Strain Effects in Ru‐Au Bimetallic Aerogels Boost Electrocatalytic Hydrogen Evolution

To improve the sluggish kinetics of the hydrogen evolution reaction (HER), a key component in water‐splitting applications, there is an urgent desire to develop efficient, cost‐effective, and stable electrocatalysts. Strain engineering is proving an efficient strategy for increasing the catalytic activity of electrocatalysts. This work presents the development of Ru‐Au bimetallic aerogels by a simple one‐step in situ reduction‐gelation approach, which exhibits strain effects and electron transfer to create a remarkable HER activity and stability in an alkaline environment. The surface strain induced by the bimetallic segregated structure shifts the d‐band center downward, enhancing catalysis by balancing the processes of water dissociation, OH* adsorption, and H* adsorption. Specifically, the optimized catalyst shows low overpotentials of only 24.1 mV at a current density of 10 mA cm−2 in alkaline electrolytes, surpassing commercial Pt/C. This study can contribute to the understanding of strain engineering in bimetallic electrocatalysts for HER at the atomic scale. Surface strain induced by the RuAu bimetallic aerogel of the phase‐separated structure shifs the d‐band center downward, which causes enhanced and long‐term stabilization of hydrogen evolution reaction in the alkaline.