Ion-cyclotron resonance study of elementary stages of the catalytic oxidation of CO by N2O in the presence of VIA-group metal ions

Gas phase reactions of Mo⁺ and W⁺ ions with the molecules of various oxidants (NO, O₂, N₂O, CH₂O, C₂H₄O) were studied using ion cyclotron resonance. In oxidation with N₂O the mono-, di- and trioxide metal cations are formed consecutively. The trioxide MO₃⁺ ions of both metals react with CO to form CO₂ and MO₂⁺ ions. In this way, catalytic reaction N₂O + CO N₂ + CO₂ occurs in the gas phase with MoO₃⁺ /MoO₂⁺ and WO₃⁺/WO₂⁺ couples as catalysts. The rate constants have been measured for both stages of the catalytic cycle as well as for the stages of the catalyst preparation. Metal-oxygen bond energies were estimated for MoO_x⁺ and WO_x⁺ species with various x. The mechanism of CO oxidation with MoO_x⁺ and WO_x⁺ cations as catalysts in the gas phase is discussed in comparison with that for the oxidation over classical solid oxide catalysts.