Metal–organic-framework-derived Co/nitrogen-doped porous carbon composite as an effective oxygen reduction electrocatalyst
Metal–organic-framework-derived Co/nitrogen-doped porous carbon composite as an effective oxygen reduction electrocatalyst
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DOI：
10.1007/s10853-018-1989-x
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发表时间：
2018-01
影响因子：
4.5
通讯作者：
Tianrong Zhan;Sisi Lu;Haoqing Rong;W. Hou;H. Teng;Yong-hong Wen
中科院分区：
文献类型：
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作者：
Tianrong Zhan;Sisi Lu;Haoqing Rong;W. Hou;H. Teng;Yong-hong Wen
水热法合成了钴金属有机骨架（MOF）晶体。然后在不添加任何前驱体的情况下，通过直接热解MOF制备了相应的Co/氮掺杂多孔碳（Co/NPC）复合材料。结果表明，MOF衍生的Co/NPC具有多孔结构，表面积为412 m2 g-1，孔径分布窄（1.8 - 4.9 nm）。掺杂氮主要以吡啶氮和石墨氮形式存在，总含量为4.11at.%，其来源于MOF中的氮基配体。作为有效的氧还原反应（ORR）催化剂，Co/NPC显示出更正的起始电位（0.91 V vs. RHE），在0.3 V（vs. RHE）下的扩散限制电流密度为5.46 mA cm− 2。旋转圆盘电极和旋转环-盘电极的结果表明，Co/NPC催化剂在0.1M KOH中经历了一个近4 e的路径，具有比商业Pt/C催化剂更强的甲醇耐受性和更好的耐久性。Co/NPC的优良ORR催化活性可归因于引入金属Co活性物种的N掺杂多孔碳结构。本工作为以MOF为前驱体制备非贵金属有机氧化还原催化剂提供了新的思路。
A Co-metal–organic-framework (MOF) crystal has been hydrothermally synthesized. Then the corresponding Co/nitrogen-doped porous carbon (Co/NPC) composite is fabricated by direct pyrolyzation of MOF without any precursor additive. The results reveal that the MOF-derived Co/NPC exhibits a porous structure with a surface area of 412 m2g−1and a narrow pore size distribution (from 1.8 to 4.9 nm). The doped N mainly occurs in pyridine N and graphitic N types with total content as 4.11 at.%, which is originated from the N-based ligands in MOF. As an efficient oxygen reduction reaction (ORR) catalyst, Co/NPC shows a more positive onset potential (0.91 V vs. RHE) with a diffusion-limited current density of 5.46 mA cm−2at 0.3 V (vs. RHE). The rotating disk electrode and rotating ring-disk electrode results suggest that the Co/NPC catalyst experiences a nearly 4e pathway with a stronger methanol tolerance and better durability than commercial Pt/C catalyst in 0.1 M KOH. The excellent ORR catalytic activity of Co/NPC can be attributed to the N-doped porous carbon structure with incorporated metallic Co active species. This work affords a new strategy for preparation of non-noble metal ORR catalysts employing MOF as a precursor.