Abstract: How to achieve low energy consumption and high degradation efficiency (DRE) under mild conditions is an important issue in the field of sulfur hexafluoride (SF₆) treatment. In this work, a new route of SF₆ degradation promoted by Ni-doped ceria (NiO-CeO₂) in a packed bed dielectric barrier discharge (PB-DBD) was proposed. The effects of Ni/Ce molar ratio, input power, SF₆ concentration and flow rate on the DRE of SF₆ were investigated. Compared with DBD or CeO₂-DBD alone, the combination of DBD and NiO-CeO₂ can significantly promote the SF₆ degradation at lower input power. The experimental results show that when the dosage of catalyst 1.5NiO-CeO₂ (Ni/Ce mole ratio is 1.5%) is 5 g, DBD input power is 50 W and SF₆ (1.5% SF₆/98.5% Ar) flow rate is 100 ml·min^-1, the highest DRE can reach 97.7% and the energy yield can reach 11.5 g·(kW·h)^-1. Adjusting the catalyst dosage according to the flux of SF₆ (e.g., using 10 g catalyst to degrade SF₆ with a concentration of 1.5% and a flow rate of 80 ml·min^-1), the DRE of nearly 99% can be achieved for a long time, which is crucial for industrial application. The mechanism deduction shows that the rich surface and mesopores of the catalyst are beneficial to the adsorption of SF₆ and intermediates, while the doping of Ni can significantly increase the content of oxygen vacancies to improve the degradation. Meanwhile, when NiO-CeO₂ is activated by DBD, the free O· can further promote the degradation. It is this coupling effect that leads to the high efficiency and low energy consumption of SF₆ degradation under mild conditions. It can be expected that this coupling technology route will have a good application prospect in the field of SF₆ treatment.

Key words: SF₆, Packed bed dielectric barrier discharge, NiO-CeO₂, Degradation efficiency, Energy yield

摘要： How to achieve low energy consumption and high degradation efficiency (DRE) under mild conditions is an important issue in the field of sulfur hexafluoride (SF₆) treatment. In this work, a new route of SF₆ degradation promoted by Ni-doped ceria (NiO-CeO₂) in a packed bed dielectric barrier discharge (PB-DBD) was proposed. The effects of Ni/Ce molar ratio, input power, SF₆ concentration and flow rate on the DRE of SF₆ were investigated. Compared with DBD or CeO₂-DBD alone, the combination of DBD and NiO-CeO₂ can significantly promote the SF₆ degradation at lower input power. The experimental results show that when the dosage of catalyst 1.5NiO-CeO₂ (Ni/Ce mole ratio is 1.5%) is 5 g, DBD input power is 50 W and SF₆ (1.5% SF₆/98.5% Ar) flow rate is 100 ml·min^-1, the highest DRE can reach 97.7% and the energy yield can reach 11.5 g·(kW·h)^-1. Adjusting the catalyst dosage according to the flux of SF₆ (e.g., using 10 g catalyst to degrade SF₆ with a concentration of 1.5% and a flow rate of 80 ml·min^-1), the DRE of nearly 99% can be achieved for a long time, which is crucial for industrial application. The mechanism deduction shows that the rich surface and mesopores of the catalyst are beneficial to the adsorption of SF₆ and intermediates, while the doping of Ni can significantly increase the content of oxygen vacancies to improve the degradation. Meanwhile, when NiO-CeO₂ is activated by DBD, the free O· can further promote the degradation. It is this coupling effect that leads to the high efficiency and low energy consumption of SF₆ degradation under mild conditions. It can be expected that this coupling technology route will have a good application prospect in the field of SF₆ treatment.

关键词: SF₆, Packed bed dielectric barrier discharge, NiO-CeO₂, Degradation efficiency, Energy yield