Facile solvothermal synthesis of highly active and robust Pd_1.87Cu_0.11Sn electrocatalyst towards direct ethanol fuel cell applications

Abstract

Ordered intermetallic Pd_1.87Cu_0.11Sn ternary electrocatalyst has been synthesized by sodium borohydride reduction of precursor salts Pd(acac)₂, CuCl₂.2H₂O and SnCl₂ using one-pot solvothermal synthesis method at 220 ℃ with a reaction time of 24 h. To the best of our knowledge, here for the first time we report surfactant free synthesis of a novel ordered intermetallic ternary Pd_1.87Cu_0.11Sn nanoparticles. The ordered structure of the catalyst has been confirmed by powder x-ray diffraction, transmission electron microscopy (TEM). Composition and morphology of the nanoparticles have been confirmed through field emission scanning electron microscopy, energy-dispersive spectrometry and TEM. The electrocatalytic activity and stability of the ternary electrocatalyst towards ethanol oxidation in alkaline medium was investigated by cyclic voltammetry and chronoamperometry techniques. The catalyst is proved to be highly efficient and stable upto 500th cycle and even better than commercially available Pd/C (20 wt%) electrocatalysts. The specific and mass activity of the as synthesized ternary catalyst are found to be ∼4.76 and ∼2.9 times better than that of commercial Pd/C. The enhanced activity and stability of the ordered ternary Pd_1.87Cu_0.11Sn catalyst can make it as a promising candidate for the alkaline direct ethanol fuel cell application.