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Article

Insights into the Pyrolysis Properties of Environmentally Friendly PMVE/N2 Gas Mixtures: A Collaborative Analysis Based on Density Functional Theory and Reaction Kinetics

by
Haibo Dong
,
Haonan Chu
,
Yunhao Liu
,
Shicheng Liu
,
Wenyu Ye
* and
Jiaming Yan
*
School of Electrical Engineering, China University of Mining and Technology, Xuzhou 221116, China
*
Authors to whom correspondence should be addressed.
Appl. Sci. 2025, 15(10), 5272; https://doi.org/10.3390/app15105272
Submission received: 4 April 2025 / Revised: 3 May 2025 / Accepted: 8 May 2025 / Published: 9 May 2025
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Abstract

:
With growing environmental concerns, the search for alternative gases to replace SF6 has become a key focus in the power industry. Perfluoromethyl vinyl ether (PMVE), with its low global warming potential (GWP) and excellent insulation properties, is a promising candidate. When mixed with N2, PMVE not only decreases the liquefaction temperature but also enhances insulation performance, making the gas mixture more suitable for engineering applications. In this study, reactive molecular dynamics (ReaxFF-MD) and density functional theory (DFT) calculations were combined to investigate the influence of temperature on the decomposition characteristics of a PMVE/N2 mixture. The reaction pathways and reaction enthalpy of PMVE and its major decomposition products were analyzed in detail. The results showed that, as temperature increases, the decomposition intensity of PMVE is enhanced, leading to a higher reaction rate and accelerated formation of decomposition products. Moreover, the main decomposition products of the PMVE/N2 mixture include C, C2F2, CF2, CN, CO, CF2O, F, O, and other small molecules and free radicals. The dynamic balance between the generated free radicals helps maintain the system’s insulation capacity. However, toxic decomposition byproducts such as CF2O, C2N2, and CO were also detected. This study provides valuable insights into the engineering applications of PMVE/N2 mixtures.

1. Introduction

Sulfur hexafluoride (SF6) is widely used in gas-insulated switchgear (GIS), compact GIS (c-GIS), and other high-voltage power equipment due to its exceptional insulation and arc-extinguishing properties [1]. However, SF6 has a global warming potential (GWP) of 23,500 and an atmospheric lifetime exceeding 3200 years, making it one of the six most harmful greenhouse gases [2,3]. Studies indicate that the global average temperature could rise by more than 4 °C by 2100 [4,5]. In line with global environmental protection initiatives, reducing SF6 usage in power equipment has become a critical priority. Consequently, there is an urgent need to develop an alternative insulating gas that balances both insulation performance and environmental sustainability.
In recent years, perfluoroketone (CnF2nO) insulating media have attracted significant attention from researchers worldwide due to their excellent insulation performance and favorable environmental properties [6,7]. As a member of this family, perfluorom-ethyl vinyl ether (PMVE) gas is emerging as a research hotspot. PMVE exhibits very low global warming potential and zero ozone depletion potential (ODP), meaning that perfluoroketones do not deplete the atmospheric ozone layer, in accordance with the ‘Montreal Protocol on Substances that Deplete the Ozone Layer’ [8]. Some scholars have explored the potential of PMVE as a substitute for SF6 from the perspective of the total electron scattering cross-section (TCS) [9]. For instance, Nidhi Sinha et al. investigated the electron collision–scattering behavior of PMVE and revealed that its critical dielectric strength (475 Td) is higher than that of SF6 (355 Td) [10]. Additionally, Xiao Song and Zhang Xiaoxing compared the partial discharge characteristics of PMVE and SF6 under different pressures using a comprehensive insulation performance test platform. Their findings demonstrated that PMVE exhibits a small difference between the initial voltage of local discharge (PDIV) and the extinction voltage (PDEV), as well as a stable breakdown voltage, which is advantageous for suppressing discharge and indicates its potential to replace SF6 [11]. Despite its excellent insulation capabilities, PMVE’s liquefaction temperature is higher than that of SF6, necessitating its mixture with inert gases such as CO2 or N2 to enhance both safety and insulation performance.
CO2 is widely regarded as a greenhouse gas and is commonly used to measure the atmospheric greenhouse effect. Its liquefaction temperature is higher than that of N2, which has a global warming potential (GWP) value of 0. According to the GWP calculation formula stipulated in regulations [12], the use of N2 in combination with PMVE does not exacerbate the overall greenhouse effect but instead promotes environmental protection. N2, as an inert gas with strong chemical stability and an extremely low liquefaction temperature, is frequently mixed with insulating gases that have higher liquefaction temperatures [13,14]. Nidhi Sinha’s team investigated the synergistic effects of mixing PMVE with N2 and found that the combination enhanced the insulation performance of the gas mixture. As the proportion of PMVE increased, the insulation performance improved, and when the PMVE/N2 mixing ratio approached 6:4, the insulation performance of the mixture was comparable to that of SF6 [10].
Currently, most research primarily focuses on the insulation characteristics of PMVE, with limited studies on its decomposition properties. Gas-insulated switchgear (GIS) systems inevitably experience faults, such as discharge and overheating, during operation. The temperature in the central area of partial discharge typically ranges from 700 to 1200 K, while arc discharge temperatures can reach as high as 3000 to 12,000 K. Such high temperatures lead to the decomposition of the insulating medium, which reduces dielectric insulation performance and hinders the stable operation of power equipment [15,16]. Heechol Choi et al. studied the decomposition characteristics of PMVE using density functional theory and found that the main decomposition products of PMVE molecules include C2F2, C2F4, and other carbon fluorides, as well as small molecules like COF2 and CO [17].
However, research on PMVE/N2 mixed gases is still relatively limited. In order to ensure the insulation performance of PMVE and better understand the effect of N2 on PMVE, it is necessary to further study the pyrolysis characteristics of PMVE/N2 mixed gases. In this paper, the pyrolysis process of PMVE/N2 mixed gases was simulated by the reaction kinetic method (ReaxFF-MD), and the effect of temperature on the pyrolysis characteristics of PMVE/N2 mixed gases was analyzed to better understand its pyrolysis mechanism. Finally, this study used transition state theory and thermodynamic calculations to combine thermodynamics with kinetics to explore the pyrolysis pathway of PMVE/N2. The research results provide theoretical support for continuing to explore the practical engineering applications of PMVE/N2 mixed gases.

2. Calculation Methods

2.1. Reaction Dynamics Simulation

ReaxFF molecular dynamics (ReaxFF-MD) has been widely utilized to investigate the reaction mechanisms of environmentally friendly insulating gas pyrolysis [2,18]. The ReaxFF reaction force field describes the breaking and formation of chemical bonds based on bond order and the positions of each atom. The system’s energy in ReaxFF is defined as follows:
E system = E bond + E over + E under + E val + E pen + E tors + E coa + E conj + E vdWaals + E Coulomb
where Esystem represents the total energy of the system, Ebond denotes to the bond energy, and Eover and Eunder are the energy correction terms for overcoordination and undercoordination, respectively. Eval, Epen, and Ecoa correspond to the bond angle energy term, penalty energy term, and three-body conjugation term, respectively. Etors refers to the torsion energy, and Econj denotes the four-body energy conjugation. EvdWaals and ECoulomb represent the non-bonding van der Waals and Coulomb interactions, respectively. The reaction dynamics simulation in this study involves force field parameters for O-F, C-F, F-N, and C-N bonds, and others. Therefore, the relevant parameters for F and N were fitted based on the existing ReaxFF force field, with the fitting methods described in references [19,20]. The reaction kinetics simulations for insulating gases, such as C5F10O, CF3SO2F, and C4F7N, were performed using the fitted parameters. The simulation results were consistent with those reported in the previous literature [6,14,18] and with the simulated force fields in [21], confirming the validity of the force fields used in this study. Additionally, the simulation results for PMVE gas in this paper align with the findings from previous studies [9,10], further validating the reliability of the selected fitting force field.
To explore the decomposition mechanism of the PMVE/N2 gas mixture, one-periodic cube models were established, as shown in Figure 1. Considering both computational efficiency and cost, the number of PMVE molecules was set to 100. Table 1 presents the key parameters and simulation conditions for different mixing ratios. These parameters are consistent with the actual conditions of the mixed gas at 25 °C and 0.1 MPa.
The time scale for reaction kinetics simulations is significantly different from the actual reaction time, and appropriately increasing the temperature does not alter the original reaction pathway. To reduce the computational cost of kinetic calculations, the temperature was increased to enhance the reaction rate during the simulation process [22]. It is important to emphasize that under typical macroscopic experimental conditions, N2 does not decompose at temperatures ranging from 1600 to 2600 K [23]. However, in ReaxFF-MD simulations, temperature primarily influences the reaction rate rather than altering the reaction pathways [24,25,26]. Therefore, the simulation temperature can be appropriately adjusted to balance computational efficiency, facilitate trajectory observation, and ensure simulation accuracy. The reaction kinetics simulation begins by minimizing the system energy over 5 ps at 5 K using the NVE ensemble, followed by system equilibration for 5 ps at 300 K using both the NVT and NPT ensembles. Reaction kinetics were then simulated at different temperatures and mixing ratios in the NVT ensemble, with a simulation step size of 0.1 fs and a total simulation time of 1000 ps. This 1000 ps simulation time is sufficient for analyzing the primary decomposition products and their respective pathways. The simulation utilized periodic boundary conditions, and temperature control was achieved using the Berendsen thermostat method with a damping constant of 0.1 ps [27]. In addition, in order to reflect the randomness of the simulation and the reliability of the results, this paper carried out 5 ReaxFF-MD simulations of 1000 ps. Each simulation used a different initial velocity to reflect the randomness of the simulation, and the average of the 5 simulation results was taken to obtain the simulation results of this paper.

