| dc.description.abstract | In this study, novel double perovskite-type catalysts are developed and tested for VOCs removal. The research could be divided into 2 aspects: (1) catalytic activities of double perovskite-type catalysts for removal of VOCs, and (2) performance of plasma catalysis (including post-plasma catalysis and in-plasma catalysis) for VOCs removal. Experimental results indicate that double perovskite-type catalysts show higher activities for C7H8 removal if compared with traditional perovskite-type catalysts. Especially, C7H8 conversion and mineralization efficiencies achieved with La2CoMnO6 could reach 100% at 300oC and 30,000 h-1. In addition, various VOCs such as isopropanol (C3H8O), acetaldehyde (C2H4O), and ethylene (C2H4) could be converted completely at 150oC, 250oC, and 350oC, respectively, as La2CoMnO6 is applied as catalyst. Additionally, results indicate that double perovskite-type catalysts not only possess tolerance for CO2 and H2O(g), but also present good durability. The analysis of catalyst surface indicates that double perovskite-type catalysts have good mobility of oxygen due to high lattice oxygen ratio, therefore, they are of good oxidation-reduction property to promote VOCs oxdication reaction although they have lower BET specific surface area. On the other hand, DBD-type plasma-alone system is first tested for C7H8 removal at different parameters and is further used to elucidate the mechanism of plasma catalysis in removing C7H8. For post-plasma catalysis system, C7H8 conversion and O3 decomposition efficiency are closely correlated. For example, the highest C7H8 conversion and mineralization efficiency achieved with post-plasma catalysis system with La2CoMnO6 are 100% and 66% at 120oC, while O3 could be removed completely at 12-19 kV.
In addition, in-plasma catalysis system exhibits significant positive effect. Results indicate that C7H8 conversions and mineralization efficiencies achieved with in-plasma systems are higher than that of plasma-alone at room temperature or 120oC. For in-plasma catalysis with La2CoMnO6, the highest C7H8 conversion and mineralization efficiency are 100% and 98% at 120oC, respectively. In addition, formation of NOx could be inhibited in the presence of perovskite-type catalysts at 120oC. Overall, this study demonstrates that double perovskite-type catalysts can be applied for catalysis system for effective removal of VOCs. Further, high performance is achieved as double perovskite-type catalyst is integrated nontherma plasma to form plasma catalysis, demonstrating that double perovskite-type catalysts indeed have good potential to remove VOCs from gas streams.
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