Heterogeneous single-atom spin catalysts combined with magnetic fields provide a powerful means for accelerating chemical reactions with enhanced metal utilization and reaction efficiency. However, designing these catalysts remains challenging due to the need for a high density of atomically dispersed active sites with a short-range quantum spin exchange interaction and long-range ferromagnetic ordering. Here, we devised a scalable hydrothermal approach involving an operando acidic environment for synthesizing various single-atom spin catalysts with widely tunable substitutional magnetic atoms (M₁) in a MoS₂ host. Among all the M₁/MoS₂ species, Ni₁/MoS₂ adopts a distorted tetragonal structure that prompts both ferromagnetic coupling to nearby S atoms as well as adjacent Ni₁ sites, resulting in global room-temperature ferromagnetism. Such coupling benefits spin-selective charge transfer in oxygen evolution reactions to produce triplet O₂. Furthermore, a mild magnetic field of ~0.5 T enhances the oxygen evolution reaction magnetocurrent by ~2,880% over Ni₁/MoS₂, leading to excellent activity and stability in both seawater and pure water splitting cells. As supported by operando characterizations and theoretical calculations, a great magnetic-field-enhanced oxygen evolution reaction performance over Ni₁/MoS₂ is attributed to a field-induced spin alignment and spin density optimization over S active sites arising from field-regulated S(p)–Ni(d) hybridization, which in turn optimizes the adsorption energies for radical intermediates to reduce overall reaction barriers.

异质单原子自旋催化剂与磁场相结合，为加速化学反应提供了有力的手段，同时提高了金属利用率和反应效率。然而，由于需要具有短程量子自旋交换相互作用和长程铁磁有序性的高密度原子分散活性位点，设计这些催化剂仍然具有挑战性。在这里，我们设计了一种可扩展的水热方法，涉及操作酸性环境，用于在MoS _{2主体中合成具有广泛可调的取代磁性原子（M 1}）的各种单原子自旋催化剂。在所有M ₁ /MoS ₂物种中，Ni ₁ /MoS ₂采用扭曲的四方结构，促进与附近的S原子以及相邻的Ni ₁位点的铁磁耦合，从而产生全局室温铁磁性。这种耦合有利于析氧反应中的自旋选择性电荷转移以产生三线态O ₂。此外，~0.5 T 的温和磁场使析氧反应磁电流比 Ni ₁ /MoS ₂增强~2,880% ，从而在海水和纯水裂解电池中具有优异的活性和稳定性。_{根据操作表征和理论计算的支持，Ni 1} /MoS ₂上出色的磁场增强析氧反应性能归因于场调节的 S( p )–Ni( d)杂化，进而优化自由基中间体的吸附能，以降低总体反应势垒。