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

Various perovskite-type catalysts including LaCoMnO, LaCoO, and LaMnO are first evaluated for the activities toward CH removal. Experimental results indicate that double-type LaCoMnO 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 CH conversion (100%) and mineralization efficiency (96.8%) can be achieved with the applied voltage of 18 kV and temperature of 120 °C when LaCoMnO 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 CH 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 LaCoMnO as catalyst has a higher overall energy constant. This study reveals that double-type LaCoMnO is of higher activity than single perovskites for CH removal, and demonstrates that double-type LaCoMnO is of high potential to form plasma catalysis system for VOCs removal.