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Abstract

This paper presents experimental data on the bonding of CO and NO to vacuum-cleaved MgO(100) and NiO(100) and compares them with theoretical results. In the case of CO and NO on NiO(100) we find that the bonding energies obtained for the vacuum-cleaved single crystals agree well with results of recent studies on thin NiO(100) films grown by oxidation of Ni(100) whereas they are at variance with theoretical results. On the other hand, for CO on MgO(100) the experimental data fit well to recent theoretical studies while they contradict studies of adsorption on MgO(100) films grown on Mo(100). The experimentally determined values for the adsorption energies are 0.30 and 0.57 eV for adsorption of CO and NO on NiO(100), respectively, and 0.14 and 0.22 eV for adsorption on MgO(100). We suggest that the stronger bonding to NiO(100) as compared to MgO(100) is due to the influence of the 3d electrons of NiO.