Cheng Jiahao, Zhang Zheng, Shao Jibin, Wang Tang, Li Rui, Zhang Wang
College of Materials Science and Engineering, Zhejiang University of Technology, Hangzhou, 310014, P. R. China.
College of Environment, Zhejiang University of Technology, Hangzhou, 310014, P. R. China.
Small. 2024 Oct;20(40):e2402583. doi: 10.1002/smll.202402583. Epub 2024 May 28.
The introduction of axial-coordinated heteroatoms in Fe─N─C single-atom catalysts enables the significant enhancement of their oxygen reduction reaction (ORR) performance. However, the interaction relationship between the axial-coordinated heteroatoms and their carbon supports is still unclear. In this work, a gas phase surface treatment method is proposed to prepare a series of X─Fe─N─C (X = O, P, and S) single-atom catalysts with axial X-coordination on graphitic-N-rich carbon supports. Synchrotron-based X-ray absorption near-edge structure spectra and X-ray photoelectron spectroscopy indicate the formation of an axial charge transfer channel between the graphitic-N-rich carbon supports and single-atom Fe sites by axial O atoms in O─Fe─N─C. As a result, the O─Fe─N─C exhibits excellent ORR performance with a half-wave potential of 0.905 V versus RHE and a high specific capacity of 884 mAh g for zinc-air battery, which is superior to other X─Fe─N─C catalysts without axial charge transfer and the commercial Pt/C catalyst. This work not only demonstrates a general synthesis strategy for the preparation of single-atom catalysts with axial-coordinated heteroatoms, but also presents insights into the interaction between single-atom active sites and doped carbon supports.
在铁氮碳单原子催化剂中引入轴向配位杂原子能够显著提高其氧还原反应（ORR）性能。然而，轴向配位杂原子与其碳载体之间的相互作用关系仍不明确。在这项工作中，提出了一种气相表面处理方法，以在富含石墨氮的碳载体上制备一系列具有轴向X配位的X-Fe-N-C（X = O、P和S）单原子催化剂。基于同步加速器的X射线吸收近边结构光谱和X射线光电子能谱表明，O-Fe-N-C中的轴向O原子在富含石墨氮的碳载体和单原子Fe位点之间形成了轴向电荷转移通道。结果，O-Fe-N-C表现出优异的ORR性能，相对于可逆氢电极（RHE）的半波电位为0.905 V，锌空气电池的比容量高达884 mAh g，优于其他没有轴向电荷转移的X-Fe-N-C催化剂和商业Pt/C催化剂。这项工作不仅展示了一种制备具有轴向配位杂原子的单原子催化剂的通用合成策略，还揭示了单原子活性位点与掺杂碳载体之间的相互作用。
