Recent Advances in Ionizing Radiation as a Nonequilibrium Chemical Field for Catalysis

ABSTRACT Energy input is a defining variable in catalysis because it governs the formation, lifetime, transport, and utilization of reactive species. Ionizing radiation offers a distinct nonequilibrium mode of energy delivery: γ‐rays, electron beams, and ion beams induce ionization, excitation, and radiolysis to generate solvated electrons, radicals, radical ions, secondary electrons, excited states, and solid‐state defect centers directly within reaction media and interfaces. These radiation‐generated species and structural perturbations provide a common chemical basis for catalyst construction and reaction promotion, enabling precursor reduction, nucleation control, defect and interface engineering, framework evolution, carbon‐network reorganization, oxidation, reductive small‐molecule conversion, and radical‐mediated bond formation. In this Review, we develop a catalysis‐centered framework that treats ionizing radiation as a nonequilibrium chemical field rather than as a conventional processing or modification technique. By linking materials evolution with reaction‐network regulation, we show that its catalytic significance lies not simply in accelerating synthesis or enabling milder reaction conditions, but in accessing structural states and reaction pathways that are difficult to reach using established thermal, photochemical, or electrochemical methods. Future advances will require two complementary efforts: in situ/operando characterization and mechanistic modeling that make radiation‐induced species, structural evolution, and selectivity predictable, and reactor/dosimetry engineering that translates these nonequilibrium pathways into scalable and energy‐efficient catalytic processes.