Trace doping of early transition metal enabled efficient and durable oxygen reduction catalysis on Pt-based ultrathin nanowires

Abstract

Discovering an active and durable catalyst for oxygen reduction reaction is crucial to the commercialization of fuel cells, but remains grand challenging. Here we report, for the first time, the trace doping of early transition metal (ETM) Re into ultrathin PtNiGa nanowires (Re-PtNiGa NWs) to construct a novel catalyst integrating the superior activity, long-time durability, and high utilization efficiency of Pt atoms. Impressively, the Re-PtNiGa tetrametallic NWs present a 19.6-fold enhancement in mass activity (3.49 A mg−1Pt) compared to commercial Pt/C catalyst and only a 10.6% loss in mass activity after 20,000 cycles of durability test. Moreover, the real fuel cell assembled by Re-PtNiGa NWs on the cathode strongly supports its great potential in fuel cells. The density functional theory calculations reveal that introduction of ETM Re into PtNiGa NWs could weaken binding strength of oxygenated species and elevate dissolution potential, well rationalizing the great enhancements in activity and durability.