Gold Nanoparticle: Enhanced CO Oxidation at Low Temperatures by Using Fe-Doped TiO2 as Support

Abstract

Iron doped TiO2 materials were prepared by the sol–gel method and used as supports of gold nanoparticles synthesized by the deposition–precipitation technique. The gold–iron–titania catalysts were characterized by X-ray diffraction, Raman spectroscopy, N2 physisorption, UV–Vis spectroscopy as a function of temperature, H2-temperature programmed reduction, transmission electronic microscopy and X-ray photoelectron spectroscopy. The gold–iron catalysts were catalytically active during the CO oxidation reaction at low temperatures, reaching CO conversion percentages of almost 80% at room temperature. The Au/TiO2–Fe catalyst surface was characterized through infrared spectroscopy (DRIFTS) during the CO oxidation reaction to elucidate the active sites and the real carbon monoxide interaction during the reaction. A 24-h deactivation test corroborated a final deactivation of the catalysts of only 25% for both Au/TiO2–Fe 1 and the bare Au/TiO2. The results here obtained corroborate that the activity of the iron-doped TiO2 catalyst was higher than that of the bare TiO2 due to the iron incorporation into the TiO2 lattice, which allows the formation of surface oxygen vacancies and new adsorption sites which favor the CO adsorption and its oxidation to CO2.