Oxygen plasma-catalytic conversion of NO over MnOx: Formation and reactivity of adsorbed oxygen

Dielectric barrier discharge (DBD) reactor packed with a MnOx catalyst was used to investigate nitric oxide (NO) conversion. Characterization of MnOx with and without O2 plasma treatment was carried out by powder XRD, XAFS, XPS and BET methods. The results show that plasma treatment increases the adsorbed oxygen on the surface of MnOx catalyst, and also changes the oxidation state of partial concentration of Mn cation from Mn(III) to Mn(IV). Reactive surface oxygen species can be generated from lattice oxygen and/or direct interaction with plasma generated species. The adsorbed oxygen species formed on the catalyst surface of MnOx can enhance the oxidation performance of the plasma-catalytic process.