Infrared spectroscopic study of molecular and dissociative adsorption of ammonia on magnesium oxide, calcium oxide and strontium oxide

Abstract

The adsorption of ammonia on highly dispersed alkaline-earth oxides has been studied by infrared spectroscopy. Desorption experiments have shown that several species are formed and that ammonia is adsorbed as a molecular species on those cations and anions which are in low coordination on the surface. A small fraction (<10%) of ammonia is adsorbed in a heterolytic dissociation process on adjacent cation and anions of low coordination to form NH^–₂ and OH^– groups.