One‐Step Preparation of Fe/N/C Single‐Atom Catalysts Containing Fe?N <sub>4</sub> Sites from an Iron Complex Precursor with 5,6,7,8‐Tetraphenyl‐1,12‐Diazatriphenylene Ligands
One‐Step Preparation of Fe/N/C Single‐Atom Catalysts Containing Fe?N <sub>4</sub> Sites from an Iron Complex Precursor with 5,6,7,8‐Tetraphenyl‐1,12‐Diazatriphenylene Ligands
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用5,6,7,8-四苯基-1,12-二氮杂苯并菲配体一步制备含Fe?N <sub>4</sub>位点的铁配合物前体Fe/N/C单原子催化剂
DOI：
10.1002/chem.202103545
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发表时间：
2021
期刊：
影响因子：
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通讯作者：
Onoda Akira
中科院分区：
文献类型：
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作者：
Matsumoto Koki;Kato Masaru;Yagi Ichizo;Xie Siqi;Asakura Kiyotaka;Noro Shin‐ichiro;Tohnai Norimitsu;Campidelli St?phane;Hayashi Takashi;Onoda Akira
通过热解制备的含有 Fe-Nx 位点的 Fe/N/C 单原子催化剂由于其高氧还原反应（ORR）活性，是燃料电池和金属空气电池的有前途的正极材料。我们开发了含有 N2 或 N3 螯合配位结构的铁络合物，其在 1,12-二氮杂苯并菲骨架中具有预组织芳环，束缚溴取代基作为前体，在 Fe/N/C 催化剂中精确构建 Fe−N4 位点。铁络合物与炭黑的一步热解形成原子分散的 Fe−N4 位点，而没有铁聚集体。 X射线吸收光谱（XAS）和电化学测量表明，与RHE相比，具有N3配位的铁配合物可以更有效地转化为催化ORR的Fe−N4位点，其TOF值为0.21 e 位点−1s−1（在0.8 V时）。这表明 Fe−N4 位点的形成是通过精确调节铁配合物前体的化学结构来控制的。
Fe/N/C single‐atom catalysts containing Fe−Nxsites prepared by pyrolysis are promising cathode materials for fuel cells and metal‐air batteries due to their high oxygen reduction reaction (ORR) activities. We have developed iron complexes containing N2‐ or N3‐chelating coordination structures with preorganized aromatic rings in a 1,12‐diazatriphenylene framework tethering bromo substituents as precursors to precisely construct Fe−N4sites in an Fe/N/C catalyst. One‐step pyrolysis of the iron complex with carbon black forms atomically dispersed Fe−N4sites without iron aggregates. X‐ray absorption spectroscopy (XAS) and electrochemical measurements revealed that the iron complex with N3‐coordination is more effectively converted to Fe−N4sites catalyzing ORR with a TOF value of 0.21 e site−1s−1at 0.8 V vs. RHE. This indicates that the formation of Fe−N4sites is controlled by precise tuning of the chemical structure of the iron complex precursor.