Temperature Dependence of Plasma−Catalysis Using a Nonthermal, Atmospheric Pressure Packed Bed; the Destruction of Benzene and Toluene

A nonthermal, atmospheric pressure, packed-bed plasma reactor has been used to study the effect of temperature on the plasma−catalytic destruction of toluene and benzene in air. The plasma reactor was packed with BaTiO3 beads to which TiO2, γ-Al2O3, and Ag, Pt, or Pd impregnated catalysts were added. The reactor can be heated up to ∼500 °C, and the destruction efficiencies for toluene and benzene were determined for plasma alone, catalyst alone, and the combined plasma−catalyst configuration. Comparisons have been made to determine the relative contributions of the catalyst and plasma and to discover any synergistic effects. Plasma−catalysis shows greater destruction than catalysis alone with increasing temperature for both benzene and toluene. Catalysis alone has a threshold temperature of ∼300 °C for the destruction of toluene and benzene, but plasma−catalysis with Pd- and Pt-impregnated alumina achieves >95% destruction at this temperature and has a threshold of ∼100 °C. Toluene is more easily destroyed than benzene at all temperatures, by all catalysts.