Adsorption mechanism of the environmentally friendly insulating gas C5F10O and its main decomposition products on a Cu (111) surface
Adsorption mechanism of the environmentally friendly insulating gas C5F10O and its main decomposition products on a Cu (111) surface
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环保绝缘气体C5F10O及其主要分解产物在Cu(111)表面的吸附机理
DOI：
10.1088/1361-6463/abd274
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发表时间：
2021
影响因子：
3.4
通讯作者：
Tang Ju
中科院分区：
文献类型：
--
作者：
Zeng Fuping;Feng Xiaoxuan;Lei Zhicheng;Wu Siying;She Congdong;Miao Yulong;Zhang Shiling;Tang Ju
全氟酮C5 F10 O不仅具有良好的环境相容性，而且具有优良的绝缘性能，在中低压开关柜中具有替代SF 6的潜力。研究了C5 F10 O及其主要分解产物与设备内铜材的相容性，具体构建了C5 F10 O及其主要分解产物在Cu（111）表面的吸附模型。从体系结构、电子密度分布和态密度角度研究了吸附机理。结果表明，C5 F10 O主要通过羰基氧原子在Cu表面发生化学吸附.其最大吸附能为− 24.48 kcal mol− 1，电子从铜表面转移到吸附的氧原子上;主要分解产物CF 4、C2 F6、C3 F8、C3 F6、CF 2 O、C2 F4 O和CO 2与表面的吸附能均小于− 9.56 kcal mol− 1。这些分解气体与铜表面之间没有明显的电子转移，属于物理吸附;而C3 F6 O、C2 F4和CO在顶位、桥位和Hcc位的吸附能分别为− 9.661 kcal mol− 1、− 14.651 kcal mol− 1和− 25.489 kcal mol− 1，铜表面的电子转移到C3 F6 O的氧原子和C2 F4及CO的碳原子上，形成稳定的化学键，属于化学吸附。通过进一步的电子态密度分析，发现C5 F10 O和C3 F6 O主要通过羰基氧原子上的p轨道与铜表面键合，赝能隙分别为3.2eV和2.5eV。C2 F4和CO通过碳原子的sp杂化轨道键合到铜表面，赝能隙约为4 eV。由以上分析可知，C 5 F 10 O及其主要分解产物C 3 F 6 O、C 2 F 4和CO与金属铜的相容性较差。
The perfluoroketone C 5 F 10 O, not only has good environmental compatibility, but also has excellent insulation properties and has the potential to replace SF 6 in medium and low voltage switchgear. This paper focuses on the compatibility of C 5 F 10 O and its main decomposition products with the copper material inside the equipment and specifically constructs several adsorption models of C 5 F 10 O and its main decomposition products on a Cu (1 1 1) surface. The adsorption mechanism was studied from a system structure, electron density distribution and density of states perspective. The results showed that C 5 F 10 O mainly adsorbed chemically on the Cu surface through carbonyl oxygen atoms. Its maximum adsorption energy is− 24.48 kcal mol− 1, with electrons transferring from the copper surface to the adsorbed oxygen atom; and the adsorption energies of the main breakdown products CF 4, C 2 F 6, C 3 F 8, C 3 F 6, CF 2 O, C 2 F 4 O and CO 2 with the surface are all less than− 9.56 kcal mol− 1. There is no obvious electron transfer between these decomposition gases and the copper surface, and thus, they belong to physical adsorption; while the adsorption energies of C 3 F 6 O, C 2 F 4 and CO in the top, bridge and Hcc sites are respectively− 9.661 kcal mol− 1,− 14.651 kcal mol− 1 and− 25.489 kcal mol− 1, electrons on the copper surface transfer to the oxygen atom of C 3 F 6 O and carbon atoms of C 2 F 4 and CO, forming stable chemical bonds, which belong to chemical adsorption. Through further analysis of the electron density of states, it is found that C 5 F 10 O and C 3 F 6 O bonded to the copper surface mainly by p orbitals on carbonyl oxygen atom and the pseudogaps are 3.2 eV and 2.5 eV. C 2 F 4 and CO bonded to the copper surface by sp hybrid orbitals of carbon atoms, with a pseudogap of about 4 eV. Based on the above analysis, it can be seen that C 5 F 10 O and its main decomposition products C 3 F 6 O, C 2 F 4 and CO have poor compatibility with metal copper.