Interaction between SO and NO in their adsorption and photocatalytic conversion on TiO.

The simultaneous adsorption and photocatalytic conversion of SO and NO on P25-TiO were studied. In particular, the interaction of SO and NO on each other's adsorption and photocatalytic oxidation was discussed. The adsorption of NO on P25 was negligible when comparing to that of SO, while with the coexistence of NO and SO in flue gas, both the adsorption of SO and NO were improved. In the presence of water and oxygen, the photocatalytic oxidation efficiency of NO with an efficiency of >69% was observed on irradiated TiO surface, which lasted for at least 1000 min. Oxygen was found to have much more important effect than water on the photocatalytic oxidation of NO. In the presence of SO however, the photocatalytic process of NO was largely reshaped. The whole process was controlled by the photocatalytic oxidation of SO. A dramatic efficiency decease (breakthrough of the catalyst bed) was observed for both NO and SO due to the catalyst deactivation caused by the poisoning of SO oxidation products. Before the breakthrough, the photocatalytic conversion efficiency of NO increased with increasing the SO concentration, which was mainly due to the improved NO adsorption in the presence of SO.