And Catalytic Chemistry Research Of SnO₂-based Catalysts

SnO2is a kind of important catalytic materials, which draws people’s attention gradually to be applied as catalysts in the CO oxidation and the CH4combustion. In this work, a series of SnO2and Pd-SnO2catalysts were prepared with different methods, analyzed by XRD, N2-BET, H2-TPR, UV-Vis, TG-DSC and XPS for their structure and properly. In addition, their catalytic activities were evaluated by CO oxidation and CH4combustion.First, SnO2catalysts were prepared with the precipitation method by varying the pH and SnCl4concentration. For comparison, another two SnO2samples were also synthesized with sol-gel and combustion methods. All of the catalysts were characterized by N2-BET, XRD and H2-TPR. It was found that the CO oxidation activity of the precipitation samples increases with an increase in pH, while the CH4oxidation activity seems unchanged. The change of the SnCl4concentration has little influence on the activity for both CO and CH4oxidation. The sol-gel sample has relatively higher CO but similar CH4oxidation activity, due to its higher surface area and finer particle sizes. On the contrary, the combustion sample displays the lowest activity for both reactions, due to its extra low surface area and inert oxygen species. Second, a series of Pd-SnO2catalyst with different Pd content were prepared by deposition precipitation, sol-gel and impregnation methods, then analyzed by a series of characterization methods. It is found that the addition of Pd with different methods has influence on the performance of the catalysts. The catalysts prepared with sol-gel method show the highest activity among all of the catalysts.