Twin Boundary-Regulated Platinum–Yttrium Elemental Distributions for Boosting Electrochemical Alcohol Oxidation

Metastable crystal defects endow nanocrystals with optimized electronic configurations and remarkable electrocatalytic properties. Nevertheless, how the crystal defects, such as twin boundaries, regulate the nucleation and growth of multimetallic heterostructures requires further study. Herein, platinum-yttrium (PtY) alloys with a metastable twin structure were fabricated by overgrowth on Au nanoparticles, resulting in the formation of Au@PtY multibranched nanodendrites (Au₄₆Pt₄₀Y₁₄). The branched Au@PtY nanoparticle exhibits a Y-rich twin structure on the surface, as affirmed by both experimental investigation and theoretical calculation. Impressively, branched Au@PtY nanoparticles demonstrate superior mass activity and stability toward the alcohol oxidation reaction, compared to core-shell Au@PtY nanoparticles (Au₆₇Pt₂₅Y₈), PtY nanodendrites (Pt₇₃Y₂₇), and commercial Pt/C catalysts. Density functional theory calculations, together with operando infrared reflection absorption spectroscopy, suggest that the superior electrochemical characteristics could be ascribed to the Y-rich twin on the surface. This work opens the way for the rational design of heterometallic nanostructures with crystal defects for catalytic applications.