Scalable synthesis of Robust, high-loading nitrogen-infused intermetallic FePt@Pt (core@shell) catalyst for proton exchange membrane fuel cells
Abstract
In this study, we propose PtFe IM N@Pt/C, featuring a Pt shell on a nitrogen-infused PtFe intermetallic core structure, and attempt large-scale synthesis of catalysts with high metal content (>50 wt%). Using the ultrasound-assisted polyol synthesis method, we synthesize core@shell structured PtFe@Pt/C catalysts with approximately 60 wt% metal content at a 10 g scale in a single step. Post-treatments, including annealing, acid treatment, and nitriding in high-pressure NH 3 gas, follow to synthesize the target catalysts. Optimizing the annealing temperature reveals a trade-off relationship affecting catalyst activity and durability. The PtFe IM N@Pt/C_600 °C, synthesized under optimized conditions, exhibits superior electrochemical performance and durability compared to commercial Pt/C catalysts. The accelerated stability test (AST) further shows significantly enhanced durability when nitrogen is included in the core. In the single cell tests, PtFe IM N@Pt/C_600 °C demonstrates approximately four times higher mass activity than commercial Pt/C catalysts and a 29.9 mV voltage drop at 0.8 A cm −2 after AST, meeting the U.S. Department of Energy's targets. • 10 g-scale synthesis of N-infused core@shell structured Pt-based catalysts for ORR. • Annealing conditions optimized to ensure optimal activity and durability. • A trade-off relationship with annealing temperature has been identified. • Optimal PtFe IM N@Pt/C_600 °C catalyst outperforms commercial catalysts. • PtFe IM N@Pt/C_600 °C meets the 2020 US DOE target for mass activity and durability.