Structural analysis of several commercial Pt-Re/Al2O3 catalysts deactivated through industrial Naphtha Reforming. DRIFT, TG-DTA, MS-TP analysis and test reaction with cyclohexane studies

Pt-Re/Al2O3 catalysts are commonly used in reforming naphtha, in this paper it is explained how todo a fast analysis and study about the origin and possible mechanism of deactivation for severalcatalysts from industrial reforming. Several studies using DRIFT, TG-DTA and MS-TP analysis weredid, they showed as the coke is deposited over the acid and metallic centers of the catalysts. Testreaction using cyclohexane shows as the catalysts have less .for isomerization and more fordehydrogenation producing as principal product the benzene. The deactivation increases with thetime and the amount of coke species over the catalyst (TG-DTA studies show clearly these results).Not paraffins were found over the catalyst (DRIFT and MS-TP results), only carbonaceous specieswhich in first time are deposited over the acid centers. In our test reaction the deactivation isprincipally over the metallic centers because the acid places were deactivated before in the industrialreforming.