result indicated that the catalyst prepared using the compound containing more pyridinic N as ligand had enhanced activity, and the S element in ligand can improve the activity of Fe-Nx/C catalyst. The stability of the Fe-Nx/C catalyst in the voltage region having ORR kinetic limiting was tested by fixing a electrode potential to record the change in current density with time. The obtained degradation rates for this catalyst is 0.0048 mA/(cm2\5h).

Key words: Protonexchange membrane fuel cell(PEMFC), 2,6-Diaminopurine(Hdap), Fe-Nx/C electro-catalyst, Oxygen reduction reaction activity

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