Superior electrocatalytic activity of ultrathin PtPdBi nanowires towards ethanol electrooxidation

摘要

Bimetallic catalysts, PtBi, PtPd and PdBi have been explored and may be promising candidates for nextgeneration anodic catalysts of direct alcohol fuel cells due to their enhanced catalytic activity and longterm durability. However, ternary PtPdBi alloy catalysts are rarely reported because of the synthetic difficulty in manipulating three metallic precursors. Here, ternary metallic PtxPd93-xBi7 alloy nanowires were prepared for systematically investigating their electrocatalytic activity towards ethanol oxidation in basic solution by cyclic voltammetric and amperometric techniques. PtxPd93-xBi7 alloy nanowire, whether loaded on Vulcan XC72 carbon (C) or reduced graphene oxide (RGO), has better catalytic activity than PtPd, PtBi, PdBi, Pt/C, or Pd catalyst. Nevertheless, the catalytic activity of PtxPd93-xBi7 closely depends on the Pt : Pd atomic ratio. Pt55Pd38Bi7 alloy nanowire with the optimal Pt : Pd atomic ratio can produce the maximum enhancement towards ethanol electrooxidation. RGO replacing C as catalyst supporter can further improve the catalytic performance of catalyst. Pt55Pd38Bi7/RGO exhibits a superior catalytic performance, the mass activity of which reaches similar to 3.60 A mg(-1), similar to 6 times better than commercial Pt/C.