Catalisadores à Base PtxPdy/C para a Eletro-oxidação de Etanol em Eletrólito Ácido

This work shows a comparative study of the electrochemical activity of Pt/C, Pd/C and PtxPdy/C electrocatalysts prepared by chemical reduction of ions in aquose solution using Sodium Borohydride as reductor [1], the precursors were H2PtCl3.6H2O and PdCl2.The materials were morphological characterized by X-ray Powder Diffraction (XRD), Energy-dispersive X-ray Spectroscopy (EDX) and High Resolution Transmission Electron Spectroscopy (HRTEM), the amount of metal , lattice parameter (a), particle size (d) and crystallite size (t) are shown in table 1. Moreover the materials were electrochemical characterized with cyclic voltammetry in presence and absence of the ethanol in the electrolyte. For electrochemical experiments were used a single compartment glass-electrochemical cell with Ag/AgCl/KClsat reference electrode, Pt auxiliary electrode and the glass carbon with the material as working electrode. The cyclic voltammetry were registered between -0.2 and 0.85 V at 0.02 V s-1 in 0.5 mol L-1 H2SO4 and 0.3 mol L-1 CH3CH2OH and the maximum current and the onset potential are shown in table 1. The materials with Pd show particle size and crystallite size larger than Pt and show a petty increase in the onset potential. The Pd insertion on platinum lattice increases the maximum current of ethanol oxidation reaction [2].