2.2. Density Functional Theory Simulation

Density functional theory (DFT), a quantum computational method used to determine the reaction enthalpy by calculating the ground state energy, has been widely applied in the study of environmentally friendly insulating gases [2,28,29]. To verify the validity of the PMVE/N2 mixture gas decomposition pathway, transition state searches and reaction enthalpy calculations were performed [30]. In this study, all structures were optimized using the Gaussian 16 software package [31], the three-parameter hybrid function B3LYP [32], and the 6-311 G++ (d, p) basis set [33,34], and Grimme’s D3BJ dispersion [35] was also considered. This calculation method has been shown to provide good agreement with experimental data from previous studies [28]. At the same computational level as the geometry optimization, the zero point energy (ZPE) was calculated, and ZPE and enthalpy corrections were performed to improve the accuracy of the results [36]. The reaction energy can be calculated as follows:
Δ E = E P r o d u c t s − E R e a c t a n t s
where ΔE represents the reaction energy, EProducts is the energy of the products calculated after geometric optimization, and EReactants is the energy of the reactants calculated after geometric optimization.

3. Results

3.1. Effect of Temperature on the Decomposition Process

3.1.1. Decomposition Rate of PMVE/N2 Gas Mixture

To investigate the decomposition process of the PMVE/N2 mixture at different temperatures, the reaction kinetics of the PMVE/N2 mixture with 60% N2 content were simulated over a temperature range of 1600–2600 K. Figure 2 illustrates the decomposition behavior of PMVE and N2 within this temperature range. It is evident that the thermal decomposition rate of PMVE increases gradually with temperature. At 1600 K, the decomposition of PMVE was slow, with only 11 PMVE molecules decomposed within the limited simulation time. However, when the temperature reached 2600 K, 88 PMVE molecules had decomposed. In contrast, the thermal decomposition rate of N2 remained relatively consistent across the temperature range. N2 decomposed rapidly between 0 and 200 ps, and after 300 ps, the decomposition process of N2 molecules reached saturation, with this quantity remaining stable.
Figure 3 shows the time evolution of the total potential energy of the PMVE/N2 system in the temperature range of 1600 K to 2600 K, thus revealing the energy change characteristics during the reaction. It can be seen from the figure that the total potential energy of the system increases with time, indicating that the decomposition process of the PMVE/N2 gas mixture is an endothermic reaction. This is consistent with the actual situation. When the temperature is lower than 2000 K, the change in the system’s potential energy is not obvious, which indicates that the decomposition degree of PMVE/N2 is low, and the decomposition process is not violent. When the temperature rises to 2200 K, the potential energy of the system increases significantly, indicating that the increase in temperature accelerates the decomposition of the gas mixture. In summary, the significant decomposition of the PMVE/N2 mixture mainly occurs in the temperature range above 2000 K.

3.1.2. Distribution of Decomposition Products

Figure 4 presents the distribution of major decomposition products at different temperatures. The results indicate that the decomposition of the PMVE/N2 mixture primarily produces C, C2F2, CF2, CN, CO, CF2O, F, O, C2F3 and CF3. The yields of CN, CO, and F increase linearly with temperature. Below 2000 K, the production of C, CN, CF2O, F, and O remains low. However, when the temperature rises to 2200 K, their yields increase significantly, which correlates with the accelerated decomposition rate of PMVE at this temperature. At 2400 K, C2F2 and CF2O exhibit a saturation growth trend. The yield of C2F2 shows a decreasing trend across all temperatures, likely due to the presence of O radicals, which promote the depletion of C2F2 [14]. The quantities of CF3 and C2F3 fluctuate, first increasing and then decreasing, suggesting the occurrence of radical recombination and decomposition during the decomposition process. Additionally, carbon (C) was detected during the simulation, and it readily combined with oxygen (O) to form CO. Notably, the presence of particulate carbon can negatively impact the insulation performance of the system.
In addition to the aforementioned primary decomposition products, a significant number of low-abundance free radicals and small molecules were also generated during the reaction process. Figure 5 illustrates the maximum quantity distribution of these species in the PMVE/N2 mixture over a temperature range of 1600 K to 2600 K. The decomposition of the PMVE/N2 gas mixture also leads to the formation of radicals such as NF, NF2, C2F3O, CFO, C2N, CF, CF3O, and CF2N, along with small molecules including NF3, CFN, C2N2, and C2F4.
Notably, C2F3O and C2N2 appear only when the temperature reaches 1800 K, while C2F4 is formed exclusively at 2200 K. The generation of C2N2 and C2F4 is closely related to the presence of CN and C2F3, respectively. Throughout the reaction, small molecules such as C2F4, C2F2, CO, and CF2O are produced, aligning with experimental findings reported in previous studies [11]. This consistency further verifies the reliability of the simulation results.

