The N2O decomposition can be catalyzed by reacting with CO to produce CO2.14 Many experimental and theoretical studies reported that this reaction could be catalyzed by various transition metal cations in the gas phase. The reaction was proposed into two consecutive steps (i) the N2O decomposition to N2O and active O and followed by (ii) the oxidation of CO with the active O. The reactivity of transition metal cation has a key role for the oxidation of CO.