Nanoscale PtCuMn Hexapods for Methanol Electrocatalysis

Pt-based nanocrystals with a three-dimensional (3D) branched structure represent a class of the most efficient catalysts for the methanol oxidation reaction because of their large accessible surfaces and high atomic utilization. Herein, nanoscale PtCuMn hexapods (HPDs) have been synthesized by a facile one-pot solvent method. Strikingly, the as-synthesized HPDs each contain a rhombic dodecahedral host and six nanopods protruding from its ⟨100⟩ vertices. Evolution experiments demonstrate that four stages are responsible for formation of the HPDs: the preferential formation of Cu-enriched nuclei, the galvanic substitution reaction between Cu-enriched nuclei and a Pt precursor, the selective growth of Pt, and the deposition of Pt, Cu, and Mn. Moreover, the morphology of the HPDs can be tuned by adjusting the dosage of cetyltrimethylammonium bromide because of its ability to affect the size of the preformed Cu-enriched nuclei and the rate of the galvanic substitution reaction during the synthesis. For methanol electrocatalysis, the PtCuMn HPDs exhibit substantially enhanced electrocatalytic activity and durability in comparison with the commercial Pt/C catalyst. It is expected that this work may provide an idea for the facile synthesis of Pt-based catalysts with high efficiency and stability.