Copper-Palladium Core-Shell Bifunctional Nanoelectrocatalyst for Ethanol Oxidation and Hydrogen Evolution Reactions

Abstract

Ethanol oxidation reaction (EOR) and hydrogen evolution reaction (HER) are two of the most important technical challenges during the manifestation of ethanol and H2-O2 fuel cells. Herein we explore the electrocatalytic activity of copper-palladium core-shell nanostructures on pencil graphite (Cu@Pd/PGE) for EOR and HER. A maximum peak current density of 261 ± 11 mA cm−2 with excellent retention for 1000 potential cycling is observed for EOR. High performance liquid chromatography and Raman analysis indicate upto 12-electron transfer oxidation with the formation of carbon dioxide or carbonate, which imply the superiority of the catalyst. High HER current near to its thermodynamic potential of ∼0 V vs RHE, together with a stable performance for 1000 voltammetric cycles, make Cu@Pd/PGE as a potential catalyst for HER in acidic media. The catalytic efficiency is also manifested by the well resolved voltammetric features during HER activity with a Tafel slope comparable to commercial Pt/C catalysts. The excellent bifunctional activity of Cu@Pd/PGE provides a new route for commercialisation of low-cost electrocatalysts for fuel cell applications.