A catalyst of the type Pd/Co/Ba/Al was examined for lean NOx trap (LNT) applications, and compared with Pd/Ba/Al and Pt/Ba/Al reference catalysts for NOx storage and reduction using H-2 and/or CO as reducing agents. The activity of Pt/Ba/Al was greatly depressed when using CO as reductant at low temperatures owing to the strong poisoning effect of CO on Pt. The Pd/Co/Ba/Al catalyst exhibited higher activity for NO oxidation to NO2 and better NOx storage capacity than Pt/Ba/Al and Pd/Ba/Al catalysts, also showed higher NO reduction activity with CO compared to the other two catalysts. However, it shows relatively low NO removal efficiency below 250 degrees C, especially using CO as reductants, indicating that regeneration of stored NO is the rate limiting step. By employing non-thermal plasma in the rich phase to assist reduction of the stored NOx, the Pd/Co/Ba/Al sample exhibited excellent NO removal efficiency under plasma assisted lean/rich cycling conditions, affording NOx conversions close to 99% over a broad temperature window of 150-350 degrees C, even when using CO as the reducing agent. (C) 2015 Elsevier B.V. All rights reserved.