Wang Wenqing, Rui Kun, Wu Kaili, Wang Yisha, Ke Longwei, Wang Xin, Xu Feng, Lu Yan, Zhu Jixin
Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM), Nanjing Tech University (NanjingTech), 30 South Puzhu Road, Nanjing, 211816, P. R. China.
Institute of Flexible Electronics (IFE), Northwestern Polytechnical University (NPU), 127 West Youyi Road, Xi'an, 710072, P. R. China.
Chemistry. 2022 Jul 15;28(40):e202200789. doi: 10.1002/chem.202200789. Epub 2022 May 30.
Realizing the synergy between active site regulation and rational structural engineering is essential in the electrocatalysis community but still challenging. Here, a matrix-confined co-pyrolysis strategy based on molecular bridging is demonstrated to realize highly dispersed Fe atoms on stereoassembled carbon framework. Both polyacrylonitrile matrix and organic linker from metal-organic frameworks (MOFs) provide sufficient N-anchoring sites for the generation of Fe-N moieties. A high Fe loading of 2.9 wt.% is readily achieved based on the scalable approach without post-treatment. Owing to the presence of highly exposed Fe-N-C sites and well-tuned pore structures, isolated Fe atoms on porous carbon nanofiber framework (Fe-SA/NCF) exhibits decent oxygen reduction activity and stability in alkaline conditions via a near four-electron path, demonstrating superior performance as air cathode for zinc-air batteries (ZABs) to commercial Pt/C catalyst.
在电催化领域，实现活性位点调控与合理结构工程之间的协同作用至关重要，但仍具有挑战性。在此，展示了一种基于分子桥联的基质受限共热解策略，以在立体组装的碳框架上实现高度分散的铁原子。聚丙烯腈基质和金属有机框架（MOF）中的有机连接体都为生成Fe-N部分提供了足够的N锚定位点。基于这种可扩展方法，无需后处理即可轻松实现2.9 wt.%的高铁负载量。由于存在高度暴露的Fe-N-C位点和经过良好调谐的孔结构，多孔碳纳米纤维框架（Fe-SA/NCF）上的孤立铁原子在碱性条件下通过近四电子路径表现出良好的氧还原活性和稳定性，作为锌空气电池（ZAB）的空气阴极，其性能优于商业Pt/C催化剂。
