In situ laser Raman spectroscopic studies of the sulfiding of cobalt molybdate hydrodesulfurization catalysts were performed. Sulfiding in 10% H2S H2 at 400 °C resulted in the formation of stable MoS2 structures after 2 h. However, the Raman spectra indicated that small crystallites or surface layers of perhaps distorted MoS2 were present. Stepwise sulfiding of samples to 150, 250, and 350 °C permitted intermediate stages of sulfiding to be examined. Differences were observed for the relative rates of reduction versus sulfur incorporation for CoMoO4, Co3O4, MoO3, and aggregated or polymeric molybdate phases. Cobalt tended to increase the extent of reduction of the catalyst. A previously described model is extended to include the role of cobalt.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry