Unsupported PtxRuyIrz and PtxIry as Bi-functional Catalyst for Oxygen Reduction and Oxygen Evolution Reactions in Acid Media, for Unitized Regenerative Fuel Cell

Abstract

The effect of Ru on the activity of unsupported PtxRuyIrz material was analyzed in 0.5 M H2SO4 for O2+4H++4e- ⇆H2O reaction. PtxIrz, PtxRuyIrz Pt, Ir and Ru materials were prepared by chemical reduction. The electrocatalytic activity was evaluated by Linear Sweep Voltammetry, Rotating Disk Electrode and Cyclic Voltammetry. PtxRuyIrz showed an improvement to ORR after potential for interest reaction was applied. Ruthenium electrochemical activity disappears when to subject to anodic potential. Catalytic materials had particle sizes of 5-10 nm. PtxRuyIrz alloy formation phases were observed by High Resolution Transmission Electron Microscopy. No evident electrochemical changes were observed to PtxIrz material at ORR.