Nonequilibrium Photothermal Reactions Under Pulsed Laser Excitation: Mechanisms, Dynamics, and Applications

ABSTRACT Pulsed laser excitation offers a compelling approach for accessing nonequilibrium conditions in catalysis by delivering energy to surfaces in a highly localized and time‐controlled manner. In contrast to continuous‐wave irradiation, pulsed lasers concentrate energy into extremely short bursts—ranging from femtoseconds to nanoseconds—which can induce steep thermal gradients, localized heating, and even partial decoupling between electronic and lattice subsystems. These effects often lead to surface restructuring, altered binding of intermediates, or activation of otherwise inaccessible pathways. Such transient photothermal environments have shown considerable promise in driving reactions like CO 2 reduction, hydrogen evolution, and ammonia synthesis, where heat and charge localization strongly influence product selectivity. This review examines the growing field of pulsed photothermal catalysis, highlighting the fundamental mechanisms of laser–matter interactions, the distinction between thermal and nonthermal regimes, and how key laser parameters affect surface reactivity. We also survey selected reaction systems and discuss how recent developments in time‐resolved spectroscopy and computational modeling are helping to unravel the underlying dynamics and inform the rational design of next‐generation catalytic platforms.