Influence of Au particle size on Au/CeO2 catalysts for CO oxidation

The Au particle size dependence of CO oxidation on Au/CeO2 catalysts was extensively investigated. By keeping the size of CeO2 particle to be about 12 nm, the increasing size of Au particle from 3.9 to 7.5 nm caused significant decrease in the intrinsic activity for CO oxidation. Comparative study on sodium cyanide leaching, which effectively removed the metallic gold particles but retained the cationic gold clusters in the matrix of ceria, revealed that the cationic gold species could catalyze CO oxidation only at higher temperatures, confirming the major contribution of the metallic gold particles in the Au/CeO2 system. Therefore, it is evident that the Au–CeO2 interface determined mainly by the size of Au particle plays an essential role in achieving the high reactivity.

The Au particle size dependence of CO oxidation on Au/CeO2 catalysts was extensively investigated. The increased average size of Au particle caused significant decrease in the intrinsic activity. Comparative study on sodium cyanide leaching reveals that the cationic gold species could catalyze CO oxidation only at higher temperatures, confirming the major contribution of metallic gold particles in the Au/CeO2 system. Moreover, it is concluded that the Au–CeO2 interface determined mainly by the size of Au particle plays an essential role in achieving high reactivity.Figure optionsDownload high-quality image (156 K)Download as PowerPoint slideHighlights
► Au–CeO2 interface is mainly determined by the size of gold particle.
► CO oxidation is closely associated with the size of gold particle.
► Increasing Au particle size significantly lowers the intrinsic activity.
► Faceted gold particle mainly contribute to the activity for CO oxidation.
► Cationic gold species catalyze CO oxidation only at higher temperatures.