Decomposition of Toluene Using Nanosecond- Pulsed-Discharge Plasma Assisted With Catalysts

Volatile organic compounds (VOCs) are common air pollutants existing in various atmospheric environments; as they present both acute and chronic effects on the health of a number of different human systems and organs, methods for their efficient removal are essential. To this end, catalysis is being researched to prevent environmental pollution. While catalytic and photocatalytic oxidation, which can eliminate low concentrations of various kinds of VOCs as well as O₃, offer potential to improve indoor air quality, neither is effective in areas with high VOC concentration. To overcome this limitation, many researchers have concentrated on synergetic effects of plasma catalysis, combining the advantages of high-selectivity catalysis and fast ignition and response of a nonthermal plasma. The authors´ research group has demonstrated that our nanosecond (ns)-pulsed-discharge plasma decomposes NO_x as well as produces O₃ with an energy efficiency higher than that of the reported nonthermal discharges. However, the performance of the ns-pulsed-discharge plasma in VOC decomposition in comparison with or without catalyst has not yet been investigated systematically. Thus, this paper experimentally clarified the combined effects of MnO_x catalyst supported by Ni foam on toluene decomposition. The input energy density to our plasma catalysis reactor using a ns-pulsed discharge was 11% of a cited dielectric barrier discharge plasma catalysis when toluene removal ratio reached 100%.