Influence of the PtxRuIry electrocatalysts composition toward oxygen evolution and reduction reactions for unitized regenerative fuel cell

Abstract Electrodes based on ternary electrocatalysts for the oxygen evolution and reduction reaction in a unitized regenerative fuel cell were proposed and evaluated. Five PtxRuIry varying the amount of Pt and Ir were synthesized by chemical reduction. We analyzed the different PtxRuIry physicochemical properties and their stability electrochemical in repetitive changes to oxygen evolution and reduction reaction in 0.5 M of H2SO4. Samples showed a low crystallinity associated with different phase formation and a high particle agglomerates with an increment of Pt. The stoichiometric ratio proposes as Pt3.5Ru4.0Ir1.5 was the most promising electrocatalyst, exhibiting a high transfer coefficient and a Tafel slope of −65 mV·dec−1 after repetitive measurements.