Iron promotes the interaction between S2 and Mo(110). The exposure of Mo(110) to large amounts of S2 produces only a chemisorbed layer of sulfur, without forming molybdenum sulfides. The sulfidation of Mo occurs after exposing Fe/Mo(110) surfaces to S2 gas. Fe promotes the rate of formation of molybdenum sulfides by transferring charge to Mo (favoring in this way an electrophilic attack of S on Mo) and by changing the structure of the surface (making the penetration of S into the bulk of the sample easier). The thermal stabilities of the MoSx/Mo(110) and FeSy/MoSx/Mo(110) systems are comparable, with the bimetallic sulfide showing a somewhat lower decomposition temperature (∼1200 K). The behavior of FeMoS catalysts in hydrodesulfurization processes is discussed in light of these results.
No takes yet. Share an insight, caveat, or question.
Rodríguez et al. (1996) studied this question.