Study of self-hydrogenation of ethene on clean Ni(111)

• Published in: Surface science Vol. 126; no. 1; pp. 479 - 486
• Main Authors: Hasse, W., Günter, H.-L., Henzler, M.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.03.1983
• ISSN: 0039-6028; 1879-2758
• DOI: 10.1016/0039-6028(83)90746-X

The surface composition of a Ni(111) face and the reaction products have been studied during hydogenation of ethene using Auger electron spectroscopy and mass spectrometry. The pressure range has been extended from UHV up to 10 −1 mbar by incorporation of a reaction chamber into a UHV system, which could be closed with a small orifice close to the mass spectrometer. The reaction was studied starting with a clean surface and avoiding any ion getter and Ti sublimation pumps. The ethene decomposes to acetylene and hydrogen up to half a monolayer. During additional exposure part of the adsorbed hydrogen is replaced by ethene and used for hydrogenation of another ethene molecule. The model is supported by measurements at temperatures up to 100°C. The measured coverages and rates are reproduced by model calculations revealing a high initial sticking coefficient and a low reaction probability during hydrogenation.