K. Kishi, Keiko Chinomi, Y. Inoue
Nov 1, 1979
Citations
0
Influential Citations
68
Citations
Journal
Journal of Catalysis
Abstract
Abstract The adsorbed states of benzene, pyridine, aniline, and nitrobenzene on evaporated nickel and iron films have been investigated by X-ray photoelectron spectroscopy. Benzene adsorbed on the metals with π-d bonding exhibits a C 1s peak whose binding energy is lower by 0.8 eV on nickel and by 0.5 eV on iron than that for condensed benzene. Pyridine is also considered to chemisorb on the metal surfaces by π-d interaction as inferred from the low binding energy of the C 1s and N 1s electrons and from substitution reaction data with acetic acid. Aniline gives both a molecularly adsorbed species and an anion formed by release of a proton from the amine group. Nitrobenzene dissociates stepwise to give adsorbed nitrosobenzene with N 1s at 400.0 eV and an anion with N 1s at 397.6 eV which has released two oxygen atoms, forming surface oxygen. On the metal surfaces preoxidized by oxygen, pyridine and aniline bond to the surface through nitrogen lone pair electrons and their C 1s and N 1s electrons have virtually the same binding energies as those for condensed pyridine and aniline. Nitrosobenzene is a predominant species on the preoxidized surfaces after exposure to nitrobenzene. Benzene is not observed on the heavily oxidized surfaces.