Degradation of gas-phase o-xylene via combined non-thermal plasma and Fe doped LaMnO₃ catalysts: Byproduct control

A series of Fe doped LaMnO₃ catalysts were prepared to control the production of byproducts such as O₃, N₂O, and CO, during the degradation of volatile organic compounds with a non-thermal plasma. Eliminating these potentially toxic byproducts will make non-thermal plasma technologies applicable for a wider range of commercial applications. The modified LaMnO₃ catalysts are combined in NTP-catalysis reactor with optimal configuration. Experimental results show that doping Fe on LaMnO₃ catalysts can not only enhance the oxidation of o-xylene, but also lower the emission levels of byproducts. LaMn_0.9Fe_0.1O₃ catalyst shows the best catalytic activity among the formulations tested herein. In addition to the strong mineralization of 88.1 %, the catalyst has the highest performance for o-xylene conversion (91.3 %), O₃ inhibition efficiency (84.9 %), and N₂O inhibition efficiency (61.2 %) due to the strong concentration of active oxygen species on the surface of the catalyst. Moreover, the high reducibility of Fe³⁺ demonstrated with H₂-TPR (hydrogen temperature-programed reduction) further enhances the removal of O₃ by oxygen species exchange between Mn³⁺/Mn⁴⁺ and Fe²⁺/Fe³⁺.