Gas Phase Study of o-Xylen Hydrogenation over Pt/Al2O3: The Influence of Ce and the Catalyst reduction Temperature on Selectivity

Abstract

In the hydrogenation of o-xylene, dispersion is affected by the reduction

temperature. The activation energy (E_a^*) was found to be 67 ± 15 kJ/mol.

The selectivity towards the thermodynamically preferred product,

1.2-trans-dimethyl cyclohexane isomer increases with the increase of dispersion.

a behaviour explained by the roll over mechanism. The incorporation

of Ce with Pt increases the percentage formation and the selectivity

of the Idnetically preferred product, 1,2-cis-dimethylcyclohexane jsomer,

and also it increases the activity of the hydrogenation. The effect of Ce

was attributed to its electronic effect.