Effect of decreasing platinum amount in Pt–Sn–Ni alloys supported on carbon as electrocatalysts for ethanol electrooxidation

Literature describes the influence of morphological and structural electrocatalysts characteristics, on the catalytic activity toward ethanol electrooxidation. Thus, in this work Pt and ternary Pt–Sn–Ni alloys nanoparticles, supported on Vulcan carbon, were obtained by impregnation/reduction method. The aim of this work was to evaluate the influence of the decrease of platinum and increase of nickel content of the electrocatalysts obtained. The electrocatalysts were characterized by Rutherford backscattering spectroscopy, X-ray diffraction, transmission electronic microscopy, cyclic voltammetry and electrochemical impedance spectroscopy. The results obtained showed that it was possible to obtain Pt–Sn–Ni nanoparticles with a uniform size distribution in a narrow particle size range with a composition control. Moreover, the simultaneous addition of Sn and Ni to Pt did not affect reticular lattice a value, but the crystallite size decreases significantly. Besides, electrochemical results suggest that the substitution of platinum by nickel, in the electrocalatyst alloys studied, does not compromise the catalytic activity toward ethanol eletrooxidation.

► This work aimed to obtain Pt–Sn–Ni nanoparticles by impregnation/reduction method. ► It was possible to obtain Pt–Sn–Ni nanoparticles with a composition control. ► Sn and Ni added to Pt does not affect the reticular lattice a but decreases the crystallite size. ► The EIS results showed the RCT values decrease with Sn and Ni addition to Pt. ► The increase in Ni amount, decreasing Pt/Sn ratio, promoted similar catalytic activity to EOR.