Kinetics and Mechanisms of Hds Reactions

Kinetics and Mechanisms of Hds Reactions. - Earlier work and outstanding problems are summarized in the earlier Report. Much of the work reviewed in the present Report concerns thiophen and benzo- and dibenzothiophens that have been of particular interest as model compounds in residual oil and coal hds. Recent reviews include discussions of mechanisms. An outstanding question is whether S elimination from a heterocyclic ring is preceded by ring hydrogenation. The obvious, but important, point has been made that failure to detect a compound in the gas phase, specifically tetrahydrothiophen during thiophen hds, does not exclude the possible importance of a reaction path in which a particular compound is a surface intermediate, since its surface reaction may be faster than its desorption. 

Titova, D. P. Pchelina, and I. Goryuch, Khim. Tverd. Topi. Moscow), 1978, 5 Chem. Abstr., 1979, 90,41 156). 

Kraus and M. Zdrazil,i eact Kinet. Catal. Lett., 1977, 6, 475. 

The oligomerization of dienes could play an important role in catalyst deactivation. 

The ratios of activity for H2S elimination [step (ii)] over hydrogenation-dehydrogenation [step (01 correlated with polarities of catalysts (estimated from differences in the adsorption of alkanes and aromatic hydrocarbons) and decreased in the order AI2O3 Co-Mo/AI2O3 M0S2 

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