Dehydrogenation of acetylene and ethylene studied on clean and oxygen covered palladium surfaces
1986 (English)In: Surface Science, ISSN 0039-6028, E-ISSN 1879-2758, Vol. 173, 148- p.Article in journal (Refereed) Published
The interaction of acetylene and ethylene with a clean and oxygen covered Pd surface has been studied at a temperature of 473 K. The measurements were performed on a hydrogen sensitive Pd-MOS structure making it possible to obtain direct information on the dissociation of both hydrogen and oxygen containing species on a palladium surface. Desorption studies were also performed as well as ultraviolet photoelectron spectroscopy and work function measurements. The studies show that both acetylene and ethylene adsorb dissociatively at this temperature leaving mainly carbon on the surface. When an oxygen covered Pd surface is exposed to C2H2 or C2H4 carbon dioxide and water will be formed and desorb until the surface is oxygen free. In the case of acetylene the presence of preadsorbed oxygen does not block or prevent the C2H2 dissociation on the surface. For C2H4, a large preadsorbed oxygen coverage ( 0.45) will have an impeding effect on the dissociation. The CO2 desorption is oxygen coverage dependent contrary to the H2O desorption. This is due to the fact that hydrogen has a large lateral mobility on the surface while carbon has not. Both the CO2 and H2O reactions are, however, due to the same type of mechanisms.
Place, publisher, year, edition, pages
1986. Vol. 173, 148- p.
National CategoryPhysical Sciences
IdentifiersURN: urn:nbn:se:liu:diva-67279DOI: 10.1016/0039-6028(86)90113-5OAI: oai:DiVA.org:liu-67279DiVA: diva2:409127