Cobalt-copper dual-atom catalyst boosts electrocatalytic nitrate reduction from water

Electrochemical nitrate reduction reaction (NO₃RR) presents a promising approach for sustainable water denitrification. Yet its practical implementation is hindered by sluggish reaction kinetics. Herein, we develop a nitrogen-doped carbon supported cobalt-copper dual-atom catalyst (CoCu-NC DAC) to significantly enhance the electro-catalytic NO₃RR performance. The optimized CoCu-NC DAC demonstrates exceptional activity, achieving a faraday efficiency of 95.3 % and a high NH₄⁺ yield rate of 2.41 mg h^-1 cm^-2 at -0.6 V_RHE, surpassing the performance of conventional Cu/Co single-atom catalysts. In-situ analysis and density functional theory calculations confirm that the synergistic effects arising from (1) optimized electronic structure for balanced intermediate adsorption, and (2) enhanced surface H concentration facilitating NO_x hydrogenation. This work not only provides fundamental insights into the DACs, but also offers a practical solution for groundwater nitrate remediation, opening new avenues for the application of atomically dispersed catalysts.