Direct Cl─Cl Coupling Over Atomically Dispersed Ir ₂ Pairs for Efficient Chlorine Electrosynthesis

Abstract

ABSTRACT Chlorine evolution reaction underpins the chlor‐alkali industry, yet its conventional dimensionally stable anodes (DSAs) suffer from low noble‐metal utilization and limited intrinsic activity. Here, we report a molecularly precise strategy to construct atomically dispersed iridium diatomic (Ir 2 ) pairs anchored on MnO 2 nanorods (i.e., Ir 2 ─MnO 2 ), representing a well‐defined dual‐atom catalyst (DAC) for efficient chlorine electrosynthesis. Spherical aberration‐corrected microscopy and x‐ray absorption spectroscopy (XAS) validate the diatomic features of Ir 2 pairs with an interatomic distance of 3.16 Å. The Ir 2 ─MnO 2 electrocatalyst exhibits competitive CER performance, delivering an overpotential of 36.9 mV at 10 mA cm −2 and a low Tafel slope of 34.6 mV dec −1 in NaCl electrolyte. Kinetic analysis, operando Raman spectroscopy, and theoretical calculations collectively reveal that adjacent Ir–Ir dual‐atoms synergistically stabilize two *Cl intermediates, enabling a thermodynamically favored direct *Cl─*Cl coupling mechanism. Notably, Ir 2 ─MnO 2 maintains satisfactory selectivity and durability over 500 h at large current densities in natural seawater electrolysis. This work breaks the technical challenges of atomic‐scale dispersion and diatomic pairing of DACs, establishing diatomic site engineering as a powerful paradigm for efficient chlorine electrosynthesis.