On the molecular models of lewis acid sites on the surface of γ-Al2O3 and in zeolites: a density functional study of CO adsorption

Adsorption complexes of CO-Lewis acid sites with 3- and 5-coordinated Al3+ are modeled by the density functional method using the cluster approach. Cluster models of the site with 4-coordinated Al3+ on the surface of γ-Al2O3 and in zeolites are suggested. For these models of adsorption complexes, C-O vibration frequencies are calculated and the energetics of CO adsorption is evaluated.