Palladium nanoparticles supported on a chitosan-functionalized hybrid carbon material for ethanol electro-oxidation

Catalytic performances of the Pd catalyst towards ethanol electro-oxidation in alkaline media are improved by employing a hybrid carbon support composed of chitosan-functionalized carbon nanotubes and graphite nanoplates. Series of characterization results reveal that Pd nanoparticles have a uniform distribution on the hybrid support with small particle sizes. Electrochemical measurements indicate that the hybrid carbon material-supported Pd catalyst has a large electrochemical active surface area, a high catalytic activity as well as a good poison resistance towards ethanol electro-oxidation. This is attributed to the unique structure of the hybrid carbon support. The stacking of the two-dimensional graphene nanoplates is prevented by carbon nanotubes, thus the surfaces of the support are sufficiently utilized. Chitosan serves as a non-covalent functionalization reagent facilitating the uniform blending of graphene nanoplates and carbon nanotubes. In addition, X-ray photoelectron spectra reveal that chitosan interacts with Pd nanoparticles via the synergistic interaction. This interaction contributes to the high catalytic activity and the good poison resistance of the catalyst towards ethanol electro-oxidation.