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 the 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-coordinate Mg–O pair sites. NO adsorbed in the chain mode is highly activated and the resultant NO22− complex would be an intermediate in the O-exchange reaction between NO and MgO. Two possible configurations of N2O32− surface species have been found in the NO/MgO system. Our calculated IR frequencies of N2O32− surface complexes account well for the temperature dependence of the experimental IR spectra.