Toluene degradation using plasma-catalytic hybrid system over Mn-TiO₂ and Fe-TiO₂

This paper proposed a hybrid system that combined dielectric barrier discharge plasma with catalysis (DPC) for toluene degradation. To improve the performance of DPC, photocatalysts TiO₂ were doped by Mn and Fe, respectively. All prepared photocatalysts were characterized using UV-Visual DRS., SEM, XPS, BET, and XRD. The effects of the doping ratio, AC frequency, electric field intensity, gas flow rate, and initial concentration on toluene degradation efficiency, ozone decomposition capacity, and CO_x selectivity have been investigated. The best doping ratios of Mn and Fe were both 1.0 at%. The increase of electric field intensity in the range of 6.9-10.3 kV/cm could favor the synergism for DPC significantly, but the ascending of AC Frequency failed to do that. Fe-DPC showed slightly better performance than Mn-DPC in degradation efficiency and CO_x selectivity, while Mn-DPC was ahead of Fe-DPC for the ozone decomposition. Mn-DPC and Fe-DPC both could maintain the high toluene degradation efficiency, when gas flow rate and initial concentration increase from 2.5 to10.1 cm/s and from 700 to 2300 mg/cm³, respectively.