A highly active porous Pt-PbOx/C catalyst toward alcohol electro-oxidation in alkaline electrolyte

A highly active porous Pt-PbOx/C composite toward alcohol (methanol, ethanol and ethylene glycol) oxidation in alkaline media is synthesized via a modified polyol method. The crystalline structure, morphology, elemental distribution and the chemical state of metals on surface of the Pt-PbOx/C are evaluated by X-ray diffraction, high-resolution transmission electron microscopy and X-ray photoelectron spectroscopy. The large porous Pt-PbOx/C composite are composed of both Pt and PbOx primary nanoparticles of 1-2 nm which mixed geometrically with unchanged electronic environments of Pt and PbOx. The potentiodynamic and potentiostatic measurements for alcohol electro-oxidation over Pt-PbOx/C in alkaline media show that the activities toward C1-C2 alcohol electro-oxidation were improved remarkably compared to the commercial Pt/C due to both geometric effect, i.e., the addition of PbOx to Pt provides steric hindrance for CO adsorption, and bi-functional effect, i.e., OHad species could be generated over PbOx surface at lower potentials which facilitates the dehydrogenation of the intermediate methoxy.