Physico-chemical properties of deuteriated compounds. 6th Communication. The H/D exchange in mixtures between hydrogen and heptane,methylcyclohexane or cycloheptane over Ni-catalyst

The isotopic exchange between hydrogen and saturated hydrocarbons over Nicatalysts has been studied as a function of temperature and degree of deuteriation. The experimental results can be explained by a model containing four parameters. Two different adsorbed species are assumed: in the ‘alkyl’-species one H-atom is exchanged in a single adsorption step; the ‘olefin’-species exchanges at least two H-atoms at the same time. Both species can undergo multiple exchange per adsorption step.