Decoupling activity and stability in PtNiMoRu nanowires for durable acid oxygen electroreduction

Unlocking the full potential of PtNi alloy electrocatalysts for the acidic oxygen reduction reaction (ORR) is significantly restricted by the inevitable dissolution of Ni species. Herein, we present a rational design of tetrametallic PtNiMoRu nanowires (NWs) that decouples the origins of stability and activity via a dual-doping strategy. By coordinating the distinct roles of constituent elements, we demonstrate that Mo doping primarily acts as a lattice stabilizer by increasing the Ni vacancy formation energy to immobilize Ni atoms, while Ru doping optimizes the d-band center of Pt active sites to facilitate intermediate kinetics. Consequently, the optimized PtNiMoRu NWs/C exhibits an exceptional mass activity of 1.04 A·mg_Pt⁻¹ and specific activity of 2.81 mA·cm⁻² at 0.9 V vs. reversible hydrogen electrode (RHE), representing 5.2- and 8.3-fold enhancements over commercial Pt/C, respectively. Most notably, the catalyst demonstrates superior durability with a negligible half-wave potential decay of only 9 mV after 30,000 accelerated durability test cycles. In a proton exchange membrane fuel cell (PEMFC), this nanowire catalyst delivers a peak power density of 1.18 W·cm⁻². This work provides a paradigm for designing durable multi-metallic catalysts by precisely engineering element-specific functionalities within the alloy architecture.