Study on ceria-modified SnO2 for CO and CH4 oxidation

Sn-Ce-O binary catalysts with different Sn/Ce molar ratios were prepared with co-precipitation method and applied for CO and CH4 oxidation. The catalysts were characterized by means of N2-BET, XRD and H2-TPR techniques. It was found that for those Sn rich samples such as SnCe91 and SnCe73, Ce cations were doped into the matrix of tetragonal rutile SnO2 to form SnO2-based solid solution. As a consequence, the oxidation activity as well as the thermal stability was significantly improved compared with pure SnO2. In contrast, for Ce rich samples such as SnCe19, SnCe37 and SnCe55, though the thermal stability was improved, the activity was worse than SnO2, due to the presence of much less amount of active oxygen species. Co-precipitation was found to be the best method to prepare Sn-Ce binary catalysts among all of the methods tried in this study.