Preparation and Properties of Tremella-like Fe-N-C Composite Catalyst for Oxygen Reduction Reaction / 分析化学

ABSTRACT

The Fe-N-C composite catalyst was prepared by the thermal decomposition of the chelate precursors based on Fe 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.