Harnessing Thermodynamically Driven Restructuring for Ultra‐Stable Catalysts

Heterogeneous catalysts often deactivate at high temperatures due to thermodynamic restructuring into more stable phases. Herein, we transform this typically detrimental process into a constructive design principle for ultra-stable catalysts. This is achieved by strategically constructing homologous-heterovalent interfaces, such as Ce⁴⁺/Ce³⁺ heterointerfaces, through the controlled integration of two solid phases formed during high-temperature restructuring of Ce-based oxides. Within these interfaces, the amplified strain directly promotes the formation of single oxygen-atom vacancies (SOVs), which efficiently activate the N─H bond in NH₃. Consequently, the resulting cerium-tantalum oxide catalysts exhibit outstanding activity for NO_x reduction by NH₃, even after severe hydrothermal aging at 1,100°C-a condition that deactivates conventional catalysts. The generality of this approach is demonstrated by extending it to lanthanum-nickel oxide catalysts with tailored Ni³⁺/Ni²⁺ heterointerfaces for CO oxidation, achieving sustained stability up to 1,100°C. These findings establish a general design concept to overcome the persistent activity-stability trade-off in heterogeneous catalysis.