The catalysts towards the oxygen reduction reaction (ORR) are the key materials for fuel cells and have stimulated continuous investigations on rational designs. Apart from the popular strategies reported, we demonstrate here a facile method resulting in a nanocomposite composed of molybdenum carbide (Mo₂C) nanoparticles embedded and buried in Fe–N-doped carbon nanolayers by directly pyrolyzing the mixture of Fe₂(MoO₄)₃ and dicyandiamide. The underlying Mo₂C donates electrons of higher energy to the exterior N-containing carbon nanolayers (NC) and strongly couples with the active sites induced by Fe in the NC layer, leading to significant improvement at half-wave potential with respect to the control sample without Mo₂C. The catalyst as a whole exhibits a fairly good ORR performance comparable to commercial Pt/C. Moreover, the method is extremely simplified and the material shows better long-term stability and tolerance to the methanol crossover in comparison with Pt/C.

中文翻译：

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易制备Fe-N掺杂的碳纳米层上的碳化钼促进剂，以增强氧的还原

用于氧还原反应（ORR）的催化剂是燃料电池的关键材料，并刺激了对合理设计的不断研究。除了所报道的流行策略外，我们在这里展示了一种简便的方法，该方法通过直接热解Fe ₂（MoO ₄）的混合物，将纳米碳化物（Mo ₂ C）纳米颗粒嵌入并掩埋在Fe–N掺杂的碳纳米层中，从而形成纳米复合材料。₃和双氰胺。潜在的Mo ₂C将较高能量的电子提供给外部含N的碳纳米层（NC），并与NC层中Fe诱导的活性位点强烈耦合，从而导致半波电势相对于不含Mo ₂的对照样品显着提高C.催化剂总体上表现出与商业Pt / C相当的ORR性能。此外，与Pt / C相比，该方法非常简化，并且该材料显示出更好的长期稳定性和对甲醇穿透的耐受性。