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.