化学学报 ›› 2018, Vol. 76 ›› Issue (9): 723-728.DOI: 10.6023/A18060231 上一篇    

研究论文

酞菁钴催化剂载体表面含氮官能团对其在燃料电池中氧还原性能的影响

黄文姣, 张浩宇, 胡硕真, 钮东方, 张新胜   

  1. 华东理工大学 化学工程联合国家实验室 上海 200237
  • 收稿日期:2018-06-12 出版日期:2018-09-15 发布日期:2018-08-14
  • 通讯作者: 钮东方, 张新胜 E-mail:dfniu@ecust.edu.cn;xszhang@ecust.edu.cn
  • 基金资助:

    项目受华东理工大学基本科研业务费专项基金(No.222201814008)和上海市浦江人才计划(No.18PJ1402000)资助.

Effect of Nitrogen-Containing Functional Groups of Cobalt Phthalocyanine Catalyst on the Oxygen Reduction Performance in Fuel Cells

Huang Wenjiao, Zhang Haoyu, Hu Shuozhen, Niu Dongfang, Zhang Xinsheng   

  1. State Key Laboratory of Chemical Engineering, East China University of Science and Technology, Shanghai 200237
  • Received:2018-06-12 Online:2018-09-15 Published:2018-08-14
  • Contact: 10.6023/A18060231 E-mail:dfniu@ecust.edu.cn;xszhang@ecust.edu.cn
  • Supported by:

    Project supported by the Special Foundation for Basic Scientific Research Business of East China University of Science and Technology (No. 222201814008), and the Shanghai Pujiang Talent Plan (No. 18PJ1402000).

以酞菁钴为催化剂,纳米碳管为载体,分别通过超声法和四氢呋喃法混合分散,并在氮气氛围高温热处理制备了两种酞菁钴催化剂.热重分析(TGA)结果显示超声法制备的酞菁钴催化剂(CoPc-CNT-S)含钴的质量分数为8.1 wt%,四氢呋喃混合法制备的酞菁钴催化剂(CoPc-CNT-R)含钴的质量分数为7.0 wt%.X射线光电子谱(XPS)结果显示CoPc-CNT-R催化剂的含氮量是CoPc-CNT-S催化剂的两倍多,且两种催化剂含氮官能团的种类及比例不同.相比较而言,CoPc-CNT-S表面有更多的吡咯型氮.将两种催化剂应用于混合酸碱燃料电池中发现:CoPc-CNT-S对电催化氧还原有较高的活性和稳定性,将CoPc-CNT-S作为燃料电池的阴极催化剂分别工作5 h和15 h后,电荷转移电阻相对CoPc-CNT-R为阴极催化剂时均较低.原因可能是相近比例的吡啶型N和吡咯型N的协同作用有利于电催化氧还原.

关键词: 非贵金属催化剂, 酞菁钴, 纳米碳管, 燃料电池, 电催化氧还原

An ultrasonic method and a tetrahydrofuran-mixed dispersion method were used to synthesize two heat-treated cobalt phthalocyanine catalysts supported on carbon nanotubes, CoPc-CNT-S and CoPc-CNT-R,respectively. The ultrasonic process was that mixing cobalt phthalocyanine and carbon nanotubes in isopropanol under ultrasound condition within 30 min, while the tetrahydrofuran-mixed dispersion method was that mixing cobalt phthalocyanine and carbon nanotubes in tetrahydrofuran at 80℃ lasting 4 h. Then the pyrolysis process was carried out in a tube furnace under Argon (Ar) atmosphere with a heating rate of 5℃/min to 800℃ and lasting 2 h. Thermogravimetric Analysis (TGA) results showed that cobalt content of CoPc-CNT-S was 8.1 wt% while CoPc-CNT-R was 7.0 wt%. Moreover, X-ray photoelectron spectroscopy (XPS) results gave a conclusion that nitrogen content of CoPc-CNT-R (5.22%) is twice more than CoPc-CNT-S (2.08%). In comparsion with CoPc-CNT-R, CoPc-CNT-S has more pyrrole nitrogen on the surface. The fuel cell tests in a PEM/AEM hybrid fuel cell showed that the activity and stability of CoPc-CNT-S performed better than CoPc-CNT-R. Power density of CoPc-CNT-S hold at 18.6 mW/cm2 in H2/O2 hybrid AEM/PEM fuel cell for 15 h and CoPc-CNT-R can only hold at 9 mW/cm2. The current density of CoPc-CNT-S maintain at 68 mA/cm2 after stability test in H2/O2 hybrid AEM/PEM fuel cell for 20 h under 50 mV, but the stablity of CoPc-CNT-S fluctuate between 20 mA/cm2 to 40 mA/cm2. The reason can be concluded that ultrasonic method and tetrahydrofuran-mixed dispersion method can cause different kind of nitrogen doped on catalyst to influence electrocatalytic properties. The phenomenon that the electron transfer resistance of CoPc-CNT-S was lower than CoPc-CNT-R after working in PEM/AEM fuel cells for 5 h and 15 h can prove indirectly that the activity of CoPc-CNT-R using for the cathode catalyst H2/O2 hybrid AEM/PEM fuel cell is obviously less than CoPc-CNT-S. These observations may result from the cooperative effect from the similar ratio of pyridinic and pyrrolic nitrogen which may accelerate the catalytic activity of CoPc-CNT-S toward oxygen reduction reaction.

Key words: non-noble metal catalysts, cobalt phthalocyanine, carbon nanotubes, fuel cell, oxygen reduction reaction