Low temperature infrared spectra of CO adsorbed on the surface of MgO(001) thin films

Reflection-absorption infrared spectra of CO adsorbed on the surface of thin MgO(0 0 1) films are reported in the temperature range 30-90 K. The observed bands are identical with those reported earlier for MgO single crystals and powder samples. By selective population of low-coordinated (LC) sites and from the analysis of respective TPD spectra a desorption energy for LC sites of similar to 25 kJ mol(-1) was derived, in perfect agreement with recent findings on MgO powders. Experiments with (CO)-C-12/(CO)-C-13 give evidence for substantial infrared intensity transfer between neighboring CO oscillators and the formation of adsorbate complexes containing more than one CO molecule on low-coordinated sites. (c) 2005 Elsevier B.V. All rights reserved.