Electrochemical N₂ reduction reaction (NRR) has received much attention in recent times. Aiming for, discovering potential electrocatalysts with superior activity, stability and selectivity, a series of 3 d transition metal dimers were studied by density functional theory (DFT) calculations. The investigation reveals that most of the metal dimers have admirable stability, and partial density of states (PDOS) confirms that the unoccupied and occupied d orbitals of metal atoms are the key for effective activation of N₂. Especially, two metal dimers bonded to nitrogen-doped graphene, FeFe and CoCo, can selectively adsorb and activate N₂ for efficient conversion. Their limiting potentials are −0.44 and −0.45 V, which are superior than to most of the catalysts and they can well suppress the hydrogen evolution reaction (HER). Moreover, the desorption free energy of NH₃ is 0.54 and 0.57 eV respectively for FeFe and CoCo, guarantees the good durability of the catalysts.

近年来，电化学N ₂还原反应（NRR）备受关注。为了发现具有较高活性，稳定性和选择性的潜在电催化剂，通过密度泛函理论（DFT）计算研究了一系列3d过渡金属二聚体。研究表明，大多数金属二聚体具有令人钦佩的稳定性，部分态密度（PDOS）证实金属原子的未占据和占据的d轨道是N ₂有效活化的关键。特别是，两个与氮掺杂石墨烯键合的金属二聚体FeFe和CoCo可以选择性地吸附和活化N _2。进行高效转换。它们的极限电势为-0.44和-0.45 V，优于大多数催化剂，并且它们可以很好地抑制氢释放反应（HER）。此外，FeFe和CoCo的NH ₃脱附自由能分别为0.54和0.57eV，保证了催化剂的良好耐久性。