Oxidation of TCE by Combining Perovskite-Type Catalyst with DBD

A novel hybrid system constituting of La-Mn-based perovskite-type catalyst with nonthermal plasma (NTP) is developed and evaluated for the removal of trichloroethylene (TCE) from gas streams. Ce and Ni were used as promoter for modification LaMnO ₃ because addition of Ce and Ni could enhance redox property and activity of catalyst. First, the activities of various perovskites including LaMnO ₃ , La _0.8 Ce _0.2 MnO ₃ , and La _0.8 Ce _0.2 Mn _0.8 Ni _0.2 O ₃ were evaluated for TCE removal via catalysis, and the results indicate that La _0.8 Ce _0.2 Mn _0.8 Ni _0.2 O ₃ has the highest activity for TCE removal among three perovskites prepared. The three perovskites are individually combined with NTP to form various plasma catalysis systems for TCE removal. Experimental results indicate that 100% TCE removal efficiency can be achieved with plasma catalysis (La _0.8 Ce _0.2 Mn _0.8 Ni _0.2 O ₃ ) when the system is operated with the applied voltage of 16 or 17 kV. On the other hand, the highest TCE removal efficiency achieved with NTP alone is 73.2% with the applied voltage of 17 kV. In addition, CO ₂ mineralization efficiencies achieved with plasma catalysis combined with La _0.8 Ce _0.2 Mn _0.8 Ni _0.2 O ₃ (31.1%-46.6%) are significantly higher than that of NTP alone (8.4%-13.1%). It is worth noting that concentrations of O ₃ and NO _x generated with plasma catalysis are significantly lower than that of NTP alone, implying that formation of O ₃ and NO _x could be effectively decomposed as plasma catalysis is applied for TCE removal. Overall, perovskite-type catalyst can be integrated with NTP to form plasma catalysis system for effective removal of TCE from gas streams.