State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190, China.
National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, College of Engineering and Applied Sciences, Nanjing University, Nanjing, 210093, China.
Nat Commun. 2023 Jun 19;14(1):3634. doi: 10.1038/s41467-023-39366-9.
Electrochemical conversion of nitrate to ammonia offers an efficient approach to reducing nitrate pollutants and a potential technology for low-temperature and low-pressure ammonia synthesis. However, the process is limited by multiple competing reactions and NO adsorption on cathode surfaces. Here, we report a Fe/Cu diatomic catalyst on holey nitrogen-doped graphene which exhibits high catalytic activities and selectivity for ammonia production. The catalyst enables a maximum ammonia Faradaic efficiency of 92.51% (-0.3 V(RHE)) and a high NH yield rate of 1.08 mmol h mg (at - 0.5 V(RHE)). Computational and theoretical analysis reveals that a relatively strong interaction between NO and Fe/Cu promotes the adsorption and discharge of NO anions. Nitrogen-oxygen bonds are also shown to be weakened due to the existence of hetero-atomic dual sites which lowers the overall reaction barriers. The dual-site and hetero-atom strategy in this work provides a flexible design for further catalyst development and expands the electrocatalytic techniques for nitrate reduction and ammonia synthesis.
电化学将硝酸盐转化为氨是一种减少硝酸盐污染物的有效方法，也是一种在低温低压下合成氨的潜在技术。然而，该过程受到多种竞争反应和阴极表面上 NO 吸附的限制。在这里，我们报告了一种在具有孔的氮掺杂石墨烯上的 Fe/Cu 双原子催化剂，该催化剂在氨生产方面表现出高催化活性和选择性。该催化剂可实现最大氨法拉第效率为 92.51%（-0.3 V(RHE)) 和高 NH 生成速率为 1.08 mmol h mg（在-0.5 V(RHE))。计算和理论分析表明，NO 与 Fe/Cu 之间的较强相互作用促进了 NO 阴离子的吸附和解吸。由于存在杂原子双位，氮氧键也被削弱，从而降低了整体反应势垒。这项工作中的双位和杂原子策略为进一步的催化剂开发提供了灵活的设计，并扩展了硝酸盐还原和氨合成的电催化技术。
