Kinetics of thermal synthesis of cerium sulfides

One of the most promising applications for cerium sulfide is as a refractory for molten metal processing, particularly for reactive actinides. Separate processes were used to synthesize cerium monosulfide, cerium sesquisulfide (Ce2S3) and cerium hydride (CeH2). High purity Ce2S3 was produced by reacting ceria (CeO2) and hydrogen sulfide (H2S) in an induction furnace using a carbon catalyst at temperatures above 2000 °C. CeH2 was synthesized from cerium metal and hydrogen gas at 100 °C. Ce2S3 and CeH2 were subsequently reacted together in an induction furnace at temperatures above 1700 °C to produce CeS. X-ray diffraction was used to analyze synthesized samples and the kinetics of the CeS synthesis reaction was modeled using a diffusion-limited reaction model. The activation energy for the process was estimated to be 190 kJ/mol.