Several catalysts for NO decomposition have been reported in the literature to include the following: Cu/ZSM-5; Cu/Zeolite-Y; Cu/mordenite; Cu/{beta} zeolite; Cu/alumina; and Cu/silica which have been studied less than Cu/ZSM-5. The catalytic properties for NO conversion are found to be different on these samples with the ZSM-5 supported catalysts showing the highest activity in a dry environment free from sulfur oxides. One of the goals of this study is to have a better fundamental understanding on the different roles of Cu and the support in the catalytic reaction. The authors use stable, cationic metal complexes in non-aqueous solvents as sources of the Cu ions in producing model catalysts for which the fate of the source molecule is known and is controlled during the ion exchange/impregnation. Molecular models of these systems can be used to identify the possible configurations of the metal complexes within the zeolite support. The authors compare the performance of the model catalysts to one prepared by aqueous impregnation of ZSM-5 zeolite. The performance of the dinuclear metal complex on silica is compared to the same complex in ZSM-5 and Y-zeolites.