DFT study of Pd-doped ZrCl₂: a promising solution for dissolved gas molecule analysis in transformer oil

The application of 2D materials for detecting dissolved gas molecules is essential for identifying faults in oil-immersed transformers. This study investigates the adsorption properties of ZrCl₂ monolayer (ML) and Pd-doped ZrCl₂ ML with six gas molecules (CO, CO₂, CH₄, C₂H₂, C₂H₄, C₂H₆) in transformer oil using the density functional approach. The adsorption behaviour was analysed by calculating and comparing the structures, charge transfer and adsorption energies. Additionally, the chemical interaction and electronic properties of gas molecules on ZrCl₂/Pd-ZrCl₂ ML are examined through PDOS (projected density of states), band structure, recovery time and work function. The pristine ZrCl₂ ML has a weak interaction for all six gas molecules, whereas Pd doping on ZrCl₂ ML has considerably increased the adsorption strength for C₂H₄, CO and C₂H₂ gases. The results presented in this paper offer a theoretical framework for utilizing Pd-ZrCl₂ ML in monitoring transformer performance and gas detection.