Electrooxidation of methanol and ethanol catalyzed by high-performance three-dimensional graphene-supported PdM (Co, Cu) binder-free electrode.

PdM/RGN (M = Co, Cu) self-supporting composite electrodes were synthesized via a simple two-step spontaneous reduction process using Ni foam as the substrate and reduced graphene oxide as support layer. The composites were characterized using X-ray diffraction, scanning electron microscopy, and X-ray photoelectron spectroscopy. Cyclic voltammetry, chronoamperometry, and electrochemical impedance spectroscopy were performed to study the electrocatalytic activities of the prepared electrodes for methanol and ethanol oxidation. The performances of PdM/RGN for methanol and ethanol oxidation increased and then decreased as the atomic ratio of Pd to M (Co, Cu) increased. The Pd 6 Co 1 /RGN and Pd 6 Cu 1 /RGN electrodes exhibited markedly superior catalytic activity and long-term stability. The peak current densities of Pd 6 Cu 1 /RGN and Pd 6 Co 1 /RGN electrodes reached 0.36 and 0.29 A/cm2 for methanol electrooxidation and which reached 0.8 and 0.5 A/cm2 for the ethanol electrooxidation, respectively. This excellent performance is owing to the three-dimensional structure of nickel foam, the improving specific surface area and the synergistic effect between Pd and M. [Display omitted] • The electrode manufacture process is facile, green, low energy consumption and binder-free. • Three-dimensional graphene substrate support resulted in excellent stability of PdM/RGN (Co,Cu). • Good synergy in PdM nanoparticles promotes electron transport and increases surface area. • The PdM/RGN (Co,Cu)electrode exhibitshigh catalytic performance for MOR and EOR. [ABSTRACT FROM AUTHOR]