Direct alcohol fuel cells not only possess high efficiency and cleanness, but also exhibit their own specific advantages due to rich resources. In alcohol fuel cells, Pt based branched nanostructures are highly suitable as efficient anode electrocatalysts due to their large surface areas and high-density active sites. Meanwhile, metal oxides are believed to play a critical role in promoting the dissociative adsorption of water and the subsequent removal of poisoning intermediates. In this work, we report a simple hydrothermal method for synthesizing PtCu-O alloyed highly excavated octahedra nanostructures built from nanodendrites (EONDs), where the ratio of Cu(0) to Cu(ii) is 1:2.2 on the surface. The EONDs are composed of in-plane branches with abundant undercoordinated sites and highly excavated octahedral nanostructures with three dimensional open surfaces. Because of their advantageous nanoarchitectures and the bifunctional synergetic effects arising from the CuO-rich compositions, the PtCu-O EONDs exhibit mass activity values of 4.48 A mg-1 and 3.08 A mg-1, which are 5.27 and 2.38 times higher than those of commercial Pt/C for the electrooxidation of methanol and glycerol, respectively. This journal is © The Royal Society of Chemistry.