Thermal Decomposition of Chemisorbed Hydrocarbons

The modes of decomposition of chemisorbed hydrocarbon as the temperature is raised from an initial low value to ambient or even higher have been investigated extensively and in very great detail, using all the techniques of structure assessment 

Much attention has been given to the way in which di- 7 adsorbed ethene (4) is transformed into ethylidyne, especially on Pt(l 11), and every conceivable technique, theoretical as well as experimental, has been applied to this problem (see Further Reading section). The activation energy for the conversion as measured 

Self-hydrogenation of adsorbed ethene to ethane using hydrogen atoms released when some of the molecules decompose is apparently confined to platinum, several of whose surfaces show this reaction on other metals, the hydrogen atoms desorb as molecules, leaving dehydrogenated species behind these end up as 

Formation of ethylidyne is not confined to single crystal surfaces it has been 

Rh/Al203 and even Ni/Si02, and it is presumably mainly responsible for the all-too-frequently observed deactivation during the catalysis of hydrocarbon reactions. Nor does it arise only from ethene alkylidynes have also been formed on Ni/Al203 from higher 1-alkenes, but they were unstable, and reverted to ethylidyne at higher temperatures. It is also formed from ethyne, both on supported 

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