A Low‐Temperature Solid Chemistry to Ru Clusterrene for Scalable Hydrogen Production

ABSTRACT Platinum‐group‐metal (PGM) nanomaterials are prominent in chemical and energy conversions. To date, their scalable manufacturing is confined by complex post‐processing or high‐temperature calcination (≥ 800°C), which are often required for conventional small‐sized nanoparticles. Herein, we have successfully developed a thermal buffer‐assisted low‐temperature (250°C) calcination strategy to create a sub‐nano Ru metallene called “Ru clusterrene” for anion exchange membrane water electrolysis (AEMWE). The rational use of NaCl is pivotal for successful synthesis, serving as a “buffer” to prevent thermal runaway. Consequently, the Ru clusterrene exhibits an ultra‐thin, fluid‐like structure that enables strong interaction with the substrate and ensures maximized active site exposure. Importantly, this strategy costs only US$39.42/g Ru , which is substantially lower than that of commercial Ru/C (Premetek, US$1407.50/g Ru ). The Ru clusterrene delivers an outstanding activity of 1.73 V@2 A cm ‒2 and 2.0 V@5.4 A cm ‒2 , as well as an unprecedented stability for 1000 h at 2 A cm ‒2 (80°C) and 3500 h at 1 A cm ‒2 (50°C). More significantly, it exhibits a high stack performance in AEMWE (3.6 V@1 A cm ‒2 and 2000 h@25 A), representing the most advanced level for AEMWE cathode catalyst.