The surface properties of metal oxides. Part II. An infrared study of the adsorption of carbon dioxide on γ-alumina
Abstract
The interaction of carbon dioxide with γ-alumina has been studied by infrared spectroscopy. Four different adsorbed species have been observed and firm assignments made for three of them. Absorption near 1800 cm.–1 may be due to a weakly held form of carbon dioxide, adsorbed directly on aluminium cation sites. The other species are physically adsorbed carbon dioxide (2346–2367 cm.–1), bicarbonate groups (3605, 1640, 1480, and 1233 cm.–1), and a bridged structure (1850 and 1180 cm.–1). A reaction scheme showing the relationship between these species is proposed.