Reactions of Cyclopropane and Deuterium over Supported Metal Catalysts

DOI: 10.1039/ft9908603815

Source and publish data:

Journal of the Chemical Society - Faraday Transactions p. 3815 - 3822 (1990)

Update date:2022-08-04

Topics:

Authors:

Brown, Ronald

Kemball, Charles

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Article abstract of DOI:10.1039/ft9908603815

The reaction of cyclopropane and deuterium has been studied at low temperatures over a number of supported metal catalysts.The main reaction was normally ring-opening, yielding a mixture of isotopic propanes which were analysed mass-spectrometrically and by deuterium NMR spectroscopy.The patterns of isotopic propanes varied substancially with the nature of the metal and provided information about the types of adsorbed intermediates involved in the mechanism of the reactions. The rection of propene and deuterium was also followed over supported platinum catalysts.In contrast to the results with cyclopropane, exchange of propene occured and the propanes formed from propene were markedly different from those from cyclopropane, reflecting differences in the mechanism of the reactions. Evidence of dual-function catalysis was obtained using alumina-supported iridium with cyclopropane and deuterium; exchange took place on the support and ring-opening on the metal.Similar dual functionality was observed for reactions of methylcylopropane or 1,1-dimethylcyclopropane with deuterium over the same Ir/Al2O3 catalyst.As a consequence of the present work, the high selectivity for the exchange of primary hydrogen atoms in various hydrocarbons over Ir/Al2O3 is now considered to be a function of the support rather than of the metal.