One-pot synthesis of Palladium Silver nanoparticles decorated reduced graphene oxide and their application for ethanol oxidation in alkaline media

Highlights: • Graphene oxide is synthesized by electrochemical method. • Reduced graphene supported Palladium silver is prepared via impregnation method. • Pd-Ag(1:1)/G is more stable than Pd/G in alkaline media. • Ethanol oxidation activity in alkaline media was 1000 mAcm⁻²mg⁻¹Pd for Pd-Ag(1:1)/G. • Tafel slope of PdAg/G is much lower than that of Pd/G. - Abstracts: We report a Pd-Ag (1:1)/graphene (PdAg/G) catalyst through a one-step strategy, for the ethanol oxidation in alkaline media. Graphene is synthesized from graphite electrodes using ionic liquid-assisted electrochemical exfoliation. Graphene-supported Pd-Ag electrocatalystis then was reduced by ethylene glycol as a stabilizing agent to prepare highly dispersed PdAg nanoparticles on carbon graphene oxide to be used as ethanol oxidation in direct ethanol fuel cell (DEFC) catalysts. X-ray diffractometer and scanning electron microscopy techniques are used to investigate the crystallite size and the surface morphologies respectively. The electrochemical characteristics of the Pd-Ag(1:1)/G,Pd/G and Ag/G catalysts are investigated by cyclic voltammetry (CV) in nitrogen saturated sulfuric acid aqueous solutions and in mixed sulfuric acid and ethanol aqueous solutions. Detailed electrochemical studies (involving chronoamperometry, cyclic voltammetry and linear sweep voltammetry) prove that the electro-catalytic oxidation of ethanol at the Pd-Ag(1:1)/G is more stable, occurring at lower potential, giving lower Tafel slopes compared to Pd/G and Ag/G catalysts, which can reveal the particular properties of the exfoliated graphene supports and PdAg alloy