Study on CuO-CeO₂ catalysts for HCl catalytic oxidation to prepare Cl₂

Copper modified CeO₂ catalysts (CuO-CeO₂ and CuO/CeO₂) were prepared by bulk-template and surface-template methods, respectively. The catalysts were characterized by XRD, N₂ adsorption-desorption, Raman and H₂-TPR. The performance of the catalysts for gas-phase HCl catalytic oxidation to prepare Cl₂ was also investigated. The results of XRD, Raman and H₂-TPR show that the bulk-template method is favorable in preparing catalysts with higher copper dispersion, which could improve oxygen vacancy concentrations of the catalysts. It is found that the oxygen vacancy concentration is the key factor in determining the catalytic activity after studying the relationship between these two parameters. The catalytic activities of the catalysts before and after acid treatment show that highly dispersed CuO contributes little on catalytic activity under low temperatures, but it could effectively promote catalytic performance under higher temperatures. However, crystallized CuO contributes little on catalytic activity.