One pot synthesis of Pd@CuO core-shell nanoparticles for electro catalytic oxidation of ethylene glycol for alkaline direct fuel cell

Abstract

A facile one pot synthesis route has been adopted for [email protected]/C core-shell nanostructure for ethylene glycol oxidation. Pd nanoparticles are embedded in the porous CuO shell through an intermediate redox reaction leading to the formation of [email protected]/C core-shell nanostructure. The crystallinity, surface chemistry, bonding environment, morphology and surface area of the synthesized nanostructure has been characterised by X-ray diffraction, X-ray photoelectron spectroscopy, X-ray absorbance spectroscopy, transmission electron microscopy, and Brunauer-Emmett-Teller analysis. The observed results indicated that a uniform dispersion of [email protected] core-shell nanostructure on functionalised carbon have an average size of ~8.5 nm. The nanostructure of Pd covered by a CuO enriched shell in carbon support ([email protected]/C) shows enhanced electro-catalytic performance, e.g. 2.3 times forward peak current density, 2.9 times mass activity, and 2 times specific activity towards ethylene glycol oxidation in alkaline media than that by Pd/C. The onset potential is 110 mV more negative in [email protected]/C than Pd/C. Further, [email protected]/C exhibit much lower Tafel slope (96.34 mV/dec) and charge transfer resistance (Rct) than Pd/C, signifying faster charge transport in ethylene glycol oxidation reaction. The enhancement of electrocatalytic activity, excellent stability and durability towards ethylene glycol oxidation in [email protected]/C compared to different types of Pd nano, bimetallic and different substrate is attributed to the modification of the electronic structure of Pd and CuO due to the formation of core-shell nanostructure.