Currently Pt-based electrocatalysts contribute to a large portion of the cost (55%) of a state-of-the-art PEMFC stack. Searching for low-cost and efficient catalysts for the oxygen reduction reaction (ORR) has been actively pursued in the recent years to reduce fuel cell cost and increase performance. Pt-M alloys (M = Cu,Ni,Mn,Co,Sn,Fe,Pd,Ti) have been systematically studied as electrocatalysts for ORR. The electronic properties of the metal layer can be significantly altered by varying the composition (usually adding transition metals). The Pt surface d-band can be broadened and lowered in energy by interactions with the subsurface 3D metals, resulting in weaker dissociative adsorption energies of hydrogen and oxygen on these surfaces. If oxygen binds too strongly to the cathode, for example, it could poison the surface and reduce its activity.

In this work, we present a highly active electrocatalyst able to promote the ORR. This material was synthesized considering a progressive study of Pt-Mn, Pt-Cu and the further combination of Cu and Mn. Pt-Cu-Mn alloys were synthesized by polyol modified method.A dispersion of Pt, Mn and Cu in ethylene-glycol was enriched with porous carbon (Multiwall Nanotubes). The reaction was left under 200 °C, basic pH, followed by heat treatment in microwave and chemical reduction with NaBH₄. Finally HNO₃ was added to completely remove all unreacted species, and obtain a stable chemical bond. The dark slurry was filtered, washed with acetone several times and dried under vacuum. The obtained powder was dried and grounded, and finally annealed at 900 °C in nitrogen atmosphere. Physico-chemical characterization was performed by XPS, XRD and BET analyses. Electrochemical measurements were carried out on a rotating disk electrode (RDE) with a standard three-electrode cell. Cyclic voltammograms (CV) were recorded in a 0.1 M HClO₄ aqueous solution at a scan rate of 10 mV s^–1. ORR electroactivity was evaluated by using linear sweep voltammetry in O₂ saturated solution (0.1 M HClO₄) at a scan rate 10 mV s^–1 with a rotational speed of 900 rpm. A standard calomel electrode (SCE) and a Pt spherical wire were used as reference and counter.

Main obtained results show that the ORR kinetics of PtCuMn/C is definitely superior to that of PtCu/C orPtMn/C in the high potential range (0.88–0.94 V).Detailed correlation between surface composition and metals interaction will be presented in the final manuscript.