Enhanced electrocatalytic activity and durability of highly monodisperse Pt@PPy-PANI nanocomposites as a novel catalyst for the electro-oxidation of methanol

Highly monodisperse Pt nanocomposites (Pt@ PPy-PANI NPs) supported on polypyrrole (PPy)-polyaniline (PANI) have been successfully synthesized for the first time by a simple one-pot process, which involves the simultaneous reduction of the conducting polypyrrole (PPy)-polyaniline (PANI) and Pt precursors using DMAB (dimethylamine borane) as a reductant under ultrasonic conditions. Pt@ PPy-PANI NPs have been characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). All the results show that highly crystalline and stable colloidal Pt@ PPy-PANI NPs have been formed as one of the most active and long-lived catalysts with superior reusability performance for the electro-oxidation of methanol at room temperature. Compared to PPy or PANI supported Pt nanoparticles, Pt@ PPy-PANI NPs exhibit extraordinary electrocatalytic activity and stability toward the electro-oxidation of methanol, showing their potential use as a new electrode material for direct methanol fuel cells (DMFCs). It should be primarily attributed to the PPy-PANI, which not only provided larger surface area and flaws for the deposition of Pt nanoparticles, but also the adsorption of more methanol molecules for further oxidation.