Interaction of an NO + O2 gas mixture with Cu/ZSM-5 catalyst, studied by EPR and TPD

At 293 K the NO₂ molecules formed in an NO + O₂ gas mixture are found to oxidize the copper ions in Cu/ZSM-5 from Cu⁺ to Cuisol2+ and to become stabilized on isolated Cuisol2+ions at temperatures < 620 K, changing the coordination of the latter to a square planar configuration in which one of the ligands is the NO₂ molecule.