Citation: HUANG Yan-Ping, YUAN Hong-Yan, ZHANG Jian, YANG Ya-Hui, LIU Hong-Tao. Preparation and Properties of Tremella-like Fe-N-C Composite Catalyst for Oxygen Reduction Reaction. Chinese Journal of Analytical Chemistry, 2017, 45(9): 1297-1302. doi: 10.11895/j.issn.0253-3820.170279 [复制]
Preparation and Properties of Tremella-like Fe-N-C Composite Catalyst for Oxygen Reduction Reaction
以无机铁盐和邻苯二胺为基础原料，经铁（Ⅲ）基螯合前驱体热解反应，制备出Fe-N-C复合催化剂。经扫描电镜观察，带有折褶的碳微纳米片相互交迭，形成银耳状的三维自支撑结构。氮气吸脱附测试表明此结构富含微孔和介孔，比表面积可达290 m2/g。通过X射线衍射（XRD）确证石墨化C和多晶Fe3C作为催化剂主相存在，X射线光电子能谱（XPS）进一步揭示N原子主要以石墨N和吡啶N形式掺杂到C骨架中。电化学测试表明银耳状Fe-N-C复合催化剂在碱性条件下催化氧还原反应为四电子过程，其催化活性可媲美商业Pt/C催化剂。经过2000次氧还原测试后，催化极限电流衰减小于5%，并且半波电势仅负移5 mV（商业Pt/C催化剂负移35 mV），表现出优异的氧还原催化稳定性。
The Fe-N-C composite catalyst was prepared by the thermal decomposition of the chelate precursors based on Fe(Ⅲ) central ions and o-phenylenediamine ligands. It was observed from the scanning electron microscopy that the crumpled carbon micro-and nano-sheets were intertwined to form a free-standing tremella-like 3D structure. The N2 adsorption/desorption experiments revealed that the composite contained ample micro-and meso-pores and had a specific surface area of 290 m2/g. Graphitic C and multi-crystal Fe3C as main components were confirmed by the X-ray diffraction, and N-doping in the general form of graphite N and pyridine N was also verified by X-ray photoelectron spectroscopy. The electrochemical measurement showed that the tremella-like Fe-N-C composite catalyzed oxygen reduction through a four-electron path in an alkaline solution, and its activity was comparable to the commercial Pt/C catalyst. After 2000 cycles, the limited current density of the Fe-N-C catalytic electrode only decreased less than 5%, and the half-wave potential shift negatively 5 mV, which suggested that the Fe-N-C composite catalyst had better catalytic stability than the commercially used Pt/C catalyst.