Ethane hydrogenolysis on evaporated iridium films

Publisher Website
Google Scholar
Abstract
The reaction of ethane with hydrogen to form methane is studied over iridium films prepared by evaporation under high vacuum. Kinetic studies in combination with the results of isotope labeling experiments support in a self‐consistent way the following mechanism of hydrogenolysis. Dissociative adsorption of ethane produces CH2–CH3(a) and H(a). The final kinetically significant elementary step on the surface is the reaction of an adsorbed hydrogen atom with CH2–CH3(a) which is accompanied by the breaking of the carbon–carbon bond. Other processes which are also kinetically significant include slow (sticking coefficient ∼10−5) ethane adsorption, slow ethane desorption [by reaction of C2H5(a) with H(a)], the reversible dehydrogenation of CH2–CH3(a) to produce CH–CH3(a) and competition of hydrogen atoms for the sites on which the hydrocarbon species are adsorbed. A Langmuir‐type approach is used to derive a rate law from this mechanism which fits the experimental data over the following range of reaction conditions: a∼3 order of magnitude variation in the partial pressure of each reactant (∼1–1000μ) and a catalyst temperature in the range 80–205°C.

This publication has 18 references indexed in Scilit: