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Title: Theoretical study of the decomposition pathways and products of C5- perfluorinated ketone (C5 PFK)

Abstract

Due to the high global warming potential (GWP) and increasing environmental concerns, efforts on searching the alternative gases to SF{sub 6}, which is predominantly used as insulating and interrupting medium in high-voltage equipment, have become a hot topic in recent decades. Overcoming the drawbacks of the existing candidate gases, C5- perfluorinated ketone (C5 PFK) was reported as a promising gas with remarkable insulation capacity and the low GWP of approximately 1. Experimental measurements of the dielectric strength of this novel gas and its mixtures have been carried out, but the chemical decomposition pathways and products of C5 PFK during breakdown are still unknown, which are the essential factors in evaluating the electric strength of this gas in high-voltage equipment. Therefore, this paper is devoted to exploring all the possible decomposition pathways and species of C5 PFK by density functional theory (DFT). The structural optimizations, vibrational frequency calculations and energy calculations of the species involved in a considered pathway were carried out with DFT-(U)B3LYP/6-311G(d,p) method. Detailed potential energy surface was then investigated thoroughly by the same method. Lastly, six decomposition pathways of C5 PFK decomposition involving fission reactions and the reactions with a transition states were obtained. Important intermediate products weremore » also determined. Among all the pathways studied, the favorable decomposition reactions of C5 PFK were found, involving C-C bond ruptures producing Ia and Ib in pathway I, followed by subsequent C-C bond ruptures and internal F atom transfers in the decomposition of Ia and Ib presented in pathways II + III and IV + V, respectively. Possible routes were pointed out in pathway III and lead to the decomposition of IIa, which is the main intermediate product found in pathway II of Ia decomposition. We also investigated the decomposition of Ib, which can undergo unimolecular reactions to give the formation of IV a, IV b and products of CF{sub 3} + CF-CF{sub 3} in pathway IV. Although IV a is dominant to a lesser extent due to its relative high energy barrier, its complicated decomposition pathway V was also studied and CF{sub 3}, C = CF{sub 2} as well as C-CF{sub 3} species were found as the ultimate products. To complete the decomposition of C5 PFK, pathway V I of Ic decomposition was fully explored and the final products were obtained. Therefore, the integrate decomposition scheme of C5 PFK was proposed, which contains six pathways and forty-eight species (including all the reactants, products and transition states). This work is hopeful to lay a theoretical basis for the insulating properties of C5 PFK.« less

Authors:
; ; ; ; ;  [1]; ;  [2]
  1. State Key Laboratory of Electrical Insulation and Power Equipment, Xi’an Jiaotong University, No. 28 XianNing West Road, Xi’an, Shaanxi Province 710049 (China)
  2. Pinggao Group Co. Ltd., Pingdingshan, Henan Province 467001 (China)
Publication Date:
OSTI Identifier:
22611419
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Advances; Journal Volume: 6; Journal Issue: 8; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; APPROXIMATIONS; ATOMS; BREAKDOWN; CAPACITY; DECOMPOSITION; DENSITY; DENSITY FUNCTIONAL METHOD; DIELECTRIC MATERIALS; DIFFUSION BARRIERS; FISSION; GASES; KETONES; MIXTURES; SIMULATION; SULFUR FLUORIDES; SURFACES

Citation Formats

Fu, Yuwei, Wang, Xiaohua, E-mail: xhw@mail.xjtu.edu.cn, E-mail: mzrong@mail.xjtu.edu.cn, Li, Xi, Yang, Aijun, Wu, Yi, Rong, Mingzhe, E-mail: xhw@mail.xjtu.edu.cn, E-mail: mzrong@mail.xjtu.edu.cn, Han, Guohui, and Lu, Yanhui. Theoretical study of the decomposition pathways and products of C5- perfluorinated ketone (C5 PFK). United States: N. p., 2016. Web. doi:10.1063/1.4960988.
Fu, Yuwei, Wang, Xiaohua, E-mail: xhw@mail.xjtu.edu.cn, E-mail: mzrong@mail.xjtu.edu.cn, Li, Xi, Yang, Aijun, Wu, Yi, Rong, Mingzhe, E-mail: xhw@mail.xjtu.edu.cn, E-mail: mzrong@mail.xjtu.edu.cn, Han, Guohui, & Lu, Yanhui. Theoretical study of the decomposition pathways and products of C5- perfluorinated ketone (C5 PFK). United States. doi:10.1063/1.4960988.
Fu, Yuwei, Wang, Xiaohua, E-mail: xhw@mail.xjtu.edu.cn, E-mail: mzrong@mail.xjtu.edu.cn, Li, Xi, Yang, Aijun, Wu, Yi, Rong, Mingzhe, E-mail: xhw@mail.xjtu.edu.cn, E-mail: mzrong@mail.xjtu.edu.cn, Han, Guohui, and Lu, Yanhui. Mon . "Theoretical study of the decomposition pathways and products of C5- perfluorinated ketone (C5 PFK)". United States. doi:10.1063/1.4960988.
@article{osti_22611419,
title = {Theoretical study of the decomposition pathways and products of C5- perfluorinated ketone (C5 PFK)},
author = {Fu, Yuwei and Wang, Xiaohua, E-mail: xhw@mail.xjtu.edu.cn, E-mail: mzrong@mail.xjtu.edu.cn and Li, Xi and Yang, Aijun and Wu, Yi and Rong, Mingzhe, E-mail: xhw@mail.xjtu.edu.cn, E-mail: mzrong@mail.xjtu.edu.cn and Han, Guohui and Lu, Yanhui},
abstractNote = {Due to the high global warming potential (GWP) and increasing environmental concerns, efforts on searching the alternative gases to SF{sub 6}, which is predominantly used as insulating and interrupting medium in high-voltage equipment, have become a hot topic in recent decades. Overcoming the drawbacks of the existing candidate gases, C5- perfluorinated ketone (C5 PFK) was reported as a promising gas with remarkable insulation capacity and the low GWP of approximately 1. Experimental measurements of the dielectric strength of this novel gas and its mixtures have been carried out, but the chemical decomposition pathways and products of C5 PFK during breakdown are still unknown, which are the essential factors in evaluating the electric strength of this gas in high-voltage equipment. Therefore, this paper is devoted to exploring all the possible decomposition pathways and species of C5 PFK by density functional theory (DFT). The structural optimizations, vibrational frequency calculations and energy calculations of the species involved in a considered pathway were carried out with DFT-(U)B3LYP/6-311G(d,p) method. Detailed potential energy surface was then investigated thoroughly by the same method. Lastly, six decomposition pathways of C5 PFK decomposition involving fission reactions and the reactions with a transition states were obtained. Important intermediate products were also determined. Among all the pathways studied, the favorable decomposition reactions of C5 PFK were found, involving C-C bond ruptures producing Ia and Ib in pathway I, followed by subsequent C-C bond ruptures and internal F atom transfers in the decomposition of Ia and Ib presented in pathways II + III and IV + V, respectively. Possible routes were pointed out in pathway III and lead to the decomposition of IIa, which is the main intermediate product found in pathway II of Ia decomposition. We also investigated the decomposition of Ib, which can undergo unimolecular reactions to give the formation of IV a, IV b and products of CF{sub 3} + CF-CF{sub 3} in pathway IV. Although IV a is dominant to a lesser extent due to its relative high energy barrier, its complicated decomposition pathway V was also studied and CF{sub 3}, C = CF{sub 2} as well as C-CF{sub 3} species were found as the ultimate products. To complete the decomposition of C5 PFK, pathway V I of Ic decomposition was fully explored and the final products were obtained. Therefore, the integrate decomposition scheme of C5 PFK was proposed, which contains six pathways and forty-eight species (including all the reactants, products and transition states). This work is hopeful to lay a theoretical basis for the insulating properties of C5 PFK.},
doi = {10.1063/1.4960988},
journal = {AIP Advances},
number = 8,
volume = 6,
place = {United States},
year = {Mon Aug 15 00:00:00 EDT 2016},
month = {Mon Aug 15 00:00:00 EDT 2016}
}