Surface strain-regulated twin-rich Au-Pt bimetallic nanowire for highly efficient alcohol oxidation reaction

Abstract

Metallic nanocrystals with abundant metastable twin boundaries have demonstrated great potential in prompting the improvement of electrocatalytic reactivity, such as alcohol oxidation reaction (AOR) in fuel cell applications. However, modulating the lattice and electronic structures of such twin-rich nanocatalysts to optimize the AOR activity remains a huge challenge. Herein, jagged Au-Pt bimetallic nanowires with abundant twin boundaries along the 〈111〉 direction have been constructed via a seeded synthesis method. Importantly, the lattice strain and electronic structures of Pt in the twin-rich nanowires have been feasibly tuned, resulting in the regulation of AOR performances. Impressively, the jagged AuPt3 nanowires, with an atomic ratio of ∼1:3, exhibit the highest mass activity toward ethanol oxidation reaction (EOR) and methanol oxidation reaction (MOR), outperforming AuPt9, AuPt, Pt nanowires and commercial Pt/C catalysts. The structure–activity correlation for the AOR follows a volcano-shaped curve with the increase of Pt ratios. Theoretical results suggest the weakened bonding of Pt-CO and strengthened Pt-OH on the AuPt3 (111)-twin site. Our work develops a simple yet effective method to synthesize twin-rich bimetallic nanostructures with controlled lattice strain and illustrates their structure-dependent properties, opening the way to develop high-performance electrocatalysts for promising applications.