Preparation of Au/TiO₂ catalyst by a liquid-phase reduction method for preferential oxidation of carbon monoxide in a hydrogen rich-stream (CO-PROX reaction)

Au nanoparticles supported on TiO₂ were prepared by a liquid-phase reduction method using HAuCl₄.3H₂O as the Au precursor, TiO₂ as the support, a solution of ethylene glycol/water as solvent and reducing agent and sodium citrate as reducing agent and stabilizer. The Au/TiO₂ catalysts were prepared using different routes and characterized by Energy-dispersive X-ray spectroscopy, X-ray diffraction and Transmission Electron Microscopy and tested for preferential oxidation of carbon monoxide in hydrogen-rich stream (CO-PROX reaction). The way that the Au precursor, the TiO₂ support and the sodium citrate is added to the ethylene glycol/water solution strongly influences the Au nanoparticle sizes and the catalytic activity of the obtained materials. (author)