Resumen

DIAZ, Juan C et al. Synthesis nano-Au supported in oxides metallic and catalytic activity in oxidation reaction of CO. Rev. LatinAm. Metal. Mater. [online]. 2013, vol.33, n.1, pp.43-53. ISSN 0255-6952.

Gold nanoparticles, Nano-Au, were prepared on different supports and used as CO oxidation catalysts. Synthesis of Nano-Au, supported on TiO₂, CeO₂ and γ-Al₂O₃ was done by precipitation in non-aqueous HAuCl₄/ethylene-glycol in a Li₂S/oxide/ethylene-glycol suspension in a minimum HClO₄ volume. All the nano-structured systems were characterized by TEM, XPS, XRD, AE, ICP and UVVisible methods. The TEM images confirm Nano-Au/ oxide formation on all the supports. Particle size distribution analysis suggest different dispersions, being Au/Al₂O₃ (~3,45 nm) the least dispersed system. XRD analysis shows the presence of Au/oxide, compared with the XRD standard, and crystal size was estimated using the Debye-Scherrer equation. UV-visible spectra shows a characteristic band near 520 nm, due to plasmon resonance in all the synthetized systems and there was no clear tendency between particle size and the absorption band displacement. XPS analysis shows two peaks with a slight displacement in bonding energy, assigned to the Au4f_7/2 y Au4f_5/2 transitions due to Au(0) and Au³⁺ from Au₂S₃. The CO oxidation catalytic activity of Nano-Au was done in a static bed reactor at low temperature, obtaining a 36% conversion with Au/TiO₂.

Palabras clave : Nanoparticles; oxidation CO; Synthesis; characterization.

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