The selective hydrogenation of NO to NH2OH governs the performance of cyclohexanone oxime electrosynthesis. However, the spin state transition during the NO-to-NH2OH process, which is directly related to reaction pathways, has long been ignored. Here, we propose a spin locking mechanism via density functional theory and sure independence screening and sparsifying operator. Magnetic sites with medium spin states stabilize the *NHO intermediate by locking the spin configuration of NO to weaken *NH2OH adsorption for high selectivity. The spin magnetic moment (µS), the angle between *N-O and the catalyst (θ), and the charge state (q) are key factors, providing a screening range of the predictive metrics (µS·θ)3 and (cos θ/q). The theoretically selected NiFe2O4 delivers 70% Faradaic efficiency for cyclohexanone oxime, and weakened *NH2OH adsorption is revealed by in situ spectroscopy. This work highlights the importance of spin regulation in adjusting the selectivity of electrosynthesis.
Yang et al. (2025) studied this question.