Oxygen reduction reaction activity and durability of Pt-Ta-Co ternary catalysts for polymer electrolyte fuel cells

Enhancing the oxygen reduction reaction (ORR) activity and durability of cathode electrocatalysts in polymer electrolyte fuel cells (PEFCs) will be crucial for the implementation of fuel cell electric vehicles (FCEVs). Here, ternary Pt-Ta-Co catalysts are developed, in which platinum, tantalum, and cobalt components are co-decorated onto a carbon support. During synthesis, the tantalum-containing electrocatalysts phase-separate into Pt-Co alloy nanoparticles and TaOx phases, forming a nanocomposite structure. The presence of tantalum oxide suppresses Pt-Co particle growth during high-temperature synthesis (leading to high initial activity) and during load cycling (suppressing Pt-Co agglomeration and ripening). Furthermore, the presence of TaOx phases prevents direct contact between the catalyst nanoparticles and the carbon support, preventing carbon corrosion during start-stop cycling. Overall, Pt-Ta-Co catalysts presented outperform conventional Pt/carbon catalysts in terms of both initial activity and durability. This work paves the way for the design of next-generation PEFCs for FCEVs.