Pd/PdO nanoparticles supported on porous graphene (PG) are synthesized by a gas-liquid interfacial plasma method using Pd(NO3)(2) center dot 2H(2)O as precursor. The Pd/PdO ratios can be controlled by changing the amount of Pd(NO3)(2) center dot 2H(2)O. The synthesized Pd/PdO electrocatalysts exhibit a high electrocatalytic activity for methanol oxidation. The Pd/PdO nanoparticles attached on PG support shows better activity than that on oxidation carbon nanotubes support for methanol oxidation. In addition, our findings show that the PdO present in the Pd nanoparticles can enhance the electrocatalytic activity. It is worth to mention that the Pd/PdO nanoparticles supported on porous graphene catalysts show better electrochemical stability than that of commercial Pd/C catalyst. (C) 2016 Elsevier B.V. All rights reserved.