Lattice Strain Engineering in Ru-Based Electrocatalysts for Efficient Acidic Overall Water Splitting and Ru Dissolution Suppression

Developing efficient and durable electrocatalysts for PEMWE is essential for advanced hydrogen production. Here, we introduce a lattice strain manipulation strategy through multiphase interface engineering, demonstrating its effectiveness in enhancing water-splitting efficiency while mitigating Ru dissolution in acidic environments. Specifically, an in situ combustion method is employed to synthesize the Ru-based hybrid (Ru/RuS2/RuO2), increasing the density of crystal boundaries and optimizing the lattice strain within the Ru/RuS2/RuO2 structure. The two-electrode system consisting of the bifunctional Ru/RuS2/RuO2 hybrid exhibits superior overall water-splitting performance (19 mV@10 mA cm–2 for HER and 177 mV@10 mA cm–2 for OER), achieving an impressive low cell voltage of 1.468 V at a current density of 10 mA cm–2 with only 14 ppb of Ru ion dissolution even after 500 h. Experimental analyses and theoretical calculations highlight the critical role of the multiphase interfaces in modulating electronic structures, enhancing hydrophilicity, and accelerating water-splitting reactions. Density functional theory calculations further reveal reduced energy barriers and increased Ru dissociation energy, attributed to the shortened Ru–O/Ru–S bonds as well as the decreased bonding band energy of these interactions. This work underscores the transformative potential of multiphase interface engineering in overcoming durability and efficiency challenges for Ru-based electrocatalysts.