TRANSIENT-RESPONSE STUDIES ON THE HYDROGENATION OF PROPENE AND MIXTURES OF PROPENE WITH ISOBUTENE OVER A PLATINUM CATALYST

The transient response method with mass-spectrometric analysis of the reaction mixture is applied to investigate the mechanism for the hydro genation of propene and mixtures of propene with isobutene over a Pt-S n/Al2O3 catalyst. It is found that the adsorbed species of both compon ents act as reactive intermediates in the hydrogenation, and the addit ion of the second hydrogen atom to the surface intermediate is a slow step in the reaction. Only a fraction of the adsorbed hydrogen is capa ble of hydrogenating olefins. Propene and isobutene show comparable ad sorptivities, although propene is held somewhat stronger on the cataly st surface.