The synthesis of Pt nanoparticles with preferential (100) orientation directly supported on carbon was done by an alcohol-reduction process using KBr as a shape directing agent. The synthesis conditions were varied and the obtained materials were characterized by transmission electron microscopy and cyclic voltammetry. The order of addition of the Pt precursor and KBr was crucial to obtain cubic Pt nanoparticles with small particle size highly dispersed on the carbon support. DEFC experiments showed that Pt nanoparticles with preferential (100) orientation supported on carbon provided superior power densities and CO2 selectivity compared to supported polycrystalline Pt nanoparticles. (C) 2016 Elsevier Inc. All rights reserved.