FeNC is a promising non-precious metal catalyst that can replace platinum-based catalysts in Proton-exchange membrane fuel cells (PEMFC) and zinc-air battery applications. The study utilized (Fe-ZIF-8) as a precursor to improve the ORR activity of the catalyst. This was achieved by growing ruthenium particles of approximately 0.32 um in situ using a physical milling method under a reducing gas atmosphere. This paper demonstrates that in situ grown ruthenium nanoparticles can alter the spin state of iron atoms from the high-spin state FeN4(II)-(t2g4eg2 )to the medium-spin state FeN4(II)-(t2g5eg1). This alteration changes the interactions of the π* antibonding orbitals of the oxygen and thus improves the ORR activity. The Rotating Ring-Disk (RDE) Electrode test resulted in a half-wave potential of +0.80 V vs. RHE in 0.1 M HClO4, indicating remarkable ORR performance. Zinc-air battery tests showed a high peak power density of 148 mW cm-2.

中文翻译：

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通过 Ru 纳米颗粒调节 FeNC 催化剂中的 Fe 自旋态以促进氧还原反应

FeNC 是一种很有前景的非贵金属催化剂，可以在质子交换膜燃料电池 (PEMFC) 和锌空气电池应用中替代铂基催化剂。该研究利用(Fe-ZIF-8)作为前驱体来提高催化剂的ORR活性。这是通过在还原性气体气氛下使用物理研磨方法原位生长约 0.32 微米的钌颗粒来实现的。本文证明，原位生长的钌纳米粒子可以将铁原子的自旋态从高自旋态 FeN4(II)-(t2g4eg2 ) 改变为中自旋态 FeN4(II)-(t2g5eg1)。这种改变改变了氧的 π* 反键轨道的相互作用，从而提高了 ORR 活性。旋转环盘 (RDE) 电极测试的结果是，0.1 M HClO4 中的半波电位相对于 RHE 为 +0.80 V，表明 ORR 性能出色。锌空气电池测试显示峰值功率密度高达 148 mW cm-2。