Herein, we introduce a La_1−xSr_xCoO₃ perovskite catalyst, substituting for Pt containing LNT catalysts, to remove efficiently NO_x from lean-burn engines. The NO_x storage/reduction occurred alternatively on the perovskite in successive lean/rich atmospheres, and the NO_x conversion reached 71.4% with 100% selectivity to N₂ at 300 °C.