Electrochemical anchoring of rhenium single atoms on NiCoMo-Se heterostructure electrocatalyst for ampere-level hydrogen evolution

The development of high-performance and non-platinum electrocatalysts capable of operating at industrial-scale current densities is crucial for cost-effective green hydrogen production. While rhenium (Re) exhibits promising attributes, its implementation is hindered by the difficulty in synthesizing metallic Re and the suboptimal activity of its bulk forms. Herein, we demonstrate a facile electrochemical strategy to immobilize Re single atoms onto a Co, Mo-doped NiSe₂/NiCoMo alloy heterostructure (Re_SA-NiCoMo-Se) in a deep eutectic solvent. The optimized electrocatalyst delivers exceptional hydrogen evolution reaction (HER) performance in alkaline media, requiring ultralow overpotentials of only 23 and 292 mV at current densities of 10 and 1000 mA·cm⁻², respectively. When configured as a cathode in a flowing alkaline water electrolyzer, it enables competitive water splitting performance and robust operational stability for over 500 h. Structural characterization and theoretical calculations reveal that the atomically dispersed Re sites act as the active centers to facilitate the water dissociation and optimize hydrogen adsorption energy, simultaneously triggering a profound electron redistribution within the heterostructure support that leads to a collective enhancement of the reaction kinetics. This study showcases the feasibility of synthesizing Re single-atom materials via the electrochemical approach and highlights their potential as high-performance and stable electrocatalysts suitable for industrial applications.