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. © 2007 American Chemical Society.