3.2. Decomposition Mechanism of PMVE/N2

Figure 6 presents the primary decomposition pathways of PMVE and their corresponding relative energy changes. From a thermodynamic perspective, pathways B and C are more likely to occur than pathway A. In the ReaxFF-MD simulation, not only was the decomposition of PMVE observed, but the recombination processes between free radicals were also detected (as shown in Figure 7). Table 2 summarizes the decomposition and recombination processes along with their corresponding reaction enthalpy changes. Path B has two paths (B1 and B2). Path B2, generating C2F4, is more common than path B1, which generated C2F2. Pathway C, requiring the lowest activation energy of only 47.12 kcal/mol, leads to the decomposition of PMVE into C2F3O and CF3, making it the most favorable pathway compared to paths A and B. Moreover, CF3 generated in pathway C can recombine with free fluorine radicals to form CF4, releasing 121.81 kcal/mol of energy. It is worth noting that CN radicals combine to form C2N2 (cyanogen), but this product decomposes at high temperatures (1600–2600 K), so it primarily exists in the form of CN and C2N free radicals in this study [37,38]. Additionally, the recombination of free carbon and oxygen radicals forms carbon monoxide (CO), a toxic gas that poses potential environmental hazards.
From a kinetic perspective, there is a dynamic equilibrium between the free radicals generated during the decomposition of PMVE. This equilibrium helps maintain the concentration of perfluorocarbons such as C2F2 and C2F4 in the decomposition products. The insulating strength of these perfluorocarbons is comparable to that of SF6 [4,18,39], thus contributing to the stability of the system’s insulation properties to some extent. Thermodynamic analysis shows that the reaction enthalpies for pathways A2 and B2 (yielding C2F2) and for pathway A3 (producing CF2O) are positive. This means that energy must be absorbed for these products to form. In contrast, the reaction enthalpies for forming C2F4, CF4, C3F6, C2F6, CO, and C2N2 are negative. These products tend to form spontaneously. The reaction enthalpy changes for molecules like CF4, C2F4, CO, and C2F6 are consistent with previous studies [40,41], further validating the reliability of the simulation.

3.3. Environmental Effects of PMVE/N2 Gas Mixture

Compared with SF6, PMVE exhibits a very low global warming potential (GWP) and N2 has a GWP value of zero. The mixing of PMVE with N2 further reduces the overall GWP of the gas mixture. Additionally, PMVE has a short atmospheric lifetime, thereby minimizing its potential for atmospheric damage. The atmospheric degradation of PMVE does not lead to the generation of long-chain acids that are of environmental concern [32]. At the same time, the safety of using a PMVE/N2 gas mixture must be carefully considered. The inhalation of C2F4 (tetrafluoroethylene, CAS: 116-14-3) has an LC50 (4 h, rat inhalation) of 164,000 mg/m3, indicating low toxicity. Similarly, the inhalation of C3F6 (hexafluoropropylene, CAS: 116-15-4) has an LC50 (4 h, rat inhalation) of 11,200 mg/m3, categorizing it as a low-toxicity substance. However, the inhalation of CF2O (carbonyl fluoride, CAS: 353-50-4) is much more hazardous, with an LC50 (4 h, rat inhalation) of 270 mg/m3, clearly classifying it as highly toxic. CF2O has a strong irritant effect on the respiratory mucosa and can lead to chemical pneumonia and pulmonary edema. Additionally, the decomposition of PMVE/N2 also produces CO (carbon monoxide, CAS: 630-08-0) and C2N2 (cyanogen, CAS: 460-19-5), which pose significant health risks. The inhalation of CO has an LC50 (4 h, rat inhalation) of 2069 mg/m3. CO binds with hemoglobin in the blood, leading to cardiovascular toxicity and potential harm to the respiratory system. The inhalation of C2N2, with an LC50 (1 h, rat inhalation) of 350 ppm, is also highly toxic, causing respiratory paralysis and irritation. Furthermore, C2N2 is flammable and poses additional safety concerns. Therefore, before the PMVE/N2 gas mixture is implemented, it is crucial to evaluate the toxicological properties of the decomposition products to ensure the safety of both equipment and personnel.

