“…4,5 There are many gas separation technologies available, mainly including adsorption, 6,7 absorption, 8 cryogenic distillation, 9 and membrane separation. 10–12 Among them, membrane gas separation, with the merits of small footprint, no moving parts, easy maintenance and no secondary pollution, has attracted much attention in the past few decades and has been considered a promising alternative to conventional gas separation processes. 13–15…”