Preparation and activity of carbon-supported porous platinum as electrocatalyst for methanol oxidation

In this paper, we reported a novel electrocatalyst, Vulcan XC-72-supported porous platinum nano-particles (Pt-p/C) for methanol oxidation. In the preparation of Pt-p/C, platinum precursor was first adsorbed on carbon and then reduced by L-ascorbic acid in ethylene glycol solution. The structure and morphology of Pt-p/C and its activity toward methanol oxidation were characterized by transmission electron microscopy (TEM), Brunauer-Emmett-Teller (BET) measurement, X-ray diffraction (XRD), energy-dispersion spectrometer (EDS), cyclic voltammetry (CV), and chronoamperometry (CA), with a comparison of the electrocatalyst prepared with sodium borohydride as reducer (Pt-p/C). It is found that both electrocatalysts have similar particle size but have different surface morphology of platinum and thus exhibit different electrocatalytic activity toward methanol oxidation. The platinum particle size of both electrocatalysts is 3-5 nm, but the corresponding BET surface areas are different significantly, 131.6 m(2) g(-1) and 87.7 m(2) g(-1) for Pt-p/C and Pt-s/C, respectively, indicative of the porous structure of platinum particles in Pt-p/C. The peak current for methanol oxidation on CV is 167 mA mg(-1) and 44 mA mg(-1) for Pt-p/C and Pt-s/C, respectively, indicative of the high electrocataytic activity of Pt-p/C toward methanol oxidation. The result from CA shows that Pt-p/C has good stability as the electrocatalyst for methanol oxidation. (c) 2010 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.