INTERACTION OF AN NO-2 GAS-MIXTURE WITH CU(O)ZSM-5 CATALYST, STUDIED BY EPR AND TPD/

At 293 K the NO2 molecules formed in an NO + O-2 gas mixture are found to oxidize the copper ions in Cu/ZSM-5 from Cu+ to Cu-isol(2+), and t o become stabilized on isolated Cu-isol(2+) ions at temperatures < 620 K, changing the coordination of the latter to a square planar configu ration in which one of the ligands is the NO2 molecule.