Dopant‐Driven Positive Reinforcement in Ex‐Solution Process: New Strategy to Develop Highly Capable and Durable Catalytic Materials
Ji‐Soo Jang, Jun Kyu Kim, Kyeounghak Kim, Wan‐Gil Jung, Wan‐Gil Jung, Chaesung Lim, Sang‐Woo Kim, Dong‐Ha Kim, Bong‐Joong Kim, Jeong Woo Han, WooChul Jung, WooChul Jung, Il‐Doo Kim
Abstract
Abstract 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. WO 3 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 WO 3 bulk lattice, which further promotes Ir ex‐solution at the oxide surface and eventually enables the formation of Ir particles (<3 nm) at temperatures as low as 300 °C. Low‐temperature ex‐solution effectively inhibits the agglomeration of WO 3 sheets while maintaining well‐dispersed ex‐solved particles. Furthermore, the Ir‐decorated WO 3 sheets show excellent durability and H 2 S selectivity when used as sensing materials, suggesting that this is a generalizable synthetic strategy for preparing highly robust heterogeneous catalysts for a variety of applications.