Effects of sulfidation of Mo nitride and CoMo nitride catalysts on thiophene HDS

Abstract

Mo and CoMo nitrides were prepared by temperature-programmed reduction of the corresponding oxides with flowing ammonia; effects of sulfidation of these catalysts on their thiophene hydrodesulfurization (HDS) activities were investigated. The HDS activity of fresh CoMo nitride is higher than that of Mo2N. The properties of nitrides vary significantly with sulfidation temperature. After sulfiding Mo2N transforms into MoS2 and the CoMo nitride into MoS2 and Co9S8. This indicates that these nitride catalysts are not resistant to sulfur under severe sulfidation conditions. The transformation, on the other hand, results in a synergistic activity of HDS among the three phases present.