Electrochemical nitrate reduction reaction (NO₃RR) holds promise for the management of wastewater contamination and synthesis of carbon−neutral ammonia (NH₃). However, high−quality catalysts with controllable reaction pathways and high activity and selectivity are still lacking. The emerging single atom alloys (SAAs) offer attractive possibilities in nitrate reduction due to their unique atomic and electronic structures. By high−throughput first−principles calculations, we explore the possible incorporation of a series of transition−metal alloyed Cu−based SAAs, referred to as TM/Cu(111), for NO₃RR toward NH₃. A hierarchical four−step screening strategy have been employed to evaluate twenty−seven SAA catalysts yielding three alloying elements (Ti, Ni and Nb) with high catalytic activity and NO₃RR selectivity. Finally, only Ni/Cu(111) possess the best activity among these three candidates because of its lowest limiting potential of − 0.29 V. After further analysis, we found that the adsorption free energy of *NO₃ can be recognized as efficient descriptor to design and predict the NO₃RR performance of SAA. Furthermore, the Cu−based SAAs were revealed to exhibit pH dependent properties, which influence the competition between the hydrogen evolution reaction (HER) and NO₃RR. This work not only indicates the significant potential of SAA in electrocatalysis for NO₃RR to NH₃, but also highlights the important influence of pH on the activity and selectivity of catalysts under reaction conditions.

电化学硝酸盐还原反应 (NO ₃ RR) 有望用于废水污染的管理和碳中性氨 (NH ₃ ) 的合成。然而，仍然缺乏具有可控反应途径和高活性和选择性的高质量催化剂。由于其独特的原子和电子结构，新兴的单原子合金 (SAA) 为硝酸盐还原提供了极具吸引力的可能性。通过高通量第一性原理计算，我们探索了可能结合一系列过渡金属合金化 Cu 基 SAA，称为 TM/Cu(111)，用于 NO 3 RR_到NH ₃. 采用分层四步筛选策略来评估 27 种 SAA 催化剂，产生具有高催化活性和 NO 3 RR 选择性的三种合金元素（Ti、Ni 和 Nb _）。_{最后，只有 Ni/Cu(111) 在这三个候选物中具有最好的活性，因为它的最低极限电位为 − 0.29 V。经过进一步分析，我们发现 *NO 3}的吸附自由能可以被认为是有效的描述符设计和预测 SAA 的 NO ₃ RR 性能。此外，Cu 基 SAA 显示出 pH 依赖性，这会影响析氢反应 (HER) 和 NO _{3之间的竞争}RR。这项工作不仅表明了 SAA 在将 NO ₃ RR 转化为 NH ₃的电催化中的巨大潜力，而且强调了在反应条件下 pH 值对催化剂的活性和选择性的重要影响。