Infrared Study of Surface Hydroxyl Groups on Zirconium Oxide

Abstract Zirconium oxide has two absorption bands, at 3780 and 3680 cm−1, after several hours’ evacuation at 500 °C. The exchange of deuterium with the surface hydroxyl groups was studied by using D2O, acetone-d6, 2-propanol-d8, and chloroform-d. D2O, acetone-d6, and 2-propanol-d8 could completely exchange the hydrogens of the surface hydroxyl groups at room temperature, while chloroform-d could not exchange them even under saturated vapor pressure at room temperature. Hydroxyls showing 3780 cm−1 band were selectively and irreversibly chlorinated by chloroform-d. After deuteration, two deuteroxyl bands were observed, at 2780 and 2705 cm−1; these were exchanged rapidly with ammonia and slowly with propylene. At room temperature propylene exchanged the hydrogen with the hydroxyls with a 2780 cm−1 band more rapidly than with the hydroxyls with a 2705 cm−1 band. In the adsorption and desorption of 2-propanol, the behavior of the 2780 cm−1 band was also found to be different from that of the 2705 cm−1 band. It was concluded that the 3780 and 3680 cm−1 bands could be assigned to surface hydroxyl groups, the nearest neighbors of which have different configurations, and the hydroxyl group of 3780 cm−1 is more reactive than the hydroxyl group of 3680 cm−1.