Bulk Unsupported MoS2 and WS2 No Promoter

Bulk Unsupported) MoS2 and WS2 No Promoter. The properties of M0S2 catalysts with different basal/edge area ratios have been compared. The basal/edge ratio, estimated from the ratio of the heat of adsorption of n- 

Ben Yaacov, Ph.D. Thesis, University of Houston, 1975, Diss. Abstr., 1976, 36, 4080B ). 

Stevens and T. Edmonds, in Proceedings Climax Second International Conference on the Chemistry and Uses of Molybdenum , ed. P. C. H. Mitchell, Climax Molybdenum Co., London, 1977, p. 155. 

Species in sulphided M0O3 (H2/thiophen) have been identified (XPS) as M0S2, M0O2, and another Mo sulphide. Comparison of Mo/S ratios from chemical analysis (5.7) and XPS (1.5-3,4) showed that the sulphided phase was concentrated at the catalyst surface. The catalyst also contained Mo (e.s.r.) and its concentration correlated with activity for thiophen hds and with the S content of the catalyst. 

M0S2 catalysts active in hds and hdm of heavy oils have been prepared in suspension by in situ sulphiding of dissolved Mo complexes (acetylace-tonate, naphthenate ). Unsupported sulphides prepared and used in suspension may have advantages in hds and hdm of residual oils and coal-derived liquids where deactivation of conventional supported catalysts by pore plugging of the support is a problem. Amorphous M0S2 may also be prepared by precipitation from M0Q4 and Li2S in tetrahydrofuran.  

---