Gold Promoted S,N-Doped TiO2: An Efficient Catalyst for CO Adsorption and Oxidation

Mesoporous S,N-TiO2 nanocomposite was prepared by a one-pot template free homogeneous coprecipitation technique using titanium oxysulfate sulfuric acid complex hydrate, thiourea, ethanol, and water. Nano gold deposition on mesoporous S,N-TiO2 was preformed by a borohydrate reduction method. To evaluate the structural and electronic properties, these catalysts were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), high-resolution transmission electron microscopy (HR-TEM), UV-vis DRS, photoluminescent (PL) spectra, Fourier transform infrared (FTIR), and TPO/TPD. CO adsorption and CO + O-2 interaction over these catalysts were investigated by in situ FTIR. Sulfur and nitrogen doping enhances the catalytic activity of Au/TiO2. Higher catalytic activity of Au/S,N-TiO2 compared to Au/TiO2 was attributed to the presence of oxygen vacancy and creation of new adsorption sites at Au/TiO2 interfaces for the adsorption and activation of O-2 molecules.