Alkaline ethanol oxidation on porous Fe/Pd–Fe nanostructured bimetallic electrodes

Abstract

In this work, to prepare nanostructured and porous Fe/Pd-Fe bimetallic catalysts, the iron coating is applied rstly onto the copper substrate by the electrochemical deposition method. Subsequently, iron-zinc alloy coating is deposited on the underlayer iron.Eventually, by immersing this alloy coating in an alkaline solution containing palladium ions, the palladium will replace the zinc, resulting in porous Fe/Pd-Fe catalysts.The X-ray diffraction (XRD) technique was used for the characterization of the physical properties of the as-prepared electrocatalysts. Their electrocatalytic activity was studied by electrochemical methods such as cyclic voltammetry (CV), chronoamperometry (CA), and electrochemical impedance spectroscopy (EIS). The XRD results showed that the zinc element was the main component of the Fe/Zn-Fe alloy and was replaced by palladium as a result of leaching-galvanic replacement. The electrochemical investigations showed that a new porous Fe/Pd-Fe bimetallic catalyst had higher electro-catalytic activity and stability than pure Pd and Fe electrodes for ethanol electro-oxidation in alkaline media. The superiority of the Fe/Pd-Fe catalyst is related to the high surface area and a synergistic effect between Fe and Pd in Fe/Pd-Fe catalysts. Therefore, the nanostructured Fe/Pd-Fe catalysts can be proposed as potential anode materials for alkaline ethanol fuel cells.