Construction of highly stable Ti3C2Tx/agZIF-62 composite glass membranes for CO2-preferential separation

Ti 3 C 2 T x is a two-dimensional sheet-like material with abundant and tunable surface functional groups, showing excellent gas adsorption and transport ability in CO 2 separation. However, it suffers from several intrinsic limitations, including susceptibility to oxidation, restacking, and humidity sensitivity, which prevent it from being used alone as a membrane material for complex application scenarios. In this work, meltable ZIF-62 was selected as the continuous phase and Ti 3 C 2 T x as the dispersed phase. Thermal treatment was used to promote the softening and flow of ZIF-62, enabling the embedding and immobilization of Ti 3 C 2 T x . Finally, self-supporting Ti 3 C 2 T x /a g ZIF-62 composite glass membranes were obtained, and their gas separation performance was evaluated. The results show that the introduction of Ti 3 C 2 T x effectively improves the CO 2 permeability of the composite membranes while maintaining high separation selectivity. Specifically, the best overall performance was achieved at a doping content of 1 wt%, where the CO 2 permeability increased from 1403 Barrer to 5124 Barrer, and the ideal CO 2 /N 2 and CO 2 /CH 4 selectivities reached 44.9 and 30.7, respectively. The CO 2 /N 2 separation performance of this membrane exceeds the latest upper bound, while its CO 2 /CH 4 separation performance also shows a competitive level. In addition, this membrane maintained relatively stable performance in humid-gas, pressure-variable, and 160 h continuous operation tests.