Zeolites in the form of mordenite were used to prepare catalyst for catalytic converter applications. The Na ions of mordenite were exchanged with Cu ion which were then precipitated to form Cu/MOR catalyst. Another catalyst in the form of Ce/MOR was also prepared by the same technique. The formation of Cu/MOR and Ce/MOR systems were confirmed by Energy Dispersive X-Ray microanalysis (EDX). Scanning Electron Microscopy (SEM) showed no evidence of external precipitation of Cu and Cc. Because of the fine size or amorphous nature of the precipitated particles X-Ray Diffraction (XRD) result did not reveal their existence.