Wang Guizhi, Deng Jiang, Yan Tingting, Zhang Jianping, Shi Liyi, Zhang Dengsong
State Key Laboratory of Advanced Special Steel, School of Materials Science and Engineering, Research Center of Nano Science and Technology, Department of Chemistry, Shanghai University, Shanghai, 200444, China.
Nanoscale. 2020 Mar 5;12(9):5601-5611. doi: 10.1039/d0nr00138d.
Iron-nitrogen-carbon (Fe-N-C) electrocatalysts have been demonstrated to be promising candidates to substitute conventional Pt/C electrocatalysts in the oxygen reduction reaction (ORR) due to the benefits of high efficiency and affordable price. Unfortunately, Fe is prone to aggregation upon high-temperature treatment, which may cover the active sites of the Fe-Nx species and further affect the ORR performance. Thus, the key issue is to avoid Fe aggregation and keep it uniformly dispersed as much as possible. In this work, Fe-N-C catalysts with robust Fe-Nx species in hollow carbon frameworks were created via in situ growth of Fe doped Zn based zeolitic imidazolate frameworks (ZIFs) on g-C3N4 with the subsequent pyrolysis treatment. The developed catalysts demonstrate superb ORR activity, high resistance to methanol and ultralong stability as compared with traditional Pt/C catalysts in alkaline solution. The brilliant performance benefits from the firm connection and robust structure of the optimal Fe-Nx species that are homogeneously dispersed in the hollow carbon frameworks. This work presents a facile and reasonable strategy for the development of excellent ORR electrocatalysts.
铁氮碳（Fe-N-C）电催化剂因其高效且价格实惠的优点，已被证明是在氧还原反应（ORR）中替代传统Pt/C电催化剂的有潜力的候选者。不幸的是，铁在高温处理时容易聚集，这可能会覆盖Fe-Nx物种的活性位点，进而影响ORR性能。因此，关键问题是避免铁聚集并尽可能使其均匀分散。在这项工作中，通过在g-C3N4上原位生长铁掺杂的锌基金属有机框架（ZIFs）并随后进行热解处理，制备出了在中空碳框架中具有稳定Fe-Nx物种的Fe-N-C催化剂。与传统Pt/C催化剂相比，所制备的催化剂在碱性溶液中表现出优异的ORR活性、高抗甲醇性和超长稳定性。这种出色的性能得益于均匀分散在中空碳框架中的最佳Fe-Nx物种的牢固连接和稳定结构。这项工作为开发优异的ORR电催化剂提供了一种简便且合理的策略。
