20717-77-5Relevant academic research and scientific papers
REACTIONS OF 2-METHYLPROPENE AND OTHER ALKENES ON ZINC OXIDE
Brown, Ronald,Kemball, Charles,Taylor, Duncan
, p. 2899 - 2914 (1983)
Studies have been made on the hydrogenation, deuteration and exchange with deuterium of ethene, propene and 2-methylpropene on zinc oxide and Arrhenius parameters for the reactions have been determined.Some general conclusions are reached about the catalytic behaviour of alkenes on zinc oxide from these and earlier results.Exchange occurs readily with alkenes which can dissociate to allyl intermediates but can also take place via the formation of vinyl intermediates with other alkenes, particularly at higher temperatures.Similar rates of alkane formation are found with different alkenes at temperatures at which the strengths of adsorption of the alkene are equivalent.The mechanism of alkane formation does not contribute to exchange of the alkene nor give rise to double-bond movement and the probable rate-determining step is the formation of adsorbed alkyl species which are then rapidly converted to alkane.
Reactions of Cyclopropane and Deuterium over Supported Metal Catalysts
Brown, Ronald,Kemball, Charles
, p. 3815 - 3822 (2007/10/02)
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.
