Dissolved gas analysis in transformer oil using Pd catalyst decorated MoSe2 monolayer: A first-principles theory

Abstract

Dissolved gas analysis (DGA) by high-sensitive gas sensors is an effective manner to estimate the operation status of electrical transformers. In this paper, based on first-principles calculations, a novel 2D material, Pd-doped MoSe2 (Pd-MoSe2) monolayer, is explored as gas sensor or scavenger for detection or removal of typical gases in transformer oil, including H2, CO and C2H2, to guarantee the safety operation for the transformers. Adsorption configuration, density of state (DOS), recovery property, band structure and frontier molecular orbital theory are used to fully investigate the adsorption and desorption behaviors for Pd-MoSe2/gas systems. It is found that Pd-MoSe2 monolayer possesses strong adsorption performance towards CO molecule, thus allowing the removal of such pollutant to guarantee the safety operation of transformers. Besides, Pd-MoSe2 monolayer would be a promising candidate for C2H2 sensing due to the desirable adsorption and desorption behaviors. However, the poor adsorption behavior of Pd-MoSe2 monolayer upon H2 molecule even at ambient temperature reveals its unsuitability for H2 detector. Our results not only expound the transition metal doping effect on pure MoSe2 monolayer, but also provide a first insight into the potential application of Pd-MoSe2 monolayer in the field of electrical engineering.