The electrochemical reduction of nitrate to ammonia (ERNA) has become a green treatment technology for nitrate wastewater. However, strong adsorption for product caused high activation energy for product desorption in scaling relations, blocking activity of electrocatalyst in ERNA. Density functional theory (DFT) calculations indicated that constructing dual active sites (Cu and Co₃O₄) could achieve strong adsorption of nitrate (−2.91 eV) with low desorbing energy barrier of ammonia (0.13 eV), breaking scaling relations. This dual active sites Co₃O₄/Cu electrode achieved a high ammonia yield rate of 684 µg ${\mathrm{mg}}_{\mathrm{cat}}^{-1}$ h⁻¹ with 94.6% faradic efficiency, surpassing single active site Co₃O₄ and Cu electrodes. For mechanism, In-situ electrochemical characterization found the vital intermediates of *NH and *NH₂, demonstrating that indirect reduction was the main pathway on Co₃O₄/Cu electrode. Thus, it is believed that building dual active sites on electrode is a reliable strategy to enhance ERNA for purifying industrial wastewater polluted by nitrate.

硝酸盐电化学还原成氨（E​​RNA）已成为硝酸盐废水的绿色处理技术。然而，对产物的强吸附导致产物解吸在比例关系中的高活化能，阻碍了ERNA中电催化剂的活性。密度泛函理论（DFT）计算表明，构建双活性位点（Cu和Co ₃ O ₄）可以实现对硝酸盐的强吸附（-2.91 eV）和低氨解吸能垒（0.13 eV），打破了比例关系。这种双活性位点 Co ₃ O ₄ /Cu 电极实现了 684 µg 的高氨产率${\mathrm{毫克}}_{\mathrm{猫}}^{-1}$h ^-1具有 94.6% 的法拉第效率，超过单活性位点 Co ₃ O ₄和 Cu 电极。对于机理，原位电化学表征发现了*NH和*NH ₂的重要中间体，表明间接还原是Co ₃ O ₄ /Cu电极的主要途径。因此，认为在电极上构建双活性位点是增强 ERNA 以净化被硝酸盐污染的工业废水的可靠策略。