Au@Pd@Pt core–shell nanoparticles with mesoporous structures and nanocavities for enhanced electrocatalytic performance

Abstract

Au@Pd@Pt core–shell nanoparticles (CSNs) with mesoporous structures and nanocavities were synthesized through a seed-mediated growth method. The process involved the initial formation of Au@Pd CSNs via the reduction of PdCl₄²⁻ by ascorbic acid (VC), followed by a reduction of PtCl₆²⁻ by VC, and a galvanic replacement reaction between the Pd shell and PtCl₆²⁻. The galvanic replacement reaction is a critical step in the formation of Au@Pd@Pt CSNs featuring distinctive voids in the mesoporous structures. The electrocatalytic performance of the as-synthesized Au@Pd@Pt CSNs for the ethanol oxidation reaction (EOR) was systematically evaluated. Due to the unique hierarchical structure featuring both mesoporosity and internal nanocavities, Au@Pd@Pt CSNs exhibited significantly enhanced electrocatalytic activity compared to Au@Pd CSNs, Au@Pt CSNs, and commercial Pd/C catalysts. This work presents a facile strategy for constructing hierarchical core–shell nanostructures, demonstrating considerable potential for application in electrocatalytic ethanol oxidation.