Highly selective PAN@MOFs composite nanofiber for removal of C4F7N/CO2 harmful decomposition products

Abstract

Perfluoroisobutyronitrile (C4F7N) mixed with CO2 has emerged as a promising eco-friendly alternative to sulfur hexafluoride (SF6) in gas-insulated equipment (GIE). However, thermal or discharge faults in GIE inevitably lead to the generation of harmful decomposition by-products, necessitating their prompt removal to safeguard equipment operation and personnel safety. In this study, we propose a nanofiber composite material comprising polyacrylonitrile (PAN) as the base and multi-metal organic frameworks (MOFs) as the primary adsorbent material for removing typical decomposition components of C4F7N/CO2 gas mixture. Utilizing grand canonical Monte Carlo (GCMC) and molecular dynamics (MD) simulations, we elucidate the selective adsorption mechanisms. Experimental results show that PAN@HKUST-1(Cu) exhibits superior adsorption efficiency for fluorocarbon gases compared to PAN@MIL-101(Cr), while the latter demonstrates better performance for nitrile gases. The PAN@HKUST-1(Cu)/MIL-101(Cr) composite adsorbent effectively removes eight typical harmful decomposition products while minimally affecting C4F7N. Our findings suggest that PAN@HKUST-1(Cu)/MIL-101(Cr) nanofiber film holds promise as an adsorbent for C4F7N/CO2 based GIE.