Dopant‐Driven Positive Reinforcement in Ex‐Solution Process: New Strategy to Develop Highly Capable and Durable Catalytic Materials

The ex‐solution phenomenon, a central platform for growing metal nanoparticles on the surface of host oxides in real time with high durability and a fine distribution, has recently been applied to various scientific and industrial fields, such as catalysis, sensing, and renewable energy. However, the high‐temperature processing required for ex‐solutions (>700 °C) limits the applicable material compositions and has hindered advances in this technique. Here, an unprecedented approach is reported for low‐temperature particle ex‐solution on important nanoscale binary oxides. WO3 with a nanosheet structure is selected as the parent oxide, and Ir serves as the active metal species that produces the ex‐solved metallic particles. Importantly, Ir doping facilitates a phase transition in the WO3 bulk lattice, which further promotes Ir ex‐solution at the oxide surface and eventually enables the formation of Ir particles (