Abstract: An Au-Cu bimetal catalyst was prepared by deposition-precipitation (urea) of gold and copper species on mesoporous TiO₂ and activation with H₂. The sample was characterized by N₂ adsorption/desorption, X-ray diffraction, ultraviolet-visible spectroscopy, and high-resolution transmission electron microscopy. The results showed that the Au and Cu species formed an Au-Cu alloy and were well dispersed on the mesoporous TiO₂. According to CO oxidation test results, it was found that the catalytic activity of gold was enhanced by copper. The Au-Cu bimetal catalyst supported on mesoporous TiO₂ showed better catalytic stability in CO oxidation than the Au catalyst supported on mesoporous TiO₂ and the nonporous TiO₂-supported catalysts. This may be related to the effects of both Au-Cu alloying and the mesostructure of TiO₂.

Key words: gold, copper, mesoporous titania, stability, carbon monoxide, oxidation