Dilatometric and electrochemical studies on hydrogen transport through RuO2 coated on palladium Original Research Article

Combined electrochemical and dilatometry measurements were used to characterize the transport of hydrogen through thin RuO2 layers coated on palladium wire electrodes. Hydrogen dissolved in aqueous solutions penetrated through the oxide in a pH-dependent mechanism that combined diffusion of molecular hydrogen and pH-dependent proton hopping through redox sites within the oxide lattice. When cathodically charged, hydrogen was generated and absorbed at the oxide–solution interface only after Ru (IV) reduction occurs, and then, transported into the metal.