Exploring the potential of dynamic periodic operation on tackling challenging reactions under traditional steady state - a review

This review explores dynamic catalytic processes, particularly exsolution-driven forced periodic operations as transformative approaches to overcoming catalyst deactivation, improving conversion, yields and selectivity as well as enhancing reaction kinetics. Exsolution, a unique regenerative process in perovskite oxides, enables in-situ nanoparticle formation in reductive environment, fostering high dispersion, superior stability and resistance against sintering and coke formation. The formed nanoparticles can be reintegrated back into the host structure under oxidative environment. Therefore, alternating between reductive and oxidative environment can influence nanoparticle growth and inhibit thermodynamic driven irreversible sintering. Meanwhile, periodic operation or chemical looping, through either controlled cycling or oscillation of reactant composition, pressure, and temperature, unlocks non-equilibrium catalytic behaviors that exceed steady-state performance. This dynamic approach has been demonstrated across various challenging catalytic reactions, such as wet lean methane oxidation, partial oxidation, dry reforming, and CO oxidation, achieving significantly higher efficiency and stability. This review systematically examines the fundamental principles, mechanistic insights, and key advancements in dynamic catalysis, offering a forecast perspective on its industrial implementation. The benefits of this approach are compared to conventional steady state and discussed in terms of pulsing strategy on the overall reaction conversion, yields, selectivity and structural dynamics of the catalysts enabling long term stability.