hide
Free keywords:
Alcohol electro-oxidation;
Alkaline electrolyte;
Electrocatalysts;
Platinum–lead oxide
Abstract:
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.
