Calculation of the Structure and Reaction Potential Barrier of the Decomposition Products of SF6/N2 Mixed Gases

The greenhouse effect caused by SF6 gas in the power system cannot be ignored, and N2 has enormous industrial potential to replace pure SF6 by mixing with SF6 due to its advantages of low environmental pollution, low price, and stable chemical performance. This article combines density functional theory (DFT) and transition state theory (TST) to calculate the molecular structure and vibrational frequency information of various reactants, products, and transition states involved in SF6/N2 gas mixtures containing water and oxygen. The single point energy of each component is calculated using the CCSD (T)/cc pvtz theory level, and all reaction barrier energies are obtained. The calculated molecular structure and vibration frequency results are in good agreement with the experimental data of NIST, proving the reliability of the calculation method in this paper. The difficulty of the reaction can be determined by obtaining all the reaction barrier energies. It was found that SF5 molecules are unstable and prone to decomposition. SF4 is very important in the SF6/N2 reaction system, and further decomposition will produce a large number of stable by-products. The calculation method in this article helps to deeply understand the decomposition reaction mechanism of SF6/N2 mixed gas, and is of great significance for the research of decomposition experiments.