4. Discussion

Our findings indicate that the decomposition of the PMVE/N2 gas mixture is an endothermic process, which is consistent with practical observations. However, the roles of the decomposition characteristics, pathways, and products of the PMVE/N2 system have not been studied. Here, we not only demonstrated the significant impact of temperature on the decomposition process from a kinetic standpoint but also systematically explored the decomposition products, pathways, and reaction enthalpy changes from a thermodynamic perspective. Notably, several decomposition products and pathways observed in our study are similar to those reported for other ketone compounds [14,28], confirming the reliability of our kinetic simulations. Additionally, the reaction enthalpy changes of the major products agree well with the previous literature [40,41], further validating our thermodynamic approach. A pronounced recombination and re-decomposition process among the generated free radicals was observed, which is consistent with earlier experimental findings [11]. This dynamic equilibrium among free radicals suggests that the PMVE/N2 gas mixture can maintain its insulation performance during decomposition, which is a critical insight for understanding both the insulation and decomposition characteristics of the gas mixture.
Furthermore, our study identified several novel fluorine-containing compounds produced during decomposition, such as C2N2. Toxic gases, including CO, CF2O, and C2N2, as well as high-greenhouse-potential gases like C2F4 and C2F2, were also detected, highlighting the importance of evaluating the environmental and safety aspects of the PMVE/N2 system.
Overall, this work evaluates the engineering application prospects of a PMVE/N2 gas mixture from the perspectives of decomposition characteristics, environmental performance, and safety. In order to fully elucidate the underlying mechanism, further breakdown experimental studies are needed to fully verify the insulation and decomposition properties of PMVE/N2 systems. Moreover, the fundamental principles of thermal decomposition and electrical breakdown are different. However, due to the lack of a mature simulation method for exploring electrolysis, this study focuses on thermal decomposition rather than electrolysis. Further exploration of electrolysis will be required in the future. It is important to emphasize that N2 dissociation should not occur under real experimental conditions at 1600 K. However, in actual environments, the temperature at the core of an arc discharge can reach up to 12,000 K. By adjusting the force field files, we were able to observe N2 dissociation within the simulation temperature range of this study, thus bridging the gap between the real environment and the simulation. Nevertheless, this research offers a novel perspective for exploring the engineering application prospects of PMVE/N2, provides a scientific basis and theoretical support for the potential deployment of PMVE/N2 gas mixtures in practical applications, and also provides a new feasible direction for subsequent research.

5. Conclusions

In summary, this study employed ReaxFF-MD and DFT methods to investigate the decomposition mechanism of a PMVE/N2 gas mixture over a temperature range of 1600–2600 K and examined the influence of temperature on the decomposition process. In addition, the environmental and safety aspects of the PMVE/N2 mixture were evaluated to assess its engineering feasibility. The following conclusions can be drawn:
(1) The decomposition of the PMVE/N2 gas mixture is an endothermic process. The decomposition rate of PMVE increases with temperature, with a marked acceleration observed at 2200 K, while the decomposition rate of N2 remains relatively stable throughout the studied temperature range.
(2) The primary decomposition products include C, C2F2, CF2, CN, CO, CF2O, F, O, C2F3, and CF3. Notably, the yields of CN, CO, and F increase linearly with time. The decomposition process involves the dynamic recombination and re-decomposition of free radicals, which leads to the formation of products such as C2F2, and C2F4. Several nitrogen-containing species (e.g., C2N2, CFN) were detected. However, C2N2 decomposes under the simulation conditions to produce significant amounts of CN and C2N radicals. Moreover, the presence of O radicals facilitates the consumption of C2F2 and reacts with particulate carbon to form CO.
(3) Three distinct decomposition pathways were identified for the PMVE/N2 gas mixture. Among these, the pathways that yield C2F3O and CF3 require the least energy. The decomposition process is accompanied by the generation of toxic byproducts, including C2N2, CF2O, and CO. Notably, C2N2 has an LC50 (1 h rat inhalation) of 330 ppm, classifying it as a highly toxic substance. The safety of PMVE/N2 must be carefully evaluated before its engineering application.

Author Contributions

Conceptualization, H.C. and W.Y.; methodology, H.C.; software, W.Y.; validation, H.D., W.Y. and J.Y.; formal analysis, H.C.; investigation, H.C. and W.Y.; resources, H.D., W.Y. and J.Y.; data curation, H.C.; writing—original draft preparation, H.C.; writing—review and editing, W.Y.; visualization, H.C.; supervision, S.L. and Y.L.; project administration, H.C. and W.Y.; funding acquisition, H.D. and W.Y. All authors have read and agreed to the published version of the manuscript.

Funding

This work was Funded by the Graduate Innovation Program of China University of Mining and Technology (SJCX25_1459) and the China Postdoctoral Science Foundation (2024M763542).

Data Availability Statement

The original contributions presented in this study are included in the article. Further inquiries can be directed to the corresponding authors.

Acknowledgments

The authors sincerely thank Tian Lu at the Beijing Kein Research Center for Natural Sciences for his help with computer simulations.

Conflicts of Interest

The authors declare no conflicts of interest.

