unique Cu@CuPt core-shell concave octahedron with enhanced methanol oxidation activity.

Although tremendous efforts have been devoted to the exploration of cost-effective, active, and stable electrochemical catalysts, quite few significant breakthroughs have been achieved up to now. Therefore, exploring new catalysts, improving catalyst activity and stability are still major tasks at present. Controllable synthesis of Pt-based alloy nanocrystals with uniform high-index surface and unique architecture has been regarded as an effective strategy to optimize their catalytic efficiency toward electrochemical reaction. Accordingly, here we present a one-pot facile solvothermal process to synthesize novel unique Cu@CuPt core-shell concave octahedron nanocrystals which exhibit both outstanding activity and long durability. By regulating temperatures during the synthesis process, we were able to control the reduction rate of Cu and Pt ions, which could subsequently lead to the sequential stack of Cu and Pt atoms. Owing to the concave structure, the as-prepared core-shell nanoparticles hold high-index surface of {312} and {413}. Such surfaces can provide high density of atomic steps and terraces, which are suggested to be favourable for electrochemical catalyst. Specifically, the Cu@CuPt core-shell concave octahedron present 8.6/13.1 times enhanced specific/mass activities toward methanol oxidation reaction in comparison to commercial Pt/C catalyst, respectively. Meanwhile, the as-prepared catalyst exhibits superior durability and anti-aggregation properties under harsh electrochemical condition. The facile method used here proposes a novel idea to the fabrication of nanocrystals with desired compositional distribution and the as-prepared product offers exciting opportunities to be applied in Direct Methanol Fuel Cells (DMFCs).