Fe-N-x Sites Enriched Carbon Micropolyhedrons Derived from Fe-Doped Zeolitic Imidazolate Frameworks with Reinforced Fe-N Coordination for Efficient Oxygen Reduction Reaction
Fe-N-x Sites Enriched Carbon Micropolyhedrons Derived from Fe-Doped Zeolitic Imidazolate Frameworks with Reinforced Fe-N Coordination for Efficient Oxygen Reduction Reaction
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Fe-N-x位点富集的碳微多面体源自Fe掺杂沸石咪唑酯框架，具有增强的Fe-N配位，可实现高效的氧还原反应
DOI：
10.1021/acssuschemeng.8b04105
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发表时间：
2018
影响因子：
8.4
通讯作者：
Suqin Liu
中科院分区：
文献类型：
--
作者：
Guanying Ye;Kuangmin Zhao;Zhen He;Rongjiao Huang;Yuchi Liu;Suqin Liu
合理设计和合成高活性、高稳定性的氧还原电催化剂是金属-空气电池领域的关键。在这里，我们提出了一个简单的两阶段热合成Fe-N共掺杂多孔碳（Fe-N/C）具有丰富的Fe-N-x活性中心和介孔从Fe掺杂的ZIF-8前体。在第二阶段碳化之前对Fe掺杂的ZIF-8前体进行第一阶段预热处理是促进掺杂的Fe与含N配体之间配位的关键，这有助于最终碳化产物中更高的N含量和更多的Fe-N-x位点。此外，预热和Fe掺杂均影响所制备的Fe-N/C的形貌、孔结构和催化性能。优化后的Fe-N/C催化剂在0.1 M KOH溶液中具有良好的ORR催化性能，半波电位为0.88 V，极限电流密度为6.0 mA cm（-2）。使用优化的Fe-N/C催化剂作为阴极，用中性电解质组装的镁-空气电池在0.72 V下表现出72 mW cm（-2）的优异功率密度。这种开发的两阶段合成策略是容易的，并且预热阶段可以集成到任何碳化过程中作为中间步骤，用于制造具有增强的电催化性能的各种金属、N共掺杂的碳材料。
Rational design and facile synthesis of highly active and stable electrocatalysts for oxygen reduction reaction (ORR) are crucial in the field of metal-air batteries. Here, we present a facile two-stage thermal synthesis of Fe-N codoped porous carbon (Fe-N/C) with abundant Fe-N-x active sites and mesopores from Fe-doped ZIF-8 precursors. The first-stage preheating treatment of the Fe-doped ZIF-8 precursors before the second-stage carbonization is the key to boost the coordination between the doped Fe and N-containing ligands, which contributes to a higher N content and more Fe-N-x sites in the final carbonized product. Besides, the preheating and Fe doping both affect the morphology, porous structure, and catalytic performance of the fabricated Fe-N/C. The optimized Fe-N/C catalyst exhibits an outstanding ORR catalytic performance with a half-wave potential of 0.88 V and limiting current density of 6.0 mA cm(-2) in 0.1 M KOH. A Mg-air battery assembled with a neutral electrolyte using the optimized Fe-N/C catalyst as the cathode exhibits an excellent power density of 72 mW cm(-2) at 0.72 V. This developed two-stage synthesis strategy is facile, and the preheating stage could be integrated into any carbonization process as an intermediate step for the fabrication of various metal, N codoped carbon materials with enhanced electrocatalytic performance.