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

• M′-OMS-2 catalysts improved VOCs removal efficiency and CO2 selectivity of plasma.
• M′-OMS-2 catalysts decomposed ozone generated by plasma.
• Co-OMS-2 has more redox couple, oxygen vacancies, and oxygen mobility on surface.
• Co-OMS-2 exhibited the best catalytic activity for post plasma-catalysis.
• M′-OMS-2 dissociated ozone and produced active oxygen species to oxide acetaldehyde.

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, H2-TPR in this work. The obtained materials were supported on Al2O3 pellets and investigated for acetaldehyde degradation in a post plasma-catalysis system. The results showed that the introduction of M′-OMS-2/Al2O3 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/Al2O3 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.

Metals modified manganese oxide octahedral molecular sieves (M′-OMS-2) as catalysts in post plasma-catalysis for acetaldehyde degradation.Figure optionsDownload high-quality image (94 K)Download as PowerPoint slide