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In Situ Study of Ethanol Electrooxidation on Monodispersed Pt 3 Sn Nanoparticles

2014; Wiley; Volume: 1; Issue: 5 Linguagem: Inglês

10.1002/celc.201300254

2196-0216

T. Herranz, María Ibáñez, José Luis Gómez de la Fuente, Francisco J. Pérez‐Alonso, M.A. Peña, Andreu Cabot, Sergio Rojas,

Advanced battery technologies research

Abstract Monodispersed Pt 3 Sn nanoparticles were prepared through a mild thermal synthesis in the presence of surfactants. The performance of Pt 3 Sn for the electrooxidation of ethanol and adsorbed carbon monoxide (CO ad ) in acid medium was studied by a combination of electrochemical and in situ spectroscopic methods, namely, infrared reflection absorption spectroscopy and differential electrochemical mass spectrometry (DEMS), and the results were compared to those obtained with the use of Pt black. The formation of the Pt 3 Sn solid solution promoted the oxidation of CO ad at less‐positive potentials than those required for Pt black. Also, the electrooxidation of ethanol, especially at lower potentials, was more favorable with Pt 3 Sn, as deduced from the higher faradaic currents recorded during the ethanol oxidation reaction (EOR). However, the distribution of products as deduced by DEMS analysis suggested that the formation of C 1 products, CO 2 inclusive, is less significant on Pt 3 Sn than on Pt. In fact, the higher faradaic current recorded with the former catalyst can be attributed to the greater amounts of acetaldehyde and acetic acid formed. After the EOR, the surface of both Pt and Pt 3 Sn remained covered by ethanol adsorbates. Whereas C 2 fragments were the main adsorbates at the surface of Pt 3 Sn after the EOR, both C 1 and C 2 species remained adsorbed at Pt black.