Research on the adsorption of environmentally friendly insulating gas C <sub>4</sub> F <sub>7</sub> N decomposed components on the surface of <i>γ</i> ‐Al <sub>2</sub> O <sub>3</sub>
Song Xiao, Junyi Chen, Peng Wu, Qiang Yao, Long Li, Xuanpei Pang, Shiling Zhang, Xiaoxing Zhang, Yi Li
Abstract
Abstract 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.