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

✍ Scribed by S.Y. Shen; T.S. Zhao; J.B. Xu

• Publisher: Elsevier Science
• Year: 2010
• Tongue: English
• Weight: 996 KB
• Volume: 55
• Category: Article
• ISSN: 0013-4686
• DOI: 10.1016/j.electacta.2010.09.018

✦ Synopsis

Carbon-supported bimetallic PdIr catalysts are synthesized by the simultaneous reduction method using NaBH 4 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 PdIr/C catalysts with different Pd/Ir atomic ratios. The catalytic activity and stability of the PdIr/C catalysts for ethanol oxidation in alkaline media are examined and compared with that of the Pd/C catalyst by cyclic voltammetry, linear sweep voltammetry and chronopotentiometry. Results show that Ir addition can significantly improve the ethanol oxidation kinetics on Pd in alkaline media, and the Pd 7 Ir/C catalyst exhibits the highest activity and stability than the other samples do. The improvement in catalytic performance is attributed to the fact that Ir addition to Pd can facilitate the removal of adsorbed ethoxi intermediates, as the hydroxyl groups are more easily adsorbed on metallic Ir and iridium oxide (IrO 2 ) at lower potentials.