Fe₃O₄ is barely taken into account as an electrocatalyst for oxygen reduction reaction (ORR), an important reaction for metal—air batteries and fuel cells, due to its sluggish catalytic kinetics and poor electron conductivity. Herein, how strain engineering can be employed to regulate the local electronic structure of Fe₃O₄ for high ORR activity is reported. Compressively strained Fe₃O₄ shells with 2.0% shortened Fe─O bond are gained on the Fe/Fe₄N cores as a result of lattice mismatch at the interface. A downshift of the d-band center occurs for compressed Fe₃O₄, leading to weakened chemisorption energy of oxygenated intermediates, and lower reaction overpotential. The compressed Fe₃O₄ exhibits greatly enhanced electrocatalytic ORR activity with a kinetic current density of 27 times higher than that of pristine one at 0.80 V (vs reversible hydrogen electrode), as well as potential application in zinc-air batteries. The findings provide a new strategy for tuning electronic structures and improving the catalytic activity of other metal catalysts.

中文翻译：

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核壳氧还原电催化剂中的压缩应变 Fe3O4 可提高锌空气电池性能


Fe ₃ O ₄ 由于其催化动力学缓慢，几乎没有被考虑作为氧还原反应（ORR）的电催化剂，ORR是金属空气电池和燃料电池的重要反应且电子传导性差。在此，报道了如何利用应变工程来调节 Fe ₃ O ₄ 的局部电子结构以获得高 ORR 活性。由于在界面。压缩的Fe ₃ O ₄ d带中心发生下移，导致含氧中间体的化学吸附能减弱，反应超电势降低。压缩的 Fe ₃ O ₄ 表现出大大增强的电催化 ORR 活性，在 0.80 V 下（相对于可逆氢电极），其动态电流密度比原始材料高 27 倍。作为锌空气电池的潜在应用。这些发现为调整电子结构和提高其他金属催化剂的催化活性提供了一种新策略。