高等学校化学学报 ›› 2017, Vol. 38 ›› Issue (8): 1423-1430.doi: 10.7503/cjcu20160941

• 物理化学 • 上一篇    下一篇

自组装合成Fe-N-C-PANI有序介孔结构催化剂及其在酸性条件下的氧还原活性

康欢, 李赏, 刘畅, 郭伟, 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:2016-12-27 修回日期:2017-07-10 出版日期:2017-08-10 发布日期:2017-07-10
  • 通讯作者: 李赏,女,博士,副研究员,主要从事质子交换膜燃料电池方面的研究.E-mail:lishang@whut.edu.cn E-mail:lishang@whut.edu.cn
  • 基金资助:

    国家自然科学基金(批准号:21406173)资助.

Synthesis of Ordered Mesoporous Fe-N-C-PANI Catalyst via Self-assembly and Its Oxygen Reduction Reaction Activity in Acid Medium

KANG Huan, LI Shang, LIU Chang, GUO Wei, PAN Mu   

  1. State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Key Laboratory of Hubei Province for Fuel Cell, Wuhan University of Technology, Wuhan 430070, China
  • Received:2016-12-27 Revised:2017-07-10 Online:2017-08-10 Published:2017-07-10
  • Supported by:

    Supported by the National Natural Science Foundation of China(No.21406173).

摘要:

采用乙醇挥发自组装法,以F127为模版,甲阶酚醛树脂为碳源,聚苯胺为配体,加入硝酸铁和硅酸盐,制备了有序多级孔的Fe-N-C-PANI催化剂.催化剂的成分和形貌表征结果表明,在热处理温度为800℃时,有序介孔的结构最清晰,拥有整齐的孔道和最高的比表面积(1007 m2/g);XPS分析结果表明,吡啶氮原子和石墨氮原子含量(摩尔分数)为3.86%.热处理温度升高过程中Fe(Ⅲ)被还原,向单质Fe转化,并促进了N的掺杂,使碳化铁转化为Fe-Nx活性位点,提高了催化剂的氧还原反应(ORR)催化活性,热处理温度达到900℃时,过多的单质铁使其氧还原活性下降.在酸性溶液中,Fe-N-C-PANI-800催化剂的起始电位可达0.89 V,半波电势为0.81 V.有序介孔结构使催化剂更易石墨化,提高了材料的稳定性.

关键词: 质子交换膜燃料电池, 非贵金属催化剂, 有序介孔, 氧化还原

Abstract:

Highly ordered mesoporous Fe-N-C-PANI electrocatalysts were synthesized by ethanol evaporation induced self-assembly using triblock copolymer Pluronic F127 as template, phenol-formaldehyde resin as carbon precursor and polyaniline as the N precursor. XRD, TEM, BET, XPS and RDE techniques were used to characterize the composition, morphology and electrocatalytic activity of the catalysts. The results show that the catalyst pyrolyzed at 800℃ has distinctly ordered mesoporous structure and straightest channel, and its speci-fic surface area is as high as 1007 m2/g. The results of XPS show that the percentage of pyidinic N and Graphitic N of Fe-N-C-PANI-800 is 3.86%(molar fraction). In the process of heat treatment, Fe(Ⅲ) was reduced to metallic Fe, and the introduction of N was facilitated, which made iron carbide turn into Fe-Nx active sites, and enhanced the ORR catalytic performance of catalysts. But when the temperature rise to 900℃, the formation of metallic Fe decreases its ORR activity. In the acid medium, Fe-N-C-PANI-800 has an onset potential of 0.89 V(vs. RHE) and a half-wave potential of 0.81 V(vs. RHE). Ordered mesoporous catalyst had higher graphitization structure, which improved its stability.

Key words: Proton exchange membrane fuel cell, Non-noble metal electrocatalyst, Ordered mesoporous, Oxygen reduction reaction(ORR)

中图分类号: