Modified manganese oxide octahedral molecular sieves M′-OMS-2 (M′ = Co,Ce,Cu) as catalysts in post plasma-catalysis for acetaldehyde degradation

Abstract Metal ions-modified cryptomelane-type manganese oxide octahedral molecular sieves M′-OMS-2 (M′ = Co,Ce,Cu) were synthesized and characterized by XRD, BET, EDS, ICP, TEM, XPS, FTIR, H 2 -TPR in this work. The obtained materials were supported on Al 2 O 3 pellets and investigated for acetaldehyde degradation in a post plasma-catalysis system. The results showed that the introduction of M′-OMS-2/Al 2 O 3 catalysts improved acetaldehyde removal efficiency and inhibited ozone formation of plasma significantly, while the intermediates such as acetic acid, amine and nitromethane were suppressed. Co-OMS-2/Al 2 O 3 exhibited the best catalytic activity to combine with plasma among all the prepared catalysts. The excellent activity is ascribed to the redox property, oxygen vacancies, oxygen mobility and surface area of catalyst. It can be inferred that, ozone formed in plasma was catalytically dissociated into active oxygen species by metal ions in M′-OMS-2 catalysts and contributed to acetaldehyde oxidation and intermediates removal.