PtRuNi/C electrocatalysts (carbon-supported PtRuNi nanoparticles) were prepared by an alcohol-reduction process using H2PtCl6.6H20,RuCl3.1,5H20 and NiCl2.6Hi'"/ as metal sources, ethylene glycol as solvent and reducing agent, and Vulcan XC 72R as carbon support.The electrocatalysts were characterized by energy dispersive X-ray analysis (EDX), X-ray diffraction (XRD), transmission electron microscopy (TEM), thermogravimetric analysis (TGA) and cyclic voltammetry (CV).The electro-oxidation of methanol was studied by cyclic voltammetry and chronoamperometry aiming direct methanol fuel cell (DMFC) applications.Initially, PtRuNi/C electrocatalysts (20 wt%.) with Pt:Ru:Ni atomic ratio of 50:40:10 were prepared in acid and alkaline medium (OHVmetais molar ratio = 8)In alkaline medium, a solution of KOH 1 mol L"^ was added to the reaction medium.For the material prepared in acid medium only the reduction of Pt(IV) and Ru(lll) occurs, while the Ni(ll) ions remains in solution.The reduction of Ni(ll) ions and its incorporation into the nanoparticles were observed for the materials prepared in alkaline medium.In this case, it was observed a face centered cubic structure (fee) characteristic of Pt and Pt alloys and a smaller crystallite size.On the other hand, the total amount of metals deposited on the carbon support was only 10 wt%.The Pt:Ru:Ni atomic ratio was varied (70:20