A Facile Preparation of Palladium nanoparticles Supported on polypyrrole functionalized CNTs with enhanced electrocatalytic performance for ethanol electrooxidation

Due to the rapidly growing global energy needs and the quickly decreasing fossil fuel resources, it is essential to seek renewable, high performance, cost-effective and enviromentally beneficialgreen energy sources. In recent years, direct ethanol fuel cells (DEFCs) are attracting increasingattention owing to their wide applications [1]. Pd and Pd based catalysts have good electrocatalytic activity and excellent anti-CO toxic ability in comparison with Pt[2]. on the other hand the choice of a suitable support with large surface area, good conductivity and strong adsorption of metals is another key factor affecting the electrocatalytic performance of thecatalysts, because it can affect the size and dispersion of the metal nanoparticles[3]. Polypyrrole (PPy) with low dimensional nanostructures has been used as a promising support material because of its high electrical conductivity and feasibility to anchor metal nanoparticles onto thesurface [4]. In this study, a facile and reproducible method for synthesis of Pd nanoparticles (PdNPs) and conducting polymer as a supporting material was demonstrated. Pd NPs were synthesized using chemical reduction process with NaBH4 under certain conditions.Polypyrrole@carbon nanotubes (PPy@CNT) nanocomposite was fabricated through in-situemulsion polymerization using sodium dodecyl sulfate (SDS) as an emulsifier and ammonium persulfate (APS) as an oxidant. Field Emission SEM (FE-SEM) images of Pd NPs andPPY@CNT are shown in Fig. 1. CNTs are distributed in the form of an extended network over a large area. The surface morphology was found to be uniform and tubular walls are sufficiently decorated with nanoparticles. Ethanol electrooxidation on the as-synthesized Pd/PPy@CNT/GCE and Pd/GCE was then investigated and compared in alkaline media by cyclic voltammetry and chronoamperometry studies at room temperature. these measurements showed higher current density and longer term stability in ethanol oxidation with the Pd/PPy@CNT nanocatalyst. The facile synthetic process and excellent catalytic performance of the as-prepared catalysts demonstrate that they can be used as a promising catalyst for DEFCs.

کلیدواژه ها:

Ethanol electrooxidation ، Conducting polymer ، Palladium nanoparticles ، cyclic voltammetry