Herein, we have designed the all-nanoporous composite (ANC) membranes with metal–organic framework (MOF) fillers and hydrogen-bonded organic framework (HOF) matrix, achieving high-permeance H₂ purification. The hetero-MOF facilitates the heterogeneous nucleation, offsetting the need for a highly supersaturated solution to achieve sufficient nucleation density during solution processing. Continuous MOF/HOF ANC membranes are realized by suppressing the homogeneous nucleation, equilibrating the nucleation driving force with the molecular attachment rate, and balancing the nutrient supply and demand. The optimized copper 1,4-benzene dicarboxylate nanosheets (ns-CuBDC)/HOF-30-100 (30 means that HOF monomer concentration is 30 mg·mL⁻¹ and 100 represents that the temperature for solvent evaporation is 100 °C) ANC membrane shows synchronously improved H₂ permeance and H₂/CH₄ selectivity by 562% and 241% compared to the pristine HOF membrane. The ns-CuBDC/HOF-30-100 ANC membrane inherits the pressure-responsive behavior from the parent HOF, exhibiting further improved H₂ permeance up to 9842 gas permeation units (GPU) and slightly changed H₂/CH₄ selectivity of 30.01 at 2.0 bar. The MOF/HOF ANC membrane manifests that incorporating a porous hetero-phase effectively upgrades the gas separation performance, and the HOF matrix circumvents the performance constraints of the traditional polymer matrix while preserving the solution-processability.

As an emerging zero-dimensional nano crystalline porous material, porous organic cages (POCs) with soluble properties in organic solvents, are promising candidates as molecular fillers in mixed matrix membranes (MMMs). The pore structure of POCs should be adjusted to trigger efficient gas separation performance, and the interaction between filler and matrix should be optimized. In this work, ionic liquid (IL) was introduced into the molecular fillers of CC3, to construct the IL@CC3/PIM-1 membrane to effectively separate CO₂ from CH₄. The advantages of doping IL include: (1) narrowing the cavity size of POCs from 4.4 to 3.9 Å to enhance the diffusion selectivity, (2) strengthening the CO₂ solubility to heighten the gas permeability, and (3) improving the compatibility between filler and matrix to upgrade membrane stability. After the optimization of the membrane composite, the IL@CC3/PIM-1-10% membrane possesses the CO₂ permeability of 7868 Barrer and the CO₂/CH₄ selectivity of 73.4, which compared to the CC3/PIM-1-10% membrane, improved by 15.9% and 106.2%, respectively. Furthermore, the membrane has maintained a stable separation performance at varied temperatures and pressures during the long-term test. The proposed method offers an efficient way to improve the performance of POCs-based MMMs in gas separation.