Infrared spectroscopic study of O –2 on the surface of Cr2O3: the effect of surface pretreatment

Abstract

Adsorption of oxygen (at 298–673 K) on the Cr₂O₃ surface was studied by IR spectroscopy. It was shown that the nature of the adsorbed species depends on the oxide pretreatment conditions. Adsorption of oxygen at 298 K on the oxide, pretreated in vacuo at a high temperature (773 K) is accompanied by formation of the molecular form of the adsorbed oxygen type σ-O^–₂. On the surface of oxide reduced in CO at 673 K for 4 h, adsorption of oxygen leads to formation of various MO groups (M is metal).