On the activity and stability of Sr3NiPtO6 and Sr3CuPtO6 as electrocatalysts for the oxygen reduction reaction in a polymer electrolyte fuel cell

Sr3NiPtO6 and Sr3CuPtO6 were evaluated as low-platinum alternative oxygen reduction catalysts in a solid polymer electrolyte fuel cell at 80 °C. The oxides were synthesised using a new method based on an organometallic precursor route. The electrochemical evaluation showed similar oxygen reduction performance for Sr3NiPtO6 and Sr3CuPtO6, with a slightly higher activity for Sr3NiPtO6. In comparison with the oxides, the oxygen reduction activity for a commercial Pt/C catalyst was approximately 10 times higher. XRD analysis of the used electrodes revealed that the oxides were not stable in the PEMFC environment, and converted into platinum during operation. Elemental analysis of the used electrodes also showed a difference in platinum formation, where the platinum content on the surface of the electrode facing the gas diffusion layer was several times higher for Sr3NiPtO6 than Sr3CuPtO6. This indicates that the Sr3NiPtO6 electrode may be more susceptible to platinum migration.