Synergistic interaction and controllable active sites of nitrogen and sulfur co-doping into mesoporous carbon sphere for high performance oxygen reduction electrocatalysts
Synergistic interaction and controllable active sites of nitrogen and sulfur co-doping into mesoporous carbon sphere for high performance oxygen reduction electrocatalysts
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DOI：
10.1016/j.apsusc.2018.01.186
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发表时间：
2018-05
影响因子：
6.7
通讯作者：
Taeseob Oh;Myeongjin Kim;Dabin Park;Jooheon Kim
中科院分区：
文献类型：
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作者：
Taeseob Oh;Myeongjin Kim;Dabin Park;Jooheon Kim
通过一种经济、简便的热解工艺制备了氮硫共掺介孔碳球(NSMCS)作为无金属催化剂。以羧甲基纤维素钠为碳源制备了介孔碳球，以尿素和对苯二硫酚为原料制备了氮和硫掺杂剂。通过控制热解温度，可以很容易地调节制备的NSMCS中氮和硫的掺杂程度和化学状态。由于共掺杂的协同作用，在900 °C下热解的介孔碳球(NSMCS-900)表现出比单独掺氮或硫的介孔碳球更高的氧还原反应活性。在所有NSMCS样品中，NSMCS-900由于存在由吡啶N、石墨N和噻吩S组成的高活性中心而表现出良好的ORR催化活性。值得注意的是，NSMCS-900催化剂的起始电位和半波电位与商品铂/C相当，在碱性电解液中的ORR耐久性优于铂/C。该方法可用于制备用于能量转换和存储的无金属电催化剂。
Nitrogen and sulfur co-doped mesoporous carbon sphere (NSMCS) was prepared as a metal-free catalyst by an economical and facile pyrolysis process. The mesoporous carbon spheres were derived from sodium carboxymethyl cellulose as the carbon source and the nitrogen and sulfur dopants were derived from urea and p-benzenedithiol, respectively. The doping level and chemical states of nitrogen and sulfur in the prepared NSMCS can be easily adjusted by controlling the pyrolysis temperature. The NSMCS pyrolyzed at 900 °C (NSMCS-900) exhibited higher oxygen reduction reaction activity than the mesoporous carbon sphere doped solely with nitrogen or sulfur, due to the synergistic effect of co-doping. Among all the NSMCS samples, NSMCS-900 exhibited excellent ORR catalytic activity owing to the presence of a highly active site, consisting of pyridinic N, graphitic N, and thiophene S. Remarkably, the NSMCS-900 catalyst was comparable with commercial Pt/C, in terms of the onset and the half-wave potentials and showed better durability than Pt/C for ORR in an alkaline electrolyte. The approach demonstrated in this work could be used to prepare promising metal-free electrocatalysts for application in energy conversion and storage.