Encapsulating Iridium Nanoparticles Inside a 3D Cage‐Like Organic Network as an Efficient and Durable Catalyst for the Hydrogen Evolution Reaction

Abstract Developing efficient and durable electrocatalysts is key to optimizing the electrocatalytic hydrogen evolution reaction (HER), currently one of the cleanest and most sustainable routes for producing hydrogen. Here, a unique and efficient approach to fabricate and embed uniformly dispersed Ir nanoparticles in a 3D cage‐like organic network (CON) structure is reported. These uniformly trapped Ir nanoparticles within the 3D CON (Ir@CON) effectively catalyze the HER process. The Ir@CON electrocatalyst exhibits high turnover frequencies of 0.66 and 0.20 H 2 s −1 at 25 mV and small overpotentials of 13.6 and 13.5 mV while generating a current density of 10 mA cm −2 in 0.5 m H 2 SO 4 and 1.0 m KOH aqueous solutions, respectively, as compared to commercial Pt/C (18 and 23 mV) and Ir/C (20.7 and 28.3 mV). More importantly, the catalyst shows superior stability in both acidic and alkaline media. These results highlight a potentially powerful approach for the design and synthesis of efficient and durable electrocatalysts for HER.