Plasma catalytic oxidation of toluene over double perovskite-type oxide via packed-bed DBD.

Various perovskite-type catalysts including La2CoMnO6, LaCoO3, and LaMnO3 are first evaluated for the activities toward C7H8 removal. Experimental results indicate that double-type La2CoMnO6 shows better activity if compared with single perovskites due to high lattice oxygen content and good reducibility. Subsequently, perovskite catalysts are combined with plasma (NTP) to form in-plasma catalysis (IPC) and post-plasma catalysis (PPC) systems. The results indicate that IPC systems have better higher performance than that of NTP-alone and PPC. Especially, high C7H8 conversion (100%) and mineralization efficiency (96.8%) can be achieved with the applied voltage of 18 kV and temperature of 120 °C when La2CoMnO6 is integrated with NTP to form IPC system. Also, it owns the highest energy efficiency (0.14 g/kWh). It is concluded that IPC performance for C7H8 removal is closely related with the properties of catalyst surface. In addition, the kinetics of IPC systems are investigated by a simplified model, and the result indicates that IPC with La2CoMnO6 as catalyst has a higher overall energy constant. This study reveals that double-type La2CoMnO6 is of higher activity than single perovskites for C7H8 removal, and demonstrates that double-type La2CoMnO6 is of high potential to form plasma catalysis system for VOCs removal.