PdAg Alloy Nanowires: Facile One-Step Synthesis and High Electrocatalytic Activity for Formic Acid Oxidation

Bimetallic alloy PdAg nanowires were synthesized by a facile one-step wet chemical strategy. The unique nanostructure with large surface area and active surface (111) planes make them promising electrocatalysts for direct-liquid fuel cells. The electrochemical studies indicated that the PdAg alloy nanowires exhibit enhanced electrocatalytic activity toward formic acid oxidation with larger oxidation current density, higher tolerance to CO poisoning, and more negative onset potential in comparison with the commercial Pd/C catalysts. At the same potentials, the as-synthesized PdAg nanowires show higher long-term stability than Pd/C catalysts in the chronoamperometric analyses. The electron transfer kinetics of HCOOH oxidation on the PdAg nanowires was studied with electrochemical impedance spectroscopy (EIS). It was found that the charge transfer resistance (R-CT) of formic acid oxidation on PdAg nanowires is much smaller than that obtained from a Pd/C catalyst, which suggests that the electron-transfer kinetics for formic acid oxidation at the synthesized PdAg nanowires is highly facilitated. The present work highlights the facile synthesis of the homogeneous PdAg alloy nanowires and their potential application as anode electrocatalyst of fuel cells.