Abstract: The performance of NOx oxidation-storage and desorption over Mn/Ba/Al2O3 catalyst were investigated at different temperatures. The catalysts were prepared by equal volume impregnation method and characterized by XRD and TPD. The results showed that Mn/Ba/Al2O3 catalyst had high catalytic activity for NO oxidation and large NOx storage capacity. BaMnO3 was the major active component. Mn could catalyze the oxidation of NO, having certain NOx storage capacity. Ba was the major storage component, NOx were stored with the formation of the nitrate that can be decomposed between 300~600 ℃ to release NOx. When Mn/Ba/Al2O3 was aged at 800 ℃ for 6 h, both the catalylic activity for NO oxidation and the NOx storage capacity were slightly decreased. The catalylic activity for NO oxidation and the NOx storage capacity were hardly affected by low concentration SO2. However, higher concentration SO2 decreased the catalylic activity for NO oxidation and the NOx storage capacity, leading to deactivation of the catalyst.

Key words: Nitrogen oxide, Oxidation-storage, Thermal stability, Sulfur tolerance, Mn/Ba/Al2O3