Preparation, characterization and electrocatalytic activity of transition metal @ platinum on carbon support for alkaline ethanol electro-oxidation

The effect of adding a transition metal (M) to the core structure of M@Pt/C electrocatalyst on its electrocatalytic activity towards ethanol oxidation reaction in alkaline medium was studied. Copper or nickel or cobalt was reduced on Vulcan XC-72R carbon black surface using sodium borohydride followed by introducing platinum ions in the shell structure. The crystalline nature and the electrocatalyst morphology were investigated using XRD and TEM analysis techniques. Cyclic voltammetry, electrochemical impedance spectroscopy and chronoamperometry were applied to evaluate the electrocatalytic characteristics of prepared nanocatalysts during alcohol electro-oxidation. The electrocatalytic activity showed an ascending behavior as Cu@Pt/C < Ni@Pt/C ∼ Co@Pt/C. The exchange current density at Co@Pt/C was 11.28 folds higher than that at Pt/C. Lowered charge transfer resistance values were also measured at all M@Pt/C electrocatalysts when related to that at Pt/C. The enhanced performance of core–shell structured M@Pt/C electrocatalysts suggests the application of this developed method for fabricating efficient multimetallic nanocomposites for fuel cells.