Oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) both have sluggish kinetics, which normally requires the use of noble metal-based catalysts (e.g. RuO₂, IrO_x and Pt). Unfortunately, the high cost of these noble metals has severely restricted their large-scale applications. Herein, we report the fabrication of a cost-effective OER/ORR bifunctional catalyst by embedding atomic Fe-Ni dual metal pairs into nitrogen-doped carbon hollow spheres (Fe-NiNC-50). The resultant catalyst shows exceptional catalytic performance towards both OER and ORR, which is even comparable to the noble metal-based benchmarks. By virtue of its bi-functionality, a rechargeable zinc-air battery is constructed and presents high power density (∼220 mW cm^-2), stable discharge voltage and large specific energy density (∼932.66 Wh kg_Zn^-1). Moreover, the rechargeable Zn-air battery exhibits long-term durability in a charge-discharge cycling test (100 h) with negligible performance degradation. The outstanding bifunctional catalytic performance can be ascribed to the formation of Fe-Ni atomic pairs, which imposes mutual effects for tuning electronic structures of both Fe and Ni sites. Experiments and theoretical calculations further unravel that the electronically modified Ni and Fe atoms are the active sites for OER and ORR, respectively, facilitating both OER and ORR by tuning the binding energy of the reaction intermediates.

氧气析出反应（OER）和氧气还原反应（ORR）都具有缓慢的动力学，这通常需要使用贵金属基催化剂（例如RuO ₂，IrO _x和Pt）。不幸的是，这些贵金属的高成本严重限制了它们的大规模应用。在这里，我们报道了通过将原子的Fe-Ni双金属对嵌入氮掺杂的碳空心球（Fe-NiNC-50）中来制造具有成本效益的OER / ORR双功能催化剂。所得催化剂对OER和ORR均显示出优异的催化性能，甚至可以与基于贵金属的基准相比。凭借其双重功能，可构造的可充电锌空气电池具有很高的功率密度（约220 mW cm ^-2），稳定的放电电压和较大的比能密度（〜932.66 Wh kg _Zn ^-1）。此外，可再充电锌空气电池在充放电循环测试（100小时）中表现出长期耐久性，而性能下降可忽略不计。出色的双功能催化性能可归因于Fe-Ni原子对的形成，这对调节Fe和Ni位点的电子结构具有相互影响。实验和理论计算进一步阐明，电子修饰的Ni和Fe原子分别是OER和ORR的活性位点，通过调节反应中间体的结合能来促进OER和ORR。