PtRu/C electrocatalysts were prepared by impregnation of the complex (eta-C2H4)(Cl)Pt(muCl)(2)Ru(Cl)(eta(3)eta(3)-C10H16) on to a carbon support. The complex/support was subjected to different thermal treatments and tested for ethanol electro-oxidation using the thin porous coating electrode technique. The electrocatalysts were characterized by transmission electron microscopy (TEM), EDAX and cyclic voltammetry. The electrocatalyst treated under hydrogen flow and subjected to an oxidative thermal treatment had a superior performance to that of a commercial catalyst, which could be attributed to the better control of the metallic platinum and oxidized ruthenium species on the PtRu nanoparticle surface. (C) 2003 Elsevier B.V. All rights reserved.