# A comparative study of $CO$ and $N_2$ adsorbed on clean and promoted transition metal surfaces by a combined use of EELS, XPES and UVPES

Rao, CNR and Rao, Ranga G and Rajumon, MK and Prabhakaran, K (1987) A comparative study of $CO$ and $N_2$ adsorbed on clean and promoted transition metal surfaces by a combined use of EELS, XPES and UVPES. In: Spectrochimica Acta Part A: Molecular Spectroscopy, 43 (12). pp. 1479-1486.

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## Abstract

CO and $N_2$ adsorbed on transition metal surfaces in the end-on (perpendicular)configuration and possessing bond orders not far below 3, show two-peak u.v. photoelectron spectra with little separation between the $1\pi$ and $5\sigma$ levels. When the molecules are adsorbed on transition metal surfaces modified by Ba or At, the bond order of the adsorbate is close to unity in the case of CO and slightly less than two in the case of $N_2$. These precursor states which undergo facile dissociation to atomic species show three.peak u.v. spectra with well-separated $1\pi$ and $5\sigma$ levels. The ordering of the $1\pi$ and $5\sigma$ levels seems to be different in CO and $N_2$ adsorbed on the promoted. surfaces; furthermore, the $4\sigma$ level is shifted to higher energies in the former. UVPES results suggest that the orientation of the two molecules on the promoted surfaces are likely to be different.

Item Type: Journal Article Copyright of this article belongs to Elsevier B.V. Division of Chemical Sciences > Solid State & Structural Chemistry Unit 10 Apr 2008 19 Sep 2010 04:44 http://eprints.iisc.ernet.in/id/eprint/13721