Explicit Spin Regulation as an Emerging Design Paradigm in Heterogeneous Catalysis

Conspectus Catalytic activity, selectivity, and durability arise from coupled electronic, structural, interfacial, transport, and spin-related processes. Conventional catalyst design has relied largely on electronic effects, strain or stress engineering, active-site construction, and local reaction environment control. Although these strategies have enabled major advances, they do not fully capture the spin degrees of freedom associated with open-shell transition-metal centers and magnetically responsive catalysts. Spin state, spin polarization, magnetic moment, spin density, and magnetic ordering can influence adsorbate binding, transition-state stabilization, charge transfer, and reaction pathways, yet their catalytic consequences are often grouped under the broad label of magnetic enhancement without a clear mechanistic assignment. In this Account, we develop explicit spin regulation as a framework for magnetism-informed catalysis. Magnetic enhancement describes an observed response to a magnetic field, a magnetic component, or a magnetic environment. Explicit spin regulation, by contrast, requires deliberate modulation of spin-related variables at or near catalytically active sites and a mechanistic connection to catalytic function. We organize this framework around two routes. Catalyst-integrated spin levers use promoters, interfaces, or interphases to tune the active-site spin/electronic structure, whereas field-induced spin levers introduce external fields or catalyst-localized magnetic perturbations during catalysis. Although implemented differently, both routes seek to control how the active-site spin governs adsorption, transition-state energetics, charge transfer, selectivity, stability, and durability. Our studies provide representative evidence for this framework. Promoter-induced spin modulation stabilizes the N–N dissociation transition state beyond conventional electrostatic promotion, establishing the spin-promotion effect as a catalyst-integrated design principle. In electrocatalysis, external fields, embedded nanomagnets, and magnetic proximity effects provide progressively localized perturbations that can be connected to spin-sensitive active sites, key intermediates, or local magnetic ordering. These examples also show why performance enhancement alone is insufficient. A convincing assignment should connect the imposed perturbation, the active-site spin/electronic response, the affected intermediate or transition state, and the resulting catalytic consequence. Magnetic measurements, electron paramagnetic resonance spectroscopy, element-specific X-ray spectroscopies, operando methods, kinetic analysis, and spin-polarized theory provide complementary elements of this evidence loop. Building on this mechanistic framework, we further translate the active-site spin into catalyst-design descriptors. The local metal-center spin moment can be correlated with oxygen-intermediate adsorption and activity trends, enabling descriptor-guided screening of dual-atom catalysts. Spin-related variables may also inform stability and durability through their connections to phase stability, surface reconstruction, active-site preservation, dissolution resistance, and long-term operation. Generalizing these insights requires paired, standardized, and machine-readable datasets that connect magnetic perturbations, active-site structures, spin-sensitive measurements, catalytic metrics, and durability under comparable conditions. Artificial intelligence-assisted literature mining, knowledge graph construction, high-throughput spin-polarized calculations, active learning, and magnetism-aware machine-learning interatomic potentials may help identify transferable spin descriptors and extend spin-regulated catalyst design to dynamic interfaces. The broader aim is to move magnetism-informed catalysis from phenomenological enhancement toward predictive control through deliberate regulation of the active-site spin.