Sulfur hexafluoride (SF₆), a potent greenhouse gas with a global warming potential 23,900 times that of carbon dioxide, has seen its emissions steadily rise over time. In response to this environmental challenge, researchers have proposed an innovative solution: hydrate-based technology for SF₆ sequestration.

The research team led by Prof. Lei Jiang from the Department of Experimental Study under Deep-sea Extreme Conditions (IDSSE), in collaboration with the National University of Singapore and the Guangzhou Institute of Energy Conversion at the Chinese Academy of Sciences, recently conducted a study on the thermodynamic and kinetic properties of sulfur hexafluoride (SF₆) hydrates.

The study, conducted by a leading research team, unveiled the following key findings:

1.Thermodynamic Stability: Experiments confirmed that SF₆ hydrates remain stable under low-pressure conditions, offering a viable approach to sequestration (Figure 1a).

2.Molecular Insights: Advanced molecular simulations revealed that SF₆ molecules exclusively occupy large cages within the hydrate structure. Raman spectroscopy further validated this, identifying a distinct Raman shift  from ~770 cm⁻¹ to ~777 cm⁻¹ as a signature of SF₆ encapsulation (Figure 1b, 1c).

3.Kinetic Advancements: Kinetic studies demonstrated that low-pressure conditions in seawater systems significantly enhance the formation of SF₆ hydrates, paving the way for efficient capture and storage (Figure 1d).

Figure 1. (a) Measurements and predictions along the three-phase coexisting curve for the SF₆ hydrate system, (b) Snapshots captured at different moments for the SF₆ hydrate system, (c) S–F stretching bands of SF₆ in large cages and gas phase, (d)the gas consumption for the SF₆–seawater system

These findings mark a significant step forward in mitigating SF₆ emissions and highlight the potential of hydrate-based technology as a promising solution for environmental sustainability.

The research paper titled “Hydrate–based SF₆ capture and sequestration: Insights from thermodynamics, kinetics, in–situ Raman spectroscopy, and molecular dynamic simulation” has been published in the international academic journal “Chemical Engineering Journal”. Dr. Jiyue Sun, a postdoctoral researcher, is the first author of the paper, and Prof. Lei Jiang serves as the co-corresponding author.