Catalytic oxidation of toluene in air using manganese incorporated catalyst by non-thermal plasma system

Mn/MCM-41 and imp-Mn/MCM-41 catalysts were prepared in this study through metal heteroatom substitution and impregnation methods, respectively, and their catalytic oxidation performance of toluene under non-thermal plasma (NTP) in a dielectric barrier discharge reactor was studied. The stability of the catalyst and the parameters of catalytic oxidation conditions (initial concentration of toluene, O₂ ratio, and relative humidity of carrier gas) were optimized. Characterization proved that the impregnation method resulted in the existence of manganese in the form of oxides (MnO₂, Mn₂O₃) outside the pores of MCM-41. Meanwhile, the metal heteroatom substitution method implanted manganese into the mesoporous structure and replaced part of it with Si-O-Mn. NTP catalytic oxidation of toluene, ozone emission, and GC–MS by-product analysis confirmed that 60Mn/MCM-41 catalyst has high catalytic activity. Moreover, the catalyst affected the production of by-products. The stability test revealed that the 60Mn/MCM-41 catalyst still respectively reached 84.6% and 61% in the conversion of toluene and the selectivity of CO₂ under the SED of 558 J/L after 40 h discharge reaction.