Enhanced Sensing and Adsorption of C 4 F 7 N/CO 2 Decomposition Products via Modified ZSM-5 Zeolite: Experiments and Molecular Dynamics Simulations

Insulation equipment with C4F7N/CO2as the medium may decompose under overheating or discharge failure, which has an important impact on its normal operation and safety performance. Therefore, it is important to specify the decomposition characteristics of the C4F7N/CO2mixed gas under fault conditions to ensure the stable operation of insulating equipment. Thermal decomposition and absorption experiments were designed in the paper, conducting qualitative and quantitative analyses of the C4F7N/CO2mixed gas and its decomposition products, while theoretically elucidating the adsorption mechanism. Molecular dynamics simulations were employed to investigate the modification of ZSM-5 zeolite. The modification effects were compared and evaluated based on three aspects: concentration distribution function, diffusion coefficient, and radial distribution function. The results indicate that the modified ZSM-5 zeolite exhibits enhanced adsorption capacity for polar gas molecules such as C4F7N, C3F6, C3F8, CF3CN, COF2, and CF3H. Conversely, its adsorption capacity for nonpolar gases, including CO2, CO, CF4, and CNCN is relatively weak. The difference in selective adsorption facilitates the separation of C4F7N/CO2mixed gases. Furthermore, there is a foundation for subsequent structural optimization of ZSM-5 zeolite and the development of novel gas sensors based on principles of selective adsorption.