A Spin Descriptor Map Predicts NiFe ₂ O ₄ for Efficient Electrosynthesis of Cyclohexanone Oxime

Abstract The selective hydrogenation of NO to NH 2 OH governs the performance of cyclohexanone oxime electrosynthesis. However, the spin state transition during the NO‐to‐NH 2 OH 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 *NH 2 OH adsorption for high selectivity. The spin magnetic moment ( µ S ), 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 ( µ S · θ ) 3 and (cos θ / q ). The theoretically selected NiFe 2 O 4 delivers 70% Faradaic efficiency for cyclohexanone oxime, and weakened *NH 2 OH adsorption is revealed by in situ spectroscopy. This work highlights the importance of spin regulation in adjusting the selectivity of electrosynthesis.