Our recent investigations of electrocatalysts for low temperature fuel cells have shown that ordered intermetallic compounds such as PtBi and PtPb have lower oxidation onset potentials and higher current densities for formic acid oxidation than pure Pt and Pd electrodes^1,2). In this presentation, carbon black (CB)-supported Pt₃Pb NPs was synthesized as catalysts for the formic acid oxidation and oxygen-reduction reaction. Atomically disordered and ordered intermetallic Pt₃Pb NPs were prepared at room temperature using the polyol method. The Pt/carbon black (CB) and Pb(CH₃COO)₂•3H₂O were dissolved in ethylene glycol. The mixture was sonicated and then treated in the flask under reflux for 1 min with 300-W microwave radiation. The mixture in the flask was cooled to room temperature with water. The mixture was again treated with microwave radiation (focused microwave instrument, CEM) at 300 W for 9 min. After the mixture cooled, Pt₃Pb NPs/CB was collected by centrifugation, washed sequentially with methanol and dried under vacuum. The formation of ordered intermetallic Pt₃Pb after annealing was confirmed by X-ray photoemission spectroscopy, powder X-ray diffraction, and a scanning transmission electron microscope with an electron-probe microanalyser (STEM). The surface structure of atomically disordered and ordered intermetallic Pt₃Pb NPs was analyzed with high-resolution STEM. The relationship between the electrocatalytic activity and the surface structure was examined.

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