Fabrication of a novel PtPbBi/C catalyst for ethanol electro-oxidation in alkaline medium

This work presents a general strategy to fabricate a new type of ternary intermetallic PtPbBi/C nano-catalyst. X-ray diffraction, transmission electron microscope and X-ray photoelectron spectroscopy data demonstrate that some Pb atoms are imbedded into Pt lattice to form PtPb alloy particles in the microwave action. The PtPb/C catalyst surface is further modified by Bi via a spontaneous and irreversible chemisorption approach. Ethanol oxidation peak current on PtPbBi/C (217.9 mA cm(-2)) is about 4.1 times higher than that on Pt/C(53.6 mA cm(-2)) in cyclic voltammograms. Tafel plots show that both ethanol dehydrogenation and removal of CO-like species are greatly enhanced on the novel PtPbBi/C catalyst. Constant potential and linear current sweep tests indicate that the addition of Pb and Bi causes the formation of abundant oxygenated species on the catalyst surface at low potential. These oxygenated species can react with poisonous intermediates formed during ethanol oxidation, and help the release of free Pt active sites for further adsorption and electro-oxidation of ethanol molecules. (C) 2012 Elsevier Ltd. All rights reserved.