Efficient degradation of high concentration sulfur hexafluoride by Ni doped ceria combined with dielectric barrier discharge

Abstract

Non-precious Ni/CeO₂ demonstrates exceptional potential in plasma-assisted catalysis for SF₆ degradation. This study integrated Ni-doped CeO₂ with dielectric barrier discharge (DBD) to achieve energy-efficient decomposition of high-concentration SF₆. By optimizing the Ni/Ce molar ratio and reaction parameters, at 50 W, 10Ni-Ce (10:100) achieved a degradation removal rate of 93.47 % for 2 %SF₆ and an energy yield (EY) of 14.42 g/kWh, which was 3.11 times higher than DBD alone. For 1.5 %SF₆, DRE reached 99.99 %, albeit with lower EY (11.72 g/kWh). Characterization showed Ni doping reduced CeO₂ crystallinity, enlarged surface area, and boosted oxygen vacancy (V_O) content, enhancing catalytic activity. Density functional theory calculations showed that the lattice distortion caused by Ni in CeO₂ reduced the formation energy of V_O, and the highly active surface oxygen atoms promoted the degradation of SF₆. Plasma-generated active particles (O*) synergizes with V_O to accelerate S-F bond cleavage. This work highlights Ni-Ce/DBD synergy as a viable strategy for low-energy SF₆ abatement.