Cu-based catalysts have been extensively studied to enhance the performance of the electrochemical nitrate reduction reaction (NO–RR), while it is still a challenge to balance high ammonia (NH) current density and Faradaic efficiency. Here, we incorporated nitrogen coordinated iron single atom catalyst (FeNC) with copper phthalocyanine (CuPc), denoted as CuPc/FeNC, for NO–RR. Compared with the two individual catalysts, this two-component catalyst increases NH Faradaic efficiency and current density at low overpotentials, achieves efficient synergistic catalytic conversion. Experiments and theoretical calculations reveal that the enhanced electrochemical performance of CuPc/FeNC catalyst comes from the tandem process, in which NO is produced on CuPc and then transferred to FeNC and further reduced to NH. In this exceptional tandem catalyst system, an outstanding NH Faradaic efficiency close to 100% was achieved at potentials greater than –0.35 V RHE, coupled with a peak NH partial current density of 273 mA cm at –0.57 V RHE, effectively suppressing NO production across the entire potential range. This strategy provides a design platform for the continued advancement of NORR catalysts.

中文翻译：

---

铜酞菁和FeNC双组分催化剂协同催化硝酸盐转化为氨

铜基催化剂已被广泛研究以提高电化学硝酸盐还原反应（NO ₃ –RR）的性能，但平衡高氨（NH ₃）电流密度和法拉第效率仍然是一个挑战。在这里，我们将氮配位铁单原子催化剂（FeNC）与铜酞菁（CuPc）结合在一起，表示为CuPc/FeNC，用于NO ₃ –RR。与两种单独的催化剂相比，该双组分催化剂提高了NH ₃法拉第效率和低过电势下的电流密度，实现了高效的协同催化转化。实验和理论计算表明，CuPc/FeNC催化剂电化学性能的增强来自串联过程，其中NO ₂ ^-在CuPc上产生，然后转移到FeNC并进一步还原为NH ₃。在这种特殊的串联催化剂系统中，在高于 –0.35 V vs. RHE的电位下，实现了接近 100% 的出色 NH ₃法拉第效率，并且在–0.57 V vs. RHE 时峰值 NH ₃部分电流密度为 273 mA cm ^–2 . RHE，在整个潜在范围内有效抑制NO ₂ ^{-的产生。}_{该策略为NO 3} ^– RR催化剂的持续发展提供了设计平台。