Large atom induced strain and dislocation coupling in PtCu nanowires for efficient oxygen reduction electrocatalysis

Pb incorporation creates strained, dislocation-rich PtCu nanowires. • Oversized Pb atoms couple lattice strain with electronic modulation. • Pb-PtCu NWs deliver 0.932 V E 1/2 and 1.042 A mg Pt −1 MA. • Pb-PtCu NWs show only 10 mV E 1/2 loss after 10,000 cycles. • Strain-dislocation coupling enables durable acidic ORR catalysis. Strain and defect engineering offer powerful routes to improve Pt-based oxygen reduction reaction (ORR) electrocatalysts, but constructing stable high-energy defects under harsh electrochemical conditions remains challenging. Herein, we report a Pb-induced dislocation engineering strategy to develop highly strained PtCu nanowires (NWs) for efficient and durable ORR catalysis. Owing to the large atomic-size mismatch between Pb and the PtCu lattice, oversized Pb atoms disrupt lattice periodicity and generate abundant lattice distortion, dislocation defects, and heterogeneous strain fields within the nanowire framework. Structural and spectroscopic analyses reveal that Pb incorporation not only stabilizes the defect-rich strained structure but also modulates the electronic structure of Pt sites, downshifting the d-band center and weakening the adsorption of oxygen-containing intermediates. Consequently, the Pb-PtCu NWs deliver excellent ORR activity in acidic media, with a half-wave potential of 0.932 V and a mass activity of 1.042 A mg Pt −1 at 0.9 V, 9.1 times that of commercial Pt/C. Moreover, they exhibit outstanding durability, showing only a 10 mV half-wave potential loss after 10, 000 cycles. This work provides an effective design principle for creating defect-rich Pt-based catalysts through the introduction of oversized main-group metals. Oversized Pb atoms are incorporated into PtCu nanowires to induce strong lattice distortion, dislocation defects, and heterogeneous strain fields. The resulting strain-dislocation coupling stabilizes defect-rich PtCu nanowires and modulates the electronic structure of Pt sites, weakening oxygen-intermediate adsorption and enabling efficient and durable oxygen reduction in acidic media. Download: Download high-res image (172KB) Download: Download full-size image