Mn2O3/γ-Al2O3 catalysts synergistic double dielectric barrier discharge (DDBD) degradation of toluene, ethyl-acetate and acetone.

ABSTRACT

Mn2O3/γ-Al2O3 catalysts was combined with double dielectric barrier discharge (DDBD) for degradation of acetone, toluene and ethyl acetate. Mn2O3/γ-Al2O3 catalysts with different Mn loading were synthesized by hydrothermal method. XRD, SEM, XPS and H2-TPR were applied to characterize the catalysts. Among the catalysts prepared, the Mn2O3/γ-Al2O3 catalysts with 5 wt% Mn loading presented the best performance in multicomponent VOCs degradation, which the highest removal efficiency (58.8% for acetone, 96.3% for toluene and 85.8% for ethyl acetate), the best carbon balance (87.5%) and CO2 selectivity (51.9%) were obtained at a specific input energy (SIE) of 700 J L-1. The formation of ozone was obviously inhibited with the introduction of Mn2O3/γ-Al2O3 catalysts. The higher Mn3+/Mn ratio, higher O2/O2- ratio and excellent low-temperature reducibility were beneficial for the VOCs degradation. Highly dispersed Mn2O3 crystals on the surface of γ-Al2O3 also might be an explanation for the improvement of VOCs degradation. According to the result of GC-MS, the variety of organic by-products gradually decreased with the increase of SIE, and the degradation mechanism of the mixed VOCs in plasma and on catalyst surface was discussed.