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.
Zheng et al. (Thu,) studied this question.