Precisely controlling the local coordination structure of atomic Fe sites has been widely recognized as the key to attain highly efficient oxygen reduction reaction (ORR) catalysts for replacing Pt-based materials. Here, we use pre-synthesized pentagon-rich defective carbon (PDC) as a matrix material to realize a custom-made pentagon defect-coordinated Fe-C configuration via a chemical vapor deposition method. The intrinsic activity of as-prepared PDC-supported Fe single-atom catalysts (Fe-PDC), in terms of specific kinetic current density (J), mass activity, and turnover frequency (TOF), is valued to be several times higher than that of other N-coordinated counterparts. Density functional theory (DFT) calculations demonstrate that the excellent ORR activity of pentagon-type Fe-C sites originates from the optimized electronic state with more charge transfer and down-shifted d-band center. Our work gives new insight into boosting the ORR performance of atomic single-site catalysts via purposely and precisely constructing more unique defect-stabilized single atomic species.

中文翻译：

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在缺陷碳中精确构建五边形捕获的单原子铁位点以实现有效的氧电还原


精确控制原子Fe位点的局部配位结构已被广泛认为是获得高效氧还原反应（ORR）催化剂以替代Pt基材料的关键。在这里，我们使用预先合成的富含五边形缺陷碳（PDC）作为基体材料，通过化学气相沉积方法实现定制的五边形缺陷配位Fe-C构型。所制备的 PDC 负载的 Fe 单原子催化剂（Fe-PDC）的本征活性，在比动电流密度（J）、质量活性和周转频率（TOF）方面，被认为比其他 N 配位对应物的情况。密度泛函理论（DFT）计算表明，五边形型Fe-C位点优异的ORR活性源于具有更多电荷转移和下移的d带中心的优化电子态。我们的工作为通过有目的地、精确地构建更独特的缺陷稳定单原子物种来提高原子单中心催化剂的 ORR 性能提供了新的见解。