摘要
Shape-controlled synthesis of Pt-Cu alloy nanocrystals （NCs） with unique geometries is of great importance in the rational design and deterministic synthesis of highly active electrocatalysts. Herein, Pt-Cu alloy NCs with concave octahedron （COH）, porous octahedron （POH）, yolk-shell （YSH）, and nanoflower （NOF） structures were fabricated by altering the sequential reduction kinetics in a one-pot aqueous phase. The effect of the reaction kinetics on the formation of Pt-Cu bimetallic NCs with different morphologies was analyzed quantitatively. The concentrations of glycine and metal cation are demonstrated to play a key role in the reduction of Pt（Ⅳ） and Cu（Ⅱ） ions; these significantly affected the morphology of Pt-Cu NCs. These Pt-Cu alloy NCs exhibit substantially enhanced catalytic activity and durability for methanol and formic acid oxidation compared to the commercial Pt/C catalyst. Specifically, the COH and NOF Pt-Cu NCs with more step atoms, intragranular dislocations, and protrusions showed superior electrochemical properties than those of POH and YSH Pt-Cu NCs. The structure- property relationship between the Pt-Cu NCs and their electrochemical performances was also investigated in depth.
Shape-controlled synthesis of Pt-Cu alloy nanocrystals （NCs） with unique geometries is of great importance in the rational design and deterministic synthesis of highly active electrocatalysts. Herein, Pt-Cu alloy NCs with concave octahedron （COH）, porous octahedron （POH）, yolk-shell （YSH）, and nanoflower （NOF） structures were fabricated by altering the sequential reduction kinetics in a one-pot aqueous phase. The effect of the reaction kinetics on the formation of Pt-Cu bimetallic NCs with different morphologies was analyzed quantitatively. The concentrations of glycine and metal cation are demonstrated to play a key role in the reduction of Pt（Ⅳ） and Cu（Ⅱ） ions; these significantly affected the morphology of Pt-Cu NCs. These Pt-Cu alloy NCs exhibit substantially enhanced catalytic activity and durability for methanol and formic acid oxidation compared to the commercial Pt/C catalyst. Specifically, the COH and NOF Pt-Cu NCs with more step atoms, intragranular dislocations, and protrusions showed superior electrochemical properties than those of POH and YSH Pt-Cu NCs. The structure- property relationship between the Pt-Cu NCs and their electrochemical performances was also investigated in depth.
基金
This work was supported by the China Postdoctoral Science Foundation （No. 2017M610405）, the Shandong Provincial Natural Science Foundation （Nos. ZR2015BM008 and ZR2017BB029） and Scientific Research Foundation for the Returned Overseas Chinese Scholars, State Education Ministry.
