INFRARED SPECTROSCOPIC STUDY OF O-2(-) ON THE SURFACE OF CR2O3 - THE EFFECT OF SURFACE PRETREATMENT

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 sigma-O2-. On the surface of oxide reduced in CO at 673 K for 4 h, adsorption of oxygen leads to formation of various M = O groups (M is metal).