A simple, facile, green, and controlled one-step electrodeposition method was developed for preparation of well-defined urchin-like Pd nanoparticles on a glassy carbon electrode, using nitrite ions as the growth directing agent. No any organic solvent, template, surfactant, seed, or complex apparatus was involved. The as-prepared Pd nanostructures had "clean" surfaces because of the surfactant-free formation process. The obtained Pd deposits were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD). The experimental parameters including deposition potential, the dosage of H2PdCl4 and nitrite ions, and deposition time were investigated in details. The urchin-like Pd nanopartides demonstrated better tolerance, enhanced electrocatalytic activity, and superior stability toward methanol oxidation in alkaline media. (C) 2014 Elsevier B.V. All rights reserved.