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.

Herein, Pt and Pd catalysts (in the absence and presence of Fe, concomitantly or not with rutin or quercetin), PtPd and PtAu alloys, and Pt under Au are generated on a glassy carbon (GC) surface by using direct electrodeposition. The electrochemical profiles of these materials are investigated by using cyclic voltammetry and microgravimetry (electrochemical quartz crystal microbalance). Their electrocatalytic activity toward the oxygen‐reduction reaction (ORR) is studied by using hydrodynamic cyclic voltammetry. Physical characterization of the samples is performed by using SEM and energy‐dispersive X‐ray microanalysis. Electrodeposited catalysts that contain Pt exhibit high electrocatalytic activity toward the ORR and reproducible response, in particular at low Pt concentrations in the electrodeposition solution, thus suggesting the possibility of applying these catalysts to acid fuel cells. Large nanorock structures are formed on the GC electrode that is modified with Pt(0.50)/Pd(0.50)+rutin, whereas the GC electrode that is modified with Pd in the presence or absence of Fe, concomitantly or not with rutin or quercetin, shows poor electrocatalytic activity.

One-pot-produced XC-72 carbon-supported metal nanodendrites with Pt or Pt–Pd surfaces proved highly catalytic toward the ORR.

The aims of this study are to synthesize porous nanostars (PNSs) composed of a Pt, Pd, or Pt–Pd alloy shell supported on a gold core and to demonstrate their improved electrocatalytic activity towards the oxygen reduction reaction (ORR). The catalysts contain homogeneous, porous, star‐shaped, large‐sized structures (50 or 20 nm on average), with a covering pattern of Pt or Pt–Pd alloy nanodendritic particles of up to 5 nm. The synthesized PNS catalysts catalyze the ORR effectively, offering high performance in terms of Pt group metals mass‐specific activity, electrochemically active surface area (ECSA), specific ECSA, and specific activity, with high half‐wave potential values (0.93–0.96 V).

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