Nox Storage Catalyst and Method for Preparing the Same

A NOX storage catalyst includes CHA zeolite, a transition metal ion-exchanged in the CHA zeolite, and a rare earth metal that is different the transition metal and is supported on the CHA zeolite. A method for preparing a NOX storage catalyst includes preparing a synthetic mother liquid including a zeolite raw material as a source of silica and alumina, a structure-inducing material, a complexing material, and a solvent, reacting the synthetic mother liquid to prepare a CHA zeolite, and supporting a transition metal and a rare earth metal that is different from the transition metal on the prepared CHA zeolite.