Liu Yun , Zhang zhao shun , Xu li , Zhang an jie , Shi Chuan *

(Laboratory of Plasma Physical Chemistry, Dalian University of Technology, Dalian, 116024)

Abstract: The performance of NO_x storage capacity (NSC) and the activity of storage-reduction over Pd/Ba/Al₂O₃ and Pd/Mn/Ba/Al₂O₃ catalyst were investigated at different temperatures. The Pd catalysts were prepared by incipient impregnation and characterized by TPD、TPSR and DRIFTS. The results indicated that the addition of Mn can promote the NO_x storage performance of the Pd/Ba/Al catalyst at low temperatures due to the easier adsorption of NO in the form of nitrite on Mn. Therefore, the NSC increased 87 %、59 %、32 % and 91 %, respectively, at 30 ℃、100 ℃、200 ℃ and 300 ℃. The results of storage-reduction cyclings showed that the NO_x conversion of Pd/Mn/Ba/Al increased 5 % and37 % at 200 ℃ and 300 ℃，while slightly decreased at 400 ℃.

Key words: NO_x; Pd/Mn/Ba/Al; storage; reduction

E-mail: chuanshi@dlut.edu.cn

Journal of Molecular Catalysis, Vol. 25, Issue 3, 2011, 226~232