No abstract

The sluggish four-electron-transfer kinetics of the oxygen evolution reaction (OER) is a great challenge for the development of efficient and cost-effective OER electrocatalysts. Herein, we report single-atomic Ir and Mo co-confined in the lattice of a Co layered hydroxide (Co-LH) nanobox as an efficient OER electrocatalyst via a sacrificial template method. With the hollow structure and synergetic electronic interactions among Ir, Mo, and Co-LH, the catalyst delivers an ultralow overpotential of 220 mV at 10 mA cm–2 and high durability of over 800 h at 50 mA cm–2 in 1 M KOH, which significantly outperform the commercial Ir black catalyst. Density functional theory calculations indicate that adjacent Mo and Ir enhance the OER activities on the Ir sites at defects (defect-Ir) and Mo sites in the plane (in-plane-Mo), respectively. This study provides not only a highly efficient OER catalyst but also a strategy for confining dual-active centers with mutually improved catalytic activities.