(451b) Alternating Magnetic Field Regulates Thermal Catalytic Reactions Beyond Temperature-Controlled Limits

Magnetic Induction Heating (MIH), where ferromagnetic nanoparticles can be utilized as self-heating susceptors in the catalyst bed, is viewed as a scalable and energy-efficient alternative heating approach for thermal reactors. Concisely, when these magnetic nanoparticles are exposed to an alternating magnetic field (MF_alt), their unpaired electron spin/magnetic moments align in response to the field; when the field is reversed, the aligned electron spin switches direction. This rapid cyclic motion of electron spins converts electromagnetic energy from MF_alt to internal energy gains. However, does the internal energy gain fully translate to apparent heat, or part of it can be infused into the intrinsic catalysis, since both the internal energy gain and catalysis originate from electron spin regulations? In our exploration of nominal thermal catalysis via MIH reaction mode_, we report that in addition to supplying reaction heat, the MF_alt can directly impact the thermal catalytic chemistry. With the typical ferromagnetic Pt/Fe₃O₄ nanocatalysts and CO oxidation reaction as a model system, we found MF_alt to be effective for regulating CO oxidation beyond temperature controls and new catalytic structure creation. Despite the much-enhanced reactivity in the MIH mode, the more negative reaction order of CO is highly unusual, which usually links to strong *CO adsorption to overkill the catalytic sites. We performed mechanistic studies using zero, static, and MF_alt fields to deconvolute the dynamic catalysis. The abundant ^*CO coverage, and facile CO₂ generation in dynamic cycles due to spin regulation seem to be the key. This beneficial alternating field-enhanced thermal catalytic reactivity was also preliminarily observed for CO₂ reduction and ammonia decomposition reactions, boding well for the opportunities in leveraging dynamic magnetic field to reimagine the otherwise static thermal catalysis.