Transition metal‐coordinated nitrogen sites on carbon catalysts (M‐N‐C) hold potential for CO2 electroreduction (CO2ER), but optimal morphology and active sites are unclear. We introduce a novel approach, developing zeolitic imidazolate framework‐8 (ZIF‐8)‐derived carbon catalysts with Fe‐N and graphitic‐N sites (Fe2‐NC) via molecular confinement and thermal activation. Fine‐tuning ZIF‐8 size and activation temperature yielded 44.98% active N sites. The 300 nm Fe2‐NC catalyst displayed outstanding CO2‐to‐CO conversion, with a 170 mV overpotential and 94.3% Faradaic efficiency at −0.5 V, outperforming state‐of‐the‐art materials. Enhanced CO2ER kinetics and conductivity contributed to this superiority. Results highlight the correlation between maximum CO Faradaic efficiency and cumulative Fe‐N/graphitic‐N sites, dependent on size and activation. The 300 nm Fe2‐NC in a gas diffusion electrode‐loaded flow cell achieved a 15.3‐fold CO partial current density increase. In a Zn‐CO2 battery, the 300 nm Fe2‐NC demonstrated a peak power density of 0.618 mW cm−2, showcasing energy storage potential.

中文翻译：

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优化颗粒形态：具有石墨-N的原子铁-氮中心可实现高效CO2电还原

碳催化剂（M-N-C）上过渡金属配位的氮位点具有 CO 潜力2电还原（CO2ER），但最佳形态和活性位点尚不清楚。我们引入了一种新方法，开发具有 Fe-N 和石墨-N 位点（Fe2‐NC）通过分子限制和热激活。微调 ZIF-8 大小和活化温度产生了 44.98% 的活性 N 位点。300 nm Fe2-NC 催化剂表现出出色的 CO2- 至 -CO 的转化，在 -0.5 V 时具有 170 mV 的过电势和 94.3% 的法拉第效率，优于最先进的材料。增强型二氧化碳2ER 动力学和电导率促成了这一优势。结果强调了最大 CO 法拉第效率与累积 Fe-N/石墨-N 位点之间的相关性，具体取决于大小和活化。300 nm 铁2‐气体扩散电极负载流通池中的 NC 实现了 15.3 倍的 CO 部分电流密度增加。在 Zn-CO2电池，300 nm Fe2‐NC 的峰值功率密度为 0.618 mW cm−2，展示了储能潜力。