Infrared study of the adsorption of 16O2, 16O18O and 18O2 on Cr2O3

Abstract

Absorption bands occur between 1030 and 850 cm^–1 from the adsorption of oxygen ¹⁶O₂ on amorphous Cr₂O₃ and on crystalline α-Cr₂O₃ prepared according to the method of Zecchina et al.(A. Zecchina, S. Coluccia, E. Guglielminotti and G. Ghiotti, J. Phys. Chem., 1971, 75, 2774). Broad overlapping absorptions occur for oxygen adsorbed on the amorphous oxide and multiple resolvable bands occur for crystalline α-Cr₂O₃.

Through adsorption of pure ¹⁶O₂, pure ¹⁸O₂ and the ¹⁶O₂+¹⁶O¹⁸O +¹⁸O₂ equilibrium mixture it is clearly shown that all these absorptions arise from mono-oxygen surface species, probably approximating to CrO, on different sites. No bands from dioxygen species were observed.