In-Situ DRIFT Study of Au-Ir/Ceria Catalysts: Activity and Stability for CO Oxidation
Por:
Aguirre, Alejo, Barrios, Celina E., Aguilar-Tapia, Antonio, Zanella, Rodolfo, Baltanas, Miguel A., Collins, Sebastian E.
Publicada:
1 feb 2016
Resumen:
Monometallic gold and iridium, and bimetallic gold-iridium on ceria catalysts were synthesized by deposition-precipitation with urea. The activity of these ceria supported catalysts for CO oxidation was: Au-Ir Au > Ir. The bimetallic catalyst was highly active and stable during the carbon monoxide oxidation reaction, showing synergism between both metals. The catalysts were thoroughly characterized chemical and structurally. High-resolution electron microscopy coupled with energy dispersive spectroscopy and X-ray photoelectron spectroscopy showed evidences of iridium-gold intimacy. In situ infrared spectroscopy in the diffuse reflectance mode was used to investigate the reactivity of the active sites. Concentration-modulation excitation spectroscopy allowed selective identification of intermediates and 'spectator' species. CO chemisorbed onto iridium sites (2096, 2060 and 2012 cm-1) was found inactive, whereas carbon monoxide on metallic gold sites (Au0-CO, 2110 cm-1) exhibited reactivity for CO oxidation. In the bimetallic catalyst, new active sites (Aud--CO, 2095 and 2026 cm-1) together with Au0-CO species were observed, most likely produced by the isolation and stabilization of gold atoms by iridium. © 2015 Springer Science+Business Media New York.
Filiaciones:
Aguirre, Alejo:
Univ Nacl Litoral, Inst Desarrollo Tecnol Ind Quim INTEC, Guemes 3450, RA-3000 Santa Fe, NM, Argentina
Consejo Nacl Invest Cient & Tecn, Guemes 3450, RA-3000 Santa Fe, NM, Argentina
Barrios, Celina E.:
Univ Nacl Litoral, Inst Desarrollo Tecnol Ind Quim INTEC, Guemes 3450, RA-3000 Santa Fe, NM, Argentina
Consejo Nacl Invest Cient & Tecn, Guemes 3450, RA-3000 Santa Fe, NM, Argentina
Univ Nacl Autonoma Mexico, Ctr Ciencias Aplicadas & Desarrollo Tecnol, Circuito Exterior S-N, Mexico City 04510, DF, Mexico
Aguilar-Tapia, Antonio:
Univ Nacl Autonoma Mexico, Ctr Ciencias Aplicadas & Desarrollo Tecnol, Circuito Exterior S-N, Mexico City 04510, DF, Mexico
Zanella, Rodolfo:
Univ Nacl Autonoma Mexico, Ctr Ciencias Aplicadas & Desarrollo Tecnol, Circuito Exterior S-N, Mexico City 04510, DF, Mexico
Baltanas, Miguel A.:
Univ Nacl Litoral, Inst Desarrollo Tecnol Ind Quim INTEC, Guemes 3450, RA-3000 Santa Fe, NM, Argentina
Consejo Nacl Invest Cient & Tecn, Guemes 3450, RA-3000 Santa Fe, NM, Argentina
Collins, Sebastian E.:
Univ Nacl Litoral, Inst Desarrollo Tecnol Ind Quim INTEC, Guemes 3450, RA-3000 Santa Fe, NM, Argentina
Consejo Nacl Invest Cient & Tecn, Guemes 3450, RA-3000 Santa Fe, NM, Argentina
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