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• Interaction between C4F7N and ZnO surface is stronger that on Zn surface. • The CN group shows a strong activity on the ZnO surface. • Activation energy of C 4 F 7 N dissociation on ZnO surface is higher than on Cu and Al. • Zinc shows potentials to be anti-corrosion material when using C 4 F 7 N. Recently, C 4 F 7 N has been considered as one of the most promising candidates to replace SF 6 due to its excellent insulation performance and environmental-friendly property. Metal zinc is widely used as a coating material in gas-insulated electrical equipment. However, its compatibility with C 4 F 7 N has never been explored before. In this paper, the adsorption properties of C 4 F 7 N on Zn(0 0 0 1) and ZnO(1 0 1 ¯ 0) surfaces were theoretically studied by a first-principles calculation. Adsorption energy, total charge transfer, density of states, and electron density difference were calculated to evaluate the compatibility of C 4 F 7 N with Zn and ZnO. The results demonstrated that the interaction between C 4 F 7 N and ZnO(1 0 1 ¯ 0) is stronger than that of Zn(0 0 0 1). The dissociation pathway of C 4 F 7 N after adsorption on the ZnO(1 0 1 ¯ 0) surface was also determined, which shows that ZnO(1 0 1 ¯ 0) has a catalytic effect on the decomposition process of C 4 F 7 N. Compared with Al(1 1 1) and Cu(1 1 1), the dissociation of C 4 F 7 N on ZnO(1 0 1 ¯ 0) has a higher energy barrier, indicating that the reaction is more difficult to occur. As a result, Zn and ZnO have certain compatibility with C 4 F 7 N, which was also verified by experiments. Therefore, we infer that Zn shows potentials to be used as anti-corrosion coating in C 4 F 7 N gas-insulated electrical equipment. [ABSTRACT FROM AUTHOR]

• C 5 F 10 O starts to decompose at 500 ℃ and CO 2 , C 3 F 6 , and C 4 F 10 are dominant by-products. • A unique by-products C 2 F 6 O 3 is produced under partial discharge in C 5 F 10 O-air mixture. • Decomposition products CF 4 , C 3 F 6 , CF 2 O, CHF 3 , and C 3 HF 7 have good compatibility with Al (1 1 1) and Cu (1 1 1) surfaces. • The O atoms in C 2 F 6 O 3 show strong reaction activity with Al (1 1 1) and Cu (1 1 1) surfaces. Perfluoroketone C 5 F 10 O has drawn much attention in recent years as a promising environmental-friendly gas to substitute SF 6 in power equipment. In this paper, the decomposition characteristics of C 5 F 10 O and C 5 F 10 O/air mixture under pyrolysis and partial discharge conditions were explored by experiments using a gas chromatography/mass spectrometer. Besides, the compatibility of decomposition products with the copper and aluminum was evaluated based on the density functional theory calculation. We found that C 5 F 10 O has good thermal stability at 300 ℃. At 500 ℃, C 5 F 10 O starts to decompose and it produces CO, CO 2 , C 2 F 6 , C 2 F 4 , C 3 F 8 , C 3 F 6 , C 4 F 10 , C 4 F 8 and CHF 3 , among which CO 2 , C 3 F 6 , and C 4 F 10 are dominant. For C 5 F 10 O/air mixtures, the pyrolysis products are mainly saturated fluorocarbons and more CO 2 is produced. Partial discharges in C 5 F 10 O/air mixture mainly produce CO 2 , saturated fluorocarbons and a unique compound C 3 F 6 O 3. It is found that CF 4 , C 3 F 6 , CF 2 O, CHF 3 , and C 3 HF 7 have good compatibility with Al (1 1 1) and Cu (1 1 1) surfaces, while the interactions between C 2 F 6 O 3 and Al (1 1 1), Cu (1 1 1) surfaces are relatively strong, which are chemisorption. The identified by-products of C 5 F 10 O and C 5 F 10 O/air mixture under different conditions as well as their compatibility with metal materials is essential for online fault-diagnostic and long-term maintenance in engineering applications. [ABSTRACT FROM AUTHOR]