Asymmetric dual-metal-hybridization in dual-atom dimers trigger a spin transition for electrochemical degradation from nitrate to ammonia

The dual-atom dimer with half-filled 3d orbital demonstrates a great advantage in electrochemical degradation from nitrate to ammonia, because their binding interaction and electron transfer between reactants and active sites are spin-dependent. Herein, we suggest a local structure distortion caused by a bimetallic hybridization to regulate the spin configuration from low to high by implanting one Fe atom into the Mn/Mn dimer on holey nitrogen-doped graphene, which makes the Mn magnetic moment increase to 3.31 μ_B from 0.48 μ_B. Meanwhile, the activation energy of the formed *NOH at rate-limiting step can be decreased to 0.79 eV, which is obviously lower than the pristine Fe/Fe (1.38 eV) and Mn/Mn (1.12 eV) dimers. These findings enlighten an intriguing strategy to enhance the reactive activity of dual-atom catalysts by regulating their spin configuration.