Realizing Negatively Charged Metal Atoms through Controllable d‐Electron Transfer in Ternary Ir ₁₋ <i> _x </i> Rh <i> _x </i> Sb Intermetallic Alloy for Hydrogen Evolution Reaction

Abstract Alloying noble metals with non‐noble metals is a promising method to fabricate catalysts, with the advantages of reduced noble metal usage and excellent activity. In this work, electron‐abundant Ir/Rh sites, as highly active centers for the hydrogen evolution reaction (HER), are realized by fabricating Ir 1− x Rh x Sb alloys through the arc‐melting method. The electron transfer from Sb to Ir/Rh makes the latter negatively charged, leading to considerably optimized adsorption for active H species during HER. As a result, the Ir 1− x Rh x Sb alloy exhibits outstanding activity for HER, with an optimized overpotential of 22 mV at 10 mA cm –2 and a Tafel slope of 47.6 mV dec –1 . This work provides insights into highly active alloys and sheds light on the utilization of electron‐abundant metal atoms.