On the role of electrodeposited nanostructured Pd-Co alloy on Au for the electrocatalytic oxidation of glycerol in alkaline media

The catalytic activity and stability of electrodeposited Pd-Co alloy layers on Au electrode was evaluated for glycerol oxidation reaction (GOR) in an alkaline solution. The morphology and structural characteristics of the Pd and Pd-Co alloy were investigated by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). The electro-oxidation of glycerol on the Pd/Au and Pd-Co/Au was studied by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and chronoamperometry (CA) techniques. By varying Co concentration in the deposition solution, it was demonstrated that the Pd (61%)-Co (4%) catalyst [denoted Pd-Co(3)/Au] has the highest electrocatalytic activity. Obtained results showed that the Pd-Co(3)/Au has the excellent activity in terms of the specific peak current density and onset potential compared to pure Pd for oxidation of glycerol. For Pd-Co (3)/Au, the onset potential shifts to negative values by 80 mV compared to the onset potential of Pd/Au. The stability tests indicated that the presence of Co has a significant effect on the poisoning tolerance of the Pd toward glycerol electro-oxidation. Form the obtained results; one can conclude that the Pd-Co alloy exhibits suitable activity as a promising catalyst for alcohol electro-oxidation reactions in fuel cells.