Plasma Chemistry and Plasma Processing, Vol.36, No.6, 1485-1499, 2016
MnOx/TiO2 Catalysts for VOCs Abatement by Coupling Non-thermal Plasma and Photocatalysis
Mn3O4 with different particle sizes was prepared and mixed with titanium oxide to prepare catalytic systems. Those systems were characterized and then used for ethanol removal from air. Commercial beta-MnO2 was also used for comparison. Prepared solids were characterized by X-ray Diffraction, N-2-physisorption, Raman, Scanning Electron Microscopy and Photoluminescence. MnOx/TiO2 catalysts were tested in the ethanol oxidation reaction (at low concentration: 30 ppm) under ultraviolet light and under non-thermal plasma (E-spe = 14 J L-1). The combination of those both technologies was also tested. This study shows that the combination of photocatalysis and non-thermal plasma enhances significantly the oxidation of ethanol. Indeed, very high ethanol conversion rate was obtained with an important carbon dioxide selectivity and low residual ozone concentration. Besides, well dispersed nanoparticles of Mn3O4 are more efficient than beta-MnO2 microparticles in the minimization of undesirable byproduct. Actually, under combined ultraviolet light and non-thermal plasma the O-3 activation seems to be more efficient on Mn3O4, which additionally enhances the ethanol decomposition and the CO2 selectivity.