Electrochemical reduction of nitrate (NO ₃ ⁻) to ammonia (NH ₃) has attracted considerable interest due to its great promises for eliminating harmful pollutants and simultaneously producing valuable NH ₃ , in which the development of highly efficient and selective catalysts still remains huge challenges. Herein, by means of density functional theory (DFT) computations, we explored the potential of a series of single transition metal atoms anchored on graphdiyne (TM/GDY) as the electrocatalysts for nitrate reduction reaction (NO ₃ RR) to NH ₃ . By systematically evaluating the activity and selectivity of various TM/GDY candidates, Os/GDY was identified as an ideal NO ₃ RR catalyst with a low limiting potential (−0.37 V) and great suppressing effect on the competing reactions. Moreover, the volcano plot was established based on the scaling relation of free adsorption energies of various intermediates, and the origin of the catalytic activity NO ₃ RR was well rationalized by the descriptor of the adsorption strength and the polarized charge on the adsorbed NO ₃ * species. Our results not only proposed an eligible electrocatalyst to boost NO ₃ RR for ammonia synthesis, but also deeply understand the mechanism of NO₃RR process.

_{硝酸盐（NO 3} ^- ）电化学还原为氨（NH _{3 ）因其在消除有害污染物的同时产生有价值的NH 3}的巨大前景而引起了人们的极大兴趣，其中高效和选择性催化剂的开发仍然是巨大的挑战。在此，我们通过密度泛函理论 (DFT) 计算，探索了锚定在石墨二炔 (TM/GDY) 上的一系列单过渡金属原子作为硝酸盐还原反应 (NO ₃ RR) 生成 NH ₃的电催化剂的潜力。通过系统评估各种 TM/GDY 候选物的活性和选择性，Os/GDY 被确定为理想的 NO ₃RR 催化剂具有低限制电位（-0.37 V）和对竞争反应的巨大抑制作用。此外，基于各种中间体的自由吸附能的比例关系建立了火山图，并通过吸附强度和吸附NO ₃ *上的极化电荷的描述子很好地合理化了催化活性NO ₃ RR的起源。物种。我们的研究结果不仅提出了一种合格的电催化剂来促进氨合成中的 NO ₃ RR，而且还深入了解了 NO ₃ RR 过程的机理。