Effect of nickel loading in Ni@Pt/C electrocatalysts on their activity for ethanol oxidation in alkaline medium

Abstract Core-shell nanoparticles of Ni@Pt/C electrocatalysts have been prepared in different Pt:Ni atomic ratios ranging from 1:0.25 to 1:3 through a two-step strategy using ethylene glycol as a reducing agent. Their electrocatalytic activity for ethanol oxidation was investigated in alkaline medium. X-ray diffraction and transmission electron microscopy were employed to evaluate crystal structure and surface morphology. Highly dispersed Pt nanoparticles were distributed in all prepared Ni@Pt/C electrocatalysts. Cyclic voltammetry, chronoamperometry and electrochemical impedance spectroscopy have been applied to examine the electrochemical performance of Ni@Pt/C electrocatalysts. Increasing nickel content was found to enhance the resultant electrocatalytic activity towards ethanol oxidation. Ni@Pt/C containing Pt:Ni atomic ratio of 1:3 exhibited the highest oxidation current density and stability when contrasted to Pt/C and other Ni@Pt/C electrocatalysts.