High-Density Co-Ir-Co Triple-Atom Sites in Salphen-Fused Nanoribbons Break the Activity-Stability Dilemma in Alkaline Oxygen Evolution.

The development of stable, active, and well-defined electrocatalysts for water oxidation is vital for large-scale green hydrogen production. However, the inherent trade-off between activity and stability of electrocatalysts imposes fundamental limitations on their practical applications. Herein, we fabricated a molecularly precise triatomic catalyst featuring highly dispersed atomic iridium (14.3 wt.%) along with dense atomic cobalt grippers (10.4 wt.%) anchored on a Salphen-fused nanoribbon (Co2Ir-SNR), enabling highly effective and durable oxygen evolution reaction (OER). In situ infrared spectroscopy together with theoretical calculations reveals that the Co2Ir-SNR follows the infrequent oxide path mechanism (OPM) with a reduced energy barrier, where the active iridium sites confined in two cobalt grippers promote direct O-O radical coupling for O2 evolution. Consequently, the triatomic catalyst achieves a remarkable overpotential of 212 ± 3 mV at 10 mA cm-2 and possesses durability with stable operation for up to 1000 h at an ampere-level current density under alkaline conditions. This work presents a viable strategy to break the activity-stability dilemma encountered in OER, providing crucial guidance for developing catalysts that withstand the stringent requirements of industrial hydrogen production.