Tailoring multifunctional iron-ruthenium interfaces to minimize competitive adsorption of hydrogen and hydroxyl species for enhanced alkaline hydrogen evolution reaction

Alleviating the competition adsorption between H* and OH* adsorption on catalysts represents a fundamental challenge for optimizing the catalytic efficiency of alkaline hydrogen evolution reactions (HER). Herein, a multiphase heterojunction of Ru nanoparticles modified FeOOH/FeS (Ru-FeOOH/FeS) was designed to minimize OH*-induced site blocking and free Ru active sites for efficient HER. Typically, the optimized Ru-FeOOH/FeS demonstrated superior performance, requiring only 22.26 and 259.74 mV of overpotentials to reach current densities of 10 and 500 mA cm⁻², respectively, and maintaining stable operation over 70 h. Additionally, the mass activity at an overpotential of 200 mV was increased 3.5-fold over commercial Pt/C (5.44 A·mg_Ru⁻¹ vs 1.57 A·mg_pt⁻¹, Pt/C). Density functional theory calculations confirmed that the disparity in OH* adsorption energy was established at the Ru-FeOOH interface, where FeOOH with a strong affinity for OH* effectively promoted the regeneration of Ru active sites. Meanwhile, the synergistic effect of Ru sites and the support of FeS optimized the RuH binding strength, which facilitated the transform of H* to hydrogen. This work provides a strategy to precisely control the interaction between electrocatalysts and reaction intermediates for achieving efficient hydrogen production.