PtAg bimetallic nanowires: Facile synthesis and their use as excellent electrocatalysts toward low-cost fuel cells

Abstract

Facile chemical synthesis of PtAg nanowires with different compositions through co-reduction of Ag and Pt precursors has been demonstrated. A facet-matching coupled autocatalytic growth mechanism, which favors reducing the exposed surface area while minimizing the interface mismatch energy with the formation of a coherent interface, is supported by SEM, TEM, XRD and EDS characterizations. Interestingly, tunable electrocatalytic activities have also been shown, which can be up to three times higher toward the direct methanol oxidation reaction in acid media for the dealloyed Pt94Ag6 than that of the commercial Pt/C catalyst based on the same mass of Pt. Such an excellent catalytic performance can be ascribed to the synergy effect of enhanced electric conductivity, clean surface, significantly increased caves, as well as the hetero-atomic interactions on the surface of alloyed nanoparticles.