• Covalent integration of ZIF-8-NH2 with Kapton polyamide acid eliminates filler aggregation, enabling high filler loading (45% mass) without compromising membrane integrity.
• The optimized MMM achieves H2 permeability of 297 barrer and H2/N2 and H2/CH4 selectivities of 43.9 and 62.2, respectively, surpassing the Robeson 2008 upper bound.
• The covalent bridging between filler and polymer matrix creates a defect-free interface, significantly improving gas separation performance.
• This work provides a novel strategy for fabricating high-performance MMMs for hydrogen purification and other gas separation applications.