Phosphated IrMo bimetallic cluster for efficient hydrogen evolution reaction

Developing low-cost, high-performance electrocatalysts for the hydrogen evolution reaction (HER) is essential for producing hydrogen from renewable energy sources. Herein, we report phosphated IrMo bimetallic clusters supported by macroporous nitrogen-doped carbon (IrMoP/MNC) as a highly efficient alkaline HER catalyst. The experimental and theoretical results demonstrate that P and Mo synergistically tune the electronic structure of atomically dispersed Ir to improve adsorption of the reactant H2O and desorption of the product OH−. P itself serves as an active site and cooperates with the nearby Ir atom to significantly enhance the HER kinetics. Even with only 2.6 ​wt% Ir in the catalyst, IrMoP/MNC exhibits an ultralow overpotential of 14 ​mV at 10 ​mA ​cm−2, as well as an unprecedented high mass activity of 18.58 A mgIr−1 at an overpotential of 100 ​mV, superior to commercial Pt/C and overwhelmingly better than other Ir-based electrocatalysts. This study demonstrates a multi-level design strategy to effectively improve the atom efficiency of a noble metal, involving spatial geometry, local electronic structure, and dual-atom synergy. [Display omitted] •Phosphated IrMo clusters with high noble metal utilization are synthesized as an electrocatalyst for the alkaline hydrogen evolution reaction.•Phosphorus optimizes the electronic structure of Ir and synergistically decomposes water molecules with Ir to enhance the HER kinetics.•Macroporous carbon-supported IrMoP clusters exhibit an ultralow overpotential and high mass activity for the alkaline HER.