Melt-quenching K,Na-A zeolite/MOF crystal-glass composite membrane for efficient CO2/N2 separation

The development of high-performance membranes for CO 2 /N 2 separation remains challenging due to the trade-off between permeability and selectivity. A novel strategy has been developed to fabricate K,Na-A zeolite/ZIF-62 crystal-glass composite membranes through a melt-quenching process. The high viscosity of molten ZIF-62 enables the uniform distribution of zeolite particles, preventing their aggregation and sedimentation. The synergistic effect between the highly porous K,Na-A zeolite and the continuous ZIF-62 glass matrix leads to enhanced membrane porosity and efficient gas transport channels. Benefiting from the molecular sieving effect of K,Na-A zeolite and the excellent interfacial compatibility of ZIF-62 glass matrix, the composite membranes demonstrate superior gas separation capability. Systematic investigation revealed that the optimized a g (ZIF-62) 0.7 /(K,Na-A) 0.3 membrane exhibited remarkable CO 2 separation performance with a CO 2 permeability of 58,824 barrer and a CO 2 /N 2 selectivity of 43.1, surpassing the 2019 upper bound. This facile and scalable strategy opens up new opportunities for developing high-performance composite membranes for practical gas separation applications.