The effect of intermolecular interactions on spectral characteristics of CO adlayers on highly dispersed mono- and polymetallic systems is investigated in pressure range 10^-4 - 10 torr by experimental and calculation methods. It was shown that the CO molecules are distributed on the surface irregularly, arranging on the certain sites and they form the MCO and M_nCO species. On the basis of the analyses of the dependence of the frequencies and halfwidth of absorption bands on gas pressure (coverage) it was established that in the case of some adsorbents including Rh, Co, Ir even at the lowest coverage (approximately 0.03) individual CO molecules are absent. Intermolecular interactions between chemisorbed gas molecules promote ordering in overlayers which results in the 'islands' or clusters from the CO molecules with MCO- bonds. The low local density of CO molecules with M_nCO- bonds does not result in ordered structures. The experimental data on CO adlayers on highly dispersed metallic systems enable us to make conclusions about the formation of ordered structures in the case of nonuniform surface.

Date Published: 3 March 1997
PDF: 3 pages
Proc. SPIE 3090, 12th Symposium and School on High-Resolution Molecular Spectroscopy, (3 March 1997); doi: 10.1117/12.267785

Published in SPIE Proceedings Vol. 3090:
12th Symposium and School on High-Resolution Molecular Spectroscopy
Leonid N. Sinitsa; Yurii N. Ponomarev; Valery I. Perevalov, Editor(s)