Synthesis of <scp>MIL</scp> ‐160 membrane using formate‐activated <scp>AlOOH</scp> template for efficient xylene isomer separation

Abstract The efficient separation of para‐xylene from its isomers is critical in the chemical industry. Metal–organic framework membranes like MIL‐160 are promising but often exhibit defects due to poor nucleation and uncontrolled crystal growth. To address this, we fabricated a MIL‐160 membrane using a sodium formate‐activated AlOOH nanoflake template. This strategy directed crystal growth along the template surface, ensuring seamless boundary fusion. The formate ions pre‐coordinated with Al nodes on AlOOH, weakening Al–O bonds and facilitating coordination with the 2,5‐furandicarboxylate linker, which was crucial for promoting efficient heterogeneous nucleation. The resulting membrane achieved a para‐xylene permeance of 4.42 × 10 −7 mol m −2 s −1 Pa −1 and a selectivity of 24.2 for an equimolar para‐xylene/ortho‐xylene mixture. This work provides a scalable approach for high‐performance membrane‐based aromatic isomer separation.