Reasonable design and scalable preparation of low-cost, effective and durable electro-catalysts as substitutes to expensive Pt-derived catalysts for oxygen reduction reaction (ORR) is highly desired toward the progress of future sustainable energy storage devices. In this work, we scalably prepare a highly active ORR electrocatalyst which consists of both Fe₃N nanoparticles and Fe-N-C active sites in N-doped carbon frameworks (named as Fe₃N/Fe-N-C) and derives from walnut shells as precursors followed by iron ion incorporation and a pyrolysis process in NH₃ atmosphere. The X-ray diffraction (XRD), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopic (XPS) measurements strongly evidence the coexistence of Fe₃N nanoparticles and iron-nitrogen-carbon active sites. Benefiting from the synergistic mechanism between Fe₃N nanoparticles and Fe-N-C sites in N-doped carbon frameworks, the resultant catalyst presents desirable ORR performance with impressive E_onset, E_1/2, higher long-term stability, and satisfactory resistance to methanol interference, overtopping commercial Pt/C catalyst. The present research not only proposes a cost-effective and available ORR electro-catalyst to substitute Pt-based catalysts, but also provides a reliable and versatile technology to realize large-scale preparation for practical applications.

低成本，有效和耐用的电催化剂的合理设计和可扩展制备，可替代昂贵的Pt衍生的氧还原反应（ORR）催化剂，对未来可持续的储能设备的发展非常重要。在这项工作中，我们按比例制备了一种高活性的ORR电催化剂，该催化剂由Fe ₃ N纳米颗粒和N掺杂碳骨架中的Fe-NC活性位（称为Fe ₃ N / Fe-NC）组成，并以核桃壳为前体然后在NH ₃气氛中引入铁离子并进行热解过程。X射线衍射（XRD），透射电子显微镜（TEM）和X射线光电子能谱（XPS）测量有力地证明了Fe ₃的共存N纳米颗粒和铁-氮-碳活性位。得益于Fe ₃ N纳米颗粒与N掺杂碳骨架中Fe-NC位点之间的协同机制，所得催化剂具有令人满意的ORR性能，具有令人印象深刻的E_起始，E _1/2，更高的长期稳定性以及令人满意的耐甲醇性干扰，超过了商用Pt / C催化剂。本研究不仅提出了一种经济有效且可用的ORR电催化剂来代替Pt基催化剂，而且还提供了一种可靠且用途广泛的技术来实现大规模制备用于实际应用。