For electrocatalysis, the development of highly active and low-cost stable electrocatalysts, which would be directly applied in cathodes for fuel cells that are regarded as the most promising candidates for clean energy conversion in the quest for alternatives to conventional fossil fuel technology, remains a massive challenge. In this context, oxygen reduction reaction (ORR) is a critical process under intense research for the direct conversion of chemical energy into electricity. Herein, a facile synthetic method is proposed for the preparation of hierarchically porous 2-dimensional nanosheets consisting of Fe4C and FeCo nanoparticles incorporated in N/S-doped carbon materials at 900 °C, denoted as InFeCo@CNS900. This composite can be conveniently prepared by directly calcining the crystalline indium-organic framework of InOF-24, which is impregnated with the ferric thiocyanate and cobalt ammonium complexes under Ar atmosphere, in which Fe4C and FeCo nanoparticles were in situ formed and embedded into the well-developed carbon materials, which display the hierarchically porous nanosheets with microporous and mesoporous structures. Due to the synergistic effects between different active substances, high specific surface area, suitable graphitization degree, and rich active sites, the as-obtained InFeCo@CNS900 electrocatalyst exhibits an excellent ORR activity, which shows a lower Tafel slope of 59.5 mV dec-1, higher diffusion limit current of 5.15 mA cm-2, and better stability than the commercial 20 wt% Pt/C catalyst. This study provides a facile approach for the design and synthesis of highly efficient non-noble metal-doped carbon materials with a unique 2-dimensional morphology, which are potentially applied in energy science and technology.

中文翻译：

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源自MOF的超薄杂原子掺杂碳纳米片，用于改善氧还原。

对于电催化，高活性和低成本稳定的电催化剂的开发仍将继续发展，该催化剂将直接应用于燃料电池的阴极，燃料电池的阴极被认为是清洁能源转化的最有希望的候选者。巨大的挑战。在此背景下，氧还原反应（ORR）是将化学能直接转化为电能的一项重要过程，目前正在深入研究中。本文提出了一种简便的合成方法，用于制备由Fe4C和FeCo纳米粒子组成的分层多孔二维纳米片，该纳米片在900°C掺入N / S掺杂的碳材料中表示为InFeCo @ CNS900。通过直接煅烧InOF-24的晶体铟-有机骨架，可以方便地制备该复合材料，在Ar气氛下将其浸渍到硫氰酸铁和钴铵络合物中，其中就地形成了Fe4C和FeCo纳米颗粒，并嵌入到发达的碳材料中，这些材料显示出具有微孔和中孔结构的分层多孔纳米片。由于不同活性物质之间的协同作用，高比表面积，合适的石墨化程度和丰富的活性位点，所获得的InFeCo @ CNS900电催化剂表现出优异的ORR活性，其Tafel斜率较低，为59.5 mV dec-1与市售的20 wt％Pt / C催化剂相比，具有更高的5.15 mA cm-2扩散极限电流和更好的稳定性。