Efficient and Stable Degradation of SF ₆ by Modified ZSM-5 Zeolite Synergized with Dielectric Barrier Discharge: Performance and Mechanisms

Growing emissions of sulfur hexafluoride (SF6) from the power industry have created a pressing need for its efficient decomposition. This study developed a packed-bed dielectric barrier discharge (PB-DBD) plasma-catalytic system for SF6 degradation by optimizing the Si/Al ratio and calcination temperature of ZSM-5 zeolite. Under optimal conditions, ZSM-5 with a Si/Al ratio of 25 (Si/Al 25) calcined at 450 °C achieved complete degradation of 2% SF6, which was markedly higher than the 87% degradation and removal efficiency (DRE) obtained with the uncalcined catalyst. The DRE remained above 94% after 120 min of reaction, corresponding to a relative improvement of 14.9%. Mechanistic analysis revealed that calcination generates abundant oxygen vacancies (Ovac) and reactive oxygen species (ROS) on Si/Al 25, which synergistically enhance the SF6 degradation performance in the PB-DBD system. This work demonstrates that a simple calcination treatment can significantly enhance the catalytic activity and stability, offering an efficient and economically viable strategy with promising potential for industrial application.