Polyhedron-Assembled Ternary PtCuCo Nanochains: Integrated Functions Enhance the Electrocatalytic Performance of Methanol Oxidation at Elevated Temperature.

ABSTRACT

Recently, the preparation of a high-performance one-dimensional alloy nanostructure for fuel cells has been given increasing attention due to its smart-structure merits and electronic effect triggered by alloying different kinds of metals at the nanoscale. In this study, unique ternary PtCuCo nanochains assembled with small polyhedra are first achieved and used as high-performance anode electrocatalysts toward methanol oxidation at elevated temperature (60 °C) that is closer to the operating temperature of direct methanol fuel cells than room temperature. The specific activity/mass activity of Pt45Cu35Co20 one-dimensional nanochains can reach up to 18.24 mA cm-2/4.19 A mg-1Pt that is 9.25/10.47 times that of commercial Pt black in sulfuric acid medium. After a 3600 s durability test, the remaining current density of Pt45Cu35Co20 one-dimensional nanochains is 73.3 times that of commercial Pt black. The structure characterizations show that the high density of surface active sites, d-band center of the Pt downshift, moderate strain effect, and synergetic effect are jointly responsible for the enhanced electrocatalytic performance of one-dimensional ternary PtCuCo nanochains.