Atomic Defect-Directed Epitaxial Growth of Multimetallic Nanorods for High-Efficiency Alcohol Electro-Oxidation

Abstract

Site-selective epitaxial growth of metals onto shaped nanoparticles represents a versatile strategy for tailoring nanostructures to optimize the optical and catalytic properties. In this study, we systematically elucidate the critical factors governing the epitaxial growth of silver and platinum atoms onto gold nanorods (Au NRs), revealing that atomic defects on the Au NR surface dictate the deposition sites of Ag and Pt. By precisely modulating epitaxial growth conditions and density of surface atomic defects, we achieve the synthesis of dumbbell-shaped (DS) and thorny-shell (TS) structured Au-AgPt NRs. Notably, the DS-Au-AgPt_0.24 NR catalyst demonstrated exceptional catalytic performance in alcohol fuel cell reactions, driven by their abundant atomic defects and strong strain effects localized at the crown structure. For ethylene glycol electro-oxidation, these DS-Au-AgPt_0.24 NRs achieved a mass activity of 23.5 A mg_Pt^–1 and a specific activity of 156.9 mA cm^–2, which were 4.1 and 11.2 times higher than that of commercial platinum–carbon (Pt/C) catalysts (5.7 A mg_Pt^–1 and 14.0 mA cm^–2), respectively. Our findings not only advance the mechanistic understanding of defect-mediated epitaxial growth in multimetallic systems but also provide a blueprint for designing high-performance catalysts through atomic-scale structural engineering.