References

  1. Chen, D.; Zhang, X.; Tang, J.; Cui, Z.; Cui, H. Pristine and Cu decorated hexagonal InN monolayer, a promising candidate to detect and scavenge SF6 decompositions based on first-principle study. J. Hazard. Mater. 2019, 363, 346–357. [Google Scholar] [CrossRef] [PubMed]
  2. Sulbaek Andersen, M.P.; Kyte, M.; Andersen, S.T.; Nielsen, C.J.; Nielsen, O.J. Atmospheric Chemistry of (CF3)2CF–C≡N: A Replacement Compound for the Most Potent Industrial Greenhouse Gas, SF6. Environ. Sci. Technol. 2017, 51, 1321–1329. [Google Scholar] [CrossRef]
  3. Fang, X.; Hu, X.; Janssens-Maenhout, G.; Wu, J.; Han, J.; Su, S.; Zhang, J.; Hu, J. Sulfur hexafluoride (SF6) emission estimates for China: An inventory for 1990–2010 and a projection to 2020. Environ. Sci. Technol. 2013, 47, 3848–3855. [Google Scholar] [CrossRef] [PubMed]
  4. Kieffel, Y.; Irwin, T.; Ponchon, P.; Owens, J. Green gas to replace SF6 in electrical grids. IEEE Power Energy Mag. 2016, 14, 32–39. [Google Scholar] [CrossRef]
  5. Obama, B. The irreversible momentum of clean energy. Science 2017, 355, 126–129. [Google Scholar] [CrossRef]
  6. Stoller, P.; Doiron, C.; Tehlar, D.; Simka, P.; Ranjan, N. Mixtures of CO2 and C5F10O perfluoroketone for high voltage applications. IEEE Trans. Dielectr. Electr. Insul. 2017, 24, 2712–2721. [Google Scholar] [CrossRef]
  7. Li, Y.; Zhang, X.; Tian, S.; Xiao, S.; Li, Y.; Chen, D. Insight into the decomposition mechanism of C6F12O-CO2 gas mixture. Chem. Eng. J. 2019, 360, 929–940. [Google Scholar] [CrossRef]
  8. Niemeyer, L. A systematic search for insulation gases and their environmental evaluation. In Gaseous Dielectrics VIII; Springer: Berlin/Heidelberg, Germany, 1998; pp. 459–464. [Google Scholar]
  9. Park, Y.; Choi, Y.R.; Kim, D.-C.; Kim, Y.; Song, M.-Y.; Kim, Y.-W.; Cho, H.; Jang, H.-J.; Oh, Y.-H.; Song, K.-D. Total electron scattering cross section of C3F6O at the intermediate-energy region for developing an alternative insulation gas to SF6. Curr. Appl. Phys. 2022, 41, 111–115. [Google Scholar] [CrossRef]
  10. Sinha, N.; Song, M.-Y.; Chang, H.; Choi, H.; Jang, H.-J.; Oh, Y.-H.; Song, K.-D. Electron impact cross sections and transport studies of C3F6O. Appl. Sci. 2023, 13, 12612. [Google Scholar] [CrossRef]
  11. Xiao, S.; Chen, Y.; Tang, M.; Tian, S.; Xia, H.; Wang, Y.; Tang, J.; Li, Y.; Zhang, X. Characteristics of perfluoromethyl vinyl ether: A new eco-friendly alternative gas for SF6. High Volt. 2024, 9, 509–517. [Google Scholar] [CrossRef]
  12. Couperus, A. Annual Report on the Implementation of Council Regulation (EC) No 812/2004–2018; Centre for Fishery Research (CVO): Ijmuiden, The Netherlands, 2019. [Google Scholar]
  13. Luo, Z.; Wei, C.; Wang, T.; Su, B.; Cheng, F.; Liu, C.; Wang, Y. Effects of N2 and CO2 dilution on the explosion behavior of liquefied petroleum gas (LPG)-air mixtures. J. Hazard. Mater. 2021, 403, 123843. [Google Scholar] [CrossRef] [PubMed]
  14. Zhang, Y.; Zhang, X.; Li, Y.; Li, Y.; Chen, Q.; Zhang, G.; Xiao, S.; Tang, J. AC breakdown and decomposition characteristics of environmental friendly gas C5F10O/air and C5F10O/N2. IEEE Access 2019, 7, 73954–73960. [Google Scholar] [CrossRef]
  15. Raymond, W.J.K.; Illias, H.A.; Mokhlis, H. Partial discharge classifications: Review of recent progress. Measurement 2015, 68, 164–181. [Google Scholar] [CrossRef]
  16. Loeb, L.B. The mechanism of spark discharge in air at atmospheric pressure. Science 1929, 69, 509–512. [Google Scholar] [CrossRef]
  17. Sinha, N.; Choi, H.; Song, M.-Y.; Jang, H.-J.; Oh, Y.-H.; Song, K.-D. Perfluoro-methyl-vinyl-ether as SF6 alternative in insulation applications: A DFT study on the physiochemical properties and decomposition pathways. Comput. Theor. Chem. 2023, 1225, 114159. [Google Scholar] [CrossRef]
  18. Zhao, D.; Yan, J.; He, R.; Geng, Y.; Liu, Z.; Wang, J. Decomposition mechanism of C4F7N/CO2 gas mixture based on molecular dynamics and effect of O2 content. J. Appl. Phys. 2024, 135, 024401. [Google Scholar] [CrossRef]
  19. Te Velde, G.t.; Bickelhaupt, F.M.; Baerends, E.J.; Fonseca Guerra, C.; van Gisbergen, S.J.; Snijders, J.G.; Ziegler, T. Chemistry with ADF. J. Comput. Chem. 2001, 22, 931–967. [Google Scholar] [CrossRef]
