Here we propose a new strategy in which two isomorphic metal-organic frameworks (MOFs) [FJU-40-H (a) and FJU-40-NH2 (b)] are used to construct the core-shell material MOF@MOF. This strategy based on nitrogen doping and specific surface has resulted in an N-doped porous carbon (NPC) material in a one-step thermal treatment in N2 atmosphere; this material displays high catalytic activity for the oxygen reduction reaction (ORR). The materials were analyzed by SEM, XPS, Raman, specific surface area, pore size distribution and electrochemical measurements. It was found that NPC derived from the core-shell MOF@MOF can provide excellent catalytic ORR performance exceeding that of the single MOF. The onset potential is NPC-b@a-4h (-0.068 V)>NPC-a@b-4h (-0.075 V)>NPC-a-4h (-0.109 V)>NPC-b-4h (-0.113 V). Moreover, the results also show that the performance of NPC-b@a (n=4.15) is better than that of NPC-a@b (n=3.32), which means the different nitrogen content of ligands inside and outside of the core affects the ORR properties.

中文翻译：

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MOF @ MOF的热转化：合成具有出色ORR性能的N掺杂碳材料。

在这里，我们提出了一种新的策略，其中使用了两个同构的金属有机框架（MOF）[FJU-40-H（a）和FJU-40-NH2（b）]来构造核-壳材料MOF @ MOF。这种基于氮掺杂和比表面的策略已导致在N2气氛中一步热处理形成N掺杂的多孔碳（NPC）材料。这种材料对氧还原反应（ORR）表现出很高的催化活性。通过SEM，XPS，拉曼，比表面积，孔径分布和电化学测量来分析材料。发现由核-壳MOF @ MOF衍生的NPC可以提供优于单个MOF的出色的催化ORR性能。起始电位为NPC-b @ a-4h（-0.068 V）> NPC-a @ b-4h（-0.075 V）> NPC-a-4h（-0.109 V）> NPC-b-4h（-0.113 V） ）。而且，