1D PtCo nanowires as catalysts for PEMFCs with low Pt loading

The high cost of platinum (Pt)-group metal (PGM)-based catalysts used in proton-exchange membrane fuel cells (PEMFCs) poses a critical roadblock to their widespread adoption. Although using low PGM loading PEMFCs can largely address this challenge, high current density performance will be severely compromised consequently. To overcome this dilemma, we report the development of ultra-thin platinum-cobalt nanowires (PtCoNWs) as the cathode catalysts for ultralow Pt loading and high-performance membrane electrode assembly (MEA). The PtCoNWs delivered a record-high mass activity (MA) of 1.06 ± 0.14 AmgPt−1 of Pt-alloy catalysts towards oxygen reduction reaction (ORR) in MEA, yielding an impressive total Pt utilization of 5.14 WratedmgPt−1. The PtCoNWs retained a respectable end-of-life MA of 0.45 A mgPt−1 after the 30,000 cycles square-wave accelerated stability test, which is still above the Department of Energy 2020 beginning-of-life target for catalysts. In-situ X-ray absorption spectroscopy studies suggest that the high degree of alloying in the PtCoNWs stabilizes the ultrathin structure and may contribute to the high ORR activity and power density performance in PEMFC.