Mastery over the structure at nanoscale can efficiently tune the catalytic properties of catalysts, enabling great enhancement in electrocatalytic performance toward liquid fuel electrooxidation reactions. Herein, we demonstrate a facile one-pot method for the successful fabrication of binary PdCu nanocatalysts bounded with 3D open-structured nanocages, which show the advantages of high surface areas, facile mass/electron transport, and strong synergistic effect. Impressively, the resultant 3D open-structured PdCu nanocages (NCs) show large promotion in electrocatalytic performance toward ethanol oxidation reaction (EOR) with the mass activity of 1790.8 mA mg(-1), being 3.3 times higher than that of commercial Pd/C (536.2 mA mg(-1)). Besides, the specific activity for EOR on PdCu NCs (7.7 mA cm(-2)) is also comparable to many Pt-based electrocatalysts, suggesting the dramatically improved electrocatalytic activity. The outstanding electrocatalytic performance of binary PdCu catalysts is attributed to the highly open 3D nanocage structure and strong electronic effect of Pd and Cu. (C) 2019 Elsevier Inc. All rights reserved.