Adsorption and catalytic ozonation of toluene on Mn/ZSM-5 at low temperature

Abstract

In this study, a series of Mn/ZSM-5 catalysts with different Mn contents (2, 4, and 6 wt%) were prepared as adsorbents and catalysts. The adsorption of toluene and the regeneration performance of ozone catalytic oxidation at room temperature were investigated. The results showed that the toluene conversion reaches 90 % at 30 ℃ through 4 wt% Mn/ZSM-5 catalytic oxidation. The cycling and ozone utilization rate experiments reflected that after four consecutive adsorption-ozonation cycles, 4 wt% Mn/ZSM-5 still maintained good toluene adsorption capacity. In the regeneration process, the molar ratio of ozone consumption to toluene degradation was about 7.7:1, which was approximate to the theoretical molar ratio (6:1). The product distribution on the surface of ZSM-5 and 4 wt%Mn/ZSM-5 during toluene degradation was determined by GC-MS analysis, and possible mechanism for catalytic oxidation of toluene on the surface of ZSM-5 and 4 wt%Mn/ZSM-5 were proposed.