Developing efficient electrocatalysts for nitrogen reduction reaction (NRR) is crucial to replace the both energy–intensive and environment–malignant Haber–Bosch process. Here using density functional theory calculations, we systematically studied the potential of the heteronuclear 3d transition metal dimers anchored graphdiyne monolayers (FeM@ and NiM@GDY, M = Ti, V, Cr, Mn, Fe, Co, Ni, and Cu) as efficient NRR catalysts. Among all the studied double–atom catalysts (DACs), FeCo@ and NiCo@GDY are the most promising with excellent NRR catalytic activity, high ability to suppress the competing hydrogen evolution reaction (HER), and good stability. For both FeCo@ and NiCo@GDY, NRR prefers to the distal pathway with the calculated onset potentials of −0.44 and −0.36 V, respectively, which are comparable and even better than their homonuclear counterparts. Moreover, FeCo@ and NiCo@GDY have higher ability to suppress HER than Fe₂@ and Co₂@GDY, which may result from the modulated d state electronic structure due to the synergy effect of the heteronuclear atoms in the DACs. Our work not only suggests that FeCo@ and NiCo@GDY hold great promises as efficient, low–cost, and stable DACs for NRR, but also further provides a strategy, i.e. alloying the atomic metal catalysts, to improve the NRR catalytic activity and/or selectivity.

开发用于氮还原反应（NRR）的高效电催化剂对于替代能源密集型和环境恶性的Haber-Bosch工艺至关重要。在这里使用密度泛函理论计算，我们系统地研究了异核3 d的潜力过渡金属二聚体锚固的石墨二炔单分子层（FeM @和NiM @ GDY，M = Ti，V，Cr，Mn，Fe，Co，Ni和Cu）作为有效的NRR催化剂。在所有已研究的双原子催化剂（DAC）中，FeCo @和NiCo @ GDY具有极好的NRR催化活性，抑制竞争性氢释放反应（HER）的能力以及良好的稳定性，是最有前途的。对于FeCo @和NiCo @ GDY而言，NRR偏向远端途径，其计算的起始电势分别为-0.44和-0.36 V，这与同核对应物相当，甚至更好。而且，FeCo @和NiCo @ GDY比Fe ₂ @和Co ₂ @ GDY具有更高的HER抑制能力，这可能是由于调制dDAC中异核原子的协同效应，使电子结构处于电子状态。我们的工作不仅表明FeCo @和NiCo @ GDY具有作为NRR的高效，低成本和稳定DAC的广阔前景，而且还提供了一种策略，即使原子金属催化剂合金化，以提高NRR催化活性和/或选择性。