The exploration of powerful, efficient and precious metal-free electrocatalysts for facilitating the sluggish kinetics of the oxygen reduction reaction (ORR) is a crucial endeavor in the development and application of energy conversion and storage devices. Herein, we have rationally designed and synthesized bimetallic CoFe species consisting of CoFe nanoparticles and atomically dispersed dual atoms anchored on an ordered mesoporous carbon matrix (CoFe/NC) as highly efficient ORR electrocatalysts. The pyrolyzation temperature for CoFe/NC plays a vital role in regulating the morphology and composition of both the carbon matrix and CoFe species. The optimized CoFe/NC-750 exhibits a favorable ORR performance in 0.1 M KOH with a high half-wave potential (E_1/2) of 0.87 V vs. RHE, excellent tolerance to methanol and remarkable durability (no obvious decrease in E_1/2 value after 3000 cycles), all of which are superior to the performance of commercial Pt/C. Experimental measurements and density functional theory (DFT) calculations reveal that the improved ORR performance of CoFe/NC-750 is mainly attributed to the electronic structure of atomically dispersed Fe active sites modulated by the surrounding CoFe alloys and Co single atoms, which accelerates the dissociation and reduction of intermediate OH* species and promotes the ORR process.

中文翻译：

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具有二元 CoFe 原子种类的有序介孔碳，用于高效氧还原电催化

探索强大、高效且不含贵金属的电催化剂来促进氧还原反应（ORR）的缓慢动力学是能量转换和存储设备的开发和应用的关键努力。在此，我们合理设计并合成了由 CoFe 纳米颗粒和锚定在有序介孔碳基质（CoFe/NC）上的原子分散的双原子组成的双金属 CoFe 物种，作为高效的 ORR 电催化剂。 CoFe/NC 的热解温度在调节碳基体和 CoFe 物质的形态和组成方面起着至关重要的作用。优化后的 CoFe/NC-750 在 0.1 M KOH 中表现出良好的 ORR 性能，与RHE相比具有 0.87 V 的高半波电位 ( E _1/2 ) 、优异的甲醇耐受性和卓越的耐用性（ E ₁无明显下降） _/2值（3000次循环后），所有这些都优于商业Pt/C的性能。实验测量和密度泛函理论（DFT）计算表明，CoFe/NC-750的ORR性能提高主要归因于原子分散的Fe活性位点的电子结构受到周围CoFe合金和Co单原子的调节，从而加速了解离以及中间体 OH* 物质的减少并促进 ORR 过程。