Collect. Czech. Chem. Commun.
1981, 46, 340-353
https://doi.org/10.1135/cccc19810340
Chemisorption of ethylene on nickel surfaces with preadsorbed oxygen
Pavel Zachařa, Zdeněk Bastlb and Jakub Adámeka
a Department of Physical Chemistry, Charles University, 128 40 Prague 2
b J. Heyrovský Institute of Physical Chemistry and Electrochemistry, Czechoslovak Academy of Sciences, 121 38 Prague 2
Abstract
Chemisorption of ethylene was studied on thin polycrystalline layers of nickel prepared by metal deposition in high vacuum and modified by preadsorbed oxygen. The volumetric method combined with the gas-phase analysis and the measurement of the electrical resistance changes of these layers were used. Already small amounts of preadsorbed oxygen of the order of 10-2 of the monolayer affect rather substantially the extent of ethylene chemisorption. The extent of the initial irreversible chemisorption and also the total adsorption of ethylene as a function of the amount of preadsorbed oxygen have a maximum at the surface oxygen concentration of 3 . 1013 molecule cm-2. The adsorption accompanied by the extensive dissociation of ethylene C-H bonds proceeds predominantly on nickel atoms with lower coordination (atoms on the microcrystal edges, corner atoms, etc.), where also oxygen chemisorption proceeds preferentially.
