Hydrophobic Silicalite-1@Ag+ based MMM for C2H4/C2H6 separation under long-period humid conditions

Membrane technology is a promising candidate for ethylene/ethane (C 2 H 4 /C 2 H 6 ) separation, but the separation factor and long-term stability of commercially available polymer membranes remain still insufficient to meet industrial requirements. Incorporating facilitated metal-ion carriers or unsaturated metal sites of fillers into polymers shows exceptional C 2 H 4 /C 2 H 6 separation efficiency due to the intensified olefin-favorable sorption . However, their separation performance usually dropped within a few hours due to the inactivation of the facilitated transport carrier or poisoning of unsaturated sites in presence of water vapor . Herein, we adopt a facile and effective method to prepare long-term stable Silicalite-1@Ag (S-1@Ag) mixed matrix membranes (MMM) by in-situ embedding the vulnerable carrier Ag + into the pores of the hydrophobic zeolite to protect the Ag + from deactivation. The 12 wt% S-1@Ag filler uniformly dispersing within the commercial 6FDA-DAM exhibits superior separation performance that surpasses the 2013 upper bound in terms of C 2 H 4 permeability of 29.74 barrer and C 2 H 4 /C 2 H 6 selectivity up to 7.66 for equimolar mixed gas. Furthermore, the hydrophobicity nature and framework shielding towards Ag + of S-1 guarantees the excellent almost 2-months stable separation of C 2 H 4 /C 2 H 6 by S-1@Ag MMMs under the high relative humidity conditions, demonstrating its potential for industrial applications.