Gas-insulated switchgear (GIS) equipment must be protected by detecting and eliminating the toxic SF 6 partial discharge decomposition components. This study employs first-principles calculations to thoroughly investigate the interaction between a Pd-adsorbed SiN 3 monolayer (Pd-SiN 3 ) and four typical SF 6 decomposition gases (H 2 S, SO 2 , SOF 2 , and SO 2 F 2 ). The study also investigates the associated geometric, electrical, and optical characteristics along with the sensing sensitivity and desorption efficiency. The ab initio molecular dynamics (AIMD) simulations demonstrated the favorable stability of the Pd-SiN 3 monolayer. Furthermore, the Pd-SiN 3 monolayer exhibited strong chemisorption behavior toward H 2 S, SO 2 , SOF 2 , and SO 2 F 2 gases because of the higher adsorption energies of -2.717, -2.917, -2.457, and -2.025 eV, respectively. Furthermore, significant changes occur in the electronic and optical characteristics of the Pd-SiN 3 monolayer following the adsorption of these gases, resulting in remarkable sensitivity of the Pd-SiN 3 monolayer in relation to electrical conductivity and optical absorption. Meanwhile, all of these gas adsorption systems exhibited extremely long recovery times. The aforementioned theoretical findings suggest that the Pd-SiN 3 monolayer has the potential to be an effective gas scavenger for the storage or removal of the SF 6 decomposition components. Additionally, it might function as a reliable one-time sensor for detecting these gases. The results potentially provide valuable theoretical guidance for maintaining the normal operation of the SF 6 insulation devices.