煤炭工程 ›› 2018, Vol. 50 ›› Issue (5): 135-139.doi: 10.11799/ce201805037

• 研究探讨 • 上一篇    下一篇

氧化无烟煤的化学活化机理及其电化学性能研究

黄杜斌,传秀云,李爱军   

  1. 北京大学
  • 收稿日期:2016-11-27 修回日期:2017-01-25 出版日期:2018-05-20 发布日期:2018-06-14
  • 通讯作者: 传秀云 E-mail:xychuan@pku.edu.cn

Study on chemical activation mechanism of oxidized anthracite and its electrochemical properties

  • Received:2016-11-27 Revised:2017-01-25 Online:2018-05-20 Published:2018-06-14

摘要: 以无烟煤为前驱体,通过混酸预氧化,在800℃氩气氛围下使用KOH活化制备出无烟煤基活性炭。通过X射线衍射(XRD)、拉曼光谱(Raman)和场发射扫描电镜(SEM)对其结构进行了表征,对活化机理进行了探讨。在三电极体系中使用循环伏安、恒流充放电研究了其在碱性介质中的电化学性能。结果表明:无烟煤的活化以KOH与无烟煤的反应为主,也与高温下钾蒸汽进入类石墨片层层间,扩大孔径有关。氧化煤表面引入了新的反应活性点,加剧了反应的进行,最终形成多级孔道结构。电流密度为0.2A/g时,活化后的无烟煤的比电容为99.71F/g,而经过预氧化处理的无烟煤的比电容提高到112.59F/g。电流密度为20A/g时,活化后的氧化无烟煤的比电容保持率仍在50%以上。

关键词: 无烟煤, 活性炭, KOH活化, 电化学

Abstract: Anthracite based porous carbon was prepared using anthracite as precursor, treating by mixed acid pre-oxidation and activating by KOH in argon atmosphere at 800℃. The structure of porous carbons were studied based on powder X-ray diffraction (XRD), Raman spectroscopy (Raman), and Field emission scanning electron microscopy (SEM), and the activation mechanism was discussed. Electrochemical prop-erties were investigated base on the cyclic voltammetry and constant current charge discharge in the three-electrode system. The results show that the activation of anthracite is mainly due to reaction of KOH and anthracite and relate to potassium vapor running into the graphite-like layers, enlarging pore size under high temperature. New reactive points are introduced into the oxidized coal surface, which intensify the ablation and form hierachical pore structure finally. The specific capacitance of the activated anthracite is 99.71F/g, while the figure of anthracite treated by pre-oxidation increases to 112.59F/g under the current density of 0.2 A/g. The capacitance retention of oxidized anthracite after activation remains more than 50% under the current density of 20 A/g, which means it is good electrode material for supercapacitor.

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