Au/13X catalysts were prepared via the impregnation method, using the organic gold compounds Au(PPh₃)(NO₃) and the inorganic gold compounds HAuCl₄ as the precursors, respectively. N₂ adsorption/desertion, SEM-EDS, XRD, and XPS were used to characterize the catalysts. The results of N₂ adsorption/desertion, SEM-EDS and XRD showed that the Au particles uniformly distributed on the surface of Au/13X-Org, while the Au particles clustered on that for Au/13X-Ino. It was observed by XRD and SEM that the mean diameter of the Au particles on Au/13X-Ino was ca. 26.6 nm, which was a lot bigger than that on Au/13X-Org (＜5 nm＝. The CO oxidations have been studied to elucidate the catalytic activity of the samples. It was found that Au/13X-Org exhibited 30% CO conversion at 25 ℃. While, for Au/13X-Ino, there was no conversion at low temperature. The temperature of the complete oxidation of CO over the Au/13X-Org was 150 ℃, which was lower than that over the Au/13X-Ino (＞400 ℃). The different activity of Au/13X-Org and Au/13X-Ino maybe attribute to two reasons, one was the size of the Au particles, and the other was the existence of chlorine. XPS techniques verified that the Au species of the samples was only metal Au⁰.

Key words: Au/13X, catalytic oxidation of CO, phosphine-stabilized mononuclear gold complex