Deactivation of the PtRe/Al2O3 catalytic functions during a commercial cycle

PARERA, J.M.; QUERINI, C.A.; FIGOLI, N.S.

APPLIED CATALYSIS A-GENERAL

Año: 1988 vol. 44 p. 1 - 8

0926-860X

Samples of coked sulphided PtRe/Al2O3 catalyst taken from a commercial reactor during a nearly seven month operation cycle were studied. The distribution of coke over the catalyst functions was determined by temperature-programmed oxidation and the changes in the selectivity were studied by means of catalytic tests. The catalyst activity for dehydrocyclization of n-heptane follows the same pattern as the activity for acid controlled isomerization of n-pentane. Both decrease during the cycle. The catalytic dehydrogenation of cyclohexane on catalyst samples taken at the beginning of the cycle decreases with time, and then remains constant on samples taken towards the end of the cycle. It is concluded that the long-term deactivation is due to deactivation of the acid function, which determines the length of the cycle.