Study on decomposition mechanism of toluene by non-thermal plasma coupled with catalysis

The non-thermal plasma hybrid technology attracts more and more attention in the field of air pollution control because of its better VOCs(Volatile Organic Compounds) decomposition efficiency and higher energy efficiency. However, the ozone, NO_x, halide, etc. are possibly to be formed during the plasma process, and the further decomposition mechanism of the VOCs is lacking by now. In order to find out a suitable technique to remove the gas pollutants with lower energy consumption and higher selectivity, in this study the self-made composite catalysts associated with non-thermal plasma engendered by DBD (Dielectric Barrier Discharge) were used to dispose the flowing polluted air containing toluene vapor at atmosphere pressure. The synergistic effect for toluene removal was evaluated by the removal efficiency, ozone concentration, reactor input energy density and energy efficiency. Based on the GC-MS and FT-IR spectra analysis, the decomposition mechanism and reaction process of toluene decomposition were discussed. The results show that the synergistic technology results in greater enhancements of toluene removal efficiency (about 99%) and energy efficiency (which is 2.3 times higher than that of only using non-thermal plasma technology without catalysts associating). Besides, the synergistic technology inhibits effectively the formation of ozone and other byproducts during the plasma process. Therefore it shows that the technology proposed has a wide application prospect.