科研之友
微信
新浪微博
Facebook
分享链接
摘要
Background: Transition metal nitrogen doped carbon materials are promising to replace precious metal platinum-based materials as an important electrocatalyst for oxygen reduction, and have attracted extensive attention in the research fields of energy storage materials and energy conversion devices. Purpose: This study aims to develop new vanadium doped transition metal carbon materials with excellent catalytic performance, and clarify the role of the introduced of vanadium. Methods: The vanadium doped cobalt-nitrogen-carbon catalyst was designed by two-step pyrolysis method and impregnation method. The catalytic performance of the oxygen reduction reaction (ORR) was evaluated by a three electrode system using rotating disk electrode. The morphology and microstructure of catalysts were characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). X-ray diffraction (XRD) was employed to examine crystal orientation structure of catalyst whilst the element types and distribution of materials was analyzed by X-ray photoelectron spectroscopy. Finally, Co K-edge and V K-edge X-ray absorption fine structure (XAFS) spectroscopy were used to determine the local atomic configuration and electronic structure. Results: The experimental results show that vanadium doped cobalt-nitrogen-carbon catalyst exhibits superior ORR performance than the traditional cobalt-nitrogen-carbon catalyst. XAFS spectra clarifies that the electronic state of cobalt is changed by the introduction of vanadium, and the catalytic performance is further enhanced. Conclusion: The performance of Co-N-C catalyst is regulated by the high-valence state V doping, which provides an idea for the design of high-efficiency oxygen reduction catalyst.
- 单位
