Application of atmospheric non thermal plasma-catalysis hybrid system for air pollution control: Toluene removal

Abstract

The combination of heterogeneous catalysts with non-thermal plasma (DBD operated in sinusoidal mode) was investigated for the removal of toluene from air at room temperature. The DBD reactor gives the possibility to introduce the heterogeneous catalyst directly into the discharge zone ( in-plasma catalysis, IPC) or to place the catalyst downstream the plasma zone ( post-plasma catalysis, PPC). Various catalytic materials based on Ag, Au, Cu, Co, Mn, La, and Nb, supported on Al 2O 3 and CeO 2 in powder form has been tested to select the catalysts that present the highest activity in the presence of plasma. Without plasma, the reaction of toluene conversion over perovskite, Al 2O 3, and OMS-2 based catalysts are promoted at high temperature (200–400 °C). In the absence of catalysts, the toluene removal efficiencies were in the 55–60% range. When the plasma was combined to catalyst, the toluene removal efficiency strongly increased when the catalysts are in IPC position. Best results, up to 96% toluene conversion, were obtained when using 1 wt% Au/Al 2O 3 and Nb 2O 5 catalysts.