Carbon-supported bimetallic Pdlr catalysts for ethanol oxidation in alkaline media

Carbon-supported bimetallic Pdlr catalysts are synthesized by the simultaneous reduction method using NaBH4 as reductant and citrate as complexing agent and stabilizer X-ray diffraction transmission electron microscopy and X-ray photoelectron spectroscopy are used to characterize the Pdlr/C catalysts with different Pd/lr atomic I arms The catalytic activity and stability of the Pdlr/C catalysts for ethanol oxidation in alkaline media are examined and compared with that of the Pd/C catalyst by cyclic voltammetry lineal sweep voltammetry and chronopotentiometry Results show that lr addition can significantly improve the ethanol oxidation kinetics on Pd in alkaline media and the Pd(7)lr/C catalyst exhibits the highest activity and stability than the other samples do The improvement in catalytic performance is attributed to the fact that lr addition to Pd can facilitate the removal of adsorbed ethoxi intermediates as the hydroxyl groups are more easily adsorbed on metallic lr and iridium oxide (lrO(2)) at lower potentials (C) 2010 Elsevier Ltd All rights reserved