The desorption spectrum of NO adsorbed on the surface of TiO₂ powder was determined by Temperature Programmed Desorption (TPD). The changes of desorption amount were discussed. The results indicate that there exist two peak temperatures, 450 and 980 K, as N₂ desorption followed with the NO adsorption on TiO₂, and their activation energies are 0.45 and 2.5 eV, respectively. The intensity of N₂ desorption decreases if the TiO₂ powder is pretreated under O₂ atmosphere. With increasing the exposure amount of NO gas, the desorption amount of N₂ increased and the peak desorption temperature decreased. However, the desorption amount of N₂ tended to become constant when the surface coverage of NO gas was higher than a certain value.

Key words: NO, adsorption, TiO₂, temperature programmed desorption