Research on the adsorption of environmentally friendly insulating gas C4F7N decomposed components on the surface of γ-Al2O3

C 4 F 7 N is considered to be the most potential alternative gas for SF 6 . However, harmful decomposition by-products generated by the discharge or overheating faults will pose threat to safe operation and service life of gas insulated equipment (GIE). Herein, we investigated the adsorption performance of γ -Al 2 O 3 on C 4 F 7 N and its decomposition products to evaluate the possibility of using it as by-products adsorbent or exhaust treatment material. It is found that γ -Al 2 O 3 demonstrates superior adsorption capacity for CF 4 , C 2 F 6 , C 3 F 8 , C 3 F 6 , C 2 F 4 , and keeps stable after the interaction. The first-principles calculation infers that γ -Al 2 O 3 has stronger interaction with C 4 F 7 N, C 3 F 6 and C 3 F 8 than that of C 2 F 4 , C 2 F 6 and CF 4 . There exists obvious charge transfer between C 4 F 7 N and γ -Al 2 O 3 , which belongs to chemisorption. The interaction between F 2p orbital and C=C π orbital determines the gas-solid adsorption performance. The desorption properties were also explored and the recovery time was in order of CF 4 < C 2 F 6 < C 2 F 4 < C 3 F 8 < C 4 F 7 N < C 3 F 6 . Overall, the γ -Al 2 O 3 is inappropriate to be used as the adsorbent for decomposition by-products of C 4 F 7 N gas mixture-based GIE, while it can be used as exhaust treatment material for C 4 F 7 N wasted gas.