Binder-coated electrodeposited PtNiCu catalysts for the oxygen reduction reaction in high-temperature polymer electrolyte membrane fuel cells

One of the main issues hindering the commercialization of high-temperature polymer electrolyte membrane fuel cells (HT-PEMFCs) is their poor activity and stability in the presence of H3PO4. In this study, PtNiCu ternary catalysts with various compositions for oxygen reduction reaction (ORR) were prepared by a simple electrodeposition technique. The morphologies and crystalline structures were found to depend on the alloy composition. Furthermore, electrochemical characterization in the presence of poisoning phosphate anions, clearly showed that the PtNiCu catalyst exhibited 5.5-fold higher specific activity than Pt-100. The half-wave potential of the PtNiCu catalyst was also approximately 160 mV higher than that of Pt-100. From the stability test, it was confirmed that Pt-100 was severely deteriorated, where the amount of performance loss was dependent on the binders and H3PO4. However, the performances of the PtNiCu during the potential cycling in the presence of H3PO4 were substantially higher than that of Pt-100 regardless of the binders, suggesting the high resistance of the PtNiCu to phosphate adsorption as well as its superior ORR activity. Among the competing binders, the PtNiCu-PVDF catalyst has good stability over 4000 potential cycles, suggesting its use as a highly promising ORR catalyst for HT-PEMFCs.