On the path to deploying the electrochemical CO₂ reduction reaction (CO₂RR) to CO, the narrow potential range under the high Faraday efficiency of CO (FE_CO) still blocks its ultimate practical viability. Engineering the electronic structure via heteroatom doping is supposed to be efficient. However, a feasible synthesis and precise control are still challenging. Here, we propose a fast-pyrolyzing and controllable-activation strategy to construct an O-rich carbonaceous support and atomically dispersed FeN₄ site with axial O coordination (Fe₁N₄–O₁), which was confirmed by aberration-corrected electron microscopy and X-ray absorption spectroscopy. A wide potential range of 310 mV (−0.56 V to −0.87 V vs. RHE) could be achieved when FE_CO was continuously maintained at nearly 100%, which exceeded the existing results to the best of our knowledge. DFT calculations revealed that the superior performance originated from the axial O-coordination induced electronic localization enhancement, which could facilitate the desorption of CO and increase the energy barrier for the competitive hydrogen evolution reaction.

中文翻译：

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具有轴向Fe–O配位的Fe1N4–O1站点可在很宽的潜在范围内高度选择性地减少CO2

在将电化学CO ₂还原反应（CO ₂ RR）部署为CO的路径上，在高法拉第效率（FE _CO）下，狭窄的电位范围仍然阻碍了其最终的实用性。通过杂原子掺杂工程电子结构被认为是有效的。然而，可行的合成和精确控制仍具有挑战性。在这里，我们提出了一种快速热解和可控制的活化策略，以构建具有轴向O配位的富O碳质载体和原子分散的FeN ₄位点（Fe ₁ N ₄ –O ₁），这是通过像差校正电子显微镜和X射线吸收光谱法确认的。当FE _CO连续保持接近100％时，可以实现310 mV的宽电位范围（相对于RHE为-0.56 V至-0.87 V ），据我们所知，这超过了现有结果。DFT计算表明，优异的性能源自轴向O配位诱导的电子定位增强，这可以促进CO的解吸并增加竞争性放氢反应的能垒。