Platinum Systems Electrodeposited in the Presence of Iron or Palladium on a Gold Surface Effectively Catalyze Oxygen Reduction Reaction

In this study, Pt and Pd catalysts (in the absence and presence of Fe) and a Pt-Pd alloy were generated on a polycrystalline Au surface by means of a direct electrodeposition approach. The electrochemical profile of these materials was investigated using cyclic voltammetry and microgravimetry (electrochemical quartz crystal microbalance). The electrocatalytic activity toward oxygen reduction reaction (ORR) was studied using hydrodynamic cyclic voltammetry. Physical characterization of samples was performed using scanning electron microscopy, energy dispersive X-ray microanalysis, and atomic force microscopy. Electrodeposited catalysts containing Pt exhibited high electrocatalytic activity toward ORR, stability in terms of specific activity, and repeatability of responses, even at low Pt concentrations in the electrodeposition solution, thus suggesting the possibility of applying these catalysts to acid fuel cells. The Au electrode modified with Pt(0.75)/Fe(0.25) exhibited a nanorounded, low-roughness structure, whereas the Au electrode modified with Pd(0.75)/Fe(0.25) showed poor electrocatalytic activity, a nanospaghetti-shaped structure, and enhanced roughness.