Atomic-Dispersed Cu Catalysts for Electrochemical Nitrate Reduction: Coordination Engineering and Fundamental...

The development of Cu-based atomic dispersed catalysts with tailored coordination environments represents a significant step forward in enhancing the electrocatalytic reduction of nitrate to ammonia. By precisely modulating the electronic structures of Cu active centers, the binding strength of the ^*NO₃ intermediates is successfully tuned, thereby substantially improving the catalytic activity toward electrochemical nitrate reduction reaction (eNO₃RR). This study reveals that the N₄-coordinated Cu single-atom catalyst (Cu-SAC) exhibits superior performance due to its robust interaction with coordinating atoms. Notably, this optimized catalyst achieves a low limiting potential of -0.38 V, while the dual-atom system further reduces this value to -0.32 V, demonstrating exceptional activity. Detailed electronic structure analysis, including the examination of d-band centers, Bader charges, and projected density of states (PDOS), provides a comprehensive understanding of the origin of this high activity. Specifically, the high and concentrated density of states near the Fermi level plays a crucial role in facilitating the electrocatalytic nitrate reduction process. This work not only offers crucial insights into the underlying mechanisms of eNO₃RR but also provides valuable guidelines for the rational design of highly efficient electrocatalysts for this important reaction.