Surface-structure sensitivity of CeO2 for several catalytic reactions

Vapor-phase catalytic reactions of several reactants were investigated over CeO2 with different particle sizes, and the surface-structure sensitivity, i.e. crystal plane dependency, was discussed. The particle size of CeO2 was regulated by the calcination temperature. In dehydration of 1,4-butanediol and 1,3-butanediol into unsaturated alcohols, and ketonization of propanoic acid, the activities increased with increasing the CeO2 particle size. CeO2 {1 1 1} facets became predominant on the large particles. This indicates that CeO2 {1 1 1} facets have active sites for the reactions of butanediols and of propanoic acid. Therefore, dehydration of 1,4-butanediol and 1,3-butanediol, and ketonization of propanoic acid are categorized into surface-structure-sensitive reaction. The structure-sensitive reactions have feature that the main product is formed with high selectivity at temperatures lower than 400 °C. In contrast, activities of dehydration of 2-heptanol, methylation of phenol with methanol, and ketonization of propanal and 1-propanol were independent of the CeO2 particle size. These reactions are categorized into structure-insensitive reaction.

Graphical abstractVapor-phase reactions of several reactants were investigated over CeO2 catalysts with different particle sizes, and the surface-structure sensitivity was discussed. CeO2 {1 1 1} facets have active sites for the reactions of butanediols and of propanoic acid, which can be categorized into structure-sensitive reaction. The structure-sensitive reactions have feature that the main product(s) are formed with high selectivity at temperatures lower than 400 °C. Figure optionsDownload full-size imageDownload as PowerPoint slide