Mechanochemical Method-Induced Construction of the Mn-O_v-Ce Bridged Structure to Promote Oxygen Dynamic Migration and...

Urban driving conditions characterized by frequent start-and-stop operations challenge the dynamic responsiveness of three-way catalysts (TWCs), and the rapid response to oxygen is crucial to buffering air-fuel ratio fluctuations. Herein, we synthesized nonstoichiometric Mn_1.5Fe_1.5O₄ (MF) spinel with excellent oxygen storage capacity and introduced it into Rh/CeO₂-ZrO₂-Al₂O₃ (Rh/CZA) via high-energy ball milling to form the composite structure TWCs. The catalysts significantly show a wide operating window and similar steady-state catalytic effects under lean-rich burn oscillating conditions (λ = 0.98-1.02; switching frequency, 1 Hz). MF incorporation not only retains its excellent oxygen storage capacity but also results in the generation of abundant oxygen vacancies on MF-CZ heterogeneous interfaces, thus synergistically promoting the rapid formation and migration of active oxygen species. Furthermore, the lower oxygen vacancy formation energy (E_form) for the Mn-O_v-Ce bridged structure promotes the rapid formation of interfacial oxygen vacancies and the facile desorption of active oxygen species, which is important to enhance the reaction rates and buffer air-fuel ratio fluctuations. This study presents a strategy to enhance the dynamic responsiveness of TWCs and offers critical insights into the formation mechanisms and migration of the active oxygen species process on heterogeneous interfaces.