THE KEY ROLE OF ACTIVATION PROCESS IN ETHANOL ELECTROOXIDATION BY PALLADIUM NANOPARTICLES

A Keggin type polyoxometalate (POM), phosphomolybdic acid (PMo12), has been employed to encapsulated and stabilisepseudo-spherical Pd nanoparticles (PdNPs) via a green synthesis procedure. The resulting nanohybrid phosphomolybdic acid-stabilised PdNPs (PdNPs@PMo12) werecharacterised by transmission electron microscopy (TEM), high-angle annular dark field-scanningtransmission electron microscopy (HAADF-STEM), Energy-dispersive X-ray spectroscopy (EDS),Fourier transform infrared spectroscopy (FTIR) and powder X-ray diffraction (XRD). The PdNPs@PMo12 were used as an electrocatalyst for ethanol oxidation in alkaline media and the best electrocatalytic activity was assessed by applying an activation process. The electrochemical data (chronoamperometry, cyclic voltammetery and linear sweep voltammetry) allow us to attribute thesuperior performance of the nanohybrid to the generation of Pd-OHads sites at the surface of the PdNPs@PMo12, being reinforced by the formation of new molybdenum species on the surface of the electrocatalyst

Keywords:

Palladium , Polyoxometalate , electrocatalyst , activation process