One-pot synthesis of a highly active, non-spherical PdPt@Pt core–shell nanospike electrocatalyst exhibiting a thin Pt shell with multiple grain boundaries

Abstract

Co-decomposition of Pd and Pt precursors in the presence of trioctylphosphine and stearic acid gives a unique non-spherical PdPt@Pt core–shell nanospike with multiple grain boundaries in a facile one-pot synthesis. The difference in the metal–P bond strengths causes the disparate precursor decomposition kinetics, which in turn positions the Pt content on the nanoparticle surface. The core–shell composition, crystallinity, and shell thickness are conveniently controlled by simple variations in the amount of precursors and surfactants. The PdPt@Pt core–shell nanospike shows a high electrocatalytic activity toward methanol oxidation reaction. The excellent catalytic performance seems to originate from (1) the existence of multiple, surface energy-elevating grain boundaries, (2) roughened surface, and (3) lattice mismatch between the core and shell.