A quantum chemical study of the NO/MgO chemisorption system: hybrid B3LYP calculations on NO/(MgO)(n) (n = 4, 6, 8) model systems

Ab initio B3LYP cluster model calculations have been performed to explore t he adsorptive behavior of NO on MgO solid. Two adsorption modes, namely the chain mode and the bridge mode, have been found for NO adsorption at low-c oordinate Mg-O pair sites. NO adsorbed in the chain mode is highly activate d and the resultant NO22- complex would be an intermediate in the O-exchang e reaction between NO and MgO. Two possible configurations of N2O32- surfac e species have been found in the NO/MgO system. Our calculated IR frequenci es of N2O32- surface complexes account well for the temperature dependence of the experimental LR spectra. (C) 1999 Elsevier Science B.V. All rights r eserved.