Electrocatalytic nitrogen reduction reaction (NRR) is a sustainable and promising strategy for the conversion of N₂ into NH₃. However, electrocatalytic NRR is vitally dependent on metal-based catalysts, and it remains a huge challenge in achieving effective NRR on metal-free catalysts. Here we report that O-doped graphdiyne (GDY) as a metal-free NRR electrocatalyst in aqueous solution. O doping in the GDY results in the redistribution of electron density, where the sp-C atom nearest to the O atom provides enhanced capture to N₂ molecules. The influence of surface strain on the progression of NRR on O-doped GDY surface has been investigated using the density functional theory (DFT) calculation method. The DFT calculations predict that the potential-limiting steps (PLS) do not vary with the strain, which is *NHNH₂→*NH₂NH₂ for alternating mechanism and *NH₂→*NH₃ for distal mechanism under the strain range of -1%∼ +5%; the limiting potentials of alternating mechanism is higher than that of distal mechanism; the limiting potentials of two mechanisms decrease with the tensile strain. It can be inferred that the NRR activity increases with a tensile strain of 0%∼ +5%. Our study not only gets deep insights into the catalytic activity of O-doped GDY but also highlights the significance of strain engineering for catalyst design.

电催化氮还原反应（NRR）是将N ₂转化为NH ₃的可持续且有前途的策略。但是，电催化NRR非常依赖于金属基催化剂，在无金属催化剂上实现有效的NRR仍然是巨大的挑战。在这里，我们报告O掺杂的石墨二炔（GDY）作为水溶液中的无金属NRR电催化剂。GDY中的O掺杂导致电子密度的重新分布，其中最靠近O原子的sp -C原子增强了对N _2的捕获分子。使用密度泛函理论（DFT）计算方法研究了表面应变对N掺杂在O掺杂的GDY表面上NRR进行的影响。DFT计算表明，势能限制步骤（PLS）不会随应变而变化，对于交替机理，这是* NHNH ₂ →* NH ₂ NH ₂，而* NH ₂ →* NH ₃对于远侧机构，在-1％〜+ 5％的应变范围内；交替机构的极限电位高于远端机构的极限电位。两种机制的极限电势随拉伸应变而降低。可以推断出，NRR活性随着拉伸应变为0％〜+ 5％而增加。我们的研究不仅深入了解了O掺杂GDY的催化活性，而且强调了应变工程对催化剂设计的重要性。