Determining the Ce 2 O 2 S-CeO x Phase Boundary for Conditions Relevant to Adsorption and Catalysis Determining the Ce 2 O 2 S-CeO x Phase Boundary for Conditions Relevant to Adsorption and Catalysis Determining the Ce 2 O 2 S-CeO x Phase Boundary for Con

Abstract The interaction of sulfur with ceria under highly reducing conditions was investigated. The phase boundary between CeO 1.83 and Ce 2 O 2 S was determined for temperatures between 873 and 1073 K. This data was used to derive an empirical equation for ΔG f º of Ce 2 O 2 S in this temperature range. This equation along with thermodynamic data for cerium oxides and sulfides obtained form the literature was used to predict Ce-O-S phase diagrams at 873 and 973 K. These phase diagrams provide insight into the mechanism of the deactivation of ceria-based catalysts by sulfur under reducing conditions