The pathway of activity and durability nanocatalysts for formic acid electrooxidation strongly depends on the amount of three neighboring Pt or Pd atoms in the surface of Pd-or Pt-based nanocatalysts.In this paper, Pt decorated Pd/C (donated as Pt-Pd/C) nanocatalysts with various Pt/Pd molar ratios were designed and then synthesized through a facile galvanic displacement where the amount of three neighbouring Pt or Pd atoms significantly decreased.The nanocatalysts were characterized by X-ray photoelectron spectroscopy, cyclic voltammetry and chronoamperometric measurements for establishing the correlation between the electrocatalytic properties and the catalyst structures.As a result, the Pt-Pd/C (the optimal molar ratio, Pt∶Pd=1∶250) nanocatalysts exhibited the superior activity and durability than Pd/C and commercial Pt/C (J-M, 20%) nanocatalysts for formic acid electrooxidation.The discontinuous Pd and Pt sites inhibited CO formation and exhibited unprecedented electrocatalytic performance toward formic acid oxidation while the cost was almost the same as that of Pd/C.This finding provided important insights into the design of decorated surface and the synthesis of novel nanocomposites for formic acid electrooxidation.