Preparation of PtRu/C Anode Electrocatalysts using NaBH 4 as Reducing Agent and OH - ions as Stabilizing Agent E.V. Spinacé, L. A. Indelicato do Vale, A. Oliveira Neto and M. Linardi Instituto de Pesquisas Energéticas e Nucleares – IPEN/CNEN-SP, 05508-900 São Paulo – SP, Brazil PtRu/C electrocatalysts were prepared using NaBH 4 as reducing agent and OH- ions as stabilizing agent. The electrocatalysts were characterized by EDX, XRD, TEM and cyclic voltammetry. The electro-oxidation of methanol was studied by cyclic voltammetry using the thin porous coating. Active PtRu/C electrocatalysts for methanol oxidation could be prepared by a simple methodology. Introduction A Direct Alcohol Fuel Cell (DAFC) is a device in which the alcohol is fed directly into the fuel cell without any previous chemical modification and is oxidized at the anode, while oxygen is reduced to water at the cathode. Thus, DAFC are very attractive as power sources for mobile and portable applications because it is not necessary to convert the fuel into hydrogen in a reformer. However, alcohols are very difficult to electro- oxidize completely and up to now methanol has been considered the most promising organic fuel because it is more efficiently oxidized than other alcohols (1-4). PtRu/C electrocatalysts have good activity as anode in direct methanol fuel cell. The synthesis of highly dispersed supported platinum-ruthenium nanoparticles with high loadings still remains a challenge (5). The conventional methods for synthesis of PtRu/C electrocatalysts are impregnation and colloidal methods. The impregnation method usually leads to large average particle size and broad size distribution, while colloidal methods produce ultrafine particles homogeneously distributed on the support, but the synthesis are normally very complex (5). In this work, PtRu/C electrocatalysts were prepared using NaBH 4 as reducing agent and OH - ions as stabilizing agent. The PtRu/C electrocatalysts were tested for methanol oxidation using cyclic voltammetry aiming fuel cell application. Experimental PtRu/C electrocatalysts (20 wt%) with Pt:Ru atomic ratio of 50:50 were prepared using H 2 PtCl 6 .6H 2 O (Aldrich) and RuCl 3 .xH 2 O (Aldrich) as metal sources and Carbon Vulcan XC72R as support. Carbon support was suspended in an aqueous solution containing the Pt(IV) and Ru(III) ions and an aqueous solution of sodium borohydride was added dropwise with stirring at room temperature. The suspension was filtered to recover the solid product and it was washed with water and dried at 70 o C for 2h. The electrocatalyst prepared in the presence of OH - ions as stabilizing agent KOH was added in the reaction medium with OH - /PtRu molar ratio of 8. XRD analyses were performed using a Rigaku diffractometer model Multiflex with a Cu K α radiation source. The mean