Dynamic interfacial structure of au/CeO₂ catalyst upon thermal activation

The dynamic behavior of oxide-supported metal catalyst interfaces under thermal and gaseous activation critically determines their catalytic performance. Using in situ TEM, we reveal the atomic-scale evolution of Au nanoparticles on CeO₂ supports during thermal treatment. The Au/CeO₂ interface structure depends on three key factors: epitaxial matching, nanoparticle morphology, and metal-support interactions, all governed by the balance between Au surface energy, cohesive energy, and interfacial energy with CeO₂. Thermal activation induces significant structural reorganization in Au nanoparticles, exhibiting size- and support-dependent facet reorientation that follows temperature-driven wetting and sintering trends. These transformations are facilitated by crystalline defects (e.g., twin boundaries and dislocations) that reduce the energy barrier for atomic rearrangement.