Modulating electronic structure and hydrogen bond network via asymmetric S-Ru-O interfaces for superior alkaline hydrogen oxidation catalysis

Triggering structural asymmetry can induce charge redistribution and modify electronic structures, which is of great significance for the design of high-performance hydrogen oxidation reaction (HOR) electrocatalysts. Herein, we propose a dual anion-induced strategy to create an innovative RuS 2 -RuO 2 heterostructure featuring abundant S-Ru-O interfaces (RuS 2 -RuO 2 @C). This RuS 2 -RuO 2 @C demonstrates an impressive mass activity of 2.61 mA μ g R u - 1 and an exchange current density of 2.96 mA cm −2 , surpassing Pt/C and other comparative samples by over 20 times. Durability assessments confirm the superior stability of RuS 2 -RuO 2 @C, with only minimal performance loss during operation. Density functional theory (DFT) calculations indicate that the asymmetric S-Ru-O configuration optimizes the interfacial electronic structure and shifts the d -band center closer to the Fermi level, effectively reducing the energy barrier of the rate-determining step (RDS) in the alkaline HOR process. Moreover, in situ attenuated total reflection surface-enhanced infrared absorption spectroscopy (ATR-SEIRAS) characteristics disclose the formation of a substantial hydrogen bond network at the S-Ru-O interface, which aids in the desorption of H 2 O ad and facilitates the vital Volmer step in the HOR pathway.