DEHYDROCYCLIZATION OF N-OCTANE - ROLE OF ALKENE INTERMEDIATES IN THE REACTION-MECHANISM

The objective of the present study is to define whether alkenes, forme d during alkane dehydrocyclization, are reconverted to the alkane and to elucidate the role of alkanes in the dehydrocyclization mechanism. In a competitive conversion, an alkene is converted much more rapidly than n-octane (C8D18) The lack of H/D exchange indicates that the adso rption of the n-octane is essentially irreversible, whereas some H/D e xchange in the added alkene suggests that alkene desorption does occur ; however, the added alkene does not desorb as the alkane, in conformi ty with irreversible adsorption of the alkane. The results demonstrate that the addition of a labeled alkene cannot provide data to establis h the validity of the sequential dehydrogenation reaction pathway. (C) 1997 Academic Press.