  20. Van Duin, A.C.; Dasgupta, S.; Lorant, F.; Goddard, W.A. ReaxFF: A reactive force field for hydrocarbons. J. Phys. Chem. A 2001, 105, 9396–9409. [Google Scholar] [CrossRef]
  21. Raymand, D.; Van Duin, A.C.; Baudin, M.; Hermansson, K. A reactive force field (ReaxFF) for zinc oxide. Surf. Sci. 2008, 602, 1020–1031. [Google Scholar] [CrossRef]
  22. Chenoweth, K.; Cheung, S.; Van Duin, A.C.; Goddard, W.A.; Kober, E.M. Simulations on the thermal decomposition of a poly (dimethylsiloxane) polymer using the ReaxFF reactive force field. J. Am. Chem. Soc. 2005, 127, 7192–7202. [Google Scholar] [CrossRef]
  23. Thielen, K.; Roth, P. N atom measurements in high-temperature N2 dissociation kinetics. AIAA J. 1986, 24, 1102–1105. [Google Scholar] [CrossRef]
  24. Paajanen, A.; Vaari, J. High-temperature decomposition of the cellulose molecule: A stochastic molecular dynamics study. Cellulose 2017, 24, 2713–2725. [Google Scholar] [CrossRef]
  25. Zheng, M.; Li, X.; Liu, J.; Wang, Z.; Gong, X.; Guo, L.; Song, W. Pyrolysis of Liulin coal simulated by GPU-based ReaxFF MD with cheminformatics analysis. Energy Fuels 2014, 28, 522–534. [Google Scholar] [CrossRef]
  26. Zheng, M.; Li, X.; Wang, M.; Guo, L. Dynamic profiles of tar products during Naomaohu coal pyrolysis revealed by large-scale reactive molecular dynamic simulation. Fuel 2019, 253, 910–920. [Google Scholar] [CrossRef]
  27. Berendsen, H.J.; Postma, J.v.; Van Gunsteren, W.F.; DiNola, A.; Haak, J.R. Molecular dynamics with coupling to an external bath. J. Chem. Phys. 1984, 81, 3684–3690. [Google Scholar] [CrossRef]
  28. Zhang, X.; Li, Y.; Tian, S.; Xiao, S.; Chen, D.; Tang, J.; Zhuo, R. Decomposition mechanism of the C5-PFK/CO2 gas mixture as an alternative gas for SF6. Chem. Eng. J. 2018, 336, 38–46. [Google Scholar] [CrossRef]
  29. Zhang, X.; Li, Y.; Xiao, S.; Tang, J.; Tian, S.; Deng, Z. Decomposition mechanism of C5F10O: An environmentally friendly insulation medium. Environ. Sci. Technol. 2017, 51, 10127–10136. [Google Scholar] [CrossRef]
  30. Kirschner, K.N.; Heiden, W.; Reith, D. Relative electronic and free energies of octane’s unique conformations. Mol. Phys. 2017, 115, 1155–1165. [Google Scholar] [CrossRef]
  31. Frisch, M.; Trucks, G.; Schlegel, H.; Scuseria, G.; Robb, M.; Cheeseman, J.; Scalmani, G.; Barone, V.; Petersson, G.; Nakatsuji, H. Global Optimization by Basin-Hopping and the Lowest Energy Structures of Lennard-Jones Clusters Containing up to 110 Atoms. J. Phys. Chem. A 1997, 101, 5111–5116. [Google Scholar]
  32. Stephens, P.J.; Devlin, F.J.; Chabalowski, C.F.; Frisch, M.J. Ab initio calculation of vibrational absorption and circular dichroism spectra using density functional force fields. J. Phys. Chem. 1994, 98, 11623–11627. [Google Scholar] [CrossRef]
  33. McLean, A.; Chandler, G. Contracted Gaussian basis sets for molecular calculations. I. Second row atoms, Z = 11–18. J. Chem. Phys. 1980, 72, 5639–5648. [Google Scholar] [CrossRef]
  34. Krishnan, R.; Binkley, J.S.; Seeger, R.; Pople, J.A. Self-consistent molecular orbital methods. XX. A basis set for correlated wave functions. J. Chem. Phys. 1980, 72, 650–654. [Google Scholar] [CrossRef]
  35. Grimme, S.; Ehrlich, S.; Goerigk, L. Effect of the damping function in dispersion corrected density functional theory. J. Comput. Chem. 2011, 32, 1456–1465. [Google Scholar] [CrossRef] [PubMed]
  36. Lu, T.; Chen, Q. Shermo: A general code for calculating molecular thermochemistry properties. Comput. Theor. Chem. 2021, 1200, 113249. [Google Scholar] [CrossRef]
  37. Slack, M.; Fishburne, E.; Johnson, A. Kinetics and Thermodynamics of the CN Molecule. II. The Dissociation of C2N2. J. Chem. Phys. 1971, 54, 1652–1658. [Google Scholar] [CrossRef]
  38. De Almeida, W.B.; Hinchliffe, A. An ab initio study of the C2N2 molecule: NCCN, CNNC and CNCN species. J. Mol. Struct. THEOCHEM 1990, 206, 77–87. [Google Scholar] [CrossRef]
  39. Wang, X.; Zhong, L.; Yan, J.; Yang, A.; Han, G.; Han, G.; Wu, Y.; Rong, M. Investigation of dielectric properties of cold C3F8 mixtures and hot C3F8 gas as Substitutes for SF6. Eur. Phys. J. D 2015, 69, 240. [Google Scholar] [CrossRef]
