Resolving the Activity-Stability Trade-off of Pd/CeO₂/Al₂O₃ Catalyst in CO Oxidation: An Interface Reconstruction...

The inherent trade-off between catalytic activity and stability presents a central challenge in heterogeneous catalysis. Herein, we demonstrate that a novel interface reconstruction strategy, facilitated by CeO₂ crystalline size control and the different affinity of Pd toward CeO₂ and Al₂O₃, effectively overcomes this limitation for Pd/CeO₂/Al₂O₃ catalyst in CO oxidation. This approach not only enhances the thermal stability of CeO₂ component but also modulates its defect structure, thereby controlling the dispersion and migration behavior of Pd within CeO₂/Al₂O₃ support. Notably, an increase in CeO₂ dimensions leads to a progressive reduction in the oxygen vacancy concentration, consequently shifting Pd deposition from preferential localization on CeO₂ to a homogeneous distribution across both CeO₂ and Al₂O₃. After thermal treatment, it was found that a catalyst with intermediate-sized CeO₂ achieves optimal performance by balancing the defect density and stability of CeO₂. This equilibrium facilitates the migration of Pd from Al₂O₃ to CeO₂ to regenerate Pd-Ce interfaces and boost lattice oxygen activation for CO oxidation. This study underscores thermal migration as an effective strategy for constructing active interfaces and offers insights into the dynamic evolution of supported metal catalysts under operational conditions.