Kinetics of thermal synthesis of cerium sulfides

Abstract 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 (Ce 2 S 3 ) and cerium hydride (CeH 2 ). High purity Ce 2 S 3 was produced by reacting ceria (CeO 2 ) and hydrogen sulfide (H 2 S) in an induction furnace using a carbon catalyst at temperatures above 2000 °C. CeH 2 was synthesized from cerium metal and hydrogen gas at 100 °C. Ce 2 S 3 and CeH 2 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.