School of Environment, Tsinghua University, Beijing 100084, China.
School of Environment, Tsinghua University, Beijing 100084, China
Proc Natl Acad Sci U S A. 2022 Feb 8;119(6). doi: 10.1073/pnas.2115504119.
Ammonia (NH) is an ideal carbon-free power source in the future sustainable hydrogen economy for growing energy demand. The electrochemical nitrate reduction reaction (NORR) is a promising approach for nitrate removal and NH production at ambient conditions, but efficient electrocatalysts are lacking. Here, we present a metal-organic framework (MOF)-derived cobalt-doped Fe@FeO (Co-Fe@FeO) NORR catalyst for electrochemical energy production. This catalyst has a nitrate removal capacity of 100.8 mg N g h and an ammonium selectivity of 99.0 ± 0.1%, which was the highest among all reported research. In addition, NH was produced at a rate of 1,505.9 μg h cm, and the maximum faradaic efficiency was 85.2 ± 0.6%. Experimental and computational results reveal that the high performance of Co-Fe@FeO results from cobalt doping, which tunes the Fe d-band center, enabling the adsorption energies for intermediates to be modulated and suppressing hydrogen production. Thus, this study provides a strategy in the design of electrocatalysts in electrochemical nitrate reduction.
氨（NH）是未来可持续氢能经济中理想的无碳电源，可满足不断增长的能源需求。电化学硝酸盐还原反应（NORR）是一种在环境条件下去除硝酸盐和生产 NH 的有前途的方法，但缺乏高效的电催化剂。在这里，我们提出了一种金属有机骨架（MOF）衍生的钴掺杂 Fe@FeO（Co-Fe@FeO）NORR 催化剂，用于电化学能源生产。该催化剂具有 100.8 mg N g h 的硝酸盐去除能力和 99.0 ± 0.1%的铵选择性，这是所有报道的研究中最高的。此外，NH 的生成速率为 1,505.9 μg h cm，最大法拉第效率为 85.2 ± 0.6%。实验和计算结果表明，Co-Fe@FeO 的高性能源于钴掺杂，它调谐了 Fe d 带中心，使中间体的吸附能得以调节，并抑制了氢气的生成。因此，本研究为电化学硝酸盐还原中电催化剂的设计提供了一种策略。