  40. Fu, Y.; Wang, X.; Li, X.; Yang, A.; Han, G.; Lu, Y.; Wu, Y.; Rong, M. Theoretical study of the decomposition pathways and products of C5-perfluorinated ketone (C5 PFK). Aip Adv. 2016, 6, 085305. [Google Scholar] [CrossRef]
  41. Hyrenbach, M.; Paul, T.A.; Owens, J. Environmental and safety aspects of AirPlus insulated GIS. Environ. Saf. Asp. Airplus Insul. GIS 2017, 2017, 132–135. [Google Scholar] [CrossRef]
Applsci 15 05272 g001
Figure 1. Snapshot of the initial configuration of the PMVE-N2 system. (Light blue for F atom, red for O atom, gray for C atom, and dark blue for N atom).
Figure 1. Snapshot of the initial configuration of the PMVE-N2 system. (Light blue for F atom, red for O atom, gray for C atom, and dark blue for N atom).
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Figure 2. Time evolution of PMVE and N2 decomposition at 1600–2600 K.
Figure 2. Time evolution of PMVE and N2 decomposition at 1600–2600 K.
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Figure 3. Time evolution of potential energy at 1600–2600 K.
Figure 3. Time evolution of potential energy at 1600–2600 K.
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Figure 4. Time evolution of PMVE/N2 decomposition products at 1600−2600 K.
Figure 4. Time evolution of PMVE/N2 decomposition products at 1600−2600 K.
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Figure 5. Maximum number of decomposition products of PMVE/N2 at 1600–2600 K.
Figure 5. Maximum number of decomposition products of PMVE/N2 at 1600–2600 K.
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Figure 6. Relative energy change in PMVE/N2 decomposition process.
Figure 6. Relative energy change in PMVE/N2 decomposition process.
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Figure 7. Free radical recombination of PMVE/N2 decomposition process. (Light blue for F atom, red for O atom, gray for C atom and dark blue for N atom).
Figure 7. Free radical recombination of PMVE/N2 decomposition process. (Light blue for F atom, red for O atom, gray for C atom and dark blue for N atom).
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Table 1. Key parameters and simulation conditions of PMVE/N2 system.
Table 1. Key parameters and simulation conditions of PMVE/N2 system.
Key ParameterPMVE/N2
N2 content (mix by mole ratio)40%
Number of PMVE 100
Number of N2400
Density (g/cm3)0.00227
Box length (Å)273.0
Table 2. Proposed decomposition mechanism and reaction enthalpies of PMVE/N2.
Table 2. Proposed decomposition mechanism and reaction enthalpies of PMVE/N2.
NoReactionReaction Enthalpy (kcal/mol), T = 298.15 K
A1C3F6O → CF3OC2F2 + F116.67
A2CF3OC2F2 → CF3O + C2F259.34
A3CF3O → CF2O + F22.37
B1C3F6O → C2F3 + CF3O103.70
B2C2F3 → C2F2 + F72.30
B3C2F3 + F → C2F4−121.12
C1C3F6O → C2F3O + CF347.12
C2CF3 + F → CF4−121.81
DC2F3 + CF3 → C3F6−103.15
E2CF3 → C2F6−89.02
FC + O → CO−354.76
G2CN → C2N2−142.87
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Dong, H.; Chu, H.; Liu, Y.; Liu, S.; Ye, W.; Yan, J. Insights into the Pyrolysis Properties of Environmentally Friendly PMVE/N2 Gas Mixtures: A Collaborative Analysis Based on Density Functional Theory and Reaction Kinetics. Appl. Sci. 2025, 15, 5272. https://doi.org/10.3390/app15105272

AMA Style

Dong H, Chu H, Liu Y, Liu S, Ye W, Yan J. Insights into the Pyrolysis Properties of Environmentally Friendly PMVE/N2 Gas Mixtures: A Collaborative Analysis Based on Density Functional Theory and Reaction Kinetics. Applied Sciences. 2025; 15(10):5272. https://doi.org/10.3390/app15105272

Chicago/Turabian Style

Dong, Haibo, Haonan Chu, Yunhao Liu, Shicheng Liu, Wenyu Ye, and Jiaming Yan. 2025. "Insights into the Pyrolysis Properties of Environmentally Friendly PMVE/N2 Gas Mixtures: A Collaborative Analysis Based on Density Functional Theory and Reaction Kinetics" Applied Sciences 15, no. 10: 5272. https://doi.org/10.3390/app15105272

APA Style

Dong, H., Chu, H., Liu, Y., Liu, S., Ye, W., & Yan, J. (2025). Insights into the Pyrolysis Properties of Environmentally Friendly PMVE/N2 Gas Mixtures: A Collaborative Analysis Based on Density Functional Theory and Reaction Kinetics. Applied Sciences, 15(10), 5272. https://doi.org/10.3390/app15105272

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