Novel Pd13Cu3S7 nanotubes with high electrocatalytic activity towards both oxygen reduction and ethanol oxidation reactions

Abstract

In the search for more effective and stable fuel cell electrocatalysts, we have developed a facile method to synthesize novel Pd₁₃Cu₃S₇ nanotubes (Pd₁₃Cu₃S₇ NTs) for the first time. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM) measurements have been used to characterize the structure, components and morphology of the Pd₁₃Cu₃S₇ NTs. Due to their novel structure and composition, the as-prepared Pd₁₃Cu₃S₇ NTs showed a high oxygen reduction reaction (ORR) catalytic performance, with similar catalytic activity to that of commercial Pt/C but with better stability than Pt/C. Furthermore, the ORR catalyzed by the Pd₁₃Cu₃S₇ NTs was calculated to be a directly 4e⁻ process. On the other hand, the Pd₁₃Cu₃S₇ NTs also exhibited excellent ethanol oxidation reaction (EOR) activity (2.7 mA cm⁻²), which is about five times that of commercial Pd/C (0.55 mA cm⁻²). An EIS study indicated that the charge transfer resistance of the Pd₁₃Cu₃S₇ NTs is much lower than that of commercial Pd/C in